module Data.NanoID where

import           Control.Monad
import qualified Data.ByteString.Char8 as C
import           Data.Maybe
import           Numeric.Natural
import           System.Random.MWC

newtype NanoID = NanoID { NanoID -> ByteString
unNanoID :: C.ByteString } deriving (NanoID -> NanoID -> Bool
(NanoID -> NanoID -> Bool)
-> (NanoID -> NanoID -> Bool) -> Eq NanoID
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: NanoID -> NanoID -> Bool
$c/= :: NanoID -> NanoID -> Bool
== :: NanoID -> NanoID -> Bool
$c== :: NanoID -> NanoID -> Bool
Eq, Int -> NanoID -> ShowS
[NanoID] -> ShowS
NanoID -> String
(Int -> NanoID -> ShowS)
-> (NanoID -> String) -> ([NanoID] -> ShowS) -> Show NanoID
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [NanoID] -> ShowS
$cshowList :: [NanoID] -> ShowS
show :: NanoID -> String
$cshow :: NanoID -> String
showsPrec :: Int -> NanoID -> ShowS
$cshowsPrec :: Int -> NanoID -> ShowS
Show)

newtype Alphabet = Alphabet { Alphabet -> ByteString
unAlphabet :: C.ByteString } deriving (Alphabet -> Alphabet -> Bool
(Alphabet -> Alphabet -> Bool)
-> (Alphabet -> Alphabet -> Bool) -> Eq Alphabet
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Alphabet -> Alphabet -> Bool
$c/= :: Alphabet -> Alphabet -> Bool
== :: Alphabet -> Alphabet -> Bool
$c== :: Alphabet -> Alphabet -> Bool
Eq, Int -> Alphabet -> ShowS
[Alphabet] -> ShowS
Alphabet -> String
(Int -> Alphabet -> ShowS)
-> (Alphabet -> String) -> ([Alphabet] -> ShowS) -> Show Alphabet
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [Alphabet] -> ShowS
$cshowList :: [Alphabet] -> ShowS
show :: Alphabet -> String
$cshow :: Alphabet -> String
showsPrec :: Int -> Alphabet -> ShowS
$cshowsPrec :: Int -> Alphabet -> ShowS
Show)

type Length = Natural

-- | Standard 'NanoID' generator function
-- >λ: g <- createSystemRandom
-- >λ: NanoID g
-- >NanoID {unNanoID = "x2f8yFadImeVp14ByJ8R3"}
--
nanoID :: GenIO -> IO NanoID
nanoID :: GenIO -> IO NanoID
nanoID = Alphabet -> Length -> GenIO -> IO NanoID
customNanoID Alphabet
defaultAlphabet Length
21

-- | Customable 'NanoID' generator function
customNanoID :: Alphabet  -- ^ An 'Alphabet' of your choice
             -> Length    -- ^ A 'NanoID' length (the standard length is 21 chars)
             -> GenIO     -- ^ The pseudo-random number generator state
             -> IO NanoID
customNanoID :: Alphabet -> Length -> GenIO -> IO NanoID
customNanoID Alphabet
a Length
l GenIO
g =
  ByteString -> NanoID
NanoID (ByteString -> NanoID)
-> (String -> ByteString) -> String -> NanoID
forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> ByteString
C.pack (String -> NanoID) -> IO String -> IO NanoID
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Int -> IO Char -> IO String
forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM (Length -> Int
forall a. Enum a => a -> Int
fromEnum Length
l) ((\Int
r -> ByteString -> Int -> Char
C.index ByteString
ua (Int
rInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1)) (Int -> Char) -> IO Int -> IO Char
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (Int, Int) -> GenIO -> IO Int
forall a (m :: * -> *).
(Variate a, PrimMonad m) =>
(a, a) -> Gen (PrimState m) -> m a
uniformR (Int
1,Int
al) GenIO
g)
  where
    ua :: ByteString
ua = Alphabet -> ByteString
unAlphabet Alphabet
a
    al :: Int
al = ByteString -> Int
C.length ByteString
ua

-- | The default 'Alphabet', made of URL-friendly symbols.
defaultAlphabet :: Alphabet
defaultAlphabet :: Alphabet
defaultAlphabet = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"ABCDEFGHIJKLMNOPKRSTUVWXYZ_1234567890-abcdefghijklmnopqrstuvwxyz")

-- * Predefined Alphabets borrowed from https://github.com/CyberAP/nanoid-dictionary

numbers :: Alphabet
numbers :: Alphabet
numbers = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"1234567890")

hexadecimalLowercase :: Alphabet
hexadecimalLowercase :: Alphabet
hexadecimalLowercase = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"0123456789abcdef")

hexadecimalUppercase :: Alphabet
hexadecimalUppercase :: Alphabet
hexadecimalUppercase = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"0123456789ABCDEF")

lowercase :: Alphabet
lowercase :: Alphabet
lowercase = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"abcdefghijklmnopqrstuvwxyz")

uppercase :: Alphabet
uppercase :: Alphabet
uppercase = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"ABCDEFGHIJKLMNOPQRSTUVWXYZ")

alphanumeric :: Alphabet
alphanumeric :: Alphabet
alphanumeric = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"ABCDEFGHIJKLMNOPKRSTUVWXYZ1234567890abcdefghijklmnopqrstuvwxyz")

nolookalikes :: Alphabet
nolookalikes :: Alphabet
nolookalikes = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"346789ABCDEFGHJKLMNPQRTUVWXYabcdefghijkmnpqrtwxyz")

nolookalikesSafe :: Alphabet
nolookalikesSafe :: Alphabet
nolookalikesSafe = ByteString -> Alphabet
Alphabet (String -> ByteString
C.pack String
"6789ABCDEFGHJKLMNPQRTUWYabcdefghijkmnpqrtwyz")