{-# LANGUAGE ApplicativeDo #-}

{- |
Copyright: (c) 2022 Dmitrii Kovanikov
SPDX-License-Identifier: MPL-2.0
Maintainer: Dmitrii Kovanikov <kovanikov@gmail.com>

Command-line arguments parsing
-}

module Sauron.Cli
    ( Cmd (..)
    , cmdP

      -- * sauron top
    , TopArgs (..)
    , CacheMode (..)
    ) where

import Options.Applicative as Opt


data Cmd
    = Top TopArgs

data TopArgs = TopArgs
    { topArgsUsername  :: Text  -- ^ Twitter username handle
    , topArgsMax       :: Int   -- ^ Max top tweets to extract
    , topArgsCacheMode :: CacheMode  -- ^ Store to file or read from file
    }

data CacheMode
    = ToFile FilePath
    | FromFile FilePath

-- | All possible commands.
cmdP :: Opt.Parser Cmd
cmdP = Opt.subparser $ mconcat
    [ Opt.command "top"
          $ Opt.info (Opt.helper <*> topP)
          $ Opt.progDesc "Top tweets of a user"
    ]

topP :: Opt.Parser Cmd
topP = do
    topArgsUsername <- Opt.strArgument $ mconcat
        [ Opt.metavar "TWITTER_NAME"
        , Opt.help "Twitter user handle: @my-name or my-name"
        ]

    topArgsMax <- Opt.option Opt.auto $ mconcat
        [ Opt.long "max"
        , Opt.short 'm'
        , Opt.metavar "POSITIVE_NUMBER"
        , Opt.help "Max number of tweets to output in the terminal"
        ]

    topArgsCacheMode <- cacheModeP

    pure $ Top TopArgs{..}

cacheModeP :: Opt.Parser CacheMode
cacheModeP = (ToFile <$> toFileP) <|> (FromFile <$> fromFileP)
  where
    toFileP :: Opt.Parser FilePath
    toFileP = Opt.strOption $ mconcat
        [ Opt.long "to-file"
        , Opt.metavar "FILE_PATH"
        , Opt.help "Save the Twitter output to a file (to avoid hitting the fetch limit)"
        ]

    fromFileP :: Opt.Parser FilePath
    fromFileP = Opt.strOption $ mconcat
        [ Opt.long "from-file"
        , Opt.metavar "FILE_PATH"
        , Opt.help "Read data from a previously saved file with the '--to-file' option"
        ]