module Main where

import           Control.Error.Util
import           Control.Monad
import           Control.Monad.Except
import           Control.Monad.Reader
import           Data.ByteString                ( ByteString )
import qualified Data.ByteString.UTF8          as UTF8
import           Data.Dates                     ( getCurrentDateTime
                                                , parseDate
                                                , DateTime(..)
                                                )
import           Data.Functor                   ( (<&>) )
import           Data.List
import           Data.Maybe
import           Data.Semigroup                 ( (<>) )
import qualified Data.Text                     as T
import           Data.Time.Calendar
import           Data.Time.Clock
import           Data.Time.Clock.POSIX
import           Data.Time.Format
import           Data.Time.Format.ISO8601
import           GHup
import           GitHub.Auth
import           GitHub.Data.Definitions
import           GitHub.Data.Name
import           GitHub.Data.Repos
import           GitHub.Data.URL
import           HPath
import           Options.Applicative
import           Safe
import           System.Console.Pretty
import           System.Exit



data Options = Options
  { optCommand :: Command
  }

data Command
  = Fork ForkOptions
  | Config ConfigOptions
  | Del DelOptions
  | ListForks ListForkOptions

data ForkOptions = ForkOptions
  {
    repo          :: ByteString
  , newBranch     :: Maybe ByteString
  , repoBasePath  :: Maybe ByteString
  }

data ListForkOptions = ListForkOptions
  {
    lSince        :: Maybe ByteString
  }

data ConfigOptions = ConfigOptions {
    oAuth :: ByteString
  , bPath :: Maybe ByteString
  }


data DelOptions = DelOptions {
  del :: ByteString
  }

opts :: Parser Command
opts = subparser
  (  command "fork"       (Fork <$> (info (forkOpts <**> helper) idm))
  <> command "config"     (Config <$> (info (configOpts <**> helper) idm))
  <> command "delete"     (Del <$> (info (delOpts <**> helper) idm))
  <> command "list-forks" (ListForks <$> (info (lForkOpts <**> helper) idm))
  )

configOpts :: Parser ConfigOptions
configOpts =
  ConfigOptions
    <$> strOption
          (short 'o' <> long "oauth" <> metavar "OAUTH" <> help
            "The OAUTH token"
          )
    <*> optional
          (strOption
            ((short 'p') <> long "base-path" <> metavar "BASE_PATH" <> help
              "The base path to clone into"
            )
          )

forkOpts :: Parser ForkOptions
forkOpts =
  ForkOptions
    <$> strOption
          (short 'r' <> long "repo" <> metavar "REPO" <> help
            "The repository to fork"
          )
    <*> optional
          (strOption
            (short 'b' <> long "branch" <> metavar "BRANCH" <> help
              "The branch to create after cloning the fork"
            )
          )
    <*> optional
          (strOption
            (short 'p' <> long "repo-path" <> metavar "REPO_PATH" <> help
              "The base path where to clone the repository to"
            )
          )

delOpts :: Parser DelOptions
delOpts = DelOptions <$> strOption
  (short 'r' <> long "repo" <> metavar "REPO" <> help "The REPO fork to delete")

lForkOpts :: Parser ListForkOptions
lForkOpts = ListForkOptions <$> optional
  (strOption
    (short 's' <> long "since" <> metavar "SINCE" <> help
      "The repository to fork"
    )
  )


main :: IO ()
main = do
  let
    run e = do
      settings <-
        exceptT
            (\_ ->
              die
                . color Red
                $ "Could not get settings, make sure to run 'ghup config' first"
            )
            pure
          $ getSettings
      (flip runReaderT) settings . runExceptT . withExceptT show $ e
  e <- execParser (info (opts <**> helper) idm) >>= \case
    Fork (ForkOptions {..}) -> run $ do
      case repoBasePath of
        Just rbp -> case parseAbs rbp of
          Just p  -> prepareRepoForPR' repo (Just p) newBranch
          Nothing -> liftIO $ die (color Red $ "Repo path must be absolute")
        Nothing -> prepareRepoForPR' repo Nothing newBranch
    Config (ConfigOptions {..}) -> do
      p <- maybe (pure Nothing) (fmap Just . parseAbs) bPath
      writeSettings (Settings (OAuth oAuth) p) <&> Right
    Del       (DelOptions {..}     ) -> run $ deleteFork' del
    ListForks (ListForkOptions {..}) -> run $ do
      mtime <- liftIO $ case lSince of
        Just t -> do
          dt <- getCurrentDateTime
          let mt =
                either (const Nothing) Just . parseDate dt . UTF8.toString $ t
          pure $ mt >>= \t ->
            (parseTimeM
              True
              defaultTimeLocale
              "%Y-%-m-%-d"
              (show (year t) <> "-" <> show (month t) <> "-" <> show (day t)) :: Maybe
                UTCTime
            )
        Nothing -> pure Nothing

      forks <- withExceptT show $ getForks mtime
      let formatted = intercalate "\n" $ fmap
            (\Repo {..} ->
              (T.unpack . getUrl $ repoHtmlUrl) <> " " <> formatShow
                (iso8601Format :: Format Day)
                (utctDay $ fromJust repoUpdatedAt)
            )
            forks
      liftIO $ putStrLn $ formatted
      pure ()
  case e of
    Right () -> pure ()
    Left  t  -> die (color Red $ t)