module Main (main) where

import Converge
import Data.Maybe (fromMaybe)
import Data.Text (Text)
import qualified Data.Text as T
import Options.Applicative
import System.IO (hPutStrLn, stderr)

data CliArgs = CliArgs
    { cliConfig :: !(Maybe FilePath)
    -- ^ Optional path to a YAML config file.
    , cliRepo :: !(Maybe FilePath)
    -- ^ Optional single repo path (requires --config to be absent).
    , cliRemote :: !Text
    -- ^ Remote name (used only in single-repo mode).
    , cliBranch :: !Text
    -- ^ Branch name (used only in single-repo mode).
    , cliDebounce :: !(Maybe Int)
    -- ^ Debounce override for both modes.
    , cliLogLevel :: !(Maybe LogLevel)
    -- ^ Log level override.
    , cliLogFile :: !(Maybe FilePath)
    -- ^ Log file path.
    , cliSync :: !Bool
    -- ^ Run a single sync cycle and exit (useful for wake-from-sleep hooks).
    }

cliParser :: Parser CliArgs
cliParser =
    CliArgs
        <$> optional
            ( strOption
                ( long "config"
                    <> short 'c'
                    <> metavar "FILE"
                    <> help "Path to YAML config file listing repositories"
                )
            )
        <*> optional
            ( strOption
                ( long "repo"
                    <> short 'r'
                    <> metavar "PATH"
                    <> help "Path to a single git repository to watch (default: cwd)"
                )
            )
        <*> strOption
            ( long "remote"
                <> metavar "NAME"
                <> value "origin"
                <> showDefault
                <> help "Remote name to pull from (single-repo mode)"
            )
        <*> strOption
            ( long "branch"
                <> short 'b'
                <> metavar "NAME"
                <> value "main"
                <> showDefault
                <> help "Branch to pull (single-repo mode)"
            )
        <*> optional
            ( option
                auto
                ( long "debounce"
                    <> short 'd'
                    <> metavar "MS"
                    <> help "Debounce window in milliseconds (overrides config file)"
                )
            )
        <*> optional
            ( option
                ( maybeReader
                    ( \s -> case T.toLower (T.pack s) of
                        "debug" -> Just Debug
                        "info" -> Just Info
                        "warn" -> Just Warn
                        "error" -> Just Error
                        _ -> Nothing
                    )
                )
                ( long "log-level"
                    <> metavar "LEVEL"
                    <> help "Minimum log level: debug, info, warn, or error (default: info)"
                )
            )
        <*> optional
            ( strOption
                ( long "log-file"
                    <> metavar "FILE"
                    <> help "Write logs to a file instead of stderr"
                )
            )
        <*> switch
            ( long "sync"
                <> short 's'
                <> help "Run a single sync cycle (commit + pull + push) and exit"
            )

parserInfo :: ParserInfo CliArgs
parserInfo =
    info
        (cliParser <**> helper)
        ( fullDesc
            <> progDesc "Auto-sync git repos by watching, committing, and pulling"
            <> header "converge - keep git repos in sync"
        )

main :: IO ()
main = do
    cli <- execParser parserInfo
    let mDebounceOverride = cliDebounce cli
    (options, configSource) <- case cliConfig cli of
        Just cfgPath -> do
            cfg <- loadConfig cfgPath
            let opts = applyOverrides mDebounceOverride (cliLogLevel cli) (cliLogFile cli) (configToOptions cfg)
            pure (opts, Just cfgPath)
        Nothing -> do
            exists <- configFileExists
            if exists
                then do
                    cfgPath <- defaultConfigPath
                    cfg <- loadConfig cfgPath
                    let opts = applyOverrides mDebounceOverride (cliLogLevel cli) (cliLogFile cli) (configToOptions cfg)
                    pure (opts, Just cfgPath)
                else
                    pure
                        ( applyOverrides
                            mDebounceOverride
                            (cliLogLevel cli)
                            (cliLogFile cli)
                            defaultOptions
                                { optRepos =
                                    [ defaultRepoConfig
                                        { rcPath = fromMaybe "." (cliRepo cli)
                                        , rcRemote = cliRemote cli
                                        , rcBranch = cliBranch cli
                                        }
                                    ]
                                , optDebounceMs = fromMaybe 5000 mDebounceOverride
                                }
                        , Nothing
                        )
    case configSource of
        Just path ->
            hPutStrLn stderr ("Using config: " <> path)
        Nothing ->
            hPutStrLn stderr "No config file found, using single-repo mode"
    let repos = optRepos options
    if cliSync cli
        then do
            hPutStrLn stderr $
                "Syncing "
                    <> show (length repos)
                    <> " repo(s)"
            mapM_ (\r -> hPutStrLn stderr ("  - " <> rcPath r)) repos
            logger <- newLogger (optLogLevel options) (optLogFile options)
            mapM_ (syncRepo options logger) repos
        else do
            hPutStrLn stderr $
                "Watching "
                    <> show (length repos)
                    <> " repo(s)"
                    <> " (debounce: "
                    <> show (optDebounceMs options)
                    <> "ms)"
            mapM_ (\r -> hPutStrLn stderr ("  - " <> rcPath r)) repos
            runConverge options

-- | Apply CLI overrides (debounce, log level, log file) to Options.
applyOverrides :: Maybe Int -> Maybe LogLevel -> Maybe FilePath -> Options -> Options
applyOverrides mDebounce mLogLevel mLogFile opts =
    opts
        { optDebounceMs = maybe (optDebounceMs opts) id mDebounce
        , optLogLevel = fromMaybe (optLogLevel opts) mLogLevel
        , optLogFile = case mLogFile of
            Just _ -> mLogFile -- CLI --log-file overrides config
            Nothing -> optLogFile opts
        }