{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE RecordWildCards #-}

{- |
Module      : Haskoin.Block.Headers
Copyright   : No rights reserved
License     : MIT
Maintainer  : jprupp@protonmail.ch
Stability   : experimental
Portability : POSIX

Block chain header synchronization and proof-of-work consensus functions.
-}
module Haskoin.Block.Headers (
    -- * Block Headers
    BlockNode (..),
    BlockHeaders (..),
    BlockWork,
    genesisNode,
    genesisBlock,
    isGenesis,
    chooseBest,

    -- ** Header Store
    parentBlock,
    getParents,
    getAncestor,
    splitPoint,
    connectBlocks,
    connectBlock,
    blockLocator,

    -- ** Header Memory Store
    HeaderMemory (..),
    ShortBlockHash,
    BlockMap,
    shortBlockHash,
    initialChain,
    genesisMap,

    -- ** Helper Functions
    appendBlocks,
    validBlock,
    validCP,
    afterLastCP,
    bip34,
    validVersion,
    lastNoMinDiff,
    nextWorkRequired,
    nextEdaWorkRequired,
    nextDaaWorkRequired,
    nextAsertWorkRequired,
    computeAsertBits,
    computeTarget,
    getSuitableBlock,
    nextPowWorkRequired,
    calcNextWork,
    isValidPOW,
    blockPOW,
    headerWork,
    diffInterval,
    blockLocatorNodes,
    mineBlock,
    computeSubsidy,
    mtp,
    firstGreaterOrEqual,
    lastSmallerOrEqual,
) where

import Control.Applicative ((<|>))
import Control.DeepSeq
import Control.Monad (guard, mzero, unless, when)
import Control.Monad.Except (
    ExceptT (..),
    runExceptT,
    throwError,
 )
import Control.Monad.State.Strict as State (
    StateT,
    get,
    gets,
    lift,
    modify,
 )
import Control.Monad.Trans.Maybe
import Data.Binary (Binary (..))
import Data.Bits (shiftL, shiftR, (.&.))
import qualified Data.ByteString as B
import Data.ByteString.Short (
    ShortByteString,
    fromShort,
    toShort,
 )
import Data.Bytes.Get
import Data.Bytes.Put
import Data.Bytes.Serial
import Data.Function (on)
import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as HashMap
import Data.Hashable
import Data.List (sort, sortBy)
import Data.Maybe (fromMaybe, listToMaybe)
import Data.Serialize (Serialize (..))
import Data.Typeable (Typeable)
import Data.Word (Word32, Word64)
import GHC.Generics (Generic)
import Haskoin.Block.Common
import Haskoin.Crypto
import Haskoin.Data
import Haskoin.Transaction.Genesis
import Haskoin.Util

{- | Short version of the block hash. Uses the good end of the hash (the part
 that doesn't have a long string of zeroes).
-}
type ShortBlockHash = Word64

{- | Memory-based map to a serialized 'BlockNode' data structure.
 'ShortByteString' is used to avoid memory fragmentation and make the data
 structure compact.
-}
type BlockMap = HashMap ShortBlockHash ShortByteString

-- | Represents accumulated work in the block chain so far.
type BlockWork = Integer

{- | Data structure representing a block header and its position in the
 block chain.
-}
data BlockNode = BlockNode
    { BlockNode -> BlockHeader
nodeHeader :: !BlockHeader
    , BlockNode -> BlockHeight
nodeHeight :: !BlockHeight
    , -- | accumulated work so far
      BlockNode -> BlockWork
nodeWork :: !BlockWork
    , -- | skip magic block hash
      BlockNode -> BlockHash
nodeSkip :: !BlockHash
    }
    deriving (Int -> BlockNode -> ShowS
[BlockNode] -> ShowS
BlockNode -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [BlockNode] -> ShowS
$cshowList :: [BlockNode] -> ShowS
show :: BlockNode -> String
$cshow :: BlockNode -> String
showsPrec :: Int -> BlockNode -> ShowS
$cshowsPrec :: Int -> BlockNode -> ShowS
Show, ReadPrec [BlockNode]
ReadPrec BlockNode
Int -> ReadS BlockNode
ReadS [BlockNode]
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
readListPrec :: ReadPrec [BlockNode]
$creadListPrec :: ReadPrec [BlockNode]
readPrec :: ReadPrec BlockNode
$creadPrec :: ReadPrec BlockNode
readList :: ReadS [BlockNode]
$creadList :: ReadS [BlockNode]
readsPrec :: Int -> ReadS BlockNode
$creadsPrec :: Int -> ReadS BlockNode
Read, forall x. Rep BlockNode x -> BlockNode
forall x. BlockNode -> Rep BlockNode x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
$cto :: forall x. Rep BlockNode x -> BlockNode
$cfrom :: forall x. BlockNode -> Rep BlockNode x
Generic, Eq BlockNode
Int -> BlockNode -> Int
BlockNode -> Int
forall a. Eq a -> (Int -> a -> Int) -> (a -> Int) -> Hashable a
hash :: BlockNode -> Int
$chash :: BlockNode -> Int
hashWithSalt :: Int -> BlockNode -> Int
$chashWithSalt :: Int -> BlockNode -> Int
Hashable, BlockNode -> ()
forall a. (a -> ()) -> NFData a
rnf :: BlockNode -> ()
$crnf :: BlockNode -> ()
NFData)

instance Serial BlockNode where
    deserialize :: forall (m :: * -> *). MonadGet m => m BlockNode
deserialize = do
        BlockHeader
nodeHeader <- forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize
        BlockHeight
nodeHeight <- forall (m :: * -> *). MonadGet m => m BlockHeight
getWord32le
        BlockWork
nodeWork <- forall (m :: * -> *). MonadGet m => m BlockWork
getInteger
        if BlockHeight
nodeHeight forall a. Eq a => a -> a -> Bool
== BlockHeight
0
            then do
                let nodeSkip :: BlockHash
nodeSkip = BlockHeader -> BlockHash
headerHash BlockHeader
nodeHeader
                forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode{BlockWork
BlockHeight
BlockHeader
BlockHash
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
..}
            else do
                BlockHash
nodeSkip <- forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize
                forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode{BlockWork
BlockHeight
BlockHeader
BlockHash
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
..}
    serialize :: forall (m :: * -> *). MonadPut m => BlockNode -> m ()
serialize BlockNode
bn = do
        forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
bn
        forall (m :: * -> *). MonadPut m => BlockHeight -> m ()
putWord32le forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeight
nodeHeight BlockNode
bn
        forall (m :: * -> *). MonadPut m => BlockWork -> m ()
putInteger forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockWork
nodeWork BlockNode
bn
        case BlockNode -> BlockHeight
nodeHeight BlockNode
bn of
            BlockHeight
0 -> forall (m :: * -> *) a. Monad m => a -> m a
return ()
            BlockHeight
_ -> forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHash
nodeSkip BlockNode
bn

instance Serialize BlockNode where
    put :: Putter BlockNode
put = forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize
    get :: Get BlockNode
get = forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize

instance Binary BlockNode where
    put :: BlockNode -> Put
put = forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize
    get :: Get BlockNode
get = forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize

instance Eq BlockNode where
    == :: BlockNode -> BlockNode -> Bool
(==) = forall a. Eq a => a -> a -> Bool
(==) forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` BlockNode -> BlockHeader
nodeHeader

instance Ord BlockNode where
    compare :: BlockNode -> BlockNode -> Ordering
compare = forall a. Ord a => a -> a -> Ordering
compare forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` BlockNode -> BlockHeight
nodeHeight

-- | Memory-based header tree.
data HeaderMemory = HeaderMemory
    { HeaderMemory -> BlockMap
memoryHeaderMap :: !BlockMap
    , HeaderMemory -> BlockNode
memoryBestHeader :: !BlockNode
    }
    deriving (HeaderMemory -> HeaderMemory -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: HeaderMemory -> HeaderMemory -> Bool
$c/= :: HeaderMemory -> HeaderMemory -> Bool
== :: HeaderMemory -> HeaderMemory -> Bool
$c== :: HeaderMemory -> HeaderMemory -> Bool
Eq, Typeable, Int -> HeaderMemory -> ShowS
[HeaderMemory] -> ShowS
HeaderMemory -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [HeaderMemory] -> ShowS
$cshowList :: [HeaderMemory] -> ShowS
show :: HeaderMemory -> String
$cshow :: HeaderMemory -> String
showsPrec :: Int -> HeaderMemory -> ShowS
$cshowsPrec :: Int -> HeaderMemory -> ShowS
Show, ReadPrec [HeaderMemory]
ReadPrec HeaderMemory
Int -> ReadS HeaderMemory
ReadS [HeaderMemory]
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
readListPrec :: ReadPrec [HeaderMemory]
$creadListPrec :: ReadPrec [HeaderMemory]
readPrec :: ReadPrec HeaderMemory
$creadPrec :: ReadPrec HeaderMemory
readList :: ReadS [HeaderMemory]
$creadList :: ReadS [HeaderMemory]
readsPrec :: Int -> ReadS HeaderMemory
$creadsPrec :: Int -> ReadS HeaderMemory
Read, forall x. Rep HeaderMemory x -> HeaderMemory
forall x. HeaderMemory -> Rep HeaderMemory x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
$cto :: forall x. Rep HeaderMemory x -> HeaderMemory
$cfrom :: forall x. HeaderMemory -> Rep HeaderMemory x
Generic, Eq HeaderMemory
Int -> HeaderMemory -> Int
HeaderMemory -> Int
forall a. Eq a -> (Int -> a -> Int) -> (a -> Int) -> Hashable a
hash :: HeaderMemory -> Int
$chash :: HeaderMemory -> Int
hashWithSalt :: Int -> HeaderMemory -> Int
$chashWithSalt :: Int -> HeaderMemory -> Int
Hashable, HeaderMemory -> ()
forall a. (a -> ()) -> NFData a
rnf :: HeaderMemory -> ()
$crnf :: HeaderMemory -> ()
NFData)

-- | Typeclass for block header chain storage monad.
class Monad m => BlockHeaders m where
    -- | Add a new 'BlockNode' to the chain. Does not validate.
    addBlockHeader :: BlockNode -> m ()

    -- | Get a 'BlockNode' associated with a 'BlockHash'.
    getBlockHeader :: BlockHash -> m (Maybe BlockNode)

    -- | Locate the 'BlockNode' for the highest block in the chain
    getBestBlockHeader :: m BlockNode

    -- | Set the highest block in the chain.
    setBestBlockHeader :: BlockNode -> m ()

    -- | Add a continuous bunch of block headers the chain. Does not validate.
    addBlockHeaders :: [BlockNode] -> m ()
    addBlockHeaders = forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ forall (m :: * -> *). BlockHeaders m => BlockNode -> m ()
addBlockHeader

instance Monad m => BlockHeaders (StateT HeaderMemory m) where
    addBlockHeader :: BlockNode -> StateT HeaderMemory m ()
addBlockHeader = forall s (m :: * -> *). MonadState s m => (s -> s) -> m ()
modify forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> HeaderMemory -> HeaderMemory
addBlockHeaderMemory
    getBlockHeader :: BlockHash -> StateT HeaderMemory m (Maybe BlockNode)
getBlockHeader BlockHash
bh = BlockHash -> HeaderMemory -> Maybe BlockNode
getBlockHeaderMemory BlockHash
bh forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall s (m :: * -> *). MonadState s m => m s
State.get
    getBestBlockHeader :: StateT HeaderMemory m BlockNode
getBestBlockHeader = forall s (m :: * -> *) a. MonadState s m => (s -> a) -> m a
gets HeaderMemory -> BlockNode
memoryBestHeader
    setBestBlockHeader :: BlockNode -> StateT HeaderMemory m ()
setBestBlockHeader BlockNode
bn = forall s (m :: * -> *). MonadState s m => (s -> s) -> m ()
modify forall a b. (a -> b) -> a -> b
$ \HeaderMemory
s -> HeaderMemory
s{memoryBestHeader :: BlockNode
memoryBestHeader = BlockNode
bn}

-- | Initialize memory-based chain.
initialChain :: Network -> HeaderMemory
initialChain :: Network -> HeaderMemory
initialChain Network
net =
    HeaderMemory
        { memoryHeaderMap :: BlockMap
memoryHeaderMap = Network -> BlockMap
genesisMap Network
net
        , memoryBestHeader :: BlockNode
memoryBestHeader = Network -> BlockNode
genesisNode Network
net
        }

-- | Initialize map for memory-based chain.
genesisMap :: Network -> BlockMap
genesisMap :: Network -> BlockMap
genesisMap Network
net =
    forall k v. Hashable k => k -> v -> HashMap k v
HashMap.singleton
        (BlockHash -> Word64
shortBlockHash (BlockHeader -> BlockHash
headerHash (Network -> BlockHeader
getGenesisHeader Network
net)))
        (ByteString -> ShortByteString
toShort (Put -> ByteString
runPutS (forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize (Network -> BlockNode
genesisNode Network
net))))

-- | Add block header to memory block map.
addBlockHeaderMemory :: BlockNode -> HeaderMemory -> HeaderMemory
addBlockHeaderMemory :: BlockNode -> HeaderMemory -> HeaderMemory
addBlockHeaderMemory BlockNode
bn s :: HeaderMemory
s@HeaderMemory{BlockMap
BlockNode
memoryBestHeader :: BlockNode
memoryHeaderMap :: BlockMap
memoryBestHeader :: HeaderMemory -> BlockNode
memoryHeaderMap :: HeaderMemory -> BlockMap
..} =
    let bm' :: BlockMap
bm' = BlockNode -> BlockMap -> BlockMap
addBlockToMap BlockNode
bn BlockMap
memoryHeaderMap
     in HeaderMemory
s{memoryHeaderMap :: BlockMap
memoryHeaderMap = BlockMap
bm'}

-- | Get block header from memory block map.
getBlockHeaderMemory :: BlockHash -> HeaderMemory -> Maybe BlockNode
getBlockHeaderMemory :: BlockHash -> HeaderMemory -> Maybe BlockNode
getBlockHeaderMemory BlockHash
bh HeaderMemory{BlockMap
BlockNode
memoryBestHeader :: BlockNode
memoryHeaderMap :: BlockMap
memoryBestHeader :: HeaderMemory -> BlockNode
memoryHeaderMap :: HeaderMemory -> BlockMap
..} = do
    ShortByteString
bs <- BlockHash -> Word64
shortBlockHash BlockHash
bh forall k v. (Eq k, Hashable k) => k -> HashMap k v -> Maybe v
`HashMap.lookup` BlockMap
memoryHeaderMap
    forall a b. Either a b -> Maybe b
eitherToMaybe forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Get a -> ByteString -> Either String a
runGetS forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize forall a b. (a -> b) -> a -> b
$ ShortByteString -> ByteString
fromShort ShortByteString
bs

{- | Calculate short block hash taking eight non-zero bytes from the 16-byte
 hash. This function will take the bytes that are not on the zero-side of the
 hash, making colissions between short block hashes difficult.
-}
shortBlockHash :: BlockHash -> ShortBlockHash
shortBlockHash :: BlockHash -> Word64
shortBlockHash =
    forall a c b. (a -> c) -> (b -> c) -> Either a b -> c
either forall a. HasCallStack => String -> a
error forall a. a -> a
id forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Get a -> ByteString -> Either String a
runGetS forall a (m :: * -> *). (Serial a, MonadGet m) => m a
deserialize forall b c a. (b -> c) -> (a -> b) -> a -> c
. Int -> ByteString -> ByteString
B.take Int
8 forall b c a. (b -> c) -> (a -> b) -> a -> c
. Put -> ByteString
runPutS forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize

-- | Add a block to memory-based block map.
addBlockToMap :: BlockNode -> BlockMap -> BlockMap
addBlockToMap :: BlockNode -> BlockMap -> BlockMap
addBlockToMap BlockNode
node =
    forall k v.
(Eq k, Hashable k) =>
k -> v -> HashMap k v -> HashMap k v
HashMap.insert
        (BlockHash -> Word64
shortBlockHash forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHash
headerHash forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
node)
        (ByteString -> ShortByteString
toShort forall a b. (a -> b) -> a -> b
$ Put -> ByteString
runPutS forall a b. (a -> b) -> a -> b
$ forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize BlockNode
node)

{- | Get the ancestor of the provided 'BlockNode' at the specified
 'BlockHeight'.
-}
getAncestor ::
    BlockHeaders m =>
    BlockHeight ->
    BlockNode ->
    m (Maybe BlockNode)
getAncestor :: forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
height BlockNode
node
    | BlockHeight
height forall a. Ord a => a -> a -> Bool
> BlockNode -> BlockHeight
nodeHeight BlockNode
node = forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
    | Bool
otherwise = forall {m :: * -> *}.
BlockHeaders m =>
BlockNode -> m (Maybe BlockNode)
go BlockNode
node
  where
    e1 :: a
e1 = forall a. HasCallStack => String -> a
error String
"Could not get skip header"
    e2 :: a
e2 = forall a. HasCallStack => String -> a
error String
"Could not get previous block header"
    go :: BlockNode -> m (Maybe BlockNode)
go BlockNode
walk
        | BlockNode -> BlockHeight
nodeHeight BlockNode
walk forall a. Ord a => a -> a -> Bool
> BlockHeight
height =
            let heightSkip :: BlockHeight
heightSkip = BlockHeight -> BlockHeight
skipHeight (BlockNode -> BlockHeight
nodeHeight BlockNode
walk)
                heightSkipPrev :: BlockHeight
heightSkipPrev = BlockHeight -> BlockHeight
skipHeight (BlockNode -> BlockHeight
nodeHeight BlockNode
walk forall a. Num a => a -> a -> a
- BlockHeight
1)
             in if Bool -> Bool
not (BlockNode -> Bool
isGenesis BlockNode
walk)
                    Bool -> Bool -> Bool
&& ( BlockHeight
heightSkip forall a. Eq a => a -> a -> Bool
== BlockHeight
height
                            Bool -> Bool -> Bool
|| ( BlockHeight
heightSkip forall a. Ord a => a -> a -> Bool
> BlockHeight
height
                                    Bool -> Bool -> Bool
&& Bool -> Bool
not
                                        ( BlockHeight
heightSkipPrev forall a. Ord a => a -> a -> Bool
< BlockHeight
heightSkip forall a. Num a => a -> a -> a
- BlockHeight
2
                                            Bool -> Bool -> Bool
&& BlockHeight
heightSkipPrev forall a. Ord a => a -> a -> Bool
>= BlockHeight
height
                                        )
                               )
                       )
                    then do
                        BlockNode
walk' <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader (BlockNode -> BlockHash
nodeSkip BlockNode
walk)
                        BlockNode -> m (Maybe BlockNode)
go BlockNode
walk'
                    else do
                        BlockNode
walk' <-
                            forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e2
                                forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader (BlockHeader -> BlockHash
prevBlock (BlockNode -> BlockHeader
nodeHeader BlockNode
walk))
                        BlockNode -> m (Maybe BlockNode)
go BlockNode
walk'
        | Bool
otherwise = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just BlockNode
walk

-- | Is the provided 'BlockNode' the Genesis block?
isGenesis :: BlockNode -> Bool
isGenesis :: BlockNode -> Bool
isGenesis BlockNode{nodeHeight :: BlockNode -> BlockHeight
nodeHeight = BlockHeight
0} = Bool
True
isGenesis BlockNode
_ = Bool
False

-- | Build the genesis 'BlockNode' for the supplied 'Network'.
genesisNode :: Network -> BlockNode
genesisNode :: Network -> BlockNode
genesisNode Network
net =
    BlockNode
        { nodeHeader :: BlockHeader
nodeHeader = Network -> BlockHeader
getGenesisHeader Network
net
        , nodeHeight :: BlockHeight
nodeHeight = BlockHeight
0
        , nodeWork :: BlockWork
nodeWork = BlockHeader -> BlockWork
headerWork (Network -> BlockHeader
getGenesisHeader Network
net)
        , nodeSkip :: BlockHash
nodeSkip = BlockHeader -> BlockHash
headerHash (Network -> BlockHeader
getGenesisHeader Network
net)
        }

{- | Validate a list of continuous block headers and import them to the
 block chain. Return 'Left' on failure with error information.
-}
connectBlocks ::
    BlockHeaders m =>
    Network ->
    -- | current time
    Timestamp ->
    [BlockHeader] ->
    m (Either String [BlockNode])
connectBlocks :: forall (m :: * -> *).
BlockHeaders m =>
Network
-> BlockHeight -> [BlockHeader] -> m (Either String [BlockNode])
connectBlocks Network
_ BlockHeight
_ [] = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a b. b -> Either a b
Right []
connectBlocks Network
net BlockHeight
t bhs :: [BlockHeader]
bhs@(BlockHeader
bh : [BlockHeader]
_) =
    forall e (m :: * -> *) a. ExceptT e m a -> m (Either e a)
runExceptT forall a b. (a -> b) -> a -> b
$ do
        forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless ([BlockHeader] -> Bool
chained [BlockHeader]
bhs) forall a b. (a -> b) -> a -> b
$
            forall e (m :: * -> *) a. MonadError e m => e -> m a
throwError String
"Blocks to connect do not form a chain"
        BlockNode
par <-
            forall (m :: * -> *) e a.
Functor m =>
e -> MaybeT m a -> ExceptT e m a
maybeToExceptT
                String
"Could not get parent block"
                (forall (m :: * -> *) a. m (Maybe a) -> MaybeT m a
MaybeT (forall (m :: * -> *).
BlockHeaders m =>
BlockHeader -> m (Maybe BlockNode)
parentBlock BlockHeader
bh))
        [BlockNode]
pars <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
10 BlockNode
par
        BlockNode
bb <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall (m :: * -> *). BlockHeaders m => m BlockNode
getBestBlockHeader
        forall {m :: * -> *}.
BlockHeaders m =>
BlockNode
-> [BlockNode]
-> BlockNode
-> BlockNode
-> [BlockNode]
-> [BlockHeader]
-> ExceptT String m [BlockNode]
go BlockNode
par [] BlockNode
bb BlockNode
par [BlockNode]
pars [BlockHeader]
bhs forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
            bns :: [BlockNode]
bns@(BlockNode
bn : [BlockNode]
_) -> do
                forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *). BlockHeaders m => [BlockNode] -> m ()
addBlockHeaders [BlockNode]
bns
                let bb' :: BlockNode
bb' = BlockNode -> BlockNode -> BlockNode
chooseBest BlockNode
bn BlockNode
bb
                forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (BlockNode
bb' forall a. Eq a => a -> a -> Bool
/= BlockNode
bb) forall a b. (a -> b) -> a -> b
$ forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *). BlockHeaders m => BlockNode -> m ()
setBestBlockHeader BlockNode
bb'
                forall (m :: * -> *) a. Monad m => a -> m a
return [BlockNode]
bns
            [BlockNode]
_ -> forall a. HasCallStack => a
undefined
  where
    chained :: [BlockHeader] -> Bool
chained (BlockHeader
h1 : BlockHeader
h2 : [BlockHeader]
hs) = BlockHeader -> BlockHash
headerHash BlockHeader
h1 forall a. Eq a => a -> a -> Bool
== BlockHeader -> BlockHash
prevBlock BlockHeader
h2 Bool -> Bool -> Bool
&& [BlockHeader] -> Bool
chained (BlockHeader
h2 forall a. a -> [a] -> [a]
: [BlockHeader]
hs)
    chained [BlockHeader]
_ = Bool
True
    skipit :: BlockNode -> [BlockNode] -> BlockNode -> t m BlockNode
skipit BlockNode
lbh [BlockNode]
ls BlockNode
par
        | BlockHeight
sh forall a. Eq a => a -> a -> Bool
== BlockNode -> BlockHeight
nodeHeight BlockNode
lbh = forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
lbh
        | BlockHeight
sh forall a. Ord a => a -> a -> Bool
< BlockNode -> BlockHeight
nodeHeight BlockNode
lbh = do
            Maybe BlockNode
skM <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
sh BlockNode
lbh
            case Maybe BlockNode
skM of
                Just BlockNode
sk -> forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
sk
                Maybe BlockNode
Nothing ->
                    forall e (m :: * -> *) a. MonadError e m => e -> m a
throwError forall a b. (a -> b) -> a -> b
$
                        String
"BUG: Could not get skip for block "
                            forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show (BlockHeader -> BlockHash
headerHash forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
par)
        | Bool
otherwise = do
            let sn :: BlockNode
sn = [BlockNode]
ls forall a. [a] -> Int -> a
!! forall a b. (Integral a, Num b) => a -> b
fromIntegral (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
- BlockHeight
sh)
            forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (BlockNode -> BlockHeight
nodeHeight BlockNode
sn forall a. Eq a => a -> a -> Bool
/= BlockHeight
sh) forall a b. (a -> b) -> a -> b
$
                forall e (m :: * -> *) a. MonadError e m => e -> m a
throwError String
"BUG: Node height not right in skip"
            forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
sn
      where
        sh :: BlockHeight
sh = BlockHeight -> BlockHeight
skipHeight (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1)
    go :: BlockNode
-> [BlockNode]
-> BlockNode
-> BlockNode
-> [BlockNode]
-> [BlockHeader]
-> ExceptT String m [BlockNode]
go BlockNode
_ [BlockNode]
acc BlockNode
_ BlockNode
_ [BlockNode]
_ [] = forall (m :: * -> *) a. Monad m => a -> m a
return [BlockNode]
acc
    go BlockNode
lbh [BlockNode]
acc BlockNode
bb BlockNode
par [BlockNode]
pars (BlockHeader
h : [BlockHeader]
hs) = do
        BlockNode
sk <- forall {t :: (* -> *) -> * -> *} {m :: * -> *}.
(MonadTrans t, BlockHeaders m, MonadError String (t m)) =>
BlockNode -> [BlockNode] -> BlockNode -> t m BlockNode
skipit BlockNode
lbh [BlockNode]
acc BlockNode
par
        BlockNode
bn <- forall e (m :: * -> *) a. m (Either e a) -> ExceptT e m a
ExceptT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ Network
-> BlockHeight
-> BlockNode
-> BlockNode
-> [BlockNode]
-> BlockHeader
-> BlockNode
-> Either String BlockNode
validBlock Network
net BlockHeight
t BlockNode
bb BlockNode
par [BlockNode]
pars BlockHeader
h BlockNode
sk
        BlockNode
-> [BlockNode]
-> BlockNode
-> BlockNode
-> [BlockNode]
-> [BlockHeader]
-> ExceptT String m [BlockNode]
go BlockNode
lbh (BlockNode
bn forall a. a -> [a] -> [a]
: [BlockNode]
acc) (BlockNode -> BlockNode -> BlockNode
chooseBest BlockNode
bn BlockNode
bb) BlockNode
bn (forall a. Int -> [a] -> [a]
take Int
10 forall a b. (a -> b) -> a -> b
$ BlockNode
par forall a. a -> [a] -> [a]
: [BlockNode]
pars) [BlockHeader]
hs

{- | Block's parent. If the block header is in the store, its parent must also
 be there. No block header get deleted or pruned from the store.
-}
parentBlock ::
    BlockHeaders m =>
    BlockHeader ->
    m (Maybe BlockNode)
parentBlock :: forall (m :: * -> *).
BlockHeaders m =>
BlockHeader -> m (Maybe BlockNode)
parentBlock BlockHeader
bh = forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader (BlockHeader -> BlockHash
prevBlock BlockHeader
bh)

{- | Validate and connect single block header to the block chain. Return 'Left'
 if fails to be validated.
-}
connectBlock ::
    BlockHeaders m =>
    Network ->
    -- | current time
    Timestamp ->
    BlockHeader ->
    m (Either String BlockNode)
connectBlock :: forall (m :: * -> *).
BlockHeaders m =>
Network
-> BlockHeight -> BlockHeader -> m (Either String BlockNode)
connectBlock Network
net BlockHeight
t BlockHeader
bh =
    forall e (m :: * -> *) a. ExceptT e m a -> m (Either e a)
runExceptT forall a b. (a -> b) -> a -> b
$ do
        BlockNode
par <-
            forall (m :: * -> *) e a.
Functor m =>
e -> MaybeT m a -> ExceptT e m a
maybeToExceptT
                String
"Could not get parent block"
                (forall (m :: * -> *) a. m (Maybe a) -> MaybeT m a
MaybeT (forall (m :: * -> *).
BlockHeaders m =>
BlockHeader -> m (Maybe BlockNode)
parentBlock BlockHeader
bh))
        [BlockNode]
pars <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
10 BlockNode
par
        Maybe BlockNode
skM <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor (BlockHeight -> BlockHeight
skipHeight (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1)) BlockNode
par
        BlockNode
sk <-
            case Maybe BlockNode
skM of
                Just BlockNode
sk -> forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
sk
                Maybe BlockNode
Nothing ->
                    forall e (m :: * -> *) a. MonadError e m => e -> m a
throwError forall a b. (a -> b) -> a -> b
$
                        String
"BUG: Could not get skip for block "
                            forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show (BlockHeader -> BlockHash
headerHash forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
par)
        BlockNode
bb <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall (m :: * -> *). BlockHeaders m => m BlockNode
getBestBlockHeader
        BlockNode
bn <- forall e (m :: * -> *) a. m (Either e a) -> ExceptT e m a
ExceptT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ Network
-> BlockHeight
-> BlockNode
-> BlockNode
-> [BlockNode]
-> BlockHeader
-> BlockNode
-> Either String BlockNode
validBlock Network
net BlockHeight
t BlockNode
bb BlockNode
par [BlockNode]
pars BlockHeader
bh BlockNode
sk
        let bb' :: BlockNode
bb' = BlockNode -> BlockNode -> BlockNode
chooseBest BlockNode
bb BlockNode
bn
        forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *). BlockHeaders m => BlockNode -> m ()
addBlockHeader BlockNode
bn
        forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (BlockNode
bb forall a. Eq a => a -> a -> Bool
/= BlockNode
bb') forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *). BlockHeaders m => BlockNode -> m ()
setBestBlockHeader BlockNode
bb'
        forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
bn

-- | Validate this block header. Build a 'BlockNode' if successful.
validBlock ::
    Network ->
    -- | current time
    Timestamp ->
    -- | best block
    BlockNode ->
    -- | immediate parent
    BlockNode ->
    -- | 10 parents above
    [BlockNode] ->
    -- | header to validate
    BlockHeader ->
    -- | skip node (black magic)
    BlockNode ->
    Either String BlockNode
validBlock :: Network
-> BlockHeight
-> BlockNode
-> BlockNode
-> [BlockNode]
-> BlockHeader
-> BlockNode
-> Either String BlockNode
validBlock Network
net BlockHeight
t BlockNode
bb BlockNode
par [BlockNode]
pars BlockHeader
bh BlockNode
sk = do
    let mt :: BlockHeight
mt = [BlockHeight] -> BlockHeight
medianTime forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a -> b) -> [a] -> [b]
map (BlockHeader -> BlockHeight
blockTimestamp forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) forall a b. (a -> b) -> a -> b
$ BlockNode
par forall a. a -> [a] -> [a]
: [BlockNode]
pars
        nt :: BlockHeight
nt = BlockHeader -> BlockHeight
blockTimestamp BlockHeader
bh
        hh :: BlockHash
hh = BlockHeader -> BlockHash
headerHash BlockHeader
bh
        nv :: BlockHeight
nv = BlockHeader -> BlockHeight
blockVersion BlockHeader
bh
        ng :: BlockHeight
ng = BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1
        aw :: BlockWork
aw = BlockNode -> BlockWork
nodeWork BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeader -> BlockWork
headerWork BlockHeader
bh
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Network -> BlockHeader -> Bool
isValidPOW Network
net BlockHeader
bh) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Proof of work failed: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show (BlockHeader -> BlockHash
headerHash BlockHeader
bh)
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (BlockHeight
nt forall a. Ord a => a -> a -> Bool
<= BlockHeight
t forall a. Num a => a -> a -> a
+ BlockHeight
2 forall a. Num a => a -> a -> a
* BlockHeight
60 forall a. Num a => a -> a -> a
* BlockHeight
60) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Invalid header timestamp: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHeight
nt
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (BlockHeight
nt forall a. Ord a => a -> a -> Bool
>= BlockHeight
mt) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Block timestamp too early: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHeight
nt
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Network -> BlockHeight -> BlockHeight -> Bool
afterLastCP Network
net (BlockNode -> BlockHeight
nodeHeight BlockNode
bb) BlockHeight
ng) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Rewriting pre-checkpoint chain: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHeight
ng
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Network -> BlockHeight -> BlockHash -> Bool
validCP Network
net BlockHeight
ng BlockHash
hh) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Rejected checkpoint: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHeight
ng
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Network -> BlockHeight -> BlockHash -> Bool
bip34 Network
net BlockHeight
ng BlockHash
hh) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Rejected BIP-34 block: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHash
hh
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Network -> BlockHeight -> BlockHeight -> Bool
validVersion Network
net BlockHeight
ng BlockHeight
nv) forall a b. (a -> b) -> a -> b
$
        forall a b. a -> Either a b
Left forall a b. (a -> b) -> a -> b
$ String
"Invalid block version: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockHeight
nv
    forall (m :: * -> *) a. Monad m => a -> m a
return
        BlockNode
            { nodeHeader :: BlockHeader
nodeHeader = BlockHeader
bh
            , nodeHeight :: BlockHeight
nodeHeight = BlockHeight
ng
            , nodeWork :: BlockWork
nodeWork = BlockWork
aw
            , nodeSkip :: BlockHash
nodeSkip = BlockHeader -> BlockHash
headerHash forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
sk
            }

{- | Return the median of all provided timestamps. Can be unsorted. Error on
 empty list.
-}
medianTime :: [Timestamp] -> Timestamp
medianTime :: [BlockHeight] -> BlockHeight
medianTime [BlockHeight]
ts
    | forall (t :: * -> *) a. Foldable t => t a -> Bool
null [BlockHeight]
ts = forall a. HasCallStack => String -> a
error String
"Cannot compute median time of empty header list"
    | Bool
otherwise = forall a. Ord a => [a] -> [a]
sort [BlockHeight]
ts forall a. [a] -> Int -> a
!! (forall (t :: * -> *) a. Foldable t => t a -> Int
length [BlockHeight]
ts forall a. Integral a => a -> a -> a
`div` Int
2)

{- | Calculate the height of the skip (magic) block that corresponds to the
 given height. The block hash of the ancestor at that height will be placed on
 the 'BlockNode' structure to help locate ancestors at any height quickly.
-}
skipHeight :: BlockHeight -> BlockHeight
skipHeight :: BlockHeight -> BlockHeight
skipHeight BlockHeight
height
    | BlockHeight
height forall a. Ord a => a -> a -> Bool
< BlockHeight
2 = BlockHeight
0
    | BlockHeight
height forall a. Bits a => a -> a -> a
.&. BlockHeight
1 forall a. Eq a => a -> a -> Bool
/= BlockHeight
0 = BlockHeight -> BlockHeight
invertLowestOne (BlockHeight -> BlockHeight
invertLowestOne forall a b. (a -> b) -> a -> b
$ BlockHeight
height forall a. Num a => a -> a -> a
- BlockHeight
1) forall a. Num a => a -> a -> a
+ BlockHeight
1
    | Bool
otherwise = BlockHeight -> BlockHeight
invertLowestOne BlockHeight
height

-- | Part of the skip black magic calculation.
invertLowestOne :: BlockHeight -> BlockHeight
invertLowestOne :: BlockHeight -> BlockHeight
invertLowestOne BlockHeight
height = BlockHeight
height forall a. Bits a => a -> a -> a
.&. (BlockHeight
height forall a. Num a => a -> a -> a
- BlockHeight
1)

-- | Get a number of parents for the provided block.
getParents ::
    BlockHeaders m =>
    Int ->
    BlockNode ->
    -- | starts from immediate parent
    m [BlockNode]
getParents :: forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents = forall {t} {m :: * -> *}.
(Eq t, Num t, BlockHeaders m) =>
[BlockNode] -> t -> BlockNode -> m [BlockNode]
getpars []
  where
    getpars :: [BlockNode] -> t -> BlockNode -> m [BlockNode]
getpars [BlockNode]
acc t
0 BlockNode
_ = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. [a] -> [a]
reverse [BlockNode]
acc
    getpars [BlockNode]
acc t
n BlockNode{BlockWork
BlockHeight
BlockHeader
BlockHash
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
nodeSkip :: BlockNode -> BlockHash
nodeWork :: BlockNode -> BlockWork
nodeHeight :: BlockNode -> BlockHeight
nodeHeader :: BlockNode -> BlockHeader
..}
        | BlockHeight
nodeHeight forall a. Eq a => a -> a -> Bool
== BlockHeight
0 = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. [a] -> [a]
reverse [BlockNode]
acc
        | Bool
otherwise = do
            Maybe BlockNode
parM <- forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHash
prevBlock BlockHeader
nodeHeader
            case Maybe BlockNode
parM of
                Just BlockNode
bn -> [BlockNode] -> t -> BlockNode -> m [BlockNode]
getpars (BlockNode
bn forall a. a -> [a] -> [a]
: [BlockNode]
acc) (t
n forall a. Num a => a -> a -> a
- t
1) BlockNode
bn
                Maybe BlockNode
Nothing -> forall a. HasCallStack => String -> a
error String
"BUG: All non-genesis blocks should have a parent"

-- | Verify that checkpoint location is valid.
validCP ::
    Network ->
    -- | new child height
    BlockHeight ->
    -- | new child hash
    BlockHash ->
    Bool
validCP :: Network -> BlockHeight -> BlockHash -> Bool
validCP Network
net BlockHeight
height BlockHash
newChildHash =
    case forall a b. Eq a => a -> [(a, b)] -> Maybe b
lookup BlockHeight
height (Network -> [(BlockHeight, BlockHash)]
getCheckpoints Network
net) of
        Just BlockHash
cpHash -> BlockHash
cpHash forall a. Eq a => a -> a -> Bool
== BlockHash
newChildHash
        Maybe BlockHash
Nothing -> Bool
True

{- | New block height above the last checkpoint imported. Used to prevent a
 reorg below the highest checkpoint that was already imported.
-}
afterLastCP ::
    Network ->
    -- | best height
    BlockHeight ->
    -- | new imported block height
    BlockHeight ->
    Bool
afterLastCP :: Network -> BlockHeight -> BlockHeight -> Bool
afterLastCP Network
net BlockHeight
bestHeight BlockHeight
newChildHeight =
    case Maybe BlockHeight
lM of
        Just BlockHeight
l -> BlockHeight
l forall a. Ord a => a -> a -> Bool
< BlockHeight
newChildHeight
        Maybe BlockHeight
Nothing -> Bool
True
  where
    lM :: Maybe BlockHeight
lM =
        forall a. [a] -> Maybe a
listToMaybe forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. [a] -> [a]
reverse forall a b. (a -> b) -> a -> b
$
            [BlockHeight
c | (BlockHeight
c, BlockHash
_) <- Network -> [(BlockHeight, BlockHash)]
getCheckpoints Network
net, BlockHeight
c forall a. Ord a => a -> a -> Bool
<= BlockHeight
bestHeight]

{- | This block should be at least version 2 (BIP34). Block height must be
 included in the coinbase transaction to prevent non-unique transaction
 hashes.
-}
bip34 ::
    Network ->
    -- | new child height
    BlockHeight ->
    -- | new child hash
    BlockHash ->
    Bool
bip34 :: Network -> BlockHeight -> BlockHash -> Bool
bip34 Network
net BlockHeight
height BlockHash
hsh
    | forall a b. (a, b) -> a
fst (Network -> (BlockHeight, BlockHash)
getBip34Block Network
net) forall a. Eq a => a -> a -> Bool
== BlockHeight
0 = Bool
True
    | forall a b. (a, b) -> a
fst (Network -> (BlockHeight, BlockHash)
getBip34Block Network
net) forall a. Eq a => a -> a -> Bool
== BlockHeight
height = forall a b. (a, b) -> b
snd (Network -> (BlockHeight, BlockHash)
getBip34Block Network
net) forall a. Eq a => a -> a -> Bool
== BlockHash
hsh
    | Bool
otherwise = Bool
True

-- | Check if the provided block height and version are valid.
validVersion ::
    Network ->
    -- | new child height
    BlockHeight ->
    -- | new child version
    Word32 ->
    Bool
validVersion :: Network -> BlockHeight -> BlockHeight -> Bool
validVersion Network
net BlockHeight
height BlockHeight
version
    | BlockHeight
version forall a. Ord a => a -> a -> Bool
< BlockHeight
2 = BlockHeight
height forall a. Ord a => a -> a -> Bool
< forall a b. (a, b) -> a
fst (Network -> (BlockHeight, BlockHash)
getBip34Block Network
net)
    | BlockHeight
version forall a. Ord a => a -> a -> Bool
< BlockHeight
3 = BlockHeight
height forall a. Ord a => a -> a -> Bool
< Network -> BlockHeight
getBip66Height Network
net
    | BlockHeight
version forall a. Ord a => a -> a -> Bool
< BlockHeight
4 = BlockHeight
height forall a. Ord a => a -> a -> Bool
< Network -> BlockHeight
getBip65Height Network
net
    | Bool
otherwise = Bool
True

{- | Find last block with normal, as opposed to minimum difficulty (for test
 networks).
-}
lastNoMinDiff :: BlockHeaders m => Network -> BlockNode -> m BlockNode
lastNoMinDiff :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> m BlockNode
lastNoMinDiff Network
_ bn :: BlockNode
bn@BlockNode{nodeHeight :: BlockNode -> BlockHeight
nodeHeight = BlockHeight
0} = forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
bn
lastNoMinDiff Network
net bn :: BlockNode
bn@BlockNode{BlockWork
BlockHeight
BlockHeader
BlockHash
nodeSkip :: BlockHash
nodeWork :: BlockWork
nodeHeight :: BlockHeight
nodeHeader :: BlockHeader
nodeSkip :: BlockNode -> BlockHash
nodeWork :: BlockNode -> BlockWork
nodeHeight :: BlockNode -> BlockHeight
nodeHeader :: BlockNode -> BlockHeader
..} = do
    let i :: Bool
i = BlockHeight
nodeHeight forall a. Integral a => a -> a -> a
`mod` Network -> BlockHeight
diffInterval Network
net forall a. Eq a => a -> a -> Bool
/= BlockHeight
0
        c :: BlockHeight
c = BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net)
        l :: Bool
l = BlockHeader -> BlockHeight
blockBits BlockHeader
nodeHeader forall a. Eq a => a -> a -> Bool
== BlockHeight
c
        e1 :: a
e1 =
            forall a. HasCallStack => String -> a
error forall a b. (a -> b) -> a -> b
$
                String
"Could not get block header for parent of "
                    forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show (BlockHeader -> BlockHash
headerHash BlockHeader
nodeHeader)
    if Bool
i Bool -> Bool -> Bool
&& Bool
l
        then do
            BlockNode
bn' <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader (BlockHeader -> BlockHash
prevBlock BlockHeader
nodeHeader)
            forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> m BlockNode
lastNoMinDiff Network
net BlockNode
bn'
        else forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
bn

{- | Returns the work required on a block header given the previous block. This
 coresponds to @bitcoind@ function @GetNextWorkRequired@ in @main.cpp@.
-}
nextWorkRequired ::
    BlockHeaders m =>
    Network ->
    BlockNode ->
    BlockHeader ->
    m Word32
nextWorkRequired :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextWorkRequired Network
net BlockNode
par BlockHeader
bh = do
    Maybe BlockNode
ma <- forall (m :: * -> *).
BlockHeaders m =>
Network -> m (Maybe BlockNode)
getAsertAnchor Network
net
    case forall {m :: * -> *} {m :: * -> *}.
(Alternative m, BlockHeaders m, Monad m) =>
m BlockNode -> m (BlockNode -> BlockHeader -> m BlockHeight)
asert Maybe BlockNode
ma forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Maybe (BlockNode -> BlockHeader -> m BlockHeight)
daa forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Maybe (BlockNode -> BlockHeader -> m BlockHeight)
eda forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Maybe (BlockNode -> BlockHeader -> m BlockHeight)
pow of
        Just BlockNode -> BlockHeader -> m BlockHeight
f -> BlockNode -> BlockHeader -> m BlockHeight
f BlockNode
par BlockHeader
bh
        Maybe (BlockNode -> BlockHeader -> m BlockHeight)
Nothing -> forall a. HasCallStack => String -> a
error String
"Could not determine difficulty algorithm"
  where
    asert :: m BlockNode -> m (BlockNode -> BlockHeader -> m BlockHeight)
asert m BlockNode
ma = do
        BlockNode
anchor <- m BlockNode
ma
        forall (f :: * -> *). Alternative f => Bool -> f ()
guard (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Ord a => a -> a -> Bool
> BlockNode -> BlockHeight
nodeHeight BlockNode
anchor)
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockNode -> BlockHeader -> m BlockHeight
nextAsertWorkRequired Network
net BlockNode
anchor
    daa :: Maybe (BlockNode -> BlockHeader -> m BlockHeight)
daa = do
        BlockHeight
daa_height <- Network -> Maybe BlockHeight
getDaaBlockHeight Network
net
        forall (f :: * -> *). Alternative f => Bool -> f ()
guard (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1 forall a. Ord a => a -> a -> Bool
>= BlockHeight
daa_height)
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextDaaWorkRequired Network
net
    eda :: Maybe (BlockNode -> BlockHeader -> m BlockHeight)
eda = do
        BlockHeight
eda_height <- Network -> Maybe BlockHeight
getEdaBlockHeight Network
net
        forall (f :: * -> *). Alternative f => Bool -> f ()
guard (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1 forall a. Ord a => a -> a -> Bool
>= BlockHeight
eda_height)
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextEdaWorkRequired Network
net
    pow :: Maybe (BlockNode -> BlockHeader -> m BlockHeight)
pow = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextPowWorkRequired Network
net

{- | Find out the next amount of work required according to the Emergency
 Difficulty Adjustment (EDA) algorithm from Bitcoin Cash.
-}
nextEdaWorkRequired ::
    BlockHeaders m => Network -> BlockNode -> BlockHeader -> m Word32
nextEdaWorkRequired :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextEdaWorkRequired Network
net BlockNode
par BlockHeader
bh
    | BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1 forall a. Integral a => a -> a -> a
`mod` Network -> BlockHeight
diffInterval Network
net forall a. Eq a => a -> a -> Bool
== BlockHeight
0 =
        forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextWorkRequired Network
net BlockNode
par BlockHeader
bh
    | Bool
minDifficulty = forall (m :: * -> *) a. Monad m => a -> m a
return (BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net))
    | BlockHeader -> BlockHeight
blockBits (BlockNode -> BlockHeader
nodeHeader BlockNode
par) forall a. Eq a => a -> a -> Bool
== BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net) =
        forall (m :: * -> *) a. Monad m => a -> m a
return (BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net))
    | Bool
otherwise = do
        BlockNode
par6 <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
- BlockHeight
6) BlockNode
par
        [BlockNode]
pars <- forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
10 BlockNode
par
        [BlockNode]
pars6 <- forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
10 BlockNode
par6
        let par6med :: BlockHeight
par6med =
                [BlockHeight] -> BlockHeight
medianTime forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map (BlockHeader -> BlockHeight
blockTimestamp forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) (BlockNode
par6 forall a. a -> [a] -> [a]
: [BlockNode]
pars6)
            parmed :: BlockHeight
parmed = [BlockHeight] -> BlockHeight
medianTime forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map (BlockHeader -> BlockHeight
blockTimestamp forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) (BlockNode
par forall a. a -> [a] -> [a]
: [BlockNode]
pars)
            mtp6 :: BlockHeight
mtp6 = BlockHeight
parmed forall a. Num a => a -> a -> a
- BlockHeight
par6med
        if BlockHeight
mtp6 forall a. Ord a => a -> a -> Bool
< BlockHeight
12 forall a. Num a => a -> a -> a
* BlockHeight
3600
            then forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits (BlockNode -> BlockHeader
nodeHeader BlockNode
par)
            else
                forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$
                    let (BlockWork
diff, Bool
_) = BlockHeight -> (BlockWork, Bool)
decodeCompact (BlockHeader -> BlockHeight
blockBits (BlockNode -> BlockHeader
nodeHeader BlockNode
par))
                        ndiff :: BlockWork
ndiff = BlockWork
diff forall a. Num a => a -> a -> a
+ (BlockWork
diff forall a. Bits a => a -> Int -> a
`shiftR` Int
2)
                     in if Network -> BlockWork
getPowLimit Network
net forall a. Ord a => a -> a -> Bool
> BlockWork
ndiff
                            then BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net)
                            else BlockWork -> BlockHeight
encodeCompact BlockWork
ndiff
  where
    minDifficulty :: Bool
minDifficulty =
        BlockHeader -> BlockHeight
blockTimestamp BlockHeader
bh
            forall a. Ord a => a -> a -> Bool
> BlockHeader -> BlockHeight
blockTimestamp (BlockNode -> BlockHeader
nodeHeader BlockNode
par) forall a. Num a => a -> a -> a
+ Network -> BlockHeight
getTargetSpacing Network
net forall a. Num a => a -> a -> a
* BlockHeight
2
    e1 :: a
e1 = forall a. HasCallStack => String -> a
error String
"Could not get seventh ancestor of block"

{- | Find the next amount of work required according to the Difficulty
 Adjustment Algorithm (DAA) from Bitcoin Cash.
-}
nextDaaWorkRequired ::
    BlockHeaders m => Network -> BlockNode -> BlockHeader -> m Word32
nextDaaWorkRequired :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextDaaWorkRequired Network
net BlockNode
par BlockHeader
bh
    | Bool
minDifficulty = forall (m :: * -> *) a. Monad m => a -> m a
return (BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net))
    | Bool
otherwise = do
        forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (BlockHeight
height forall a. Ord a => a -> a -> Bool
>= Network -> BlockHeight
diffInterval Network
net) forall a b. (a -> b) -> a -> b
$
            forall a. HasCallStack => String -> a
error String
"Block height below difficulty interval"
        BlockNode
l <- forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockNode
getSuitableBlock BlockNode
par
        BlockNode
par144 <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor (BlockHeight
height forall a. Num a => a -> a -> a
- BlockHeight
144) BlockNode
par
        BlockNode
f <- forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockNode
getSuitableBlock BlockNode
par144
        let nextTarget :: BlockWork
nextTarget = Network -> BlockNode -> BlockNode -> BlockWork
computeTarget Network
net BlockNode
f BlockNode
l
        if BlockWork
nextTarget forall a. Ord a => a -> a -> Bool
> Network -> BlockWork
getPowLimit Network
net
            then forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net)
            else forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockWork -> BlockHeight
encodeCompact BlockWork
nextTarget
  where
    height :: BlockHeight
height = BlockNode -> BlockHeight
nodeHeight BlockNode
par
    e1 :: a
e1 = forall a. HasCallStack => String -> a
error String
"Cannot get ancestor at parent - 144 height"
    minDifficulty :: Bool
minDifficulty =
        BlockHeader -> BlockHeight
blockTimestamp BlockHeader
bh
            forall a. Ord a => a -> a -> Bool
> BlockHeader -> BlockHeight
blockTimestamp (BlockNode -> BlockHeader
nodeHeader BlockNode
par) forall a. Num a => a -> a -> a
+ Network -> BlockHeight
getTargetSpacing Network
net forall a. Num a => a -> a -> a
* BlockHeight
2

mtp :: BlockHeaders m => BlockNode -> m Timestamp
mtp :: forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockHeight
mtp BlockNode
bn
    | BlockNode -> BlockHeight
nodeHeight BlockNode
bn forall a. Eq a => a -> a -> Bool
== BlockHeight
0 = forall (m :: * -> *) a. Monad m => a -> m a
return BlockHeight
0
    | Bool
otherwise = do
        [BlockNode]
pars <- forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
11 BlockNode
bn
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ [BlockHeight] -> BlockHeight
medianTime (forall a b. (a -> b) -> [a] -> [b]
map (BlockHeader -> BlockHeight
blockTimestamp forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) [BlockNode]
pars)

firstGreaterOrEqual ::
    BlockHeaders m =>
    Network ->
    (BlockNode -> m Ordering) ->
    m (Maybe BlockNode)
firstGreaterOrEqual :: forall (m :: * -> *).
BlockHeaders m =>
Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
firstGreaterOrEqual = forall (m :: * -> *).
BlockHeaders m =>
Bool -> Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
binSearch Bool
False

lastSmallerOrEqual ::
    BlockHeaders m =>
    Network ->
    (BlockNode -> m Ordering) ->
    m (Maybe BlockNode)
lastSmallerOrEqual :: forall (m :: * -> *).
BlockHeaders m =>
Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
lastSmallerOrEqual = forall (m :: * -> *).
BlockHeaders m =>
Bool -> Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
binSearch Bool
True

binSearch ::
    BlockHeaders m =>
    Bool ->
    Network ->
    (BlockNode -> m Ordering) ->
    m (Maybe BlockNode)
binSearch :: forall (m :: * -> *).
BlockHeaders m =>
Bool -> Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
binSearch Bool
top Network
net BlockNode -> m Ordering
f = forall (m :: * -> *) a. MaybeT m a -> m (Maybe a)
runMaybeT forall a b. (a -> b) -> a -> b
$ do
    (BlockNode
a, BlockNode
b) <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
Network -> m (BlockNode, BlockNode)
extremes Network
net
    forall {t :: (* -> *) -> * -> *}.
(MonadTrans t, MonadPlus (t m)) =>
BlockNode -> BlockNode -> t m BlockNode
go BlockNode
a BlockNode
b
  where
    go :: BlockNode -> BlockNode -> t m BlockNode
go BlockNode
a BlockNode
b = do
        BlockNode
m <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *).
BlockHeaders m =>
BlockNode -> BlockNode -> m BlockNode
middleBlock BlockNode
a BlockNode
b
        Ordering
a' <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ BlockNode -> m Ordering
f BlockNode
a
        Ordering
b' <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ BlockNode -> m Ordering
f BlockNode
b
        Ordering
m' <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall a b. (a -> b) -> a -> b
$ BlockNode -> m Ordering
f BlockNode
m
        (BlockNode, Ordering)
-> (BlockNode, Ordering) -> (BlockNode, Ordering) -> t m BlockNode
r (BlockNode
a, Ordering
a') (BlockNode
b, Ordering
b') (BlockNode
m, Ordering
m')
    r :: (BlockNode, Ordering)
-> (BlockNode, Ordering) -> (BlockNode, Ordering) -> t m BlockNode
r (BlockNode
a, Ordering
a') (BlockNode
b, Ordering
b') (BlockNode
m, Ordering
m')
        | Ordering -> Ordering -> Bool
out_of_bounds Ordering
a' Ordering
b' = forall (m :: * -> *) a. MonadPlus m => m a
mzero
        | Ordering -> Bool
select_first Ordering
a' = forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
a
        | Ordering -> Bool
select_last Ordering
b' = forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
b
        | BlockNode -> BlockNode -> Bool
no_middle BlockNode
a BlockNode
b = forall {m :: * -> *} {a}. Monad m => a -> a -> m a
choose_one BlockNode
a BlockNode
b
        | Ordering -> Ordering -> Bool
is_between Ordering
a' Ordering
m' = BlockNode -> BlockNode -> t m BlockNode
go BlockNode
a BlockNode
m
        | Ordering -> Ordering -> Bool
is_between Ordering
m' Ordering
b' = BlockNode -> BlockNode -> t m BlockNode
go BlockNode
m BlockNode
b
        | Bool
otherwise = forall (m :: * -> *) a. MonadPlus m => m a
mzero
    select_first :: Ordering -> Bool
select_first Ordering
a'
        | Bool -> Bool
not Bool
top = Ordering
a' forall a. Eq a => a -> a -> Bool
/= Ordering
LT
        | Bool
otherwise = Bool
False
    select_last :: Ordering -> Bool
select_last Ordering
b'
        | Bool
top = Ordering
b' forall a. Eq a => a -> a -> Bool
/= Ordering
GT
        | Bool
otherwise = Bool
False
    out_of_bounds :: Ordering -> Ordering -> Bool
out_of_bounds Ordering
a' Ordering
b'
        | Bool
top = Ordering
a' forall a. Eq a => a -> a -> Bool
== Ordering
GT
        | Bool
otherwise = Ordering
b' forall a. Eq a => a -> a -> Bool
== Ordering
LT
    no_middle :: BlockNode -> BlockNode -> Bool
no_middle BlockNode
a BlockNode
b = BlockNode -> BlockHeight
nodeHeight BlockNode
b forall a. Num a => a -> a -> a
- BlockNode -> BlockHeight
nodeHeight BlockNode
a forall a. Ord a => a -> a -> Bool
<= BlockHeight
1
    is_between :: Ordering -> Ordering -> Bool
is_between Ordering
a' Ordering
b' = Ordering
a' forall a. Eq a => a -> a -> Bool
/= Ordering
GT Bool -> Bool -> Bool
&& Ordering
b' forall a. Eq a => a -> a -> Bool
/= Ordering
LT
    choose_one :: a -> a -> m a
choose_one a
a a
b
        | Bool
top = forall (m :: * -> *) a. Monad m => a -> m a
return a
a
        | Bool
otherwise = forall (m :: * -> *) a. Monad m => a -> m a
return a
b

extremes :: BlockHeaders m => Network -> m (BlockNode, BlockNode)
extremes :: forall (m :: * -> *).
BlockHeaders m =>
Network -> m (BlockNode, BlockNode)
extremes Network
net = do
    BlockNode
b <- forall (m :: * -> *). BlockHeaders m => m BlockNode
getBestBlockHeader
    forall (m :: * -> *) a. Monad m => a -> m a
return (Network -> BlockNode
genesisNode Network
net, BlockNode
b)

middleBlock :: BlockHeaders m => BlockNode -> BlockNode -> m BlockNode
middleBlock :: forall (m :: * -> *).
BlockHeaders m =>
BlockNode -> BlockNode -> m BlockNode
middleBlock BlockNode
a BlockNode
b =
    forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
b forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
        Maybe BlockNode
Nothing -> forall a. HasCallStack => String -> a
error String
"You fell into a pit full of mud and snakes"
        Just BlockNode
x -> forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
x
  where
    h :: BlockHeight
h = forall a. Integral a => a -> a -> a
middleOf (BlockNode -> BlockHeight
nodeHeight BlockNode
a) (BlockNode -> BlockHeight
nodeHeight BlockNode
b)

middleOf :: Integral a => a -> a -> a
middleOf :: forall a. Integral a => a -> a -> a
middleOf a
a a
b = a
a forall a. Num a => a -> a -> a
+ ((a
b forall a. Num a => a -> a -> a
- a
a) forall a. Integral a => a -> a -> a
`div` a
2)

-- TODO: Use known anchor after fork
getAsertAnchor :: BlockHeaders m => Network -> m (Maybe BlockNode)
getAsertAnchor :: forall (m :: * -> *).
BlockHeaders m =>
Network -> m (Maybe BlockNode)
getAsertAnchor Network
net =
    case Network -> Maybe BlockHeight
getAsertActivationTime Network
net of
        Maybe BlockHeight
Nothing -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
        Just BlockHeight
act -> forall (m :: * -> *).
BlockHeaders m =>
Network -> (BlockNode -> m Ordering) -> m (Maybe BlockNode)
firstGreaterOrEqual Network
net (forall {m :: * -> *}.
BlockHeaders m =>
BlockHeight -> BlockNode -> m Ordering
f BlockHeight
act)
  where
    f :: BlockHeight -> BlockNode -> m Ordering
f BlockHeight
act BlockNode
bn = do
        BlockHeight
m <- forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockHeight
mtp BlockNode
bn
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. Ord a => a -> a -> Ordering
compare BlockHeight
m BlockHeight
act

-- | Find the next amount of work required according to the aserti3-2d algorithm.
nextAsertWorkRequired ::
    BlockHeaders m =>
    Network ->
    BlockNode ->
    BlockNode ->
    BlockHeader ->
    m Word32
nextAsertWorkRequired :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockNode -> BlockHeader -> m BlockHeight
nextAsertWorkRequired Network
net BlockNode
anchor BlockNode
par BlockHeader
bh = do
    BlockNode
anchor_parent <-
        forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e_fork
            forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHash -> m (Maybe BlockNode)
getBlockHeader (BlockHeader -> BlockHash
prevBlock (BlockNode -> BlockHeader
nodeHeader BlockNode
anchor))
    let anchor_parent_time :: BlockWork
anchor_parent_time = forall a. Integral a => a -> BlockWork
toInteger forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockTimestamp forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
anchor_parent
        time_diff :: BlockWork
time_diff = BlockWork
current_time forall a. Num a => a -> a -> a
- BlockWork
anchor_parent_time
    forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockWork -> BlockHeight -> BlockWork -> BlockWork -> BlockHeight
computeAsertBits BlockWork
halflife BlockHeight
anchor_bits BlockWork
time_diff BlockWork
height_diff
  where
    halflife :: BlockWork
halflife = Network -> BlockWork
getAsertHalfLife Network
net
    anchor_height :: BlockWork
anchor_height = forall a. Integral a => a -> BlockWork
toInteger forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeight
nodeHeight BlockNode
anchor
    anchor_bits :: BlockHeight
anchor_bits = BlockHeader -> BlockHeight
blockBits forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
anchor
    current_height :: BlockWork
current_height = forall a. Integral a => a -> BlockWork
toInteger (BlockNode -> BlockHeight
nodeHeight BlockNode
par) forall a. Num a => a -> a -> a
+ BlockWork
1
    height_diff :: BlockWork
height_diff = BlockWork
current_height forall a. Num a => a -> a -> a
- BlockWork
anchor_height
    current_time :: BlockWork
current_time = forall a. Integral a => a -> BlockWork
toInteger forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockTimestamp BlockHeader
bh
    e_fork :: a
e_fork = forall a. HasCallStack => String -> a
error String
"Could not get fork block header"

idealBlockTime :: Integer
idealBlockTime :: BlockWork
idealBlockTime = BlockWork
10 forall a. Num a => a -> a -> a
* BlockWork
60

rBits :: Int
rBits :: Int
rBits = Int
16

radix :: Integer
radix :: BlockWork
radix = BlockWork
1 forall a. Bits a => a -> Int -> a
`shiftL` Int
rBits

maxBits :: Word32
maxBits :: BlockHeight
maxBits = BlockHeight
0x1d00ffff

maxTarget :: Integer
maxTarget :: BlockWork
maxTarget = forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$ BlockHeight -> (BlockWork, Bool)
decodeCompact BlockHeight
maxBits

computeAsertBits ::
    Integer ->
    Word32 ->
    Integer ->
    Integer ->
    Word32
computeAsertBits :: BlockWork -> BlockHeight -> BlockWork -> BlockWork -> BlockHeight
computeAsertBits BlockWork
halflife BlockHeight
anchor_bits BlockWork
time_diff BlockWork
height_diff =
    if BlockWork
e2 forall a. Ord a => a -> a -> Bool
>= BlockWork
0 Bool -> Bool -> Bool
&& BlockWork
e2 forall a. Ord a => a -> a -> Bool
< BlockWork
65536
        then
            if BlockWork
g4 forall a. Eq a => a -> a -> Bool
== BlockWork
0
                then BlockWork -> BlockHeight
encodeCompact BlockWork
1
                else
                    if BlockWork
g4 forall a. Ord a => a -> a -> Bool
> BlockWork
maxTarget
                        then BlockHeight
maxBits
                        else BlockWork -> BlockHeight
encodeCompact BlockWork
g4
        else forall a. HasCallStack => String -> a
error forall a b. (a -> b) -> a -> b
$ String
"Exponent not in range: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> String
show BlockWork
e2
  where
    g1 :: BlockWork
g1 = forall a b. (a, b) -> a
fst (BlockHeight -> (BlockWork, Bool)
decodeCompact BlockHeight
anchor_bits)
    e1 :: BlockWork
e1 =
        ((BlockWork
time_diff forall a. Num a => a -> a -> a
- BlockWork
idealBlockTime forall a. Num a => a -> a -> a
* (BlockWork
height_diff forall a. Num a => a -> a -> a
+ BlockWork
1)) forall a. Num a => a -> a -> a
* BlockWork
radix)
            forall a. Integral a => a -> a -> a
`quot` BlockWork
halflife
    s :: BlockWork
s = BlockWork
e1 forall a. Bits a => a -> Int -> a
`shiftR` Int
rBits
    e2 :: BlockWork
e2 = BlockWork
e1 forall a. Num a => a -> a -> a
- BlockWork
s forall a. Num a => a -> a -> a
* BlockWork
radix
    g2 :: BlockWork
g2 =
        BlockWork
g1
            forall a. Num a => a -> a -> a
* ( BlockWork
radix
                    forall a. Num a => a -> a -> a
+ ( (BlockWork
195766423245049 forall a. Num a => a -> a -> a
* BlockWork
e2 forall a. Num a => a -> a -> a
+ BlockWork
971821376 forall a. Num a => a -> a -> a
* BlockWork
e2 forall a b. (Num a, Integral b) => a -> b -> a
^ BlockWork
2 forall a. Num a => a -> a -> a
+ BlockWork
5127 forall a. Num a => a -> a -> a
* BlockWork
e2 forall a b. (Num a, Integral b) => a -> b -> a
^ BlockWork
3 forall a. Num a => a -> a -> a
+ BlockWork
2 forall a b. (Num a, Integral b) => a -> b -> a
^ BlockWork
47)
                            forall a. Bits a => a -> Int -> a
`shiftR` (Int
rBits forall a. Num a => a -> a -> a
* Int
3)
                      )
              )
    g3 :: BlockWork
g3 =
        if BlockWork
s forall a. Ord a => a -> a -> Bool
< BlockWork
0
            then BlockWork
g2 forall a. Bits a => a -> Int -> a
`shiftR` forall a. Num a => a -> a
negate (forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockWork
s)
            else BlockWork
g2 forall a. Bits a => a -> Int -> a
`shiftL` forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockWork
s
    g4 :: BlockWork
g4 = BlockWork
g3 forall a. Bits a => a -> Int -> a
`shiftR` Int
rBits

-- | Compute Bitcoin Cash DAA target for a new block.
computeTarget :: Network -> BlockNode -> BlockNode -> Integer
computeTarget :: Network -> BlockNode -> BlockNode -> BlockWork
computeTarget Network
net BlockNode
f BlockNode
l =
    let work :: BlockWork
work = (BlockNode -> BlockWork
nodeWork BlockNode
l forall a. Num a => a -> a -> a
- BlockNode -> BlockWork
nodeWork BlockNode
f) forall a. Num a => a -> a -> a
* forall a b. (Integral a, Num b) => a -> b
fromIntegral (Network -> BlockHeight
getTargetSpacing Network
net)
        actualTimespan :: BlockHeight
actualTimespan =
            BlockHeader -> BlockHeight
blockTimestamp (BlockNode -> BlockHeader
nodeHeader BlockNode
l) forall a. Num a => a -> a -> a
- BlockHeader -> BlockHeight
blockTimestamp (BlockNode -> BlockHeader
nodeHeader BlockNode
f)
        actualTimespan' :: BlockHeight
actualTimespan'
            | BlockHeight
actualTimespan forall a. Ord a => a -> a -> Bool
> BlockHeight
288 forall a. Num a => a -> a -> a
* Network -> BlockHeight
getTargetSpacing Network
net =
                BlockHeight
288 forall a. Num a => a -> a -> a
* Network -> BlockHeight
getTargetSpacing Network
net
            | BlockHeight
actualTimespan forall a. Ord a => a -> a -> Bool
< BlockHeight
72 forall a. Num a => a -> a -> a
* Network -> BlockHeight
getTargetSpacing Network
net =
                BlockHeight
72 forall a. Num a => a -> a -> a
* Network -> BlockHeight
getTargetSpacing Network
net
            | Bool
otherwise = BlockHeight
actualTimespan
        work' :: BlockWork
work' = BlockWork
work forall a. Integral a => a -> a -> a
`div` forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockHeight
actualTimespan'
     in BlockWork
2 forall a b. (Num a, Integral b) => a -> b -> a
^ (BlockWork
256 :: Integer) forall a. Integral a => a -> a -> a
`div` BlockWork
work'

-- | Get suitable block for Bitcoin Cash DAA computation.
getSuitableBlock :: BlockHeaders m => BlockNode -> m BlockNode
getSuitableBlock :: forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockNode
getSuitableBlock BlockNode
par = do
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Ord a => a -> a -> Bool
>= BlockHeight
3) forall a b. (a -> b) -> a -> b
$ forall a. HasCallStack => String -> a
error String
"Block height is less than three"
    [BlockNode]
blocks <- (BlockNode
par forall a. a -> [a] -> [a]
:) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
Int -> BlockNode -> m [BlockNode]
getParents Int
2 BlockNode
par
    forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy (forall a. Ord a => a -> a -> Ordering
compare forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` BlockHeader -> BlockHeight
blockTimestamp forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) [BlockNode]
blocks forall a. [a] -> Int -> a
!! Int
1

{- | Returns the work required on a block header given the previous block. This
 coresponds to bitcoind function GetNextWorkRequired in main.cpp.
-}
nextPowWorkRequired ::
    BlockHeaders m => Network -> BlockNode -> BlockHeader -> m Word32
nextPowWorkRequired :: forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> BlockHeader -> m BlockHeight
nextPowWorkRequired Network
net BlockNode
par BlockHeader
bh
    | BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
+ BlockHeight
1 forall a. Integral a => a -> a -> a
`mod` Network -> BlockHeight
diffInterval Network
net forall a. Eq a => a -> a -> Bool
/= BlockHeight
0 =
        if Network -> Bool
getAllowMinDifficultyBlocks Network
net
            then
                if BlockHeight
ht forall a. Ord a => a -> a -> Bool
> BlockHeight
pt forall a. Num a => a -> a -> a
+ BlockHeight
delta
                    then forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net)
                    else do
                        BlockNode
d <- forall (m :: * -> *).
BlockHeaders m =>
Network -> BlockNode -> m BlockNode
lastNoMinDiff Network
net BlockNode
par
                        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
d
            else forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
par
    | Bool
otherwise = do
        let rh :: BlockHeight
rh = BlockNode -> BlockHeight
nodeHeight BlockNode
par forall a. Num a => a -> a -> a
- (Network -> BlockHeight
diffInterval Network
net forall a. Num a => a -> a -> a
- BlockHeight
1)
        BlockNode
a <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
rh BlockNode
par
        let t :: BlockHeight
t = BlockHeader -> BlockHeight
blockTimestamp forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
a
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ Network -> BlockHeader -> BlockHeight -> BlockHeight
calcNextWork Network
net (BlockNode -> BlockHeader
nodeHeader BlockNode
par) BlockHeight
t
  where
    e1 :: a
e1 = forall a. HasCallStack => String -> a
error String
"Could not get ancestor for block header"
    pt :: BlockHeight
pt = BlockHeader -> BlockHeight
blockTimestamp forall a b. (a -> b) -> a -> b
$ BlockNode -> BlockHeader
nodeHeader BlockNode
par
    ht :: BlockHeight
ht = BlockHeader -> BlockHeight
blockTimestamp BlockHeader
bh
    delta :: BlockHeight
delta = Network -> BlockHeight
getTargetSpacing Network
net forall a. Num a => a -> a -> a
* BlockHeight
2

-- | Computes the work required for the first block in a new retarget period.
calcNextWork ::
    Network ->
    -- | last block in previous retarget (parent)
    BlockHeader ->
    -- | timestamp of first block in previous retarget
    Timestamp ->
    Word32
calcNextWork :: Network -> BlockHeader -> BlockHeight -> BlockHeight
calcNextWork Network
net BlockHeader
header BlockHeight
time
    | Network -> Bool
getPowNoRetargetting Network
net = BlockHeader -> BlockHeight
blockBits BlockHeader
header
    | BlockWork
new forall a. Ord a => a -> a -> Bool
> Network -> BlockWork
getPowLimit Network
net = BlockWork -> BlockHeight
encodeCompact (Network -> BlockWork
getPowLimit Network
net)
    | Bool
otherwise = BlockWork -> BlockHeight
encodeCompact BlockWork
new
  where
    s :: BlockHeight
s = BlockHeader -> BlockHeight
blockTimestamp BlockHeader
header forall a. Num a => a -> a -> a
- BlockHeight
time
    n :: BlockHeight
n
        | BlockHeight
s forall a. Ord a => a -> a -> Bool
< Network -> BlockHeight
getTargetTimespan Network
net forall a. Integral a => a -> a -> a
`div` BlockHeight
4 = Network -> BlockHeight
getTargetTimespan Network
net forall a. Integral a => a -> a -> a
`div` BlockHeight
4
        | BlockHeight
s forall a. Ord a => a -> a -> Bool
> Network -> BlockHeight
getTargetTimespan Network
net forall a. Num a => a -> a -> a
* BlockHeight
4 = Network -> BlockHeight
getTargetTimespan Network
net forall a. Num a => a -> a -> a
* BlockHeight
4
        | Bool
otherwise = BlockHeight
s
    l :: BlockWork
l = forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$ BlockHeight -> (BlockWork, Bool)
decodeCompact forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits BlockHeader
header
    new :: BlockWork
new = BlockWork
l forall a. Num a => a -> a -> a
* forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockHeight
n forall a. Integral a => a -> a -> a
`div` forall a b. (Integral a, Num b) => a -> b
fromIntegral (Network -> BlockHeight
getTargetTimespan Network
net)

{- | Returns True if the difficulty target (bits) of the header is valid and the
 proof of work of the header matches the advertised difficulty target. This
 function corresponds to the function @CheckProofOfWork@ from @bitcoind@ in
 @main.cpp@.
-}
isValidPOW :: Network -> BlockHeader -> Bool
isValidPOW :: Network -> BlockHeader -> Bool
isValidPOW Network
net BlockHeader
h
    | BlockWork
target forall a. Ord a => a -> a -> Bool
<= BlockWork
0 Bool -> Bool -> Bool
|| Bool
over Bool -> Bool -> Bool
|| BlockWork
target forall a. Ord a => a -> a -> Bool
> Network -> BlockWork
getPowLimit Network
net = Bool
False
    | Bool
otherwise = BlockHash -> BlockWork
blockPOW (BlockHeader -> BlockHash
headerHash BlockHeader
h) forall a. Ord a => a -> a -> Bool
<= forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockWork
target
  where
    (BlockWork
target, Bool
over) = BlockHeight -> (BlockWork, Bool)
decodeCompact forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits BlockHeader
h

-- | Returns the proof of work of a block header hash as an 'Integer' number.
blockPOW :: BlockHash -> Integer
blockPOW :: BlockHash -> BlockWork
blockPOW = ByteString -> BlockWork
bsToInteger forall b c a. (b -> c) -> (a -> b) -> a -> c
. ByteString -> ByteString
B.reverse forall b c a. (b -> c) -> (a -> b) -> a -> c
. Put -> ByteString
runPutS forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize

{- | Returns the work represented by this block. Work is defined as the number
 of tries needed to solve a block in the average case with respect to the
 target.
-}
headerWork :: BlockHeader -> Integer
headerWork :: BlockHeader -> BlockWork
headerWork BlockHeader
bh = BlockWork
largestHash forall a. Integral a => a -> a -> a
`div` (BlockWork
target forall a. Num a => a -> a -> a
+ BlockWork
1)
  where
    target :: BlockWork
target = forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$ BlockHeight -> (BlockWork, Bool)
decodeCompact forall a b. (a -> b) -> a -> b
$ BlockHeader -> BlockHeight
blockBits BlockHeader
bh
    largestHash :: BlockWork
largestHash = BlockWork
1 forall a. Bits a => a -> Int -> a
`shiftL` Int
256

-- | Number of blocks on average between difficulty cycles (2016 blocks).
diffInterval :: Network -> Word32
diffInterval :: Network -> BlockHeight
diffInterval Network
net = Network -> BlockHeight
getTargetTimespan Network
net forall a. Integral a => a -> a -> a
`div` Network -> BlockHeight
getTargetSpacing Network
net

-- | Compare two blocks to get the best.
chooseBest :: BlockNode -> BlockNode -> BlockNode
chooseBest :: BlockNode -> BlockNode -> BlockNode
chooseBest BlockNode
b1 BlockNode
b2
    | BlockNode -> BlockWork
nodeWork BlockNode
b1 forall a. Eq a => a -> a -> Bool
== BlockNode -> BlockWork
nodeWork BlockNode
b2 =
        if BlockNode -> BlockHeight
nodeHeight BlockNode
b1 forall a. Ord a => a -> a -> Bool
>= BlockNode -> BlockHeight
nodeHeight BlockNode
b2
            then BlockNode
b1
            else BlockNode
b2
    | BlockNode -> BlockWork
nodeWork BlockNode
b1 forall a. Ord a => a -> a -> Bool
> BlockNode -> BlockWork
nodeWork BlockNode
b2 = BlockNode
b1
    | Bool
otherwise = BlockNode
b2

-- | Get list of blocks for a block locator.
blockLocatorNodes :: BlockHeaders m => BlockNode -> m [BlockNode]
blockLocatorNodes :: forall (m :: * -> *). BlockHeaders m => BlockNode -> m [BlockNode]
blockLocatorNodes BlockNode
best =
    forall a. [a] -> [a]
reverse forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall {m :: * -> *}.
BlockHeaders m =>
[BlockNode] -> BlockNode -> BlockHeight -> m [BlockNode]
go [] BlockNode
best BlockHeight
1
  where
    e1 :: a
e1 = forall a. HasCallStack => String -> a
error String
"Could not get ancestor"
    go :: [BlockNode] -> BlockNode -> BlockHeight -> m [BlockNode]
go [BlockNode]
loc BlockNode
bn BlockHeight
n =
        let loc' :: [BlockNode]
loc' = BlockNode
bn forall a. a -> [a] -> [a]
: [BlockNode]
loc
            n' :: BlockHeight
n' =
                if forall (t :: * -> *) a. Foldable t => t a -> Int
length [BlockNode]
loc' forall a. Ord a => a -> a -> Bool
> Int
10
                    then BlockHeight
n forall a. Num a => a -> a -> a
* BlockHeight
2
                    else BlockHeight
1
         in if BlockNode -> BlockHeight
nodeHeight BlockNode
bn forall a. Ord a => a -> a -> Bool
< BlockHeight
n'
                then do
                    BlockNode
a <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
0 BlockNode
bn
                    forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ BlockNode
a forall a. a -> [a] -> [a]
: [BlockNode]
loc'
                else do
                    let h :: BlockHeight
h = BlockNode -> BlockHeight
nodeHeight BlockNode
bn forall a. Num a => a -> a -> a
- BlockHeight
n'
                    BlockNode
bn' <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e1 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
bn
                    [BlockNode] -> BlockNode -> BlockHeight -> m [BlockNode]
go [BlockNode]
loc' BlockNode
bn' BlockHeight
n'

-- | Get block locator.
blockLocator :: BlockHeaders m => BlockNode -> m BlockLocator
blockLocator :: forall (m :: * -> *). BlockHeaders m => BlockNode -> m BlockLocator
blockLocator BlockNode
bn = forall a b. (a -> b) -> [a] -> [b]
map (BlockHeader -> BlockHash
headerHash forall b c a. (b -> c) -> (a -> b) -> a -> c
. BlockNode -> BlockHeader
nodeHeader) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *). BlockHeaders m => BlockNode -> m [BlockNode]
blockLocatorNodes BlockNode
bn

-- | Become rich beyond your wildest dreams.
mineBlock :: Network -> Word32 -> BlockHeader -> BlockHeader
mineBlock :: Network -> BlockHeight -> BlockHeader -> BlockHeader
mineBlock Network
net BlockHeight
seed BlockHeader
h =
    forall a. [a] -> a
head
        [ BlockHeader
j
        | BlockHeight
i <- (forall a. Num a => a -> a -> a
+ BlockHeight
seed) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> [BlockHeight
0 .. forall a. Bounded a => a
maxBound]
        , let j :: BlockHeader
j = BlockHeader
h{bhNonce :: BlockHeight
bhNonce = BlockHeight
i}
        , Network -> BlockHeader -> Bool
isValidPOW Network
net BlockHeader
j
        ]

-- | Generate and append new blocks (mining). Only practical in regtest network.
appendBlocks ::
    Network ->
    -- | random seed
    Word32 ->
    BlockHeader ->
    Int ->
    [BlockHeader]
appendBlocks :: Network -> BlockHeight -> BlockHeader -> Int -> [BlockHeader]
appendBlocks Network
_ BlockHeight
_ BlockHeader
_ Int
0 = []
appendBlocks Network
net BlockHeight
seed BlockHeader
bh Int
i =
    BlockHeader
bh' forall a. a -> [a] -> [a]
: Network -> BlockHeight -> BlockHeader -> Int -> [BlockHeader]
appendBlocks Network
net BlockHeight
seed BlockHeader
bh' (Int
i forall a. Num a => a -> a -> a
- Int
1)
  where
    bh' :: BlockHeader
bh' =
        Network -> BlockHeight -> BlockHeader -> BlockHeader
mineBlock
            Network
net
            BlockHeight
seed
            BlockHeader
bh
                { prevBlock :: BlockHash
prevBlock = BlockHeader -> BlockHash
headerHash BlockHeader
bh
                , -- Just to make it different in every header
                  merkleRoot :: Hash256
merkleRoot = forall b. ByteArrayAccess b => b -> Hash256
sha256 forall a b. (a -> b) -> a -> b
$ Put -> ByteString
runPutS forall a b. (a -> b) -> a -> b
$ forall a (m :: * -> *). (Serial a, MonadPut m) => a -> m ()
serialize BlockHeight
seed
                }

-- | Find the last common block ancestor between provided block headers.
splitPoint :: BlockHeaders m => BlockNode -> BlockNode -> m BlockNode
splitPoint :: forall (m :: * -> *).
BlockHeaders m =>
BlockNode -> BlockNode -> m BlockNode
splitPoint BlockNode
l BlockNode
r = do
    let h :: BlockHeight
h = forall a. Ord a => a -> a -> a
min (BlockNode -> BlockHeight
nodeHeight BlockNode
l) (BlockNode -> BlockHeight
nodeHeight BlockNode
r)
    BlockNode
ll <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
l
    BlockNode
lr <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
r
    forall (m :: * -> *).
BlockHeaders m =>
BlockNode -> BlockNode -> m BlockNode
f BlockNode
ll BlockNode
lr
  where
    e :: a
e = forall a. HasCallStack => String -> a
error String
"BUG: Could not get ancestor at lowest height"
    f :: BlockNode -> BlockNode -> m BlockNode
f BlockNode
ll BlockNode
lr =
        if BlockNode
ll forall a. Eq a => a -> a -> Bool
== BlockNode
lr
            then forall (m :: * -> *) a. Monad m => a -> m a
return BlockNode
lr
            else do
                let h :: BlockHeight
h = BlockNode -> BlockHeight
nodeHeight BlockNode
ll forall a. Num a => a -> a -> a
- BlockHeight
1
                BlockNode
pl <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
ll
                BlockNode
pr <- forall a. a -> Maybe a -> a
fromMaybe forall {a}. a
e forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *).
BlockHeaders m =>
BlockHeight -> BlockNode -> m (Maybe BlockNode)
getAncestor BlockHeight
h BlockNode
lr
                BlockNode -> BlockNode -> m BlockNode
f BlockNode
pl BlockNode
pr

-- | Generate the entire Genesis block for 'Network'.
genesisBlock :: Network -> Block
genesisBlock :: Network -> Block
genesisBlock Network
net = BlockHeader -> [Tx] -> Block
Block (Network -> BlockHeader
getGenesisHeader Network
net) [Tx
genesisTx]

-- | Compute block subsidy at particular height.
computeSubsidy :: Network -> BlockHeight -> Word64
computeSubsidy :: Network -> BlockHeight -> Word64
computeSubsidy Network
net BlockHeight
height =
    let halvings :: BlockHeight
halvings = BlockHeight
height forall a. Integral a => a -> a -> a
`div` Network -> BlockHeight
getHalvingInterval Network
net
        ini :: Word64
ini = Word64
50 forall a. Num a => a -> a -> a
* Word64
100 forall a. Num a => a -> a -> a
* Word64
1000 forall a. Num a => a -> a -> a
* Word64
1000
     in if BlockHeight
halvings forall a. Ord a => a -> a -> Bool
>= BlockHeight
64
            then Word64
0
            else Word64
ini forall a. Bits a => a -> Int -> a
`shiftR` forall a b. (Integral a, Num b) => a -> b
fromIntegral BlockHeight
halvings