-- Author:     Andy Stewart <lazycat.manatee@gmail.com>
-- Maintainer: Andy Stewart <lazycat.manatee@gmail.com>
-- 
-- Copyright (C) 2010 Andy Stewart, all rights reserved.
-- 
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- any later version.
-- 
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
-- 
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE DeriveDataTypeable #-}
module Manatee.Extension.Browser.BrowserView where

import Codec.Binary.UTF8.String
import Control.Applicative
import Control.Concurrent.STM 
import Control.Monad.State
import Data.Map (Map)
import Data.Maybe
import Data.Text.Lazy (Text)
import Data.Typeable
import Graphics.UI.Gtk hiding (Statusbar, statusbarNew, get)
import Graphics.UI.Gtk.Gdk.SerializedEvent
import Graphics.UI.Gtk.WebKit.WebFrame
import Graphics.UI.Gtk.WebKit.WebSettings
import Graphics.UI.Gtk.WebKit.WebView
import Graphics.UI.Gtk.WebKit.WebResource
import Manatee.Core.DBus
import Manatee.Core.PageView
import Manatee.Core.Config
import Manatee.Core.Types
import Manatee.Extension.Browser.BrowserBuffer
import Manatee.Toolkit.General.Basic
import Manatee.Toolkit.General.Map
import Manatee.Toolkit.General.Maybe
import Manatee.Toolkit.General.STM
import Manatee.Toolkit.Gtk.Gtk
import Manatee.Toolkit.Gtk.ScrolledWindow
import Manatee.Toolkit.Gtk.Concurrent

import qualified Data.Map as M

data BrowserView =
    BrowserView {browserViewPlugId               :: TVar PagePlugId
                ,browserViewScrolledWindow       :: ScrolledWindow
                ,browserViewView                 :: WebView
                ,browserViewBuffer               :: BrowserBuffer
                ,browserViewBroadcastChannel     :: ViewChannel BrowserBufferSignal
                ,browserViewStatusLengthLimit    :: Int
                }
    deriving Typeable

instance PageBuffer BrowserBuffer where
  pageBufferGetName             = readTVarIO . browserBufferUri
  pageBufferSetName a           = writeTVarIO (browserBufferUri a)
  pageBufferClient              = browserBufferClient
  pageBufferCreateView a pId    = PageViewWrap <$> browserViewNew a pId
  pageBufferMode                = browserBufferMode

instance PageView BrowserView where
    pageViewBuffer              = PageBufferWrap . browserViewBuffer
    pageViewPlugId              = browserViewPlugId
    pageViewFocus               = widgetGrabFocus . browserViewView
    pageViewCut                 = browserViewCut
    pageViewCopy                = browserViewCopy
    pageViewPaste               = browserViewPaste
    pageViewScrolledWindow      = browserViewScrolledWindow
    pageViewHandleKeyAction     = browserViewHandleKeyAction

-- | New browser view.
browserViewNew :: BrowserBuffer -> PagePlugId -> IO BrowserView    
browserViewNew buffer plugId = do
  -- Create UI frame.
  scrolledWindow <- scrolledWindowNew_
  
  -- Create view.
  webView <- webViewNew
  scrolledWindow `containerAdd` webView
  uri <- pageBufferGetName buffer
  webViewLoadUri webView uri
  channel <- createViewChannel (browserBufferBroadcastChannel buffer) webView
  pId <- newTVarIO plugId
  let browserView = BrowserView pId scrolledWindow webView buffer channel 100

  -- Set font.
  setting <- webViewGetWebSettings webView
  let defaultFont = "DejaVu Sans YuanTi Mono"
  set setting [webSettingsDefaultFontFamily   := defaultFont
              ,webSettingsSansFontFamily      := defaultFont
              ,webSettingsCursiveFontFamily   := defaultFont
              ,webSettingsFantasyFontFamily   := defaultFont
              ,webSettingsMonospaceFontFamily := defaultFont
              ,webSettingsSerifFontFamily     := defaultFont]

  -- Create new tab when request open new window.
  webView `on` createWebView $ browserViewNewTab browserView

  -- Synchronous other webkit view when loadCommitted signal.
  webView `on` loadCommitted $ browserViewChangeUri browserView 

  -- Record web history after load finished.
  webView `on` loadFinished $ browserRecordHistory

  -- Synchronous title when title changed.
  webView `on` titleChanged $ browserViewChangeTitle browserView

  -- Display link over mouse.
  webView `on` hoveringOverLink $ \ _ mouseUri -> 
    mouseUri ?>= \ uri -> 
        pageViewUpdateOutputStatus browserView uri (Just (browserViewStatusLengthLimit browserView))

  -- Display resource request status. 
  webView `on` resourceRequestStarting $ \ _ resource _ _ -> do
    -- Get request uri.
    uri <- webResourceGetUri resource
    pageViewUpdateOutputStatus browserView uri (Just (browserViewStatusLengthLimit browserView))

  webView `on` progressChanged $ \ progress ->
    pageViewUpdateProgressStatus browserView (i2d progress)

  -- Listen broadcast channel for synchronous view.
  browserViewListenChannel browserView

  return browserView

-- | Handle key action.
browserViewHandleKeyAction :: BrowserView -> Text -> SerializedEvent -> IO ()
browserViewHandleKeyAction view keystoke sEvent = 
  case M.lookup keystoke browserViewKeymap of
    Just action -> action view
    Nothing -> widgetPropagateEvent (browserViewView view) sEvent

-- | Keymap.
browserViewKeymap :: Map Text (BrowserView -> IO ())
browserViewKeymap = 
  M.fromList [("M-r",           browserViewReload)
             ,("M-R",           browserViewReloadBypassCache)
             ,("XF86Back",      browserViewGoBack)
             ,("XF86Forward",   browserViewGoForward)
             ,("M-,",           browserViewGoBack)
             ,("M-.",           browserViewGoForward)
             ,("M--",           browserViewZoomOut)
             ,("M-=",           browserViewZoomIn)
             ]

-- | New tab.
browserViewNewTab :: BrowserView -> WebFrame -> IO WebView
browserViewNewTab view _ = do
  -- Because WebKit API will return new webView by signal `createWebView`,
  -- we use `webViewNew` build temporary webView to intercept new uri,
  -- then we send NewTab DBus signal and stop loading temporary webView.
  webView <- webViewNew
  webView `on` loadCommitted $ \ frame -> do
    -- Intercept new uri.
    webFrameGetUri frame >?>= \uri -> 
      mkDaemonSignal (pageViewClient view) NewTab (NewTabArgs "PageBrowser" uri [])
    -- Stop loading.
    webViewStopLoading webView

  -- Don't use WebFrame in signal `createWebView` to return webView,
  -- otherwise will change current tab.
  return webView

-- | Change uri.
browserViewChangeUri :: BrowserView -> WebFrame -> IO ()
browserViewChangeUri view frame = 
  webFrameGetUri frame >?>= \uri -> do
    putStrLn $ "Change url to : " ++ show uri
    writeTVarIO (browserBufferUri $ browserViewBuffer view) uri
    writeTChanIO (viewChannel $ browserViewBroadcastChannel view) (SyncUri uri)

-- | Record browse history.
browserRecordHistory :: WebFrame -> IO ()
browserRecordHistory frame = 
  webFrameGetUri frame >?>= \ uri -> do
    title <- liftM (fromMaybe uri) $ webFrameGetTitle frame
    (BrowseHistoryList browseHistory) <- readConfig browseHistoryPath (BrowseHistoryList M.empty)
    case findMinMatch browseHistory (\ bUri bTitle -> bUri == uri && bTitle == title) of
      Just _  -> return ()
      Nothing -> writeConfig browseHistoryPath (BrowseHistoryList (M.insert uri (decodeString title) browseHistory))
  
-- | Change title.
browserViewChangeTitle :: BrowserView -> WebFrame -> String -> IO ()
browserViewChangeTitle view _ title = 
  writeTChanIO (viewChannel $ browserViewBroadcastChannel view) (SyncTitle title)

-- | Listen broadcast channel to synchronous view.
browserViewListenChannel :: BrowserView -> IO ()
browserViewListenChannel view = 
  listenViewChannel (browserViewBroadcastChannel view) $ \ signal -> 
      case signal of
        SyncUri uri -> 
            webViewGetUri (browserViewView view) >?>= \currentUri -> 
                when (currentUri /= uri) $ webViewLoadUri (browserViewView view) uri
        _ -> return ()

-- | Reload page. 
browserViewReload :: BrowserView -> IO ()
browserViewReload = 
  webViewReload . browserViewView

-- | Reload page without using any cached data.
browserViewReloadBypassCache :: BrowserView -> IO ()
browserViewReloadBypassCache = 
  webViewReloadBypassCache . browserViewView

-- | Loads the previous history item.
browserViewGoBack :: BrowserView -> IO ()
browserViewGoBack = 
  webViewGoBack . browserViewView

-- | Loads the next history item. 
browserViewGoForward :: BrowserView -> IO ()
browserViewGoForward = 
  webViewGoForward . browserViewView

-- | Increases the zoom level of WebView. 
browserViewZoomIn :: BrowserView -> IO ()
browserViewZoomIn =
  webViewZoomIn . browserViewView

-- | Decreases the zoom level of WebView. 
browserViewZoomOut :: BrowserView -> IO ()
browserViewZoomOut =
  webViewZoomOut . browserViewView

-- | Browser cut.
browserViewCut :: BrowserView -> IO Bool
browserViewCut view@ (BrowserView {browserViewView = webView}) = do
  ifM (webViewCanCutClipboard webView)
      (webViewCutClipboard webView)
      (pageViewUpdateOutputStatus view "Can't cut." Nothing)
  return True

-- | Browser copy.
browserViewCopy :: BrowserView -> IO Bool
browserViewCopy view@ (BrowserView {browserViewView = webView}) = do
  ifM (webViewCanCopyClipboard webView)
      (webViewCopyClipboard webView)
      (pageViewUpdateOutputStatus view "Can't copy." Nothing)
  return True

-- | Browser paste.
browserViewPaste :: BrowserView -> IO Bool
browserViewPaste view@ (BrowserView {browserViewView = webView}) = do
  ifM (webViewCanPasteClipboard webView)
      (webViewPasteClipboard webView)
      (pageViewUpdateOutputStatus view "Can't paste." Nothing)
  return True