{-# LANGUAGE LambdaCase #-}
-- | Common data types for PuppetDB.
module PuppetDB.Common where

import Puppet.Interpreter.Types
import PuppetDB.Remote
import PuppetDB.Dummy
import PuppetDB.TestDB

import Data.Maybe
import Data.List (stripPrefix)
import Control.Lens
import System.Environment
import Data.Vector.Lens
import Servant.Common.BaseUrl
import Network.HTTP.Client

-- | The supported PuppetDB implementations.
data PDBType = PDBRemote -- ^ Your standard PuppetDB, queried through the HTTP interface.
             | PDBDummy -- ^ A stupid stub, this is the default choice.
             | PDBTest -- ^ A slow but handy PuppetDB implementation that is backed by a YAML file.
             deriving Eq

instance Read PDBType where
    readsPrec _ r | isJust reml = [(PDBRemote, fromJust reml)]
                  | isJust rems = [(PDBRemote, fromJust rems)]
                  | isJust duml = [(PDBDummy, fromJust duml)]
                  | isJust dums = [(PDBDummy, fromJust dums)]
                  | isJust tstl = [(PDBTest, fromJust tstl)]
                  | isJust tsts = [(PDBTest, fromJust tsts)]
                  | otherwise   = []
        where
            reml = stripPrefix "PDBRemote" r
            rems = stripPrefix "remote"    r
            duml = stripPrefix "PDBDummy"  r
            dums = stripPrefix "dummy"     r
            tstl = stripPrefix "PDBTest"   r
            tsts = stripPrefix "test"      r

-- | Given a 'PDBType', will try return a sane default implementation.
getDefaultDB :: PDBType -> IO (Either PrettyError (PuppetDBAPI IO))
getDefaultDB PDBDummy  = return (Right dummyPuppetDB)
getDefaultDB PDBRemote = do
  url <- parseBaseUrl "http://localhost:8080"
  mgr <- newManager defaultManagerSettings
  pdbConnect mgr url
getDefaultDB PDBTest   = lookupEnv "HOME" >>= \case
                                Just h -> loadTestDB (h ++ "/.testdb")
                                Nothing -> fmap Right initTestDB

-- | Turns a 'FinalCatalog' and 'EdgeMap' into a document that can be
-- serialized and fed to @puppet apply@.
generateWireCatalog :: NodeName -> FinalCatalog -> EdgeMap -> WireCatalog
generateWireCatalog node cat edgemap = WireCatalog node "version" edges resources "uiid"
    where
        edges     = toVectorOf (folded . to (\li -> PuppetEdge (li ^. linksrc) (li ^. linkdst) (li ^. linkType))) (concatOf folded edgemap)
        resources = toVectorOf folded cat