<?php
/**
 * Mediawiki Slack integration extension.
 * @version 1.0.1
 *
 * Copyright (C) 2014-2015 George Goldberg <george@grundleborg.com>
 * @author George Goldberg <george@grundleborg.com>
 *
 * @license MIT
 *
 * @file The hooks of the Mediawiki Slack integration extension.
 *       For more information on Slack, see http://www.slack.com.
 * @ingroup Extensions
 */

class SlackHooks {

  public static function isCreate() {
    global $wgSlackIsCreate;

    if ($wgSlackIsCreate === true) {
      return true;
    }

    $wgSlackIsCreate = true;
    return false;
  }

  public static function encodeSlackChars($in) {
    // This function encodes chars that the Slack API expects to be encoded in the JSON values.
    // See https://api.slack.com/docs/formatting for details.
    $o = str_replace("&", "&amp;", $in);
    $o = str_replace("<", "&lt;", $o);
    $o = str_replace(">", "&gt;", $o);
    $o = str_replace('"', "&quot;", $o);

    return $o;
  }

  public static function sendToRedis($payload) {
      /*global $wgSlackWebhookURL;

    wfDebug("Slack URL: ".$wgSlackWebhookURL."\n");
    wfDebug("Slack Payload: ".$payload."\n");

    $post = "payload=".urlencode($payload);

    // POST it to Slack.
    $options = array(
      'http' => array(
        'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
         'method'  => 'POST',
         'content' => $post,
        'timeout' => 0.5, // don't wait for Slack's response
       ),
       ); */

      try {
          global $redis;
          $redis->lPush('slack:recent-changes', $payload);
      } catch (Exception $e) {
          wfDebug('sendToRedis failed: '.$e->getMessage()."\n");
      }

        /*$context  = stream_context_create($options);
    $result = file_get_contents($wgSlackWebhookURL, false, $context);

    if (!$result) {
	wfDebug("API call failed!\n");
    } else {
    	wfDebug("Slack Result: ".$result."\n");
        }*/
  }

  public static function buildMessage($wikiPage, $user, $summary, $verb) {
    global $wgSlackLinkUsers;

    // Build the message we're going to post to Slack.
    $message = '*<'.SlackHooks::encodeSlackChars($wikiPage->getTitle()->getFullURL())
                   .'|'.SlackHooks::encodeSlackChars($wikiPage->getTitle()).'>* '
              .$verb.' by *';
    if ($wgSlackLinkUsers) {
      $message .= '@';
    }
    $message .= SlackHooks::encodeSlackChars(strtolower($user->getName())).'*';
    if (!empty($summary)) {
      $message .= ': '.$summary;
    }
    $message .= '.';

    return $message;
  }

  public static function buildPayload($message) {
    global $wgSlackChannel, $wgSlackLinkUsers, $wgSlackUserName, $wgSlackIconURL;

    // Build the WebHook Payload.
    // NB: The Slack parser chokes if there is a trailing , at the end of the list of items
    //     in the payload. Make sure any optional items are in the middle to avoid this.
    $payload = '{"channel": "'.$wgSlackChannel.'",';
    if ($wgSlackLinkUsers) {
      $payload .= '"link_names": "1",';
    }
    if ($wgSlackIconURL) {
      $payload .= '"icon_url": "'.$wgSlackIconURL.'",';
    }
    $payload .= '"username": "'.$wgSlackUserName.'",'
               .'"text": "'.$message.'"'
               .'}';

    return $payload;
  }

  public static function buildRichPayload($wikiPage, $user, $summary, $diff, $verb) {
      global $wgSlackUserName, $wgSlackIconURL, $wgSlackLinkUsers;
      $attachment = array();
	$attachment['fallback'] = sprintf('%s %s by %s', $wikiPage->getTitle(), $verb, strtolower($user->getName()));
	$attachment['title'] = $wikiPage->getTitle()->getFullText();
    $attachment['title_link'] = $wikiPage->getTitle()->GetFullURL();
	if (!empty($summary)) {
		$attachment['fallback'] .= ': '.SlackHooks::encodeSlackChars($summary);
	}
	$attachment['fallback'] .= '.';
	$attachment['pretext'] = SlackHooks::encodeSlackChars($summary);
    $attachment['text'] = $diff;
	$attachment['author_name'] = strtolower($user->getName());
	$attachment['author_link'] = sprintf('https://wiki.metakgp.org/w/User:%s', $user->getName());
	$attachment['color'] = 'good';
    $payload['attachments'] = array($attachment);
    $payload['username'] = $wgSlackUserName;
    $payload['icon_url'] = $wgSlackIconURL;
    $payload['link_names'] = "1";

    return json_encode($payload, JSON_UNESCAPED_SLASHES|JSON_HEX_APOS|JSON_HEX_QUOTE);

  }

  private static function isBot($user) {
    if (in_array("bot", $user->getGroups())) {
	return true;
    }
    return false;
  }

  public static function onPageContentSaveComplete($wikiPage, $user, $content, $summary, $isMinor,
    $isWatch, $section, $flags, $revision, $status, $baseRevId) {
    global $wgSlackIgnoreMinor;

    // If this is a bot, return now
    if (SlackHooks::isBot($user)) {
	return true;
    }

    // If this is a minor edit and we want to ignore minor edits, return now.
    if ($wgSlackIgnoreMinor && $isMinor) {
      return true;
    }

    // If this is a page creation, don't notify it as being modified too.
    if (true === SlackHooks::isCreate()) {
      return true;
    }


    // Build the Slack Message.
    $message = SlackHooks::buildMessage($wikiPage, $user, $summary, "modified");

    //$oldRevision = $revision->getPrevious();


    // Build the Slack Payload.
    //$payload = SlackHooks::buildPayload($wikiPage, $user, $summary, $content->getNativeData(), "modified");

    $payload = SlackHooks::buildPayload($message);

    // Send the message to Slack.
    SlackHooks::sendToRedis($payload);

    return true;
  }

    public static function onPageContentInsertComplete($wikiPage, $user, $content, $summary, $isMinor, $isWatch, $section, $flags, $revision) {
    global $wgSlackIsCreate, $wgSlackIgnoreMinor;

    // If this is a bot, return now
    if (SlackHooks::isBot($user)) {
	return true;
    }
    // If this is a minor edit and we want to ignore minor edits, return now.
    if ($wgSlackIgnoreMinor && $isMinor) {
      return true;
    }

    // Flag this as a page creation so we don't notify it's been modified as well.
    $wgSlackIsCreate = true;

    // Build the Slack Message.
    $message = SlackHooks::buildMessage($wikiPage, $user, $summary, "created");

    // Build the Slack Payload.
    $payload = SlackHooks::buildPayload($message);

    // Send the message to Slack.
    SlackHooks::sendToRedis($payload);

    return true;
  }

}