user gets notified interatively or by email in case of a CIS error
[living-lab-site.git] / application / models / videos_model.php
index 1ba9e8f..590d1b7 100644 (file)
@@ -11,49 +11,125 @@ class Videos_model extends CI_Model {
        
        public function __construct()
        {
+               parent::__construct();
+               
                if ($this->db === NULL)
                {
                        $this->load->library('singleton_db');
                        $this->db = $this->singleton_db->connect();
                }
-               
-               $this->load->helper('url');
        }
        
        /**
-        * Retrieves information about a set of videos which are going to be
-        * displayed in the catalog.
+        * Retrieves a set of videos information which can be used for displaying
+        * that videos as a list with few details.
         *
-        * TODO: filter, limit, ordering parameters
-        * @param               int $category_id        DB category ID
-        * @param               int $offset
-        * @param               int $count
-        * @return              array   a list of videos, each one being an assoc array with:
+        * @param               int $category_id        DB category ID; pass NULL for all
+        * categories
+        * @param mixed $user an user_id (as int) or an username 
+        * (as string); pass NULL for all users
+        * @param int $offset
+        * @param int $count number of videos to retrieve; if set to TRUE this
+        * method will retrieve the number of videos that satisfy condition
+        * @param string $ordering      control videos ording by these
+        * possibilities:
+        * <ul>
+        *   <li><strong>'hottest':</strong> newest most appreciated first. An
+        *   appreciated video is one which has a bigger
+        *   score = views + likes - dislikes.</li>
+        *   <li><strong>'newest':</strong> newest first.</li>
+        *   <li><strong>'alphabetically':</strong> sort alphabetically.</li>
+        * </ul>
+        * @param bool $unactivated whether to retrieve or not ingested unactivated
+        * videos; typically only administrators should see this kind of assets
+        * @return array a list of videos, each one being an assoc array with:
         * <ul>
         *   <li>id, name, title, duration, thumbs_count, default_thumb, views => from DB</li>
         *   <li>shorted_title => ellipsized title</li>
         *   <li>video_url => P2P-Tube video URl</li>
-        *   <li>TODO: user_id, user_name</li>
+        *   <li>user_id, user_name</li>
         *   <li>thumbs => thumbnail images' URLs</li>
         * </ul>
         */
-       public function get_videos_summary($category_id, $offset, $count)
+       public function get_videos_summary($category_id, $user, $offset, $count,
+               $ordering = 'hottest', $unactivated = FALSE)
        {
                $this->load->helper('text');
                
+               $order_statement = "";
+               if ($count !== TRUE)
+               {
+                       // Ordering
+                       switch ($ordering)
+                       {
+                       case 'hottest':
+                               $order_statement = "ORDER BY date DESC, score DESC, RAND()";
+                               break;
+                       case 'newest':
+                               $order_statement = "ORDER BY date DESC";
+                               break;
+                       case 'alphabetically':
+                               $order_statement = "ORDER BY title";
+                               break;
+
+                       default:
+                               $order_statement = "";
+                       }
+               }
+               
+               // Show unactivated videos.
+               $cond_unactivated = ($unactivated
+                               ? '(a.activation_code IS NULL OR a.activation_code IS NOT NULL
+                                       AND a.cis_response = '. CIS_RESP_COMPLETION. ')'
+                               : 'a.activation_code IS NULL');
+               
+               // Category filtering
+               if ($category_id === NULL)
+                       $cond_category = "1";
+               else
+               {
+                       $category_id = intval($category_id);
+                       $cond_category = "category_id = $category_id";
+               }
+               
+               // User filtering
+               if ($user === NULL)
+                       $cond_user = "1";
+               else
+               {
+                       if (is_int($user))
+                               $cond_user = "v.user_id = $user";
+                       else if (is_string($user))
+                               $cond_user = "u.username = '$user'";
+               }
+               
+               if ($count === TRUE)
+                       $fields = "COUNT(*) count";
+               else
+                       $fields = "v.id, name, title, duration, user_id, u.username, views,
+                               thumbs_count, default_thumb,
+                               (views + likes - dislikes) AS score,
+                               a.activation_code, a.cis_response";
+               
                $query = $this->db->query(
-                       'SELECT id, name, title, duration, user_id, views, thumbs_count,
-                               default_thumb
-                       FROM `videos`
-                       WHERE category_id = ?
-                       ORDER BY name
-                       LIMIT ?, ?', // TODO summary order 
-                       array(intval($category_id), $offset, $count)); 
+                       "SELECT $fields
+                       FROM `videos` v 
+                               LEFT JOIN `videos_unactivated` a ON (id = a.video_id),
+                               `users` u
+                       WHERE v.user_id = u.id AND $cond_category AND $cond_user
+                               AND $cond_unactivated
+                       $order_statement
+                       LIMIT $offset, $count"); 
                
                if ($query->num_rows() > 0)
+               {
+                       if ($count === TRUE)
+                               return $query->row()->count;
+                       
                        $videos = $query->result_array();
+               }
                else
-                       return NULL;
+                       return array();
                
                foreach ($videos as & $video)
                {
@@ -64,31 +140,30 @@ class Videos_model extends CI_Model {
                        // Thumbnails
                        $video['thumbs'] = $this->get_thumbs($video['name'], 
                                $video['thumbs_count']);
+                       $video['json_thumbs'] = json_encode($video['thumbs']);
                                
                        // Ellipsized title
                        //$video['shorted_title'] = ellipsize($video['title'], 45, 0.75);
                        $video['shorted_title'] = character_limiter($video['title'], 50);
-                       
-                       // TODO: user information
-                       $video['user_name'] = 'TODO';
                }
                
                return $videos;
        }
        
-       public function get_videos_count($category_id)
+       /**
+        * Returns the number of videos from database from a specific category or
+        * user.
+        * NULL parameters count videos from all categories and / or all users.
+        * 
+        * @param int $category_id
+        * @param mixed $user an user_id (as int) or an username (as string)
+        * @return int number of videos or FALSE if an error occured
+        */
+       public function get_videos_count($category_id = NULL, $user = NULL,
+                       $unactivated = FALSE)
        {
-               $query = $this->db->query(
-                       'SELECT COUNT(*) count
-                       FROM `videos`
-                       WHERE category_id = ?',
-                       $category_id);
-               
-               if ($query->num_rows() > 0)
-                       return $row = $query->row()->count;
-               
-               // Error
-               return NULL;
+               return $this->get_videos_summary($category_id, $user, 0, TRUE, NULL,
+                               $unactivated);
        }
        
        /**
@@ -97,11 +172,11 @@ class Videos_model extends CI_Model {
         * If $name does not match with the video's `name` from the DB an error is
         * marked in the key 'err'. If it's NULL it is ignored.
         *
-        * @access              public
-        * @param               string $id      video's `id` column from `videos` DB table
-        * @param               string $name    video's `name` column from `videos` DB
+        * @access public
+        * @param string $id    video's `id` column from `videos` DB table
+        * @param string $name  video's `name` column from `videos` DB
         * table. NULL means there is no name provided.
-        * @return              array   an associative list with information about a video
+        * @return array        an associative list with information about a video
         * with the following keys:
         * <ul>
         *   <li>all columns form DB with some exceptions that are overwritten or new</li>
@@ -110,7 +185,7 @@ class Videos_model extends CI_Model {
         * video asset having keys: "src", "res", "par" and "ext". Value of key
         * "src" is the video torrent formated as
         * {name}_{format}.{video_ext}.{default_torrent_ext}</li>
-        *   <li>user_name => TODO: user name from `users` table</li>
+        *   <li>username => user name from `users` table</li>
         *   <li>category_title => a human-friendly category name</li>
         *   <li>tags => associative list of "tag => score"</li>
         *   <li>date => date and time when the video was created</li>
@@ -120,10 +195,14 @@ class Videos_model extends CI_Model {
        public function get_video($id, $name = NULL)
        {
                $this->load->helper('video');
+               $this->load->helper('text');
                
-               $query = $this->db->query('SELECT * 
-                                                               FROM `videos` 
-                                                               WHERE id = ?', $id);
+               $query = $this->db->query("SELECT v.*, u.username,
+                                       a.activation_code, a.cis_response
+                               FROM `videos` v 
+                                       LEFT JOIN `videos_unactivated` a ON (v.id = a.video_id),
+                                       `users` u
+                               WHERE v.user_id = u.id AND v.id = $id");
                $video = array();
                
                if ($query->num_rows() > 0)
@@ -134,8 +213,7 @@ class Videos_model extends CI_Model {
                }
                else
                {
-                       $video['err'] = 'INVALID_ID';
-                       return $video;
+                       return FALSE;
                }
                
                // Convert JSON encoded string to arrays.
@@ -156,6 +234,7 @@ class Videos_model extends CI_Model {
                foreach ($video['assets'] as & $asset)
                {
                        $def = substr($asset['res'], strpos($asset['res'], 'x') + 1) . 'p';
+                       $asset['def'] = $def;
                        $asset['src'] = site_url('data/torrents/'. $video['name'] . '_'
                                . $def . '.'. $asset['ext']
                                . '.'. $this->config->item('default_torrent_ext'));
@@ -170,27 +249,405 @@ class Videos_model extends CI_Model {
                // Thumbnails
                $video['thumbs'] = $this->get_thumbs($video['name'], $video['thumbs_count']);
                
-               // TODO: user information
-               $video['user_name'] = 'TODO';
+               // Shorted description
+               $video['shorted_description'] = character_limiter(
+                               $video['description'], 128);
                
                return $video;
        }
        
        /**
-        * Increment a video parameter from DB: `views`, `likes` or `dislikes`.
+        * Adds a new uploaded video to the DB.
+        * 
+        * @param string $name
+        * @param string $title
+        * @param string $description
+        * @param string $tags comma separated tags
+        * @param string $duration video duration formatted [HH:]mm:ss
+        * @param array $formats a dictionary corresponding to `formats` JSON
+        * column from `videos` table
+        * @param int $category_id
+        * @param int $user_id
+        * @param string $uploaded_file the raw video file uploaded by the user
+        * @return mixed returns an activation code on success or FALSE otherwise
+        */
+       public function add_video($name, $title, $description, $tags, $duration,
+                       $formats, $category_id, $user_id, $uploaded_file)
+       {
+               $this->load->config('content_ingestion');
+               
+               // Tags.
+               $json_tags = array();
+               $tok = strtok($tags, ',');
+               while ($tok != FALSE)
+               {
+                       $json_tags[trim($tok)] = 0;
+                       
+                       $tok = strtok(',');
+               }
+               $json_tags = json_encode($json_tags);
+               
+               $json_formats = json_encode($formats);
+               
+               // Thumbnail images
+               $thumbs_count = $this->config->item('thumbs_count');
+               $default_thumb = rand(0, $thumbs_count - 1);
+               
+               $query = $this->db->query("INSERT INTO `videos`
+                               (name, title, description, duration, formats, category_id,
+                                               user_id, tags, date, thumbs_count, default_thumb)
+                               VALUES ('$name', '$title', '$description', '$duration',
+                                               '$json_formats', $category_id,
+                                               $user_id, '$json_tags', utc_timestamp(),
+                                               $thumbs_count, $default_thumb)");
+               if ($query === FALSE)
+                       return FALSE;
+               
+               // Find out the id of the new video added.
+               $query = $this->db->query("SELECT id from `videos`
+                               WHERE name = '$name'");
+               if ($query->num_rows() === 0)
+                       return FALSE;
+               $video_id = $query->row()->id;
+               
+               // Activation code.
+               $activation_code = Videos_model::gen_activation_code();
+               
+               $query = $this->db->query("INSERT INTO `videos_unactivated`
+                               (video_id, activation_code, uploaded_file)
+                               VALUES ($video_id, '$activation_code', '$uploaded_file')");
+               
+               return $activation_code;
+       }
+       
+       /**
+        * Request content_ingest to the CIS in order to start the content
+        * ingestion process.
+        * 
+        * @param string $activation_code
+        * @param string $raw_video_fn uploaded video file name
+        * @param string $name
+        * @param int $raw_video_size uploaded video file size in bytes
+        * @param array $transcode_configs dictionary which must be included in
+        * the JSON data that needs to be sent to CIS
+        * @return mixed return the HTTP content (body) on success and FALSE
+        * otherwise
+        */
+       public function send_content_ingestion($activation_code, $raw_video_fn,
+                       $name, $raw_video_size, $transcode_configs)
+       {
+               $this->config->load('content_ingestion');
+               
+               $url = $this->config->item('cis_url') . 'ingest_content';
+               $data = array(
+                       'code'=>$activation_code,
+                       'raw_video'=>$raw_video_fn,
+                       'name'=>$name,
+                       'weight'=>$raw_video_size,
+                       'transcode_configs'=>$transcode_configs,
+                       'thumbs'=>$this->config->item('thumbs_count')
+               );
+               $json_data = json_encode($data);
+               
+               // Send request to CIS.
+               $r = new HttpRequest($url, HttpRequest::METH_POST);
+               $r->setBody($json_data);
+               try
+               {
+                       $response = $r->send()->getBody();
+               }
+               catch (HttpException $ex) 
+               {
+                       return FALSE;
+               }
+               
+               return $response;
+       }
+       
+       public function set_cis_response($activation_code,
+                       $response = CIS_RESP_COMPLETION)
+       {
+               return $this->db->query("UPDATE `videos_unactivated`
+                       SET cis_response = $response
+                       WHERE activation_code = '$activation_code'");
+       }
+       
+       public function send_upload_error_email($activation_code,
+                       $cis_response = CIS_RESP_INTERNAL_ERROR)
+       {
+               $query = $this->db->query("SELECT v.title, u.email
+                       FROM `videos_unactivated` a, `videos` v, `users` u
+                       WHERE a.activation_code = '$activation_code'
+                               AND a.video_id = v.id AND v.user_id = u.id");
+               
+               if ($query->num_rows() > 0)
+               {
+                       $title = $query->row()->title;
+                       $email = $query->row()->email;
+               }
+               else
+                       return FALSE;
+               
+               $subject = '['. $this->config->item('site_name')
+                               . '] Upload Error';
+               if ($cis_response == CIS_RESP_INTERNAL_ERROR)
+               {
+                       $msg = sprintf($this->lang->line(
+                                       'video_internal_cis_error_email_content'), $title);
+               }
+               else if ($cis_response == CIS_RESP_UNREACHABLE)
+               {
+                       $msg = sprintf($this->lang->line(
+                                       'video_unreachable_cis_error_email_content'), $title);
+               }
+               $headers = "From: ". $this->config->item('noreply_email');
+               
+               return mail($email, $subject, $msg, $headers);
+       }
+       
+       /**
+        * Activates a video by deleting its entry from `videos_unactivated`.
+        * 
+        * @param mixed $code_or_id use type string for activation_code or type
+        * int for video_id
+        * @return boolean TRUE on success, FALSE otherwise
+        */
+       public function activate_video($code_or_id)
+       {
+               if (is_string($code_or_id))
+                       $query = $this->db->query("SELECT uploaded_file from `videos_unactivated`
+                               WHERE activation_code = '$code_or_id'");
+               else if (is_int($code_or_id))
+                       $query = $this->db->query("SELECT uploaded_file from `videos_unactivated`
+                               WHERE video_id = '$code_or_id'");
+               else
+                       return FALSE;
+               
+               if ($query->num_rows() > 0)
+                       $uploaded_file = $query->row()->uploaded_file;
+               else
+                       return FALSE;
+               
+               if (is_string($code_or_id))
+                       $query = $this->db->query("DELETE FROM `videos_unactivated`
+                               WHERE activation_code = '$code_or_id'");
+               else if (is_int($code_or_id))
+                       $query = $this->db->query("DELETE FROM `videos_unactivated`
+                               WHERE video_id = '$code_or_id'");
+               else
+                       return FALSE;
+               
+               if (!$query)
+                       return $query;
+               
+               return unlink("data/upload/$uploaded_file");            
+       }
+       
+       public function get_unactivated_videos()
+       {
+               $query = $this->db->query("SELECT a.video_id, v.name, a.cis_response
+                       FROM `videos_unactivated` a, `videos` v
+                       WHERE a.video_id = v.id AND a.cis_response = "
+                               . CIS_RESP_COMPLETION);
+               
+               if ($query->num_rows() > 0)
+                       return $query->result_array();
+               else
+                       return FALSE;
+       }
+       
+       /**
+        * Retrieves comments for a video.
+        * 
+        * @param int $video_id
+        * @param int $offset
+        * @param int $count
+        * @param string $ordering      control comments ording by these possibilities:
+        * <ul>
+        *   <li><strong>'hottest':</strong> newest most appreciated first. An
+        *   appreciated comment is one which has a bigger
+        *   score = likes - dislikes.</li>
+        *   <li><strong>'newest':</strong> newest first.</li>
+        * </ul>
+        * @return array        an array with comments
+        */
+       public function get_video_comments($video_id, $offset, $count,
+                       $ordering = 'newest')
+       {
+               $this->load->helper('date');
+               $cond_hottest = '';
+               
+               // Ordering
+               switch ($ordering)
+               {
+               case 'newest':
+                       $order_statement = "ORDER BY time DESC";
+                       break;
+               case 'hottest':
+                       $order_statement = "ORDER BY score DESC, time DESC";
+                       $cond_hottest = "AND c.likes + c.dislikes > 0";
+                       break;
+                               
+               default:
+                       $order_statement = "";
+               }
+               
+               $query = $this->db->query(
+                       "SELECT c.*, u.username, u.time_zone, (c.likes + c.dislikes) AS score
+                               FROM `videos_comments` c, `users` u
+                               WHERE c.user_id = u.id AND video_id = $video_id $cond_hottest
+                               $order_statement
+                               LIMIT $offset, $count");
+               
+               if ($query->num_rows() == 0)
+                       return array();
+               
+               $comments = $query->result_array();
+               
+               foreach ($comments as & $comment)
+               {
+                       $comment['local_time'] = human_gmt_to_human_local($comment['time'],
+                               $comment['time_zone']);
+               }
+               
+               return $comments;
+       }
+       
+       public function get_video_comments_count($video_id)
+       {
+               $query = $this->db->query(
+                                       "SELECT COUNT(*) count
+                                               FROM `videos_comments`
+                                               WHERE video_id = $video_id");
+                               
+               if ($query->num_rows() == 0)
+                       return FALSE;
+               
+               return $query->row()->count;
+       }
+       
+       /**
+        * Insert in DB a comment for a video.
+        * 
+        * @param int $video_id
+        * @param int $user_id
+        * @param string $content
+        */
+       public function comment_video($video_id, $user_id, $content)
+       {
+               // Prepping content.
+               $content = substr($content, 0, 512);
+               $content = htmlspecialchars($content);
+               $content = nl2br($content);
+               
+               return $query = $this->db->query(
+                       "INSERT INTO `videos_comments` (video_id, user_id, content, time)
+                       VALUES ($video_id, $user_id, '$content', UTC_TIMESTAMP())");
+       }
+       
+       /**
+        * Increments views count for a video.
         * 
         * @param int $id       DB video id
-        * @param string $param DB parameter column name.
         * @return void
         */
-       public function inc_video_var($id, $var)
+       public function inc_views($id)
        {
-               // TODO error report if query returns FALSE
-               $this->db->query('UPDATE `videos` '
-                                               . 'SET `'. $var. '`=`'. $var. '`+1 '
+               return $this->db->query('UPDATE `videos` '
+                                               . 'SET `views`=`views`+1 '
                                                . 'WHERE id='. $id); 
        }
        
+       public function vote($video_id, $user_id, $like = TRUE)
+       {
+               if ($like)
+               {
+                       $col = 'likes';
+                       $action = 'like';
+               }
+               else
+               {
+                       $col = 'dislikes';
+                       $action = 'dislike';
+               }
+               
+               $query = $this->db->query("SELECT * FROM `users_actions`
+                       WHERE user_id = $user_id
+                               AND target_id = $video_id
+                               AND target_type = 'video'
+                               AND action = '$action'
+                               AND date = CURDATE()");
+               // User already voted today
+               if ($query->num_rows() > 0)
+                       return -1;
+               
+               $this->db->query("UPDATE `videos`
+                       SET $col = $col + 1
+                       WHERE id = $video_id");
+               
+               // Mark this action so that the user cannot repeat it today.
+               $this->db->query("INSERT INTO `users_actions`
+                               (user_id, action, target_type, target_id, date)
+                       VALUES ( $user_id, '$action', 'video', $video_id, CURDATE() )");
+               
+               $query = $this->db->query("SELECT $col FROM `videos`
+                       WHERE id = $video_id");
+               
+               if ($query->num_rows() === 1)
+               {
+                       $row = $query->row_array();
+                       return $row[ $col ];
+               }
+               
+               // Error
+               return FALSE;
+       }
+       
+       public function vote_comment($comment_id, $user_id, $like = TRUE)
+       {
+               if ($like)
+               {
+                       $col = 'likes';
+                       $action = 'like';
+               }
+               else
+               {
+                       $col = 'dislikes';
+                       $action = 'dislike';
+               }
+       
+               $query = $this->db->query("SELECT * FROM `users_actions`
+                               WHERE user_id = $user_id
+                                       AND target_id = $comment_id
+                                       AND target_type = 'vcomment'
+                                       AND action = '$action'
+                                       AND date = CURDATE()");
+               // User already voted today
+               if ($query->num_rows() > 0)
+                       return -1;
+       
+               $this->db->query("UPDATE `videos_comments`
+                               SET $col = $col + 1
+                               WHERE id = $comment_id");
+       
+               // Mark this action so that the user cannot repeat it today.
+               $this->db->query("INSERT INTO `users_actions`
+                                       (user_id, action, target_type, target_id, date)
+                               VALUES ( $user_id, '$action', 'vcomment', $comment_id, CURDATE() )");
+       
+               $query = $this->db->query("SELECT $col FROM `videos_comments`
+                               WHERE id = $comment_id");
+       
+               if ($query->num_rows() === 1)
+               {
+                       $row = $query->row_array();
+                       return $row[ $col ];
+               }
+       
+               // Error
+               return FALSE;
+       }
+       
        public function get_thumbs($name, $count)
        {
                $thumbs = array();
@@ -200,6 +657,188 @@ class Videos_model extends CI_Model {
                
                return $thumbs;
        }
+
+       /**
+        * Searches videos in DB based on a search query string and returns an
+        * associative array of results.
+        * If count is zero the function only return the number of results.
+        * @param string $search_query
+        * @param int $offset
+        * @param int $count
+        * @param int $category_id      if NULL, all categories are searched
+        * @return array        an associative array with the same keys as that from
+        * get_videos_summary's result, but with two additional keys: 
+        * description and date.
+        */
+       public function search_videos($search_query, $offset = 0, $count = 0, 
+                                                                       $category_id = NULL)
+       {
+               $search_query = trim($search_query);
+               $search_query = str_replace("'", " ", $search_query);
+               
+               // Search word fragments.
+               // sfc = search fragment condition
+               $sfc = "( ";
+               // sfr = search fragment relevance
+               $sfr = "( ";
+               $sep = ' +-*<>()~"';
+               $fragm = strtok($search_query, $sep);
+               while ($fragm !== FALSE)
+               {
+                       $sfc .= "(title LIKE '%$fragm%'
+                                       OR description LIKE '%$fragm%'
+                                       OR tags LIKE '%$fragm%') OR ";
+                       
+                       // Frament relevances are half of boolean relevances such
+                       // that they will appear at the end of the results.
+                       $sfr .= "0.25 * (title LIKE '%$fragm%')
+                                       + 0.1 * (description LIKE '%$fragm%')
+                                       + 0.15 * (tags LIKE '%$fragm%') + ";
+                       
+                       $fragm = strtok($sep);
+               }
+               $sfc = substr($sfc, 0, -4) . " )";
+               $sfr = substr($sfr, 0, -3) . " )";
+               
+               if (! $this->is_advanced_search_query($search_query))
+               {
+                       $search_cond = "MATCH (title, description, tags)
+                                       AGAINST ('$search_query') OR $sfc";
+                       $relevance = "( MATCH (title, description, tags)
+                                       AGAINST ('$search_query') + $sfr ) AS relevance";
+               }
+               // boolean mode
+               else
+               {
+                       $against = "AGAINST ('$search_query' IN BOOLEAN MODE)";
+                       $search_cond = "( MATCH (title, description, tags)
+                                       $against) OR $sfc";
+                       $relevance = "( 0.5 * (MATCH(title) $against)
+                                       + 0.3 * (MATCH(tags) $against)
+                                       + 0.2 * (MATCH(description) $against)
+                                       + $sfr) AS relevance";
+               }
+               
+               if ($count === 0)
+               {
+                       $selected_columns = "COUNT(*) count";
+                       $order = "";
+                       $limit = "";
+               }
+               else
+               {
+                       // TODO select data, description if details are needed
+                       $selected_columns = "v.id, name, title, duration, user_id, views,
+                                       thumbs_count, default_thumb, u.username,
+                                       (views + likes - dislikes) AS score, 
+                                       $relevance";
+                       $order = "ORDER BY relevance DESC, score DESC";
+                       $limit = "LIMIT $offset, $count";
+               }
+               
+               if ($category_id !== NULL)
+                       $category_cond = "category_id = '$category_id' AND ";
+               else
+                       $category_cond = "";
+
+               $str_query = "SELECT $selected_columns
+                       FROM `videos` v, `users` u
+                       WHERE  v.user_id = u.id AND $category_cond ( $search_cond )
+                       $order
+                       $limit";
+//             echo "<p>$str_query</p>";
+               $query = $this->db->query($str_query);
+               
+               if ($query->num_rows() > 0)
+               {
+                       if ($count === 0)
+                               return $query->row()->count;
+                       else
+                               $videos = $query->result_array();
+               }
+               else
+                       return NULL;
+               
+               $this->load->helper('text');
+               
+               foreach ($videos as & $video)
+               {
+                       // P2P-Tube Video URL
+                       $video['video_url'] = site_url(sprintf("watch/%d/%s",
+                               $video['id'], $video['name']));
+                       
+                       // Thumbnails
+                       $video['thumbs'] = $this->get_thumbs($video['name'], 
+                               $video['thumbs_count']);
+                       $video['json_thumbs'] = json_encode($video['thumbs']);
+                               
+                       // Ellipsized title
+                       //$video['shorted_title'] = ellipsize($video['title'], 45, 0.75);
+                       $video['shorted_title'] = character_limiter($video['title'], 50);
+                       
+                       // TODO: user information
+                       $video['user_name'] = 'TODO';
+               }
+               
+               return $videos;
+       }
+       
+       public function decode_search_query($search_query)
+       {
+               $search_query = urldecode($search_query);
+               
+               $search_query = str_replace('_AST_', '*', $search_query);
+               $search_query = str_replace('_AND_', '+', $search_query);
+               $search_query = str_replace('_GT_', '>', $search_query);
+               $search_query = str_replace('_LT_', '<', $search_query);
+               $search_query = str_replace('_PO_', '(', $search_query);
+               $search_query = str_replace('_PC_', ')', $search_query);
+               $search_query = str_replace('_LOW_', '~', $search_query);
+               $search_query = str_replace('_QUO_', '"', $search_query);
+               
+               return $search_query;
+       }
+       
+       public function encode_search_query($search_query)
+       {
+               $search_query = str_replace('*', '_AST_', $search_query);
+               $search_query = str_replace('+', '_AND_', $search_query);
+               $search_query = str_replace('>', '_GT_', $search_query);
+               $search_query = str_replace('<', '_LT_', $search_query);
+               $search_query = str_replace('(', '_PO_', $search_query);
+               $search_query = str_replace(')', '_PC_', $search_query);
+               $search_query = str_replace('~', '_LOW_', $search_query);
+               $search_query = str_replace('"', '_QUO_', $search_query);
+               
+               $search_query = urlencode($search_query);
+       
+               return $search_query;
+       }
+       
+       /**
+        * Return TRUE if it contains any special caracter from an advanced search
+        * query.
+        * @param string $search_query
+        * @return boolean
+        */
+       public function is_advanced_search_query($search_query)
+       {
+               return (preg_match('/\*|\+|\-|>|\<|\(|\)|~|"/', $search_query) == 0
+                       ? FALSE : TRUE);
+       }
+       
+       public static function gen_activation_code()
+       {
+               $ci =& get_instance();
+               
+               $activation_code = substr(
+                       sha1($ci->config->item('encryption_key')
+                               . mt_rand()),
+                       0,
+                       16);
+               
+               return $activation_code;
+       }
 }
 
 /* End of file videos_model.php */