{-# LANGUAGE RecordWildCards #-}

module Web.Response(response, ResponseArgs(..), responseArgs) where

import CmdLine.All
import Hoogle
import General.Base
import General.System
import General.Web
import Web.Page
import Data.Generics.Uniplate

import Data.Time.Clock
import Data.Time.Format
import System.Locale
import Network.Wai
import Network.HTTP.Types(headerContentType)
import System.IO.Unsafe(unsafeInterleaveIO)
import qualified Paths_hoogle(version)
import Data.Version(showVersion)


logFile = "log.txt"
version = showVersion Paths_hoogle.version


data ResponseArgs = ResponseArgs
    {updatedCss :: String
    ,updatedJs :: String
    ,templates :: Templates
    }

responseArgs = ResponseArgs version version defaultTemplates


response :: ResponseArgs -> CmdLine -> IO Response
response ResponseArgs{..} q = do
    logMessage q
    let response x ys = responseOK (headerContentType (fromString x) : ys) . fromString

    dbs <- unsafeInterleaveIO $ case queryParsed q of
        Left _ -> return mempty
        Right x -> fmap snd $ loadQueryDatabases (databases q) (fromRight $ queryParsed q)

    case web q of
        Just "suggest" -> fmap (response "application/json" []) $ runSuggest q
        Just "embed" -> return $ response "text/html" [hdr] $ runEmbed dbs q
            where hdr = (fromString "Access-Control-Allow-Origin", fromString "*")
        Just "ajax" -> return $ response "text/html" [] $ runQuery templates True dbs q
        Just "web" -> return $ response "text/html" [] $
            header templates updatedCss updatedJs (queryText q) ['-' | queryText q /= ""] ++
            runQuery templates False dbs q ++ footer templates version
        mode -> return $ response "text/html" [] $ "Unknown webmode: " ++ fromMaybe "none" mode


logMessage :: CmdLine -> IO ()
logMessage q = do
    time <- getCurrentTime
    args <- fmap (fromMaybe [("hoogle",queryText q)]) cgiArgs
    ip <- fmap (fromMaybe "0") $ getEnvVar "REMOTE_ADDR"
    let shw x = if all isAlphaNum x then x else show x
    appendFile logFile $ (++ "\n") $ unwords $
        [formatTime defaultTimeLocale "%FT%T" time
        ,ip] ++
        [shw a ++ "=" ++ shw b | (a,b) <- args]


runSuggest :: CmdLine -> IO String
runSuggest cq@Search{queryText=q} = do
    (_, db) <- loadQueryDatabases (databases cq) mempty
    let res = completions db q
    return $ "[" ++ show q ++ "," ++ show res ++ "]"
runSuggest _ = return ""


runEmbed :: Database -> CmdLine -> String
runEmbed dbs Search{queryParsed = Left err} = "<i>Parse error: " ++& errorMessage err ++ "</i>"
runEmbed dbs cq@Search{queryParsed = Right q}
    | null now = "<i>No results found</i>"
    | otherwise = unlines
        ["<a href='" ++ url ++ "'>" ++ showTagHTML (transform f $ self $ snd x) ++ "</a>"
        | x <- now, let url = fromList "" $ map fst $ locations $ snd x]
    where
        now = take (maybe 10 (max 1) $ count cq) $ search dbs q
        f (TagEmph x) = TagBold x
        f (TagBold x) = x
        f x = x


runQuery :: Templates -> Bool -> Database -> CmdLine -> String
runQuery templates ajax dbs Search{queryParsed = Left err} =
    parseError templates (showTagHTMLWith f $ parseInput err) (errorMessage err)
    where
        f (TagEmph x) = Just $ "<span class='error'>" ++ showTagHTMLWith f x ++ "</span>"
        f _ = Nothing


runQuery templates ajax dbs q | fromRight (queryParsed q) == mempty = welcome templates


runQuery templates ajax dbs cq@Search{queryParsed = Right q, queryText = qt} = unlines $
    (if prefix then
        ["<h1>" ++ qstr ++ "</h1>"] ++
        ["<ul id='left'><li><b>Packages</b></li>" ++ also ++ "</ul>" | not $ null pkgs] ++
        ["<p>" ++ showTag sug ++ "</p>" | Just sug <- [suggestions dbs q]] ++
        if null res then
            ["<p>No results found</p>"]
        else
            concat (pre ++ now)
    else
        concat now) ++
    ["<p><a href=\"" ++& urlMore ++ "\" class='more'>Show more results</a></p>" | not $ null post]
    where
        prefix = not $ ajax && start2 /= 0 -- show from the start, with header
        start2 = maybe 0 (subtract 1 . max 0) $ start cq
        count2 = maybe 20 (max 1) $ count cq

        src = search dbs q
        res = [renderRes i (i /= 0 && i == start2 && prefix) x | (i,(_,x)) <- zip [0..] src]
        (pre,res2) = splitAt start2 res
        (now,post) = splitAt count2 res2

        also = concatMap f (take (5 + length minus) $ nub $ minus ++ pkgs)
            where minus = [x | (False,x) <- queryPackages q]
        f x | (True,lx) `elem` queryPackages q =
                let q2 = showTagText $ renderQuery $ querySetPackage Nothing lx q in
                "<li><a class='minus' href='" ++ searchLink q2 ++ "'>" ++ x ++ "</a></li>"
            | (False,lx) `elem` queryPackages q =
                let q2 = showTagText $ renderQuery $ querySetPackage Nothing lx q in
                "<li><a class='plus pad' href='" ++ searchLink q2 ++ "'>" ++ x ++ "</a></li>"
            | otherwise =
                let link b = searchLink $ showTagText $ renderQuery $ querySetPackage (Just b) lx q in
                "<li><a class='minus' href='" ++ link False ++ "'></a>" ++
                "<a class='plus' href='" ++ link True ++ "'>" ++ x ++ "</a></li>"
            where lx = map toLower x
        pkgs = [x | (_, (_,x):_)  <- concatMap (locations . snd) $ take (start2+count2) src]

        urlMore = searchLink qt ++ "&start=" ++ show (start2+count2+1) ++ "#more"
        qstr = showTagHTML (renderQuery q)


renderRes :: Int -> Bool -> Result -> [String]
renderRes i more Result{..} =
        ["<a name='more'></a>" | more] ++
        ["<div class='ans'>" ++ href selfUrl (showTagHTMLWith url self) ++ "</div>"] ++
        ["<div class='from'>" ++ intercalate ", " [unwords $ zipWith (f u) [1..] ps | (u,ps) <- locations] ++ "</div>" | not $ null locations] ++
        ["<div class='doc " ++ (if '\n' `elem` s then " newline" else "") ++ "'><span>" ++ showTag docs ++ "</span></div>"
            | let s = showTagText docs, s /= ""]
    where
        selfUrl = head $ map fst locations ++ [""]
        f u cls (url,text) = "<a class='p" ++ show cls ++ "' href='" ++  url2 ++ "'>" ++ text ++ "</a>"
            where url2 = if url == takeWhile (/= '#') u then u else url

        url (TagBold x)
            | null selfUrl = Just $ "<span class='a'>" ++ showTagHTML (transform g x) ++ "</span>"
            | otherwise = Just $ "</a><a class='a' href='" ++& selfUrl ++ "'>" ++ showTagHTML (transform g x) ++
                                 "</a><a class='dull' href='" ++& selfUrl ++ "'>"
        url _ = Nothing

        g (TagEmph x) = TagBold x
        g x = x

        href url x = if null url then x else "<a class='dull' href='" ++& url ++ "'>" ++ x ++ "</a>"


showTag :: TagStr -> String
showTag = showTagHTML . transform f
    where
        f (TagLink "" x) = TagLink (if any (`isPrefixOf` str) ["http:","https:"] then str else searchLink str) x
            where str = showTagText x
        f x = x


searchLink :: String -> URL
searchLink x = "?hoogle=" ++% x