pierre@1: <?php
pierre@1: 
pierre@1: /**
pierre@1:  * @file
pierre@1:  * Ad Channel include file.
pierre@1:  *
pierre@1:  * Copyright (c) 2008-2009.
pierre@1:  *   Jeremy Andrews <jeremy@tag1consulting.com>.
pierre@1:  */
pierre@1: 
pierre@1: /**
pierre@1:  * Filter advertisements not in an appropriate channel, from cache.
pierre@1:  */
pierre@1: function ad_channel_cache_filter($ads) {
pierre@1:   _debug_echo("ad_channel_cache: adserve_cache_filter");
pierre@1: 
piotre@7:   // get channel array from cache
pierre@1:   $channels = adserve_cache('get_cache', 'channel');
piotre@7:   // 0 = only display advertisements not assigned to any channel if no matching
piotre@7:   // ads in selected channel; 1 = always display advertisements not assigned to
piotre@7:   // any channel; 2 = never display advertisements not assigned to any channel
piotre@7:   $nochannel_display = $channels['display'];
piotre@7:   $valid_ads = array();
piotre@7:   $nochannel_fallback_ads = array();
piotre@7:   $nochannel_percent = array();
piotre@7:   // determine which channels each advertisement is assigned to
pierre@1:   foreach ($ads as $aid) {
pierre@1:     _debug_echo("ad_channel_cache: checking aid($aid)");
pierre@1:     if (is_array($channels['ads']) && isset($channels['ads'][$aid]) &&
pierre@1:         is_array($channels['ads'][$aid])) {
pierre@1:       foreach ($channels['ads'][$aid] as $chid) {
pierre@1:         $channel = $channels['channels'][$chid];
piotre@7:         $display_by_url = $channel->display;
pierre@1:         $urls = unserialize($channel->urls);
pierre@1:         $frontpage = adserve_variable('site_frontpage') ? adserve_variable('site_frontpage') : 'node';
pierre@1:         $regexp = '/^('. preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1'. preg_quote($frontpage, '/') .'\2'), preg_quote($urls, '/')) .')$/';
pierre@1:         $match = preg_match($regexp, adserve_variable('url'));
piotre@7:         _debug_echo("ad_channel_cache: checking aid($aid) against channel($chid) path(". adserve_variable('url') .") regexp($regexp) match($match) display[$display_by_url]");
piotre@7:         // display ad on all except matching urls
piotre@7:         if ($display_by_url == 0) {
pierre@1:           if (empty($urls) || !$match) {
pierre@1:             _debug_echo("ad_channel_cache: aid($aid) is valid");
piotre@7:             $valid_ads[$chid][] = $aid;
piotre@7:             if ($nochannel_display == 1) {
piotre@7:               $nochannel_percent[$chid] = $channel->no_channel_percent;
piotre@7:               _debug_echo("ad_channel_cache: channel($chid) no_channel_percent($nochannel_percent[$chid])");
sly@2:             }
piotre@7:             else {
piotre@7:               _debug_echo("ad_channel_cache: channel($chid)");
piotre@7:             }
pierre@1:             break;
pierre@1:           }
pierre@1:         }
piotre@7:         // display ad on matching urls
piotre@7:         else {
pierre@1:           if (!empty($urls) && $match) {
pierre@1:             _debug_echo("ad_channel_cache: aid($aid) is valid");
piotre@7:             $valid_ads[$chid][] = $aid;
piotre@7:             if ($nochannel_display == 1) {
piotre@7:               $nochannel_percent[$chid] = $channel->no_channel_percent;
piotre@7:               _debug_echo("ad_channel_cache: channel($chid) no_channel_percent($nochannel_percent[$chid])");
sly@2:             }
piotre@7:             else {
piotre@7:               _debug_echo("ad_channel_cache: channel($chid)");
piotre@7:             }
pierre@1:             break;
pierre@1:           }
pierre@1:         }
piotre@7:         // no match so we didn't hit a break, ad is not valid
pierre@1:         _debug_echo("ad_channel_cache: aid($aid) is not valid");
pierre@1:       }
pierre@1:     }
pierre@1:     else {
piotre@7:       // no channel information for ad
piotre@7:       _debug_echo("ad_channel_cache: aid($aid) has no channel info, nochannel_display($nochannel_display)");
piotre@7:       switch ($nochannel_display) {
pierre@1:         case 0:
piotre@7:           $nochannel_fallback_ads[] = $aid;
piotre@7:           _debug_echo("ad_channel_cache: non-channel aid($aid) is valid if no valid ads are assigned to current channel");
pierre@1:           break;
pierre@1:         case 1:
piotre@7:           $valid_ads[0][] = $aid;
piotre@7:           _debug_echo("ad_channel_cache: non-channel aid($aid) is valid");
pierre@1:           break;
pierre@1:         case 2:
pierre@1:           _debug_echo("ad_channel_cache: aid($aid) is not valid");
pierre@1:           break;
pierre@1:       }
pierre@1:     }
pierre@1:   }
pierre@1: 
piotre@7:   // Apply frequencies, applicable to all channels
piotre@7:   if (!empty($valid_ads) && !empty($nochannel_percent)) {
piotre@7:     $frequencies = array();
piotre@7:     foreach (array_keys($valid_ads) as $chid) {
piotre@7:       if ($chid) {
piotre@7:         if (isset($nochannel_percent[$chid]) && $nochannel_percent[$chid]) {
piotre@7:           $frequencies[$chid] = $nochannel_percent[$chid];
piotre@7:           _debug_echo("ad_channel_cache: channel $chid has a non-channel ad frequency of ". $nochannel_percent[$chid]."%");
sly@2:         }
sly@2:         else {
piotre@7:           // by default, channels return 'non-channel ads' with a frequency
piotre@7:           // of 10%
piotre@7:           $frequencies[$chid] = 10;
piotre@7:           _debug_echo("ad_channel_cache: channel $chid assigned a default non-channel ad frequency of 10%");
sly@2:         }
sly@2:       }
sly@2:       else {
piotre@7:         // frequency for non-channel ads is not meaningful
sly@2:       }
sly@2:     }
piotre@7:     if (!empty($frequencies)) {
piotre@7:       $balanced_channels = array();
piotre@7:       $num_channels = sizeof($valid_ads);
piotre@7: 
piotre@7:       foreach (array_keys($valid_ads) as $chid) {
piotre@7:         if (isset($frequencies[$chid])) {
piotre@7:            // for a given channel, ensure the proper ratio to non-channel ads
piotre@7:           if ($frequencies[$chid] <=  50) { // increase occurrences of $chid
piotre@7:             $balanced_channels[] = 0;
piotre@7:             $frequency = round(100 / $frequencies[$chid]) - 1;
piotre@7:             _debug_echo("ad_channel_cache: adjusting ratio of channel($chid) to $frequency:1 relative non-channel ads");
piotre@7:             for ($i = 1; $i <= $frequency; $i++) {
piotre@7:               $balanced_channels[] = $chid;
piotre@7:             }
piotre@7:           }
piotre@7:           else { // add $chid and additional non-channel ads
piotre@7:             $balanced_channels[] = $chid;
piotre@7:             $frequency = round(100 / (100 - $frequencies[$chid])) - 1;
piotre@7:             _debug_echo("ad_channel_cache: adjusting ratio of channel($chid) to 1:$frequency relative non-channel ads");
piotre@7:             for ($i = 1; $i <= $frequency; $i++) {
piotre@7:               $balanced_channels[] = 0;
piotre@7:             }
piotre@7:           }
sly@2:         }
sly@2:       }
piotre@7:       _debug_echo('ad_channel_cache: channel 0 contains all non-channel ads');
piotre@7:       if (adserve_variable('debug') >= 2) {
piotre@7:         foreach ($balanced_channels as $key => $chid) {
piotre@7:           _debug_echo("ad_channel_cache: channel $chid => index $key");
piotre@7:         }
piotre@7:       }
sly@2:     }
piotre@7:     $random_channel = _select_channel_id($balanced_channels);
sly@2:   }
piotre@7:   else if (!empty($valid_ads)) {
piotre@7:     foreach ($valid_ads as $chid => $ads) {
piotre@7:       $chids[$chid] = $chid;
piotre@7:     }
piotre@7:     shuffle($chids);
piotre@7:     $random_channel = array_pop($chids);
piotre@7:   }
piotre@7:   else if (empty($valid_ads) && !empty($nochannel_fallback_ads)) {
pierre@1:     _debug_echo("ad_channel_cache: using ads with no channel info");
piotre@7:     $valid_ads[0] = $nochannel_fallback_ads;
piotre@7:     $random_channel = 0;
pierre@1:   }
pierre@1: 
pierre@1:   $premiere = adserve_cache('get_cache', 'premiere');
pierre@1:   if (is_array($premiere)) {
piotre@7:     $premieres = array();
piotre@7:     foreach (array_keys($valid_ads) as $chid) {
piotre@7:       foreach ($valid_ads[$chid] as $aid) {
piotre@7:         if (in_array($aid, $premiere)) {
piotre@7:           _debug_echo("ad_channel_cache: aid($aid) is premiere advertisement");
piotre@7:           $premieres[$aid] = $aid;
piotre@7:         }
piotre@7:         else {
piotre@7:           _debug_echo("ad_channel_cache: aid($aid) is not a premiere advertisement");
piotre@7:         }
pierre@1:       }
pierre@1:     }
pierre@1:     if (!empty($premieres)) {
pierre@1:       _debug_echo("ad_channel_cache: returning premiere advertisements");
pierre@1:       return $premieres;
pierre@1:     }
pierre@1:   }
piotre@7:   _debug_echo("ad_channel_cache: returning non-premiere advertisements from randomly selected channel $random_channel");
piotre@7: 
piotre@7:   if (isset($valid_ads[$random_channel])) {
piotre@7:     return ad_channel_enforce_inventory_level($random_channel, $valid_ads[$random_channel]);
piotre@7:   }
pierre@1: }
sly@2: 
sly@2: /**
piotre@7:  * Randomly select a valid channel id from an array channel ids
piotre@7:  * @param array, valid array.
sly@2:  */
piotre@7: function _select_channel_id($choices) {
piotre@7:   $selected = 0;
piotre@7:   if (is_array($choices)) {
piotre@7:     $available = sizeof($choices);
piotre@7:     _debug_echo("ad_channel_cache: randomly selecting from $available indexes.");
piotre@7:     $selected = $available > 1 ? $choices[mt_rand(0, $available - 1)] : $choices[0];
piotre@7:     _debug_echo("ad_channel_cache: randomly selected channel $selected.");
piotre@7:   }
sly@2: 
piotre@7:   return $selected;
sly@2: }
sly@2: 
piotre@7: /*
piotre@7:  * Augment the selected channel with 'remnant' ads to ensure that any specified
piotre@7:  * inventory level is honored
piotre@7:  * @param int, channel id
piotre@7:  * @param array, valid array.
sly@2:  */
piotre@7: function ad_channel_enforce_inventory_level($chid, $ads) {
piotre@7:   if ($chid > 0) {
piotre@7:     $channels = adserve_cache('get_cache', 'channel');
piotre@7:     $channel = $channels['channels'][$chid];
piotre@7:     $level = $channel->inventory;
piotre@7:     $num_ads = count($ads);
piotre@7:     if ($num_ads < $level) {
piotre@7:       _debug_echo("ad_channel_enforce_inventory_level: channel($chid) has $num_ads and needs $level");
piotre@7:       $remnants = array_values(adserve_cache('get_cache', 'remnant'));
piotre@7:       $available = count($remnants);
piotre@7:       if ($available > 0) {
piotre@7:         _debug_echo("ad_channel_enforce_inventory_level: randomly selecting from $available remnants.");
piotre@7:         while (count($ads) < $level) {
piotre@7:           shuffle($remnants);
piotre@7:           $selected = array_pop($remnants);
piotre@7:           _debug_echo("ad_channel_enforce_inventory_level: selected $selected.");
piotre@7:           $ads[] = $selected;
piotre@7:         }
piotre@7:       }
piotre@7:       else {
piotre@7:         _debug_echo("ad_channel_enforce_inventory_level: no remnants to choose from.");
piotre@7:       }
piotre@7:     }
piotre@7:     else {
piotre@7:       _debug_echo("ad_channel_enforce_inventory_level: channel($chid) no inventory level assigned");
piotre@7:     }
sly@2:   }
sly@2:   else {
piotre@7:     _debug_echo("ad_channel_enforce_inventory_level: not needed for channel($chid)");
sly@2:   }
piotre@7:   return $ads;
sly@2: }
piotre@7: