module Application.HXournal.ModelAction.Page where

import Application.HXournal.Type.XournalState
import Application.HXournal.Type.Canvas
import Data.Xournal.Simple
import Data.Xournal.Generic
import Data.Xournal.Select

import Graphics.Xournal.Render.BBoxMapPDF

import Control.Category
import Data.Label
import Prelude hiding ((.),id)
import qualified Data.IntMap as M 

getPageMap :: XournalState -> M.IntMap TPageBBoxMapPDFBuf
getPageMap xojstate = case xojstate of 
                        ViewAppendState xoj -> get g_pages xoj 
                        SelectState txoj -> get g_selectAll txoj 

setPageMap :: M.IntMap TPageBBoxMapPDFBuf -> XournalState -> XournalState
setPageMap nmap xojstate = 
  case xojstate of 
    ViewAppendState xoj -> ViewAppendState (set g_pages nmap xoj)
    SelectState txoj -> let ntxoj = set g_selectSelected Nothing
                                    . set g_selectAll nmap 
                                    $ txoj 
                        in SelectState ntxoj
   -- SelectState (set g_selectAll nmap txoj)
        
updatePageFromCanvasToXournal :: CanvasInfo -> XournalState -> XournalState 
updatePageFromCanvasToXournal cinfo xojstate = 
  let cpn = get currentPageNum cinfo 
      epg = get currentPage cinfo
      page = either id gcast epg
  in  setPageMap (M.adjust (const page) cpn . getPageMap $ xojstate) xojstate 


updatePageAll :: XournalState 
                 -> HXournalState 
                 -> HXournalState
updatePageAll xst xstate = 
  let cmap = get canvasInfoMap xstate
      cmap' = fmap (updatePage xst . adjustPage xst) cmap
  in  set canvasInfoMap cmap' xstate 

adjustPage :: XournalState -> CanvasInfo -> CanvasInfo
adjustPage xojstate cinfo =
    let cpn = get currentPageNum cinfo 
        pagemap = getPageMap xojstate
    in  adjustwork cpn pagemap              
  where adjustwork cpn pagemap = 
         if M.notMember cpn pagemap  
         then let (minp,_) = M.findMin pagemap 
                  (maxp,_) = M.findMax pagemap 
              in if cpn > maxp 
                   then set currentPageNum maxp cinfo
                   else set currentPageNum minp cinfo
         else cinfo
 


getPageFromGXournalMap :: Int -> GXournal M.IntMap a -> a
getPageFromGXournalMap pagenum xoj  = 
  case M.lookup pagenum (get g_pages xoj) of 
    Nothing -> error "something wrong in getPageFromGXournalMap"
    Just p -> p

updatePage :: XournalState -> CanvasInfo -> CanvasInfo 
updatePage (ViewAppendState xojbbox) cinfo = 
  let pagenum = get currentPageNum cinfo 
      pg = getPageFromGXournalMap pagenum xojbbox 
      Dim w h = gdimension pg
  in  set currentPageNum pagenum 
      . set (pageDimension.viewInfo) (w,h)       
      . set currentPage (Left pg)
      $ cinfo 
updatePage (SelectState txoj) cinfo = 
  let pagenum = get currentPageNum cinfo
      mspage = gselectSelected txoj 
      pageFromArg = case M.lookup pagenum (gselectAll txoj) of 
                      Nothing -> error "no such page in updatePage"
                      Just p -> p
      (newpage,Dim w h) = 
        case mspage of 
          Nothing -> (Left pageFromArg, gdimension pageFromArg)
          Just (spagenum,page) -> 
            if spagenum == pagenum 
              then (Right page, gdimension page) 
              else (Left pageFromArg, gdimension pageFromArg)
  in set currentPageNum pagenum 
     . set (pageDimension.viewInfo) (w,h)       
     . set currentPage newpage
     $ cinfo 
  
setPage :: XournalState -> Int -> CanvasInfo -> CanvasInfo
setPage (ViewAppendState xojbbox) pagenum cinfo = 
  let pg = getPageFromGXournalMap pagenum xojbbox
      Dim w h = gdimension pg
  in  set currentPageNum pagenum 
      . set (viewPortOrigin.viewInfo) (0,0) 
      . set (pageDimension.viewInfo) (w,h)       
      . set currentPage (Left pg)
      $ cinfo 
setPage (SelectState txoj) pagenum cinfo = 
  let mspage = gselectSelected  txoj 
      pageFromArg = case M.lookup pagenum (gselectAll txoj) of 
                      Nothing -> error "no such page in setPage"
                      Just p -> p
      (newpage,Dim w h) = 
        case mspage of 
          Nothing -> (Left pageFromArg, gdimension pageFromArg)
          Just (spagenum,page) -> 
            if spagenum == pagenum 
              then (Right page, gdimension page) 
              else (Left pageFromArg, gdimension pageFromArg)
  in set currentPageNum pagenum 
     . set (viewPortOrigin.viewInfo) (0,0) 
     . set (pageDimension.viewInfo) (w,h)       
     . set currentPage newpage
     $ cinfo 
                            
getPage :: CanvasInfo -> TPageBBoxMapPDFBuf
getPage cinfo = 
  case get currentPage cinfo of 
    Right tpgs -> gcast tpgs :: TPageBBoxMapPDFBuf 
    Left pg -> pg 
                  

newSinglePageFromOld :: TPageBBoxMapPDFBuf -> TPageBBoxMapPDFBuf 
newSinglePageFromOld = 
  set g_layers (NoSelect [GLayerBuf (LyBuf Nothing) []]) 

newPageBeforeAction :: TXournalBBoxMapPDFBuf -> (CanvasId, CanvasInfo) -> IO TXournalBBoxMapPDFBuf
newPageBeforeAction xoj (cid,cinfo) = do 
  let cpn = get currentPageNum cinfo
  let pagelst = M.elems . get g_pages $ xoj 
      pagekeylst = M.keys . get g_pages $ xoj 
      (pagesbefore,pagesafter) = splitAt cpn pagelst
      npage = newSinglePageFromOld (head pagesafter)
      npagelst = pagesbefore ++ (npage : pagesafter)
      nxoj = set g_pages (M.fromList . zip [0..] $ npagelst) xoj 
  putStrLn . show $ pagekeylst 
  return nxoj