<?php
/*
 * Requests Twitter Feed and Updates Transient
 */

function kebo_twitter_get_tweets() {

    // If there is no social connection, we cannot get tweets, so return false
    $twitter_data = get_option( 'kebo_twitter_connection' );
    if ( empty ( $twitter_data ) ) {
        return false;
    }

    // Grab the Plugin Options.
    $options = kebo_get_twitter_options();
    /*
     * Get transient and check if it has expired.
     */
    if (false === ( $tweets = get_transient( 'kebo_twitter_feed_' . get_current_blog_id() ) ) ) {

        // Make POST request to Kebo OAuth App.
        $response = kebo_twitter_external_request();

        // If not WP Error response is in body
        if ( ! is_wp_error( $response ) ) {

            // Response is in JSON format, so decode it.
            $response = json_decode( $response['body'] );

        }

        // Check for Error or Success Response.
        if ( isset( $response->errors ) ) {

            // If error, add to error log.
            kebo_twitter_add_error( $response );

        } else {

            // We have Tweets, linkify the text
            $tweets = kebo_twitter_linkify( $response );

            // Add custom expiry time
            $tweets['expiry'] = time() + ( $options['kebo_twitter_cache_timer'] * MINUTE_IN_SECONDS );

            // JSON encode Tweet data
            $tweets = json_encode( $tweets );

            // No error, set transient with latest Tweets
            set_transient( 'kebo_twitter_feed_' . get_current_blog_id(), base64_encode($tweets), 24 * HOUR_IN_SECONDS );

            // Decode for use
            $tweets = json_decode( $tweets, false );
        }
    }

    /*
     * If we have serialized data from the Transient we must decode it.
     */
    if ( is_string( $tweets ) && ( null != json_decode( base64_decode($tweets) ) ) ) {
        $tweets = json_decode( base64_decode($tweets), false );
    }

    /*
     * Check if Tweets have soft expired (user setting), if so run refresh after page load.
     */
    if ( ! empty( $tweets->expiry ) && $tweets->expiry < time() ) {

        // Add 30 seconds to soft expire, to stop other threads trying to update it at the same time.
        $tweets->expiry = ( time() + 30 );

        // JSON encode Tweet data
        $tweets = json_encode( $tweets );

        // Update soft expire time.
        set_transient( 'kebo_twitter_feed_' . get_current_blog_id(), base64_encode($tweets), 24 * HOUR_IN_SECONDS );

        // Decode for use
        $tweets = json_decode( $tweets, false );

        // Set silent cache to refresh after page load.
        add_action( 'shutdown', 'kebo_twitter_refresh_cache' );

    }

    return $tweets;

}

/*
 * Alias function for 'kebo_twitter_get_tweets'.
 */
if ( ! function_exists( 'get_tweets' ) ) {

    function get_tweets() {

        $tweets = kebo_twitter_get_tweets();

        return $tweets;

    }

}

/*
 * Hooks Output Function to 'wp_footer'.
 */

function kebo_twitter_print_js() {

    // Add javascript output script to 'wp_footer' hook with low priority so that jQuery loads before.
    add_action( 'wp_footer', 'kebo_twitter_slider_script', 99 );

}

/*
 * Make external request to Kebo auth script
 */

function kebo_twitter_external_request() {

    if ( false !== ( $twitter_data = get_option( 'kebo_twitter_connection' ) ) ) {

        // URL to Kebo OAuth Request App
        $request_url = 'http://auth.kebopowered.com/request/index.php';

        // Setup arguments for OAuth request.
        $data = array(
            'service' => 'twitterfull',
            'account' => $twitter_data['account'], // Screen Name
            'token' => $twitter_data['token'], // OAuth Token
            'secret' => $twitter_data['secret'], // OAuth Secret
            'userid' => $twitter_data['userid'], // User ID
        );

        // Setup arguments for POST request.
        $args = array(
            'method' => 'POST',
            'timeout' => 10,
            'redirection' => 5,
            'httpversion' => '1.1',
            'blocking' => true,
            'headers' => array(),
            'body' => array(
                'feed' => 'true',
                'data' => json_encode( $data ),
            ),
            'cookies' => array(),
            'sslverify' => false,
        );

        // Make POST request to Kebo OAuth App.
        $request = wp_remote_post( $request_url, $args );

        return $request;

    }

}

/*
 * Silently refreshes the cache (transient) after page has rendered.
 */
function kebo_twitter_refresh_cache() {

    /*
     * If cache has already been updated, no need to refresh
     */
    if ( false !== ( $tweets = get_transient( 'kebo_twitter_feed_' . get_current_blog_id() ) ) ) {

        /*
         * Check if we are already updating.
         */
        if ( get_transient( 'kebo_cron_is_running' ) ) {
            die();
        }

        /*
         * Create hash of the current time (nothing else should occupy the same microtime).
         */
        $hash = hash( 'sha1', microtime() );

        /*
         * Set transient to show we are updating and set the hash for this specific thread.
         */
        set_transient( 'kebo_cron_is_running', $hash, 5 );

        /*
         * Sleep so that other threads at the same point can set the hash
         */
        usleep( 250000 ); // Sleep for 1/4th of a second

        /*
         * Only one thread will have the same hash as is stored in the transient now, all others can die.
         */
        if ( get_transient( 'kebo_cron_is_running' ) && ( get_transient( 'kebo_cron_is_running' ) != $hash ) ) {
            die();
        }

        // Make POST request to Kebo OAuth App.
        $response = kebo_twitter_external_request();

        // If not WP Error response is in body
        if ( ! is_wp_error( $response ) ) {

            // Response is in JSON format, so decode it.
            $response = json_decode( $response['body'] );

        }

        // Grab the Plugin Options.
        $options = kebo_get_twitter_options();

        // Check for Error or Success Response.
        if ( isset( $response->errors ) ) {

            // If error, add to error log.
            kebo_twitter_add_error( $response );

        } else {

            // We have Tweets, linkify the text
            $tweets = kebo_twitter_linkify( $response );

            // Add custom expiry time
            $tweets['expiry'] = time() + ( $options['kebo_twitter_cache_timer'] * MINUTE_IN_SECONDS );

            // JSON encode Tweet data
            $tweets = json_encode( $tweets );

            // No error, set transient with latest Tweets
            set_transient( 'kebo_twitter_feed_' . get_current_blog_id(), base64_encode($tweets), 24 * HOUR_IN_SECONDS );

        }

        /*
         * Remove transient once updating is done.
         */
        delete_transient( 'kebo_cron_is_running' );

    }

}

/*
 * Converts Tweet text urls, account names and hashtags into HTML links.
 */
function kebo_twitter_linkify( $tweets ) {

    foreach ( $tweets as $tweet ) {

        // TEMPORARILY COMMENTED OUT AND REPLACED WITH REGEX

        /*
        $hash_length = 45; // Length of HTML added to hashtags
        $mention_length = 33; // Length of HTML added to mentions
        $markers = array();
         *
         */

        /*
         * Linkify Hashtags
         */
        /*
        if ( ! empty( $tweet->entities->hashtags ) ) {

            // One Hashtag at a time
            foreach ( $tweet->entities->hashtags as $hashtag ) {

                // Start offset from 0
                $offset = 0;
                // Calculate length of hastag - end minus start
                $length = $hashtag->indices[1] - $hashtag->indices[0];

                // If no markers, no need to offset
                if ( ! empty( $markers ) ) {

                    foreach ( $markers as $mark ) {

                        // If the start point is past a previous marker, we need to adjust for the characters added.
                        if ( $hashtag->indices[0] > $mark['point'] ) {

                            // Include previous offsets.
                            $offset = ( $offset + ( $mark['length'] ) );

                        }

                    }

                }
         *
         */

                /*
                 * Replace hashtag text with an HTML link
                 */
        /*
                $tweet->text = substr_replace( $tweet->text, '<a href="http://twitter.com/search?q=%23' . $hashtag->text . '">#' . $hashtag->text . '</a>', $hashtag->indices[0] + $offset, $length );

                // Set marker so we can take into account the characters we just added.
                $markers[] = array(
                    'point' => $hashtag->indices[0],
                    'length' => $hash_length + $length,
                );


            }

        }
         *
         */

        /*
         * Linkify Mentions
         */
        /*
        if ( ! empty( $tweet->entities->user_mentions ) ) {

            // One Mention at a time
            foreach ( $tweet->entities->user_mentions as $mention ) {

                $offset = 0;
                $length = $mention->indices[1] - $mention->indices[0];

                if ( ! empty($markers) ) {

                    foreach ( $markers as $mark ) {

                        if ( $mention->indices[0] > $mark['point'] ) {

                            $offset = ( $offset + ( $mark['length'] ) );

                        }

                    }

                }
         *
         */

                /*
                 * Replace mention text with an HTML link
                 */
        /*
                $tweet->text = substr_replace( $tweet->text, '<a href="http://twitter.com/' . $mention->screen_name . '">@' . $mention->screen_name . '</a>', $mention->indices[0] + $offset, $length );

                // Set marker so we can take into account the characters we just added.
                $markers[] = array(
                    'point' => $mention->indices[0],
                    'length' => $mention_length + $length,
                );


            }

        }
         *
         */

        /*
         * Check if it is the Tweet text or Re-Tweet text which we need to pre-process.
         */
        if ( ! empty( $tweet->retweeted_status ) ) {

           /*
            * Decode HTML Chars like &#039; to '
            */
           $tweet->retweeted_status->text = htmlspecialchars_decode( $tweet->retweeted_status->text, ENT_QUOTES );

           /*
            * Turn Hasntags into HTML Links
            */
           $tweet->retweeted_status->text = preg_replace( '/#([A-Za-z0-9\/\.]*)/', '<a href="http://twitter.com/search?q=$1">#$1</a>', $tweet->retweeted_status->text );

           /*
            * Turn Mentions into HTML Links
            */
           $tweet->retweeted_status->text = preg_replace( '/@([A-Za-z0-9_\/\.]*)/', '<a href="http://www.twitter.com/$1">@$1</a>', $tweet->retweeted_status->text );

           /*
            * Linkify text URLs
            */
           $tweet->retweeted_status->text = make_clickable( $tweet->retweeted_status->text );

           /*
            * Add target="_blank" to all links
            */
           $tweet->retweeted_status->text = links_add_target( $tweet->retweeted_status->text, '_blank', array( 'a' ) );

        } else {

           /*
            * Decode HTML Chars like &#039; to '
            */
           $tweet->text = htmlspecialchars_decode( $tweet->text, ENT_QUOTES );

           /*
            * Turn Hasntags into HTML Links
            */
           $tweet->text = preg_replace( '/#([A-Za-z0-9\/\.]*)/', '<a href="http://twitter.com/search?q=$1">#$1</a>', $tweet->text );

           /*
            * Turn Mentions into HTML Links
            */
           $tweet->text = preg_replace( '/@([A-Za-z0-9_\/\.]*)/', '<a href="http://www.twitter.com/$1">@$1</a>', $tweet->text );

           /*
            * Linkify text URLs
            */
           $tweet->text = make_clickable( $tweet->text );

           /*
            * Add target="_blank" to all links
            */
           $tweet->text = links_add_target( $tweet->text, '_blank', array( 'a' ) );

        }

    }

    return $tweets;

}

/*
 * Adds an error from the Twitter API to the error log.
 */
function kebo_twitter_add_error( $response ) {

    if ( is_wp_error( $response ) ) {

        // Add details of current WP error
        $error[] = array(
            'date' => time(),
            'code' => 1,
            'message' => $response->errors['http_request_failed'][0],
        );

    } else {

        // Add details of current error
        $error[] = array(
            'date' => time(),
            'code' => $response->errors[0]->code,
            'message' => $response->errors[0]->message,
        );

    }

    // Get currently stored errors
    $log = get_option( 'kebo_twitter_errors' );

    if ( $log[0] ) {

        // Add new error to start of array
        $errors = array_merge( $error, $log );

    } else {

        $errors = $error;

    }

    // Limit array to the latest 10 errors
    $errors = array_slice( $errors, 0, 10, false );

    update_option( 'kebo_twitter_errors', $errors );

}