<?php if (!defined('PmWiki')) exit();
/*
  Mainly based on PageFeed by Daniel Roesler (diafygi)
  http://www.pmwiki.org/wiki/Cookbook/PageFeed  

  http://fabien.benetou.fr/Wiki/MemoryRecipe

  TODO
	support the regex syntax function calls as done in groupkeypages.php
	test with the W3C that feeds generated are proper
	note that if backward compability of files is important the 3 formers can remain empty
		but ideally the local/config.php file should be modified
	weighting for the composite function should read local PTV
		if unsset then use the default behavior
	make the content of description easier to change
		create a variable at the head of the script
	option to regenerate the fields
		since a specified date or the first found markup
	make sure to check against https://secure.wikimedia.org/wikipedia/en/wiki/Code_smell
	consider pulling the text from a dedicated wiki page if it is present, if not use default values
*/

## Recipe version information
$RecipeInfo['MemoryManagement']['Version'] = '2011-06-28';

## Add action for pagefeed
SDV($HandleActions['memorizationMM'], 'MemorizationMM');
SDV($HandleActions['recallMM'], 'BehaviorRecallMM');
SDV($HandleActions['preparationMM'], 'PreparationMM');


function MemorizationMM($pagename, $auth = 'read'){
	GenerateFeed("startrecall", "memorization.xml", false,
		"Memorization", "Receive links as reminded to piece of information you want to consolidate as long-term."
		);
}
function BehaviorRecallMM($pagename, $auth = 'read'){
	GenerateFeed("recall", "recall.xml", false,
		"BehaviorRecall", "Receive links as reminded to periodic behaviors you want to transform to habits."
	/*
		"Day $day recall for page $page started at $daterecall"
		"$ScriptUrl/$cleaned_page_name#MemorizationDay$day"
		FeedText($page,$page,"description")
	*/
		);
}

function PreparationMM($pagename, $auth = 'read'){
	GenerateFeed("startprepare", "preparation.xml", true,
		"Preparation", "Receive links as reminded for consequent events you want to prepare."
	/*
		"Day $day of preparation for page $page started at $dateprepare"
		"$ScriptUrl/$page"
		"This is to improve preparation of things you will have to produce. Also don't forget to improve those instructions to be more and more efficient!"
	*/
		);
}


function mod_pattern_test($day,$timeforward,$step){
	$current_unix_day = strtotime(date("Y-m-d"));
	$checkdate = strtotime(preg_replace("/(\d+)\/(\d+)\/(\d+)/",'$3-$2-$1',$day));
	if ($timeforward)
		return (($current_unix_day - $checkdate) % 7*(24*60*60) == 0);
	return (($current_unix_day + $checkdate) % $step *(24*60*60) == 0);
}

function exponential_pattern_test($day,$timeforward){
	$exponential_pattern = array(1,10,30,60,120,350,700,1500,3000,7000,15000,30000,100000); //exp
		#consider comparing the value with its log
	$current_unix_day = strtotime(date("Y-m-d"));
	$checkdate = strtotime(preg_replace("/(\d+)\/(\d+)\/(\d+)/",'$3-$2-$1',$day));
	if ($timeforward)
		return in_array(($current_unix_day - $checkdate),$exponential_pattern);
	return in_array(($checkdate - $current_unix_day),$exponential_pattern);
}

# from http://www.pmwiki.org/wiki/PmWiki/Functions
function FeedTextMM($pagename, &$page, $tag) {
  $text = RetrieveAuthSection("ReadingNotes.GroupHeader","");
  $content = MarkupToHTML($pagename, $text);
  $text = RetrieveAuthSection($pagename, '##Chapter2');
  // note that if this boundary if not found, the entire page is converted
  $content .= MarkupToHTML($pagename, $text);
  return "<$tag><![CDATA[$content]]></$tag>";
}

## Create feed from page history
function GenerateFeed($varname,$targetfile,$timeforward,$ChannelTitle,$ChannelDescription) {
# GenerateFeed(FeedTitle,FeedDescription,ItemTitle,ItemDescription,Feedfile,Timedirection,Pattern)
# consider defaults : exp, +, ...
  global $FarmD, $WikiTitle, $ScriptUrl;

  $feeds = "/pub/memoryfeeds/" ;
  #### location of the resulting feed
  $feedfile = $FarmD.$feeds.$targetfile;
  if (!file_exists($feedfile)){
    if (!touch($feedfile)){
      print "Creation of the feed file fails, check write permissions for pmWiki and $feedfile.\nMake sure the target directory exists and with the right write permissions.";
      return;
    }
  }
  # open $feed as read
  $feed_oldcontent = file_get_contents($feedfile);
  $feed_newcontent = ''; 

  # this can probably be optimized by removing pages that are sure not to have varname
  $pages = ListPages();

  # 2 loops can be probably optimized since they are ordered by date
  foreach ($pages as $page) {
   $params = PageTextVar($page,$varname);
   if ( isset($params) ) {
    $params = explode(" ",$recall);
	#XXX make sure params does contain the date even when " " is not found
    $daterecall = $params[0];
    if ($daterecall=="") break;
    switch($patternrecall){
	case "daily": $pattern_matched = true; break;
	case "weekly": $pattern_matched = mod_pattern_test($daterecall,$timeforward,7); break;
	case "monthly": $pattern_matched = mod_pattern_test($daterecall,$timeforward,30); break;
	default: $pattern_matched = exponential_pattern_test($daterecall,$timeforward); break;
    }
    if ($pattern_matched) {
      # generate GUID
      $item_GUID = $page.'_'.date("Y-m-d");
      # if not present in file (using a regex on the GUID)
      if (preg_match("/$item_GUID/",$feed_oldcontent) == 0){
        # generate date
        $feed_newitemdate = date(DATE_RSS, time());
	$cleaned_page_name = str_replace(".","/",$page);
	global $FmtV;
	$pagecontent = FmtPageName($FmtV, $page);
	# does this actually work?! check FeedText() instead

	$ItemTitle = "Day $day recall for page $page started at $daterecall";
	$ItemLink = "$ScriptUrl/$cleaned_page_name#BehaviorRecallDay$day";
	$ItemDescription = "This is to improve behaviors you decided yourself were valuable. Also don't forget to improve those instructions to be more and more efficient! $pagecontent";

	# NOTE $ChannelTitle."Day" could be use but that's not really a proper name...

        $feed_newitem = "<item>\n
		<title>$ItemTitle</title>
		<link>$ItemLink</link>
		<description>$ItemDescription</description>
		<guid>$item_GUID</guid>
		<pubDate>$feed_newitemdate</pubDate>\n</item>";

        # appending the item
        $feed_newcontent .= $feed_newitem;
      }
    } # check if the next recall day is today
   } # check if the next page is tagged
  }
  # feed should be properly updated

  $feed_newdate = date(DATE_RSS, time());
  $feed_header = "<?xml version=\"1.0\"?>\n<rss version=\"2.0\">
	<channel>
	<title>$ChannelTitle feed for $WikiTitle .</title>
	<link>$ScriptUrl</link>
	<description>$ChannelTitle</description>
        <lastBuildDate>$feed_newdate</lastBuildDate>";
  $feed_footer = "\n</channel>\n</rss>";

  print $feed_header; 
  print $feed_oldcontent; 
  print $feed_newcontent; 
  print $feed_footer;

  if (strlen($feed_newcontent)==0)
	return;

  $write_result = file_put_contents($feedfile,$feed_oldcontent.$feed_newcontent);
  if (!$write_result){
    if (strlen($feed_oldcontent.$feed_newcontent)>0){
      print "Creation of the feed file fails, check write permissions for pmWiki and $feedfile.";
      return;
    } else {
      print "No item to generate, did you correctly tag your pages?";
      return;
    }
  }
}