fix conflict in phpfspot.class.php

Signed-off-by: Andreas Unterkircher <unki@netshadow.at>

8 files changed, 737 insertions, 195 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 28288cf..1ff2c36 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+phpfspot (1.7)
+
+ * feature, F-Spot photo versioning
+
+ -- Andreas Unterkircher <unki@netshadow.at>  Fri, 18 Aug 2008 06:09:00 +0200
+
 phpfspot (1.6)
 
  * bug, sort-by rates if all photos of the library are displayed works now.
diff --git a/README b/README
index 48f9ae5..abbdc44 100644
--- a/README
+++ b/README
@@ -1,5 +1,5 @@
 Package Name: phpfspot
-Version:      1.6
+Version:      1.7
 Author:       Andreas Unterkircher <unki@netshadow.at>
 Website:      http://oss.netshadow.at
 Desc:         dynamic PHP gallery for F-Spot
diff --git a/phpfspot.class.php b/phpfspot.class.php
index d7a76c3..f54a5d6 100644
--- a/phpfspot.class.php
+++ b/phpfspot.class.php
@@ -122,7 +122,8 @@ class PHPFSPOT {
 
       /* set application name and version information */
       $this->cfg->product = "phpfspot";
-      $this->cfg->version = "1.6";
+      $this->cfg->version = "1.7";
+      $this->cfg->db_version = 2;
 
       $this->sort_orders= array(
          'date_asc' => 'Date &uarr;',
@@ -200,7 +201,7 @@ class PHPFSPOT {
       }
 
       /* Check if some tables need to be created */
-      $this->check_config_table();
+      $this->check_phpfspot_db();
 
       /* overload Smarty class with our own template handler */
       require_once "phpfspot_tmpl.php";
@@ -293,6 +294,8 @@ class PHPFSPOT {
                   $_SESSION['start_action'] = 'showp';
                }
                if(isset($_GET['id']) && is_numeric($_GET['id'])) {
+                  if($_SESSION['current_photo'] != $_GET['id'])
+                     unset($_SESSION['current_version']);
                   $_SESSION['current_photo'] = $_GET['id'];
                   $_SESSION['start_action'] = 'showp';
                }
@@ -455,14 +458,19 @@ class PHPFSPOT {
    } // get_tags()
 
    /** 
-    * extract all photo details
+    * get all photo details from F-Spot database
     * 
-    * retrieve all available details from f-spot's
-    * database and return them as object
+    * this function queries the F-Spot database for all available
+    * details of the requested photo. It returns them as a object.
+    *
+    * Furthermore it takes care of the photo version to be requested.
+    * If photo version is not yet, it queries information for the
+    * original photo.
+    *
     * @param integer $idx
     * @return object|null
     */
-   public function get_photo_details($idx)
+   public function get_photo_details($idx, $version_idx = NULL)
    {
       /* ~ F-Spot version 0.3.x */
       if($this->dbver < 9) {
@@ -480,6 +488,7 @@ class PHPFSPOT {
             ";
          }
          else {
+            /* rating value got introduced */
             $query_str = "
                SELECT p.id, p.uri, p.time, p.description, p.rating
                FROM photos p
@@ -505,24 +514,47 @@ class PHPFSPOT {
          ";
       }
 
-      if($result = $this->db->db_query($query_str)) {
+      if($row = $this->db->db_fetchSingleRow($query_str)) {
 
-         $row = $this->db->db_fetch_object($result);
-
-         /* before F-Spot db version 9 there was no uri column but seperated
-            columns for directory_path and name (= filename).
+         /* before F-Spot db version 9 there was no uri column but
+            seperated fields for directory_path and name (= filename).
          */
          if($this->dbver < 9) {
             $row['uri'] = "file://". $row['directory_path'] ."/". $row['name'];
          }
 
+         /* if version-idx has not yet been set, get the latest photo version */
+         if(!isset($version_idx) || !$this->is_valid_version($idx, $version_idx))
+            $version_idx = $this->get_latest_version($idx);
+
+         /* if an alternative version has been requested */
+         if($version_idx > 0) {
+
+            /* check for alternative versions */
+            if($version = $this->db->db_fetchSingleRow("
+                  SELECT
+                     version_id, name, uri
+                  FROM
+                     photo_versions
+                  WHERE
+                     photo_id LIKE '". $idx ."'
+                  AND
+                     version_id LIKE '". $version_idx ."'
+            ")) {
+
+               $row['name'] = $version['name'];
+               $row['uri'] = $version['uri'];
+
+            }
+         }
+
          return $row;
 
       }
-   
+
       return null;
 
-   } // get_photo_details
+   } // get_photo_details()
 
    /**
     * returns aligned photo names 
@@ -697,7 +729,16 @@ class PHPFSPOT {
       }
 
       $orig_path = $this->translate_path($this->parse_uri($details['uri'], 'fullpath'));
-      $thumb_path = $this->get_thumb_path($this->cfg->photo_width, $photo);
+
+      /* if current version is already set, use it */
+      if($this->get_current_version() !== false)
+         $version = $this->get_current_version();
+
+      /* if version not set yet, we assume to display the latest version */
+      if(!isset($version) || !$this->is_valid_version($photo, $version))
+         $version = $this->get_latest_version($photo);
+
+      $thumb_path = $this->get_thumb_path($this->cfg->photo_width, $photo, $version);
 
       if(!file_exists($orig_path)) {
          $this->_error("Photo ". $orig_path ." does not exist!<br />\n");
@@ -712,7 +753,7 @@ class PHPFSPOT {
       /* If the thumbnail doesn't exist yet, try to create it */
       if(!file_exists($thumb_path)) {
          $this->gen_thumb($photo, true);
-         $thumb_path = $this->get_thumb_path($this->cfg->photo_width, $photo);
+         $thumb_path = $this->get_thumb_path($this->cfg->photo_width, $photo, $version);
       }
 
       /* get mime-type, height and width from the original photo */
@@ -763,11 +804,11 @@ class PHPFSPOT {
       $this->tmpl->assign('ExifFileSize', $meta_size);
  
       if($this->is_user_friendly_url()) {
-         $this->tmpl->assign('image_url', '/photo/'. $photo ."/". $this->cfg->photo_width);
+         $this->tmpl->assign('image_url', '/photo/'. $photo ."/". $this->cfg->photo_width .'/'. $version);
          $this->tmpl->assign('image_url_full', '/photo/'. $photo);
       }
       else {
-         $this->tmpl->assign('image_url', 'phpfspot_img.php?idx='. $photo ."&amp;width=". $this->cfg->photo_width);
+         $this->tmpl->assign('image_url', 'phpfspot_img.php?idx='. $photo ."&amp;width=". $this->cfg->photo_width ."&amp;version=". $version);
          $this->tmpl->assign('image_url_full', 'phpfspot_img.php?idx='. $photo);
       }
 
@@ -791,6 +832,14 @@ class PHPFSPOT {
       $this->tmpl->assign('photo_width', $this->cfg->photo_width);
       $this->tmpl->assign('photo_number', $i);
       $this->tmpl->assign('photo_count', count($all_photos));
+      $this->tmpl->assign('photo', $photo);
+      $this->tmpl->assign('version', $version);
+
+      /* if the photo as alternative versions, set a flag for the template */
+      if($this->get_photo_versions($photo))
+         $this->tmpl->assign('has_versions', true);
+
+      $this->tmpl->register_function("photo_version_select_list", array(&$this, "smarty_photo_version_select_list"), false);
 
       return $this->tmpl->fetch("single_photo.tpl");
 
@@ -1070,6 +1119,9 @@ class PHPFSPOT {
       if(isset($_SESSION['current_photo']))
          unset($_SESSION['current_photo']);
 
+      if(isset($_SESSION['current_version']))
+         unset($_SESSION['current_version']);
+
    } // resetPhotoView();
 
    /**
@@ -1408,7 +1460,7 @@ class PHPFSPOT {
             $img_title[$thumbs] = "Click to view photo ". htmlspecialchars($this->getPhotoName($photos[$i], 0));
             $img_rating[$thumbs] = $this->get_photo_rating($photos[$i]);
 
-            $thumb_path = $this->get_thumb_path($this->cfg->thumb_width, $photos[$i]);
+            $thumb_path = $this->get_thumb_path($this->cfg->thumb_width, $photos[$i], $this->get_latest_version($photos[$i]));
 
             if(file_exists($thumb_path)) {
                $info = getimagesize($thumb_path); 
@@ -1843,25 +1895,133 @@ class PHPFSPOT {
     * if it does not exist yet. this own is used to store
     * some necessary informations (md5 sum's, ...).
     */
-   public function check_config_table()
+   public function check_phpfspot_db()
    {
       // if the config table doesn't exist yet, create it
       if(!$this->cfg_db->db_check_table_exists("images")) {
          $this->cfg_db->db_exec("
             CREATE TABLE images (
-               img_idx int primary key,
-               img_md5 varchar(32)
+               img_idx int,
+               img_version_idx int,
+               img_md5 varchar(32),
+               UNIQUE(img_idx, img_version_idx)
+            )
+         ");
+      }
+
+      if(!$this->cfg_db->db_check_table_exists("meta")) {
+         $this->cfg_db->db_exec("
+            CREATE TABLE meta (
+               meta_key varchar(255),
+               meta_value varchar(255)
+            )
+         ");
+
+         /* db_version was added with phpfspot 1.7, before changes
+            on the phpfspot database where not necessary.
+         */
+
+         $this->cfg_db->db_exec("
+            INSERT INTO meta (
+               meta_key, meta_value
+            ) VALUES (
+               'phpfspot Database Version',
+               '". $this->cfg->db_version ."'
             )
-            ");
+         ");
       }
 
-   } // check_config_table
+      /* if version <= 2 and column img_version_idx does not exist yet */
+      if($this->get_db_version() <= 2 &&
+         !$this->cfg_db->db_check_column_exists("images", "img_version_idx")) {
+
+         if(!$this->cfg_db->db_start_transaction())
+            die("Can not start database transaction");
+
+         $result = $this->cfg_db->db_exec("
+            CREATE TEMPORARY TABLE images_temp (
+               img_idx int,
+               img_version_idx int,
+               img_md5 varchar(32),
+               UNIQUE(img_idx, img_version_idx)
+            )
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         $result = $this->cfg_db->db_exec("
+           INSERT INTO images_temp
+               SELECT
+                  img_idx,
+                  0,
+                  img_md5
+               FROM images
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         $result = $this->cfg_db->db_exec("
+            DROP TABLE images
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         $result = $this->cfg_db->db_exec("
+            CREATE TABLE images (
+               img_idx int,
+               img_version_idx int,
+               img_md5 varchar(32),
+               UNIQUE(img_idx, img_version_idx)
+            )
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         $result = $this->cfg_db->db_exec("
+            INSERT INTO images
+               SELECT *
+               FROM images_temp
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         $result = $this->cfg_db->db_exec("
+            DROP TABLE images_temp
+         ");
+
+         if(!$result) {
+            $this->cfg_db->db_rollback_transaction();
+            die("Upgrade failed - transaction rollback");
+         }
+
+         if(!$this->cfg_db->db_commit_transaction())
+            die("Can not commit database transaction");
+
+      }
+
+   } // check_phpfspot_db
 
    /**
-    * Generates a thumbnail from photo idx
+    * generates thumbnails
     *
-    * This function will generate JPEG thumbnails from provided F-Spot photo
-    * indizes.
+    * This function generates JPEG thumbnails from
+    * provided F-Spot photo indize and its alternative
+    * versions.
     *
     * 1. Check if all thumbnail generations (width) are already in place and
     *    readable
@@ -1874,6 +2034,7 @@ class PHPFSPOT {
    public function gen_thumb($idx = 0, $force = 0, $overwrite = false)
    {
       $error = 0;
+      $versions = Array(0);
 
       $resolutions = Array(
          $this->cfg->thumb_width,
@@ -1882,110 +2043,125 @@ class PHPFSPOT {
          30,
       );
 
-      /* get details from F-Spot's database */
-      $details = $this->get_photo_details($idx);
+      if($alt_versions = $this->get_photo_versions($idx))
+         $versions = array_merge($versions, $alt_versions);
 
-      /* calculate file MD5 sum */
-      $full_path = $this->translate_path($this->parse_uri($details['uri'], 'fullpath'));
+      foreach($versions as $version) {
 
-      if(!file_exists($full_path)) {
-         $this->_error("File ". $full_path ." does not exist\n");
-         return;
-      }
+         /* get details from F-Spot's database */
+         $details = $this->get_photo_details($idx, $version);
 
-      if(!is_readable($full_path)) {
-         $this->_error("File ". $full_path ." is not readable for ". $this->getuid() ."\n");
-         return;
-      }
+         /* calculate file MD5 sum */
+         $full_path = $this->translate_path($this->parse_uri($details['uri'], 'fullpath'));
+
+         if(!file_exists($full_path)) {
+            $this->_error("File ". $full_path ." does not exist\n");
+            return;
+         }
+
+         if(!is_readable($full_path)) {
+            $this->_error("File ". $full_path ." is not readable for ". $this->getuid() ."\n");
+            return;
+         }
 
-      $this->_debug("Image [". $idx ."] ". $this->shrink_text($this->parse_uri($details['uri'], 'filename'), 20) ." Thumbnails:");
+         $this->_debug("Image [". $idx ."] ". $this->shrink_text($this->parse_uri($details['uri'], 'filename'), 20) ." Thumbnails:");
 
-      /* If Nikon NEF format, we need to treat it another way */
-      if(isset($this->cfg->dcraw_bin) &&
-         file_exists($this->cfg->dcraw_bin) &&
-         is_executable($this->cfg->dcraw_bin) &&
-         preg_match('/\.nef$/i', $details['uri'])) {
+         /* If Nikon NEF format, we need to treat it another way */
+         if(isset($this->cfg->dcraw_bin) &&
+            file_exists($this->cfg->dcraw_bin) &&
+            is_executable($this->cfg->dcraw_bin) &&
+            preg_match('/\.nef$/i', $details['uri'])) {
 
-         $ppm_path = preg_replace('/\.nef$/i', '.ppm', $full_path);
+            $ppm_path = preg_replace('/\.nef$/i', '.ppm', $full_path);
+
+            /* if PPM file does not exist, let dcraw convert it from NEF */
+            if(!file_exists($ppm_path)) {
+               system($this->cfg->dcraw_bin ." -a ". $full_path);
+            }
+
+            /* for now we handle the PPM instead of the NEF */
+            $full_path = $ppm_path;
 
-         /* if PPM file does not exist, let dcraw convert it from NEF */
-         if(!file_exists($ppm_path)) {
-            system($this->cfg->dcraw_bin ." -a ". $full_path);
          }
 
-         /* for now we handle the PPM instead of the NEF */
-         $full_path = $ppm_path;
+         $file_md5 = md5_file($full_path);
+         $changes = false;
 
-      }
+         foreach($resolutions as $resolution) {
 
-      $file_md5 = md5_file($full_path);
-      $changes = false;
+            $generate_it = false;
 
-      foreach($resolutions as $resolution) {
-   
-         $generate_it = false;
+            $thumb_sub_path = substr($file_md5, 0, 2);
+            $thumb_path = $this->cfg->thumb_path ."/". $thumb_sub_path ."/". $resolution ."_". $file_md5;
 
-         $thumb_sub_path = substr($file_md5, 0, 2);
-         $thumb_path = $this->cfg->thumb_path ."/". $thumb_sub_path ."/". $resolution ."_". $file_md5;
+            /* if thumbnail-subdirectory does not exist yet, create it */
+            if(!file_exists(dirname($thumb_path))) {
+               mkdir(dirname($thumb_path), 0755);
+            }
 
-         /* if thumbnail-subdirectory does not exist yet, create it */
-         if(!file_exists(dirname($thumb_path))) {
-            mkdir(dirname($thumb_path), 0755);
-         }
+            /* if the thumbnail file doesn't exist, create it */
+            if(!file_exists($thumb_path) || $force) {
+               $generate_it = true;
+            }
+            elseif($file_md5 != $this->getMD5($idx, $version)) {
+               $generate_it = true;
+            }
 
-         /* if the thumbnail file doesn't exist, create it */
-         if(!file_exists($thumb_path)) {
-            $generate_it = true;
-         }
-         /* if the file hasn't changed there is no need to regen the thumb */
-         elseif($file_md5 != $this->getMD5($idx) || $force) {
-            $generate_it = true;
-         }
+            if($generate_it || $overwrite) {
+
+               $this->_debug(" ". $resolution ."px");
+               if(!$this->create_thumbnail($full_path, $thumb_path, $resolution))
+                  $error = 1;
 
-         if($generate_it || $overwrite) {
+               $changes = true;
+            }
+         }
 
-            $this->_debug(" ". $resolution ."px");
-            if(!$this->create_thumbnail($full_path, $thumb_path, $resolution))
-               $error = 1;
+         if(!$changes) {
+            $this->_debug(" already exist");
+         }
 
-            $changes = true;
+         /* set the new/changed MD5 sum for the current photo */
+         if(!$error) {
+            $this->setMD5($idx, $file_md5, $version);
          }
-      }
 
-      if(!$changes) {
-         $this->_debug(" already exist");
-      }
+         $this->_debug("\n");
 
-      /* set the new/changed MD5 sum for the current photo */
-      if(!$error) {
-         $this->setMD5($idx, $file_md5);
       }
 
-      $this->_debug("\n");
-
    } // gen_thumb()
 
    /**
     * returns stored md5 sum for a specific photo
     *
-    * this function queries the phpfspot database for a
-    * stored MD5 checksum of the specified photo
+    * this function queries the phpfspot database for a stored MD5
+    * checksum of the specified photo. It also takes care of the
+    * requested photo version - original or alternative photo.
+    *
     * @param integer $idx
     * @return string|null
     */
-   public function getMD5($idx)
+   public function getMD5($idx, $version_idx = 0)
    {
       $result = $this->cfg_db->db_query("
-         SELECT img_md5 
-         FROM images
-         WHERE img_idx='". $idx ."'
+         SELECT
+            img_md5
+         FROM
+            images
+         WHERE
+            img_idx='". $idx ."'
+         AND
+            img_version_idx='". $version_idx ."'
       ");
 
       if(!$result)
-         return 0;
+         return NULL;
 
-      $img = $this->cfg_db->db_fetch_object($result);
-      return $img['img_md5'];
+      if($img = $this->cfg_db->db_fetch_object($result))
+         return $img['img_md5'];
+
+      return NULL;
       
    } // getMD5()
 
@@ -1994,11 +2170,16 @@ class PHPFSPOT {
     * @param integer $idx
     * @param string $md5
     */
-   private function setMD5($idx, $md5)
+   private function setMD5($idx, $md5, $version_idx = 0)
    {
       $result = $this->cfg_db->db_exec("
-         REPLACE INTO images (img_idx, img_md5)
-         VALUES ('". $idx ."', '". $md5 ."')
+         INSERT OR REPLACE INTO images (
+            img_idx, img_version_idx, img_md5
+         ) VALUES (
+            '". $idx ."',
+            '". $version_idx ."',
+            '". $md5 ."'
+         )
       ");
 
    } // setMD5()
@@ -2115,6 +2296,25 @@ class PHPFSPOT {
    } // updateSortOrder()
 
    /**
+    * update photo version in session variable
+    *
+    * this function is invoked by RPC and will set the requested
+    * photo version in the session variable.
+    * @param string $photo_version
+    * @return string
+    */
+   public function update_photo_version($photo_idx, $photo_version)
+   {
+      if($this->is_valid_version($photo_idx, $photo_version)) {
+         $_SESSION['current_version'] = $photo_version;
+         return "ok";
+      }
+
+      return "incorrect photo version provided";
+
+   } // update_photo_version()
+
+   /**
     * rotate image
     *
     * this function rotates the image according the
@@ -2642,12 +2842,52 @@ class PHPFSPOT {
    /**
     * return the current photo
     */
-   public function getCurrentPhoto()
+   public function get_current_photo()
    {
       if(isset($_SESSION['current_photo'])) {
-         print $_SESSION['current_photo'];
+         return $_SESSION['current_photo'];
       }
-   } // getCurrentPhoto()
+
+      return NULL;
+
+   } // get_current_photo()
+
+   /**
+    * current selected photo version
+    *
+    * this function returns the current selected photo version
+    * from the session variables.
+    *
+    * @return int
+    */
+   public function get_current_version()
+   {
+      /* if current version is set, return it, if the photo really has that version */
+      if(isset($_SESSION['current_version']) && is_numeric($_SESSION['current_version']))
+         return $_SESSION['current_version'];
+
+      return false;
+
+   } // get_current_version()
+
+   /**
+    * returns latest available photo version
+    *
+    * this function returns the latested available version
+    * for the requested photo.
+    *
+    * @return int
+    */
+   public function get_latest_version($photo_idx)
+   {
+      /* try to get the lasted version for the current photo */
+      if($versions = $this->get_photo_versions($photo_idx))
+         return $versions[count($versions)-1];
+
+      /* if no alternative version were found, return original version */
+      return 0;
+
+   } // get_current_version()
 
    /**
     * tells the client browser what to do
@@ -2689,6 +2929,37 @@ class PHPFSPOT {
    } // getuid()
 
    /**
+    * photo version select list
+    *
+    * this function returns a HTML select list (drop down)
+    * to select a alternative photo version of the original photo.
+    *
+    * @param array $params
+    * @param smarty $smarty
+    * @return string
+    */
+   public function smarty_photo_version_select_list($params, &$smarty)
+   {
+      if(!isset($params['photo']) || !isset($params['current']))
+         return NULL;
+
+      $output = "<option value=\"0\">Original</option>";
+      $versions = $this->get_photo_versions($params['photo']);
+
+      foreach($versions as $version) {
+
+         $output.= "<option value=\"". $version ."\"";
+         if($version == $params['current']) {
+            $output.= " selected=\"selected\"";
+         }
+         $output.= ">". $this->get_photo_version_name($params['photo'], $version) ."</option>";
+      }
+
+      return $output;
+
+   } // smarty_photo_version_select_list()
+
+   /**
     * returns a select-dropdown box to select photo index sort parameters
     * @param array $params
     * @param smarty $smarty
@@ -2960,9 +3231,9 @@ class PHPFSPOT {
     * @param integer $photo
     * @return string
     */
-   public function get_thumb_path($width, $photo)
+   public function get_thumb_path($width, $photo_idx, $version_idx)
    {
-      $md5 = $this->getMD5($photo);
+      $md5 = $this->getMD5($photo_idx, $version_idx);
       $sub_path = substr($md5, 0, 2);
       return $this->cfg->thumb_path
          . "/"
@@ -3339,12 +3610,15 @@ class PHPFSPOT {
                break;
             case 'photo':
                if(is_numeric($options[2])) {
+                  $width = NULL;
+                  $version = NULL;
+                  if(isset($options[3]) && is_numeric($options[3]))
+                     $width = $options[3];
+                  if(isset($options[4]) && is_numeric($options[4]))
+                     $version = $options[4];
                   require_once "phpfspot_img.php";
                   $img = new PHPFSPOT_IMG;
-                  if(isset($options[3]) && is_numeric($options[3]))
-                     $img->showImg($options[2], $options[3]);
-                  else
-                     $img->showImg($options[2]);
+                  $img->showImg($options[2], $width, $version);
                }
                exit;
                break;
@@ -3396,6 +3670,116 @@ class PHPFSPOT {
 
    } // session_cleanup()
 
+   /**
+    * get database version
+    *
+    * this function queries the meta table
+    * and returns the current database version.
+    *
+    * @return integer
+    */
+   public function get_db_version()
+   {
+      if($row = $this->cfg_db->db_fetchSingleRow("
+         SELECT meta_value
+         FROM
+            meta
+         WHERE
+            meta_key LIKE 'phpfspot Database Version'
+         ")) {
+
+         return $row['meta_value'];
+
+      }
+
+      return 0;
+
+   } // get_db_version()
+
+   /**
+    * get photo versions
+    *
+    * this function returns an array of all available
+    * alterntaive versions of the provided photo id.
+    * has alternative photo versions available
+    *
+    * @param int $idx
+    * @return array
+    */
+   public function get_photo_versions($idx)
+   {
+      $versions = Array();
+
+      $result = $this->db->db_query("
+         SELECT
+            version_id
+         FROM
+            photo_versions
+         WHERE
+            photo_id LIKE '". $idx ."'");
+
+      while($row = $this->cfg_db->db_fetch_object($result)) {
+         array_push($versions, $row['version_id']);
+      }
+
+      return $versions;
+
+   } // get_photo_versions()
+
+   /**
+    * check for invalid version of photo
+    *
+    * this function validates the provided photo-id and version-id
+    *
+    * @param int $photo_idx
+    * @param int $version_idx
+    * @return bool
+    */
+   public function is_valid_version($photo_idx, $version_idx)
+   {
+      /* the original version is always valid */
+      if($version_idx == 0)
+         return true;
+
+      if($versions = $this->get_photo_versions($photo_idx)) {
+         if(in_array($version_idx, $versions))
+            return true;
+      }
+
+      return false;
+
+   } // is_valid_version()
+
+   /**
+    * get photo version name
+    *
+    * this function returns the name of the version
+    * identified by the photo-id and version-id.
+    *
+    * @param int $photo_idx
+    * @param int $version_idx
+    * @return string
+    */
+   public function get_photo_version_name($photo_idx, $version_idx)
+   {
+      if($row = $this->db->db_fetchSingleRow("
+         SELECT
+            name
+         FROM
+            photo_versions
+         WHERE
+            photo_id LIKE '". $photo_idx ."'
+         AND
+            version_id LIKE '". $version_idx ."'")) {
+
+         return $row['name'];
+
+      }
+
+      return false;
+
+   } // get_photo_version_name()
+
 } // class PHPFSPOT
 
 ?>
diff --git a/phpfspot.js b/phpfspot.js
index 57345ab..54395e2 100644
--- a/phpfspot.js
+++ b/phpfspot.js
@@ -821,6 +821,27 @@ function update_sort_order(obj)
 } // update_sort_order()
 
 /**
+ * if the photo-version ѕelect-box has changed, set the newly
+ * choosen photo version as the to-be-displayed photo version
+ */
+function update_photo_version(obj, current_photo)
+{
+   var objTemp = new Object();
+   objTemp['photo_version'] = obj.options[obj.selectedIndex].value;
+   objTemp['photo_idx'] = current_photo;
+
+   var retr = HTML_AJAX.post(web_path + '/rpc.php?action=update_photo_version', objTemp);
+
+   if(retr == "ok") {
+      showPhoto(current_photo);
+   }
+   else {
+      window.alert("Server message: "+ retr);
+   }
+
+} // update_photo_version()
+
+/**
  * show rate stars
  *
  * this function will show the requested amount of
diff --git a/phpfspot_db.php b/phpfspot_db.php
index e0cf39f..339e023 100644
--- a/phpfspot_db.php
+++ b/phpfspot_db.php
@@ -127,32 +127,30 @@ class PHPFSPOT_DB {
     */
    public function db_query($query = "")
    {
-      if($this->getConnStatus()) {
+      if(!$this->getConnStatus())
+         return false;
    
-         $this->last_query = $query;
-
-         switch($this->parent->cfg->db_access) {
-            case 'native':
-               if(($result = sqlite3_query($this->db, $query)) === false)
-                  $this->ThrowError($this->getLastError());
-               break;
-            case 'pdo':
-               try{
-                  $result = $this->db->query($query);
-                  return $result;
-               }
-               catch (Exception $e) {
-                  $this->ThrowError($e->getMessage());
-                  $result= NULL;
-               }
-               break;
+      $this->last_query = $query;
+
+      switch($this->parent->cfg->db_access) {
+         case 'native':
+            if(($result = sqlite3_query($this->db, $query)) === false)
+               $this->ThrowError($this->getLastError());
+            break;
+         case 'pdo':
+            try{
+               $result = $this->db->query($query);
+               return $result;
+            }
+            catch (Exception $e) {
+               $this->ThrowError($e->getMessage());
+               $result= NULL;
+            }
+            break;
 
-         }
-	
-         return $result;
       }
-      else 
-         $this->ThrowError("Can't execute query - we are not connected!");
+
+      return $result;
 
    } // db_query()
 
@@ -163,27 +161,30 @@ class PHPFSPOT_DB {
     */
    public function db_exec($query = "")
    {
-      if($this->getConnStatus()) {
-
-         $this->last_query = $query;
-
-         switch($this->parent->cfg->db_access) {
-            case 'native':
-               if(($result = sqlite3_exec($this->db, $query)) === false)
-                  $this->ThrowError($this->getLastError());
-               break;
-            case 'pdo':
-               try {
-                  $result = $this->db->query($query);
-               }
-               catch (Exception $e){
-                  $this->ThrowError($e->getLMessage());
-               }
-               break;
-         }
+      if(!$this->getConnStatus())
+         return false;
+
+      $this->last_query = $query;
+
+      switch($this->parent->cfg->db_access) {
+         case 'native':
+            if(($result = sqlite3_exec($this->db, $query)) === false) {
+               $this->ThrowError($this->getLastError());
+               return false;
+            }
+            break;
+         case 'pdo':
+            try {
+               $result = $this->db->query($query);
+            }
+            catch (Exception $e){
+               $this->ThrowError($e->getLMessage());
+               return false;
+            }
+            break;
       }
-      else 
-         $this->ThrowError("Can't execute query - we are not connected!");
+
+      return true;
 
    } // db_exec()
 
@@ -206,21 +207,19 @@ class PHPFSPOT_DB {
     */
    public function db_fetchSingleRow($query = "") 
    {
-      if($this->getConnStatus()) {
-
-         $result = $this->db_query($query);
-         switch($this->parent->cfg->db_access) {
-            case 'native':
-               $row = $this->db_fetch_object($result);
-               break;
-            case 'pdo':
-               $row = $result->fetch();
-               break;
-         }
-         return $row;
+      if(!$this->getConnStatus())
+         return false;
+
+      $result = $this->db_query($query);
+      switch($this->parent->cfg->db_access) {
+         case 'native':
+            $row = $this->db_fetch_object($result);
+            break;
+         case 'pdo':
+            $row = $result->fetch();
+            break;
       }
-      else 
-         $this->ThrowError("Can't fetch row - we are not connected!");
+      return $row;
       
    } // db_fetchSingleRow()
 
@@ -253,32 +252,64 @@ class PHPFSPOT_DB {
     */
    public function db_check_table_exists($table_name = "")
    {
-      if($this->getConnStatus()) {
-
-         $result = $this->db_query("SELECT name FROM sqlite_master WHERE type='table'");
-         switch($this->parent->cfg->db_access) {
-            case 'native':
-               while($table = $this->db_fetch_object($result)) {
-                  if($table['name'] == $table_name)
-                     return true;
-               }
-               break;
-            case 'pdo':
-               foreach($result as $table ){
-                  if($table['NAME'] == $table_name)
-                     return true;
-               }
-               break;
-          }
-
+      if(!$this->getConnStatus())
          return false;
-      }
-      else
-         $this->ThrowError("Can't check table - we are not connected!");
+
+      $result = $this->db_query("SELECT name FROM sqlite_master WHERE type='table'");
+      switch($this->parent->cfg->db_access) {
+         case 'native':
+            while($table = $this->db_fetch_object($result)) {
+               if($table['name'] == $table_name)
+                  return true;
+            }
+            break;
+         case 'pdo':
+            foreach($result as $table ){
+               if($table['NAME'] == $table_name)
+                  return true;
+            }
+            break;
+       }
+
+      return false;
 	 
    } // db_check_table_exists()
 
    /**
+    * PHPFSPOT_DB check column exist
+    *
+    * This function checks if the given column exists within
+    * the specified table.
+    */
+   public function db_check_column_exists($table_name, $column)
+   {
+      if(!$this->getConnStatus())
+         return false;
+
+      $result = $this->db_query("
+         SELECT sql
+         FROM
+            (SELECT * FROM sqlite_master UNION ALL
+             SELECT * FROM sqlite_temp_master)
+         WHERE
+            tbl_name LIKE '". $table_name ."'
+         AND type!='meta'
+         AND sql NOT NULL
+         AND name NOT LIKE 'sqlite_%'
+         ORDER BY substr(type,2,1), name
+      ");
+
+      while($row = $this->db_fetch_object($result)) {
+         /* CREATE TABLE xx ( col1 int, col2 bool, col3 ...) */
+         if(strstr($row['sql'], " ". $column ." ") !== false)
+               return true;
+      }
+
+      return false;
+
+   } // db_check_column_exists()
+
+   /**
     * PHPFSPOT_DB get connection status
     *
     * This function checks the internal state variable if already
@@ -333,6 +364,74 @@ class PHPFSPOT_DB {
 
    } // getLastError()
 
-}
+   /**
+    * start transaction
+    *
+    * this will start a transaction on ACID-supporting database
+    * systems.
+    *
+    * @return bool
+    */
+   public function db_start_transaction()
+   {
+      if(!$this->getConnStatus())
+         return false;
+
+      $result = $this->db_exec("BEGIN");
+
+      /* Errors? */
+      if(PEAR::isError($result))
+         $this->throwError($result->getMessage() .' - '. $result->getUserInfo());
+
+      return true;
+
+   } // db_start_transaction()
+
+   /**
+    * commit transaction
+    *
+    * this will commit an ongoing transaction on ACID-supporting
+    * database systems
+    *
+    * @return bool
+    */
+   public function db_commit_transaction()
+   {
+      if(!$this->getConnStatus())
+         return false;
+
+      $result = $this->db_exec("COMMIT");
+
+      /* Errors? */
+      if(PEAR::isError($result))
+         $this->throwError($result->getMessage() .' - '. $result->getUserInfo());
+
+      return true;
+
+   } // db_commit_transaction()
+
+   /**
+    * rollback transaction()
+    *
+    * this function aborts a on going transaction
+    *
+    * @return bool
+    */
+   public function db_rollback_transaction()
+   {
+      if(!$this->getConnStatus())
+         return false;
+
+      $result = $this->db_exec("ROLLBACK");
+
+      /* Errors? */
+      if(PEAR::isError($result))
+         $this->throwError($result->getMessage() .' - '. $result->getUserInfo());
+
+      return true;
+
+   } // db_rollback_transaction()
+
+} // PHPFSPOT_DB
 
 ?>
diff --git a/phpfspot_img.php b/phpfspot_img.php
index 3599b2b..5ef76b4 100644
--- a/phpfspot_img.php
+++ b/phpfspot_img.php
@@ -64,13 +64,17 @@ class PHPFSPOT_IMG {
     * @param integer $idx
     * @param integer $width
     */
-   public function showImg($idx, $width = 0)
+   public function showImg($idx, $width = 0, $version = NULL)
    {
       if($idx == 'rand')
          $idx = $this->parent->get_random_photo();
 
-      $details = $this->parent->get_photo_details($idx);
-   
+      /* display the lastest available version, if a wrong version has been requested */
+      if(!isset($version) || !$this->parent->is_valid_version($idx, $version))
+         $version = $this->parent->get_latest_version($idx);
+
+      $details = $this->parent->get_photo_details($idx, $version);
+
       if(!$details) {
          $this->parent->showTextImage("The image (". $idx .") you requested is unknown");
          return;
@@ -82,11 +86,15 @@ class PHPFSPOT_IMG {
       }
       /* show thumbnail */
       else {
-         /* if no entry for this photo is yet in the database, create thumb */
+
+         /* check for an entry if we already handled this photo before. If not,
+            create a thumbnail for it.
+         */
          if(!$this->parent->getMD5($idx)) {
             $this->parent->gen_thumb($idx);
          }
-         $fullpath = $this->parent->get_thumb_path($width, $idx);
+         /* get the full filesystem path to the thumbnail */
+         $fullpath = $this->parent->get_thumb_path($width, $idx, $version);
          /* if the thumb file does not exist, create it */
          if(!file_exists($fullpath)) {
             $this->parent->gen_thumb($idx);
@@ -150,7 +158,10 @@ class PHPFSPOT_IMG {
       if(!$this->parent->getMD5($idx)) {
          $this->parent->gen_thumb($idx);
       }
-      $fullpath = $this->parent->get_thumb_path($width, $idx);
+
+      $version = $this->parent­>get_latest_version($idx);
+
+      $fullpath = $this->parent->get_thumb_path($width, $idx, $version);
       /* if the thumb file does not exist, create it */
       if(!file_exists($fullpath)) {
          $this->parent->gen_thumb($idx);
@@ -196,9 +207,16 @@ if(isset($_GET['idx']) && (is_numeric($_GET['idx']) || $_GET['idx'] == 'rand'))
    $img = new PHPFSPOT_IMG;
 
    if(isset($_GET['width']) && is_numeric($_GET['width'])) 
-      $img->showImg($_GET['idx'], $_GET['width']);
+      $width = $_GET['width'];
+   else
+      $width = NULL;
+
+   if(isset($_GET['version']) && is_numeric($_GET['version']))
+      $version = $_GET['version'];
    else
-      $img->showImg($_GET['idx']);
+      $version = NULL;
+
+   $img->showImg($_GET['idx'], $width, $version);
 
    exit(0);
 }
@@ -212,5 +230,4 @@ if(isset($_GET['tagidx']) && is_numeric($_GET['tagidx'])) {
 
 }
 
-
 ?>
diff --git a/rpc.php b/rpc.php
index ada2857..17af073 100644
--- a/rpc.php
+++ b/rpc.php
@@ -135,13 +135,20 @@ class PHPFSPOT_RPC {
             }
             break;
 
+         case 'update_photo_version':
+            if(isset($_POST['photo_version']) && is_numeric($_POST['photo_version']) &&
+               isset($_POST['photo_idx']) && is_numeric($_POST['photo_idx'])) {
+               print $phpfspot->update_photo_version($_POST['photo_idx'], $_POST['photo_version']);
+            }
+            break;
+
          case 'get_export':
             /* $_GET['mode'] will be validated by getExport() */
             $phpfspot->getExport($_GET['mode']);
             break;
 
          case 'get_photo_to_show':
-            $phpfspot->getCurrentPhoto();
+            print $phpfspot->get_current_photo();
             break;
 
          case 'get_calendar_matrix':
diff --git a/themes/default/templates/single_photo.tpl b/themes/default/templates/single_photo.tpl
index e8e326d..572bef7 100644
--- a/themes/default/templates/single_photo.tpl
+++ b/themes/default/templates/single_photo.tpl
@@ -49,6 +49,14 @@
     {/section}
     <br />
    { /if }
+   { if $has_versions }
+    <br />
+    Versions:<br />
+    <select onchange="update_photo_version(this, {$photo});">
+    { photo_version_select_list photo=$photo current=$version }
+    </select>
+    <br />
+   { /if }
    { if $tags }
     <br />
     <u><img src="{$web_path}/resources/small_available_tags.png" alt="available tags" />&nbsp;Tagged with:</u><br />