module SlackBuilder.Updater
    ( latestPackagist
    , latestText
    ) where

import Data.Aeson.TH (defaultOptions, deriveJSON)
import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as HashMap
import Data.Text (Text)
import qualified Data.Text as Text
import qualified Data.Text.Encoding as Text.Encoding
import Data.Vector (Vector)
import qualified Data.Vector as Vector
import Network.HTTP.Req
    ( runReq
    , defaultHttpConfig
    , req
    , GET(..)
    , https
    , jsonResponse
    , NoReqBody(..)
    , (/:)
    , responseBody, useHttpsURI, bsResponse
    )
import Text.URI (mkURI)
import SlackBuilder.CommandLine

newtype PackagistPackage = PackagistPackage
    { version :: Text
    } deriving (Eq, Show)

$(deriveJSON defaultOptions ''PackagistPackage)

newtype PackagistResponse = PackagistResponse
    { packages :: HashMap Text (Vector PackagistPackage)
    } deriving (Eq, Show)

$(deriveJSON defaultOptions ''PackagistResponse)

latestPackagist :: PackagistArguments -> IO (Maybe Text)
latestPackagist PackagistArguments{..} = do
    packagistResponse <- runReq defaultHttpConfig $
        let uri = https "repo.packagist.org" /: "p2"
                /: vendor
                /: name <> ".json"
         in req GET uri NoReqBody jsonResponse mempty
    let packagistPackages = packages $ responseBody packagistResponse
        fullName = Text.intercalate "/" [vendor, name]

    pure $ HashMap.lookup fullName packagistPackages
        >>= fmap (version . fst) . Vector.uncons

latestText :: TextArguments -> IO (Maybe Text)
latestText (TextArguments textArguments) = do
    uri <- useHttpsURI <$> mkURI textArguments
    packagistResponse <- traverse (runReq defaultHttpConfig) $ go . fst <$> uri

    pure $ Text.strip . Text.Encoding.decodeASCII . responseBody
        <$> packagistResponse
  where
    go uri = req GET uri NoReqBody bsResponse mempty