{-
Copyright (c) 2004, Philippa Jane Cowderoy
All rights reserved.

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modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright 
      notice, this list of conditions and the following disclaimer in the 
      documentation and/or other materials provided with the distribution.
    * Neither the name of the original author nor the names of any 
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
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-}

module RecentChanges (recentChanges) where

import Text.XHtml
import PageTemplates
import PageIO
import Data.List

recentChanges env = do pns <- getPagenames
                       pds <- mapM getPageLastUpdated pns
                       pnds <- return $ filter (\(_,md) -> 
                                                    case md of 
                                                     Nothing -> False
                                                     Just d -> True
                                               )                                        
                                               (zip pns pds)
                       opnds <- return $ sortBy ordering pnds
                       count <- case (lookup "count" env) of
                                 Nothing -> return defaultCount
                                 Just x -> case (reads x) of
                                            [(i,_)]-> return i
                                            _ -> return defaultCount
                       out <- return $
                               (concat 
                                 (intersperse 
                                    "\n\n"
                                    (take count
                                          (map (\(pn,Just d) -> 
                                                  (linkTo pn) ++ 
                                                  " - " ++ 
                                                  (show d)
                                               )
                                               opnds
                                          )
                                    )
                                 )
                               )
                       page ("Showing the " 
                             ++
                             (show count)
                             ++
                             " most [:RecentChanges||RecentChanges:]:\n\n"
                             ++ 
                             out
                            )
                            "RecentChanges" 
                            env
                  where ordering (_,d1) (_,d2) = case d1 `compare` d2 of
                                                  LT -> GT
                                                  EQ -> EQ
                                                  GT -> LT
                        defaultCount = 50
                        linkTo pn = "["++pn++"|"++pn++"]"
