<?php

/**
 * @file
 *   Follow module's install and uninstall code.
 */

/**
 * Implementation of hook_install().
 */
function follow_install() {
  drupal_install_schema('follow');
}

/**
 * Implementation of hook_schema().
 */
function follow_schema() {
  $schema['follow_links'] = array(
    'description' => 'Stores sitewide and user follow links.',
    'fields' => array(
      'lid' => array(
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'description' => 'Unique identifier for the {follow_links}.',
      ),
      'name' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
        'description' => "The machine name of the {follow_links}.",
      ),
      'uid' => array(
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
        'description' => "User's {users} uid.  Sitewide {follow_links} use uid 0",
      ),
      'path' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
        'description' => 'The Drupal path or extenal URL the {follow_links} should point to.',
      ),
      'options' => array(
        'description' => 'A serialized array of options to be passed to the url() or l() function, such as a query string or HTML attributes.',
        'type' => 'text',
        'translatable' => TRUE,
        'serialize' => TRUE,
      ),
      'title' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
        'description' => 'The human readable name for the link.',
      ),
      'weight' => array(
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
        'size' => 'tiny',
        'description' => 'The weight of this {follow_links}.',
      ),
    ),
    'primary key' => array('lid'),
    'unique keys' => array(
      'uid_name' => array('uid', 'name'),
    ),
  );
  return $schema;
}

/**
 * Implementation of hook_uninstall().
 */
function follow_uninstall() {
  drupal_uninstall_schema('follow');
  variable_del('follow_user_block_title');
  variable_del('follow_site_block_title');
  variable_del('follow_site_block_user');
}

/**
 * Update for caching and schema changes.
 */
function follow_update_6000() {
  $ret = array();

  if (drupal_get_installed_schema_version('follow') == 5000) {
    drupal_set_installed_schema_version('follow', 6003);

    return $ret;
  }

  // We no longer cache the follow networks.
  cache_clear_all('follow:networks', 'cache');

  $schema = follow_schema();
  $path = $schema['follow_links']['fields']['path'];
  $options = $schema['follow_links']['fields']['options'];

  // Since we match against just uid in queries, this field must
  // come first for the index to be used.
  db_drop_unique_key($ret, 'follow_links', 'name_uid');
  db_add_unique_key($ret, 'follow_links', 'uid_name', array('uid', 'name'));
  db_add_field($ret, 'follow_links', 'path', $path);
  db_add_field($ret, 'follow_links', 'options', $options);

  // We need to populate current rows' options col with an empty array.
  $ret[] = update_sql("UPDATE {follow_links} SET options = 'a:0:{}'");
  
  return $ret;
}

/**
 * Update existing data to the new schema.
 */
function follow_update_6001(&$sandbox = NULL) {
  $ret = array();

  // Check to make sure the url column exists before running this update. The only
  // instance I can think of where this might happen is a D5 to D6 upgrade.
  if (db_column_exists('follow_links', 'url')) {
    if (!isset($sandbox['max_lid'])) {
      $sandbox['current_lid'] = 0;
      $sandbox['max_lid'] = db_result(db_query('SELECT MAX(lid) FROM {follow_links}'));
    }
    $result = db_query("SELECT lid, url FROM {follow_links} WHERE lid > %d ORDER BY lid ASC LIMIT 100", $sandbox['current_lid']);

    while ($link = db_fetch_object($result)) {
      $parsed_url = follow_parse_url($link->url);
      $path = db_escape_string($parsed_url['path']);
      $options = serialize($parsed_url['options']);

      // We can't actually pass this directly to update_sql() because of the 
      // serialized array options. @see http://j.mp/b9yAxH and http://j.mp/bR3uOe
      $result = db_query("UPDATE {follow_links} SET path = '%s', options = '%s' WHERE lid = %d", $path, $options, $link->lid);
      $ret[] = array('success' => $result !== FALSE, 'query' => check_plain("UPDATE {follow_links} SET path = '$path', options = '$options' WHERE lid = {$link->lid}"));

      $sandbox['current_lid'] = $link->lid;
    }
  
    $ret['#finished'] = empty($sandbox['max_lid']) ? 1 : ($sandbox['current_lid'] / $sandbox['max_lid']);
  }

  return $ret;
}


/**
 * Drop old schema column.
 */
function follow_update_6002() {
  $ret = array();

  db_drop_field($ret, 'follow_links', 'url');

  return $ret;
}

/**
 * Add a title field.
 */
function follow_update_6003() {
  $ret = array();

  // Check to make sure the title column doesn't exists before running this 
  // update. The only instance I can think of where this might happen is a D5 to 
  // D6 upgrade.
  if (!db_column_exists('follow_links', 'title')) {
    $schema = follow_schema();
    $title = $schema['follow_links']['fields']['title'];
  
    db_add_field($ret, 'follow_links', 'title', $title);
  }

  return $ret;
}