{-
Copyright (C) 2009 John MacFarlane <jgm@berkeley.edu>

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 2 of the License, or
(at your option) 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

{- Functions and data structures for wiki page layout.
-}

module Gitit.Layout ( PageLayout(..)
                    , Tab(..)
                    , defaultPageLayout
                    , formattedPage 
                    )
where
import Data.FileStore
import Gitit.Server
import Gitit.Framework
import Gitit.State
import Gitit.Util (orIfNull)
import Gitit.Export (exportFormats)
import Network.HTTP (urlEncodeVars)
import Codec.Binary.UTF8.String (encodeString)
import qualified Text.StringTemplate as T
import Text.XHtml hiding ( (</>), dir, method, password, rev )
import Data.Maybe (isNothing, isJust, mapMaybe, fromJust)
import Data.List (isSuffixOf)
import Prelude hiding (catch)
import Control.Exception (throwIO, catch)
import Control.Monad.Trans (liftIO)

-- | Abstract representation of page layout (tabs, scripts, etc.)
data PageLayout = PageLayout
  { pgTitle          :: String
  , pgScripts        :: [String]
  , pgShowPageTools  :: Bool
  , pgTabs           :: [Tab]
  , pgSelectedTab    :: Tab
  }

data Tab = ViewTab | EditTab | HistoryTab | DiscussTab | DiffTab deriving (Eq, Show)

defaultPageLayout :: PageLayout
defaultPageLayout = PageLayout
  { pgTitle          = ""
  , pgScripts        = []
  , pgShowPageTools  = True
  , pgTabs           = [ViewTab, EditTab, HistoryTab, DiscussTab]
  , pgSelectedTab    = ViewTab
  }

-- | Returns formatted page
formattedPage :: PageLayout -> String -> Params -> Html -> Web Response
formattedPage layout page params htmlContents = do
  let rev = pRevision params
  let path' = if isPage page then pathForPage page else page
  fs <- getFileStore
  sha1 <- case rev of
             Nothing -> liftIO $ catch (latest fs path')
                                       (\e -> if e == NotFound
                                                 then return ""
                                                 else throwIO e)
             Just r  -> return r
  user <- getLoggedInUser params
  let javascriptlinks = if null (pgScripts layout)
                           then ""
                           else renderHtmlFragment $ concatHtml $ map
                                  (\x -> script ! [src ("/js/" ++ x), thetype "text/javascript"] << noHtml)
                                  (["jquery.min.js", "jquery-ui.packed.js"] ++ pgScripts layout)
  let pageTitle = pgTitle layout `orIfNull` page
  let tabli tab = if tab == pgSelectedTab layout
                     then li ! [theclass "selected"]
                     else li
  let origPage s = if ":discuss" `isSuffixOf` s then take (length s - 8) s else s
  let linkForTab HistoryTab = Just $ tabli HistoryTab << anchor ! [href $ urlForPage page ++ "?history" ++ 
                                                                    case rev of { Just r -> "&revision" ++ r; Nothing -> "" }] << "history"
      linkForTab DiffTab    = Just $ tabli DiffTab << anchor ! [href ""] << "diff"
      linkForTab ViewTab    = if isDiscussPage page
                                 then Just $ tabli DiscussTab << anchor ! [href $ urlForPage $ origPage page] << "page"
                                 else Just $ tabli ViewTab << anchor ! [href $ urlForPage page ++
                                                                    case rev of { Just r -> "?revision=" ++ r; Nothing -> "" }] << "view"
      linkForTab DiscussTab = if isDiscussPage page
                                 then Just $ tabli ViewTab << anchor ! [href $ urlForPage page] << "discuss"
                                 else if isPage page
                                      then Just $ tabli DiscussTab << anchor ! [href $ urlForPage page ++ "?discuss"] << "discuss"
                                      else Nothing
      linkForTab EditTab    = if isPage page
                                 then Just $ tabli EditTab << anchor ! [href $ urlForPage page ++ "?edit" ++
                                              (case rev of
                                                    Just r   -> "&revision=" ++ r ++ "&" ++ urlEncodeVars [("logMsg", "Revert to " ++ r)]
                                                    Nothing  -> "")] <<
                                             if isNothing rev then "edit" else "revert"
                                 else Nothing
  let tabs = ulist ! [theclass "tabs"] << mapMaybe linkForTab (pgTabs layout)
  let searchbox = gui ("/_search") ! [identifier "searchform"] <<
                         [ textfield "patterns"
                         , submit "search" "Search" ]
  let gobox     = gui ("/_go") ! [identifier "goform"] <<
                         [ textfield "gotopage"
                         , submit "go" "Go" ]
  let messages = pMessages params
  let htmlMessages = if null messages
                        then noHtml
                        else ulist ! [theclass "messages"] << map (li <<) messages
  templ <- queryAppState template
  let filledTemp = T.render $
                   T.setAttribute "pagetitle" pageTitle $
                   T.setAttribute "javascripts" javascriptlinks $
                   T.setAttribute "pagename" page $
                   (case user of
                         Just u     -> T.setAttribute "user" u
                         Nothing    -> id) $
                   (if isPage page then T.setAttribute "ispage" "true" else id) $
                   (if pgShowPageTools layout then T.setAttribute "pagetools" "true" else id) $
                   (if pPrintable params then T.setAttribute "printable" "true" else id) $
                   (if isJust rev then T.setAttribute "nothead" "true" else id) $
                   (if isJust rev then T.setAttribute "revision" (fromJust rev) else id) $
                   T.setAttribute "sha1" sha1 $
                   T.setAttribute "searchbox" (renderHtmlFragment (searchbox +++ gobox)) $
                   T.setAttribute "exportbox" (renderHtmlFragment $  exportBox page params) $
                   T.setAttribute "tabs" (renderHtmlFragment tabs) $
                   T.setAttribute "messages" (renderHtmlFragment htmlMessages) $
                   T.setAttribute "content" (renderHtmlFragment htmlContents) $
                   templ
  ok $ setContentType "text/html" $ toResponse $ encodeString filledTemp

exportBox :: String -> Params -> Html
exportBox page params | isPage page =
  let rev = pRevision params
  in  gui (urlForPage page) ! [identifier "exportbox"] << 
        ([ textfield "revision" ! [thestyle "display: none;", value (fromJust rev)] | isJust rev ] ++
         [ select ! [name "format"] <<
             map ((\f -> option ! [value f] << f) . fst) exportFormats
         , submit "export" "Export" ])
exportBox _ _ = noHtml