module Commands (
    deps, revdeps, installed, outdated, uninstall, search, env, check, add
  ) where

import Control.Applicative hiding (many)
import Control.Monad
import Data.Char
import Data.List
import Data.Maybe
import PkgDB
import System.Exit
import System.IO
import System.Process hiding (env)
import Types
import Utils
import VerDB

----------------------------------------------------------------

search :: FunctionCommand
search _ [x] _ = do
    nvls <- getVerAlist False
    forM_ (lok nvls) $ \(n,v) -> putStrLn $ n ++ " " ++ toDotted v
  where
    key = map toLower x
    sat (n,_) = key `isPrefixOf` map toLower n
    lok [] = []
    lok (e:es)
      | sat e   = e : lok es
      | otherwise = lok es
search _ _ _ = do
    hPutStrLn stderr "One search-key should be specified."
    exitFailure

----------------------------------------------------------------

installed :: FunctionCommand
installed _ _ opts = do
    let optall = OptAll `elem` opts
        optrec = OptRecursive `elem` opts
    db' <- getPkgDB (getSandbox opts)
    flt <- if optall then allPkgs else userPkgs
    -- FIXME: the optall case does unnecessary conversion
    let pkgs = toPkgList flt db'
        db = toPkgDB pkgs
    forM_ pkgs $ \pkgi -> do
        putStr $ fullNameOfPkgInfo pkgi
        extraInfo info pkgi
        putStrLn ""
        when optrec $ printDeps True info db 1 pkgi
  where
    info = OptInfo `elem` opts

outdated :: FunctionCommand
outdated _ _ opts = do
    flt <- if OptAll `elem` opts then allPkgs else userPkgs
    pkgs <- toPkgList flt <$> getPkgDB (getSandbox opts)
    verDB <- getVerDB
    forM_ pkgs $ \p -> case lookupLatestVersion (nameOfPkgInfo p) verDB of
        Nothing -> return ()
        Just ver -> when (numVersionOfPkgInfo p /= ver) $
                        putStrLn $ fullNameOfPkgInfo p ++ " < " ++ toDotted ver

----------------------------------------------------------------

uninstall :: FunctionCommand
uninstall _ nmver opts = do
    db' <- getPkgDB (getSandbox opts)
    db <- toPkgDB . flip toPkgList db' <$> userPkgs
    pkg <- lookupPkg nmver db
    let sortedPkgs = topSortedPkgs pkg db
    if onlyOne && length sortedPkgs /= 1
       then do
        hPutStrLn stderr "The following packages depend on this. Use the \"-r\" option."
        mapM_ (hPutStrLn stderr . fullNameOfPkgInfo) (init sortedPkgs)
       else do
        unless doit $ putStrLn "The following packages are deleted without the \"-n\" option."
        mapM_ (unregister doit opts . pairNameOfPkgInfo) sortedPkgs
  where
    onlyOne = OptRecursive `notElem` opts
    doit = OptNoharm `notElem` opts

unregister :: Bool -> [Option] -> (String,String) -> IO ()
unregister doit opts (name,ver) = if doit
    then do
        putStrLn $ "Deleting " ++ name ++ " " ++ ver
        pkgconf <- pkgConfOpt opts
        when doit $ system (script pkgconf) >> return ()
    else putStrLn $ name ++ " " ++ ver
  where
    script pkgconf = "ghc-pkg unregister " ++ pkgconf ++ name ++ "-" ++ ver

pkgConfOpt :: [Option] -> IO String
pkgConfOpt opts = case getSandbox opts of
    Nothing -> return ""
    Just path -> do
        pkgConf <- getPackageConf path
        return $ "--package-conf=" ++ pkgConf ++ " "

----------------------------------------------------------------

check :: FunctionCommand
check _ _ opts = do
    pkgconf <- pkgConfOpt opts
    system (script pkgconf)
    return ()
  where
   script pkgconf = "ghc-pkg check -v " ++ pkgconf

----------------------------------------------------------------

deps :: FunctionCommand
deps _ nmver opts = printDepends nmver opts printDeps

revdeps :: FunctionCommand
revdeps _ nmver opts = printDepends nmver opts printRevDeps

printDepends :: [String] -> [Option]
             -> (Bool -> Bool -> PkgDB -> Int -> PkgInfo -> IO ()) -> IO ()
printDepends nmver opts func = do
    db' <- getPkgDB (getSandbox opts)
    pkg <- lookupPkg nmver db'
    db <- if OptAll `elem` opts
          then return db'
          else toPkgDB . flip toPkgList db' <$> userPkgs
    func rec info db 0 pkg
  where
    rec = OptRecursive `elem` opts
    info = OptInfo `elem` opts

----------------------------------------------------------------

lookupPkg :: [String] -> PkgDB -> IO PkgInfo
lookupPkg [] _ = do
  hPutStrLn stderr "Package name must be specified."
  exitFailure
lookupPkg [name] db = checkOne $ lookupByName name db
lookupPkg [name,ver] db = checkOne $ lookupByVersion name ver db
lookupPkg _ _ = do
  hPutStrLn stderr "Only one package name must be specified."
  exitFailure

checkOne :: [PkgInfo] -> IO PkgInfo
checkOne [] = do
    hPutStrLn stderr "No such package found."
    exitFailure
checkOne [pkg] = return pkg
checkOne pkgs = do
    hPutStrLn stderr "Package version must be specified."
    mapM_ (hPutStrLn stderr . fullNameOfPkgInfo) pkgs
    exitFailure

----------------------------------------------------------------

env :: FunctionCommand
env _ _ opts = case getSandbox opts of
    Nothing -> do
        putStrLn "unset CAB_SANDBOX_PATH"
        putStrLn "unsetenv CAB_SANDBOX_PATH"
        putStrLn ""
        putStrLn "unset GHC_PACKAGE_PATH"
        putStrLn "unsetenv GHC_PACKAGE_PATH"
    Just path -> do
        pkgConf <- getPackageConf path
        gPkgConf <- globalPackageDB
        putStrLn $ "export CAB_SANDBOX_PATH=" ++ path
        putStrLn $ "setenv CAB_SANDBOX_PATH " ++ path
        putStrLn ""
        putStrLn "The following commands are not necessary in normal case."
        let confs = gPkgConf ++ ":" ++ pkgConf
        putStrLn $ "export GHC_PACKAGE_PATH=" ++ confs
        putStrLn $ "setenv GHC_PACKAGE_PATH " ++ confs

globalPackageDB :: IO String
globalPackageDB = do
    res <- readProcess "ghc" ["--info"] []
    let alist = read res :: [(String,String)]
    return . fromJust $ lookup "Global Package DB" alist

----------------------------------------------------------------

add :: FunctionCommand
add _ params opts = case getSandbox opts of
    Nothing -> hPutStrLn stderr "A sandbox must be specified with \"-s\" option."
    Just sbox -> case params of
        [src] -> do
            system $ "cabal-dev add-source " ++ src ++ " -s " ++ sbox
            return ()
        _ -> hPutStrLn stderr "A source path be specified."