{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE CPP #-}
import Distribution.PackageDescription.Configuration
import Distribution.PackageDescription hiding (options)
import Distribution.Package
import Distribution.Compiler
import Distribution.License
import Distribution.System
import Distribution.Version
import Distribution.Text
import Text.PrettyPrint

import Control.Applicative
import Control.Exception (bracket)
import qualified Control.Exception as E
import Control.Monad

import System.IO.Error
import System.Process
import System.Exit
import System.Directory

import qualified Data.Map as M
import Data.Either
import Data.List
import Data.Tuple (swap)
import Data.String

import Options
import Graph
import Env
import Ver
import Printing
import Policy
import Database

import qualified Text.PrettyPrint.ANSI.Leijen as PP

unPackageName :: PackageName -> String
unPackageName (PackageName n) = n

dependencyName :: Dependency -> PackageName
dependencyName (Dependency n _) = n

dependencyConstraints :: Dependency -> VersionRange
dependencyConstraints (Dependency _ v) = v

finPkgDesc :: GenericPackageDescription -> Either [Dependency] (PackageDescription, FlagAssignment)
finPkgDesc = finalizePackageDescription [] (const True) buildPlatform (CompilerId buildCompilerFlavor (Version []{-[7, 6, 2]-} [])) []

showVerconstr c = render $ Distribution.Text.disp c

getPackageDependencies :: AvailablePackages -> PackageName -> IO [Dependency]
getPackageDependencies apkgs pn = do
    let desc = finPkgDesc <$> getPackageDescription apkgs pn Nothing
    case desc of
        Just (Right (d,_)) -> return $ buildDepends d
        _                  -> return []

getPackageDependencyNames apkgs pn =
    map dependencyName <$> getPackageDependencies apkgs pn

-- | partiion a list of arguments that refer to package
-- either by their package name, or directly to a cabal file
packageArgs :: [String] -> IO ([PackageName], [FilePath])
packageArgs args = partitionEithers <$> mapM classifyArgs args
  where classifyArgs :: String -> IO (Either PackageName FilePath)
        classifyArgs arg = do
            existingFile <- doesFileExist arg
            return $ if existingFile && hasCabalExtension
                then Right arg
                else Left $ PackageName arg
          where hasCabalExtension = ".cabal" `isSuffixOf` arg

foldallLatest :: Monad m => AvailablePackages -> a -> (a -> PackageName -> PackageDescription -> m a) -> m a
foldallLatest apkgs acc f = foldM process acc (getAllPackageName apkgs)
        where process a pn = case finPkgDesc <$> getPackageDescription apkgs pn Nothing of
                                Just (Right (pd, _)) -> f a pn pd
                                _                    -> return a

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

generateDotM boxToColor f = do
    (indexTable, depsTable) <- withGraph f
    putStrLn "digraph projects {"
    forM_ (M.toList indexTable) $ \((PackageName pn), i) -> do
        let extra = case boxToColor (PackageName pn) of
                        Nothing -> ""
                        Just c  -> ", style=filled, fillcolor=" ++ c
        putStrLn (show i ++ " [label=\"" ++ pn ++ "\"" ++ extra ++ "];")
    forM_ (M.toList depsTable) $ \(src,dsts) ->
        mapM_ (\dst -> putStrLn (show src ++ " -> " ++ show dst ++ ";")) dsts
    putStrLn "}"

unindexify :: (M.Map a GraphIndex, M.Map GraphIndex [GraphIndex]) -> [(a, [a])]
unindexify (aTable, edgeTable) = map (resolveKeyValues resolveIndex) $ M.toList edgeTable
  where resolveKeyValues r (k,l) = (r k, map r l)
        resolveIndex i = maybe (error ("internal error: unknown index: " ++ show i)) id $ M.lookup i idxTable
        idxTable = M.fromList $ map swap $ M.toList aTable

-----------------------------------------------------------------------
run apkgs hidePlatform hiddenPackages specifiedPackages = generateDotM colorize $ mapM_ (graphLoop getDeps) specifiedPackages
  where colorize pn
            | pn `elem` specifiedPackages = Just "red"
            | isPlatformPackage pn        = Just "green"
            | otherwise                   = Nothing

        getDeps :: PackageName -> IO [PackageName]
        getDeps pn = do
            let desc = finPkgDesc <$> getPackageDescription apkgs pn Nothing
            case desc of
                Just (Right (d,_)) ->
                    return
                        $ (if hidePlatform then filter (not . isPlatformPackage) else id)
                        $ filter (not . flip elem hiddenPackages)
                        $ map (\(Dependency n _) -> n) $ buildDepends d
                _ -> do
                    --liftIO $ putStrLn ("warning cannot handle: " ++ show pn ++ " : " ++ show desc)
                    return []

-----------------------------------------------------------------------
runCmd (CmdGraph (map PackageName -> hidden) hidePlatform rawArgs) = do
    (pkgNames, pkgFileNames) <- packageArgs rawArgs
    availablePackages        <- loadAvailablePackages pkgFileNames
    run availablePackages hidePlatform hidden pkgNames

-----------------------------------------------------------------------
runCmd (CmdBumpable pkgs) = do
    apkgs <- loadAvailablePackages []
    let getPkg n = (fmap fst . finPkgDesc) <$> getPackageDescription apkgs (PackageName n) Nothing
        bumpables = filter (not . null . snd) $ map checkBump pkgs
        checkBump pname = case getPkg pname of
            Nothing -> error ("no such package : " ++ show pname)
            Just resp -> (,) pname $ do
                Dependency (PackageName depname) verrange <- case resp of
                    Left d -> d
                    Right x -> buildDepends x
                v <- case getPkg depname of
                         Just (Right a) -> return (pkgVersion (package a))
                         _ -> mzero -- might be an error ?
                guard (not (withinRange v verrange))
                return $ PP.string depname PP.<+> PP.string "->" PP.<+> PP.cat (intersperse PP.dot (map PP.int (versionBranch v)))
    forM_ bumpables $ \(pname, desc) -> PP.putDoc (PP.string pname PP.<$> PP.indent 4 (PP.vcat desc) PP.<> PP.line)
-----------------------------------------------------------------------
runCmd (CmdDiff (PackageName -> pname) (fromString -> v1) (fromString -> v2)) = runDiff
  where runDiff = do
            availablePackages <- loadAvailablePackages []
            let mvers = getPackageVersions availablePackages pname
            case mvers of
                Nothing -> error ("no such package : " ++ show pname)
                Just vers -> do
                    when (not $ elem v1 vers) $ error ("package doesn't have version " ++ show v1)
                    when (not $ elem v2 vers) $ error ("package doesn't have version " ++ show v2)

                    cd <- getCurrentDirectory
                    bracket createTempDir (changeAndRemoveDirectory cd) $ \dir -> do
                        putStrLn (cd ++ " " ++ dir)
                        setCurrentDirectory dir
                        cabalUnpack pname v1
                        cabalUnpack pname v2
                        diff pname
        createTempDir = do
            tmp <- getTemporaryDirectory
            loopCreateDir (tmp ++ "/cabal-db-diff-") (0 :: Int)
          where loopCreateDir prefix i = do
                    let dir = prefix ++ show i
                    r <- E.try (createDirectory dir)
                    case r of
                        Left e | isAlreadyExistsError e -> loopCreateDir prefix (i+1)
                               | otherwise              -> E.throwIO e
                        Right () -> return dir
        changeAndRemoveDirectory cd dir =
            setCurrentDirectory cd >> removeDirectoryRecursive dir
        cabalUnpack :: PackageName -> Ver -> IO ()
        cabalUnpack (PackageName pn) v = do
            ec <- rawSystem "cabal" ["unpack", pn ++ "-" ++ show v]
            case ec of
                ExitSuccess   -> return ()
                ExitFailure i -> error ("cabal unpack failed with error code: " ++ show i)
        diff (PackageName pn) = do
            let dir1 = pn ++ "-" ++ show v1
            let dir2 = pn ++ "-" ++ show v2
            _ <- rawSystem "diff" ["-Naur", dir1, dir2]
            return ()

-----------------------------------------------------------------------
runCmd (CmdRevdeps rawArgs)
    | null rawArgs = exitSuccess
    | otherwise = do
        (pkgNames, pkgFileNames) <- packageArgs rawArgs
        availablePackages <- loadAvailablePackages pkgFileNames
    
        founds <- foldallLatest availablePackages [] $ \a pkgname pkgDesc -> do
            let found = any (\(Dependency n _) -> n `elem` pkgNames) (buildDepends pkgDesc)
            if found
                then return ((pkgname, pkgDesc):a)
                else return a
        forM_ founds $ \(pkgname,pdesc) -> do
            let deps = filter (\(Dependency n _) -> n `elem` pkgNames) $ buildDepends pdesc
            putStrLn (unPackageName pkgname ++ ": " ++ intercalate ", " (map showDep deps))
        where showDep (Dependency p v) = unPackageName p ++ " (" ++ showVerconstr v ++ ")"

-----------------------------------------------------------------------
runCmd (CmdInfo (map PackageName -> args)) = do
    availablePackages <- loadAvailablePackages []
    forM_ args $ \arg -> do
        let vers = maybe (error ("no package " ++ show arg)) id $ getPackageVersions availablePackages arg
        let pdesc = finPkgDesc <$> getPackageDescription availablePackages arg Nothing
        case pdesc of
            Just (Right (d,_)) -> do
                putStrLn (show arg)
                putStrLn ("  synopsis: " ++ synopsis d)
                putStrLn ("  versions: " ++ intercalate ", " (map show vers))
                putStrLn ("  dependencies for " ++ show (last vers) ++ ":")
                mapM_ (\(Dependency p v) -> putStrLn ("    " ++ unPackageName p ++ " (" ++ showVerconstr v ++ ")")) (buildDepends d)
            _                  -> error "cannot resolve package"

-----------------------------------------------------------------------
runCmd (CmdLicense printTree printSummary rawArgs) = do
    (pkgNames, pkgFileNames) <- packageArgs rawArgs

    availablePackages <- loadAvailablePackages pkgFileNames

    t <- M.fromList . unindexify <$> withGraph (mapM_ (graphLoop (getPackageDependencyNames availablePackages)) pkgNames)
    foundLicenses <- foldM (loop availablePackages t 0) M.empty pkgNames

    when ((not printTree && not printSummary) || printSummary) $ do
        putStrLn "== license summary =="
        forM_ (map nameAndLength $ group $ sortBy licenseCmp $ map snd $ M.toList foundLicenses) $ \(licenseName, licenseNumb) -> do
            let (lstr, ppComb) = ppLicense licenseName
            ppLine 0 (ppComb lstr PP.<> PP.colon PP.<+> PP.text (show licenseNumb))
  where
        loop apkgs tbl indentSpaces founds pn@(PackageName name)
            | M.member pn founds = return founds
            | otherwise = do
                let desc = finPkgDesc <$> getPackageDescription apkgs pn Nothing
                case desc of
                    Just (Right (d,_)) -> do
                        let found = license d
                        when printTree $ do
                            let (lstr, ppComb) = ppLicense found
                            ppLine 0 (PP.text (replicate indentSpaces ' ') PP.<> PP.text name PP.<> PP.colon PP.<+> ppComb lstr)
                        case M.lookup pn tbl of
                            Just l  -> foldM (loop apkgs tbl (indentSpaces + 2)) (M.insert pn found founds) l
                            Nothing -> error "internal error"
                    _ -> return founds
        licenseCmp l1 l2
            | l1 == l2    = EQ
            | otherwise   = compare (show l1) (show l2)

        nameAndLength []      = error "empty group"
        nameAndLength l@(x:_) = (x, length l)

        ppLicense (GPL (Just (Version [v] [])))    = ("GPLv" ++ show v, col Yellow)
        ppLicense (GPL Nothing)                    = ("GPL", col Yellow)
#if MIN_VERSION_Cabal(1,18,0)
        ppLicense (AGPL (Just (Version [v] [])))   = ("AGPLv" ++ show v, col Yellow)
#endif
        ppLicense (LGPL (Just (Version [v] [])))   = ("LGPLv" ++ show v, col Yellow)
#if MIN_VERSION_Cabal(1,16,0)
        ppLicense (Apache (Just (Version [v] []))) = ("Apache" ++ show v, col Green)
#endif
        ppLicense (UnknownLicense s)               = (s, col Red)
        ppLicense BSD3                             = ("BSD3", col Green)
        ppLicense BSD4                             = ("BSD4", col Green)
        ppLicense MIT                              = ("MIT", col Green)
        ppLicense l                                = (show l, col Magenta)

-----------------------------------------------------------------------
runCmd (CmdSearch term vals) = do
    availablePackages <- loadAvailablePackages []
    founds <- foldallLatest availablePackages [] $ \a pkgname pkgDesc -> do
        let found = any (\arg -> contains arg (accessor pkgDesc)) vals
        if found
             then return ((pkgname, pkgDesc):a)
             else return a
    mapM_ (putStrLn . unPackageName . fst) founds
  where contains searching searched = maybe False (const True) $ find (isPrefixOf searching) $ tails searched
        accessor = toAccessor term
        toAccessor SearchMaintainer = maintainer
        toAccessor SearchAuthor     = author

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

runCmd (CmdCheckRevdepsPolicy rawArgs) = do
    (pkgNames, pkgFileNames) <- packageArgs rawArgs
    availablePackages <- loadAvailablePackages pkgFileNames

    ret <- foldallLatest availablePackages M.empty $ \accOuter pkgname pkgDesc -> do
        let deps = buildDepends pkgDesc
        foldM (accOnDep pkgNames availablePackages pkgname) accOuter deps
    forM_ (M.toList ret) $ \(p, z) -> do
        let sums = map (\l -> (head l, length l)) $ group $ sort $ map snd $ M.toList z
        putStrLn ("== " ++ show p)
        forM_ (M.toList z) $ \(revDep, policy) -> do
            ppLine 2 $ PP.hcat [PP.string (unPackageName revDep), PP.colon, showPolicy policy]
        forM_ sums $ \(policy, n) ->
            ppLine 0 $ PP.hcat [PP.string (show n), PP.string " packages have a constraint set to ", showPolicy policy ]
    return ()
  where accOnDep pkgNames allPackages pkg a dep =
            case find (== dependencyName dep) pkgNames of
                Nothing              -> return a
                Just packageMatching ->
                    let vr = dependencyConstraints dep
                     in return $ updatePolTree a packageMatching pkg (getPolicy allPackages vr)

        updatePolTree :: M.Map PackageName (M.Map PackageName Policy)
                      -> PackageName
                      -> PackageName
                      -> Policy
                      -> M.Map PackageName (M.Map PackageName Policy)
        updatePolTree a withPkg pkg pol = M.alter updateRoot withPkg a
          where updateRoot :: Maybe (M.Map PackageName Policy) -> Maybe (M.Map PackageName Policy)
                updateRoot Nothing  = Just (M.alter x pkg M.empty)
                updateRoot (Just l) = Just (M.alter x pkg l)
                x :: Maybe Policy -> Maybe Policy
                x Nothing          = Just pol
                x (Just actualPol) =
                    case actualPol of
                        Policy_Many ps | pol `elem` ps -> Just actualPol
                                       | otherwise     -> Just $ Policy_Many (pol:ps)

                        _ | actualPol == pol -> Just actualPol
                          | otherwise        -> Just $ Policy_Many (pol:[actualPol])

runCmd (CmdCheckPolicy rawArgs) = do
    (pkgNames, pkgFileNames) <- packageArgs rawArgs

    availablePackages <- loadAvailablePackages pkgFileNames

    matched <- foldallLatest availablePackages M.empty $ \acc name pkgDesc ->
        if name `elem` pkgNames
            then return $ M.insert name pkgDesc acc
            else return acc
    forM_ (M.toList matched) $ \(name, pkgDesc) -> do
        putStrLn ("== " ++ unPackageName name)
        let packageDepends = map (\d -> (dependencyName d, getPolicy availablePackages $ dependencyConstraints d))
                           $ buildDepends pkgDesc
        let sums = map (\l -> (head l, length l)) $ group $ sort $ map snd packageDepends

        forM_ packageDepends $ \(n,p) ->
            ppLine 4 $ PP.hcat [ PP.string "* ", PP.string (unPackageName n), PP.string " = ", showPolicy p]
        forM_ sums $ \(policy, n) ->
            ppLine 2 $ PP.hcat [ showPolicy policy, PP.string " = ", PP.string (show n), PP.string " packages"]

runCmd (CmdForAll) = do
    return ()

-----------------------------------------------------------------------
main = getOptions >>= runCmd