<?php

/**
 * Implementation of hook_help().
 */
function simplecdn_help($path, $arg) {
  $output = '';
  switch ($path) {
    case "admin/help#simplecdn":
      $output = '<p>'. t("Enable a mirror CDN on certain elements of your site.") .'</p>';
      break;
  }
  return $output;
}

/**
 * Implementation of hook_perm().
 */
function simplecdn_perm() {
  return array('administer simplecdn');
}

/**
 * Implementation of hook_menu().
 */
function simplecdn_menu() {
  $items = array();
  $items['admin/settings/simplecdn'] = array(
    'title' => 'Simple CDN',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('simplecdn_admin'),
    'access arguments' => array('administer simplecdn')
  );
  $items['admin/settings/simplecdn/elements'] = array(
    'title' => 'Elements',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/settings/simplecdn/mirrors'] = array(
    'title' => 'Mirrors',
    'page callback' => 'simplecdn_mirror_list',
    'page arguments' => array('simplecdn_mirror_list'),
    'access arguments' => array('administer simplecdn'),
    'type' => MENU_LOCAL_TASK,
  );
  $items['admin/settings/simplecdn/add-new-mirror'] = array(
    'title' => 'Add new mirror',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('simplecdn_mirror_add'),
    'access arguments' => array('administer simplecdn'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 10
  );
  $items['admin/settings/simplecdn/mirror/%'] = array(
    'title callback' => 'simplecdn_title_callback',
    'title arguments' => array('Edit mirror: !name', 4),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('simplecdn_mirror_edit', 4),
    'access arguments' => array('administer simplecdn'),
    'type' => MENU_CALLBACK,
  );
  $items['admin/settings/simplecdn/mirror/%/delete'] = array(
    'title callback' => 'simplecdn_title_callback',
    'title arguments' => array('Delete mirror: !name', 4),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('simplecdn_mirror_delete', 4),
    'access arguments' => array('administer simplecdn'),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Custom titles for certain pages.
 */
function simplecdn_title_callback($title, $mid = 0) {
  $replacements = array();
  $mirror = simplecdn_mirrors($mid);
  $replacements['!name'] = $mirror['name'];
  return t($title, $replacements);
}

/**
 * Return array of CDN mirrors.
 */
function simplecdn_mirrors($mid = NULL) {
  //If cache isn't set, set it.
  if(cache_get('simplecdn_mirrors') == '') {
    simplecdn_rebuild_cache();
  }
  
  $mirrors = cache_get('simplecdn_mirrors');
  
  if($mid != NULL && isset($mirrors->data[$mid])) {
    return $mirrors->data[$mid];
  }
  else {
    return $mirrors->data;
  }
}

/**
 * Rebuild mirror cache.
 */
function simplecdn_rebuild_cache() {
  $mirrors = array();
    $result = db_query('SELECT * FROM {simplecdn_mirrors} ORDER BY name');
    while ($mirror = db_fetch_array($result)) {
      $mirrors[$mirror['mid']] = $mirror;
    }

  cache_set('simplecdn_mirrors', $mirrors);

  drupal_set_message(t('CDN Mirror cache updated.'));
}

/**
 * Return formatted list of CDN mirrors.
 */
function simplecdn_mirror_list() {
  $header = array(t('Mirror'), t('URL'), t('Actions'));
  $rows = array();
  foreach (simplecdn_mirrors() as $mirror) {
    $row = array();
    $row[] = l($mirror['name'], 'admin/settings/simplecdn/mirror/'. $mirror['mid']);
    $row[] = $mirror['url'];
      $links = array();
      $links[] = l(t('Edit'), 'admin/settings/simplecdn/mirror/'. $mirror['mid']);
      $links[] = l(t('Delete'), 'admin/settings/simplecdn/mirror/'. $mirror['mid'] .'/delete');
    $row[] = implode('&nbsp;&nbsp;&nbsp;&nbsp;', $links);
    $rows[] = $row;
  }
  $output = theme('table', $header, $rows);
  return $output;
}

/**
 * Form to add a new player.
 */
function simplecdn_mirror_add($form_state) {
  if (user_access('administer simplecdn')) {
    $form['mirror'] = array(
      '#type' => 'fieldset', 
      '#title' => t('CDN Mirror Details'), 
      '#weight' => -2, 
      '#collapsible' => FALSE, 
      '#collapsed' => FALSE,
    );
    
    $form['mirror']['name'] = array(
      '#type' => 'textfield',
      '#title' => t('Name'),
      '#default_value' => '',
      '#required' => TRUE,
      '#size' => '20',
      '#description' => t('Unique name for the CDN mirror. Please only use alphanumeric characters, underscores (_), and hyphens (-) for mirror names.'),
    );

    $form['mirror']['url'] = array(
      '#type' => 'textfield',
      '#title' => t('Mirror URL'),
      '#default_value' => '',
      '#required' => TRUE,
      '#size' => '60',
      '#description' => t('The mirror URL to replace your current site URL with on enabled elements. e.g. http://www.example.com'),
    );

    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Add new mirror'),
    );

    $form['#validate'][]  = 'simplecdn_mirror_validate';
    $form['#submit'][]    = 'simplecdn_mirror_submit';

    return $form;
  }
}

/**
 * Custom validation function for a new CDN mirror.
 */
function simplecdn_mirror_validate($form, &$form_state) {
  $mirrors = simplecdn_mirrors();
  if(isset($form_state['values']['mid'])) {
    unset($mirrors[$form_state['values']['mid']]);
  }
  foreach($mirrors as $mid => $mirror) {
    if($mirror['name'] == $form_state['values']['name']) {
      form_set_error('name', t('Mirror name has to be unique.'));
    }
  }

  if (preg_match('/[^0-9a-zA-Z_-]/', $form_state['values']['name'])) {
    form_set_error('name', t('Please only use alphanumeric characters, underscores (_), and hyphens (-) for player names.'));
  }
  if(strlen($form_state['values']['name']) > 20) {
    form_set_error('name', t('Mirror name must be shorter than 20 characters.'));
  }
  if(strlen($form_state['values']['url']) > 256) {
    form_set_error('name', t('Mirror URL must be shorter than 256 characters.'));
  }
}

/**
 * Add a new mirror.
 */
function simplecdn_mirror_submit($form, &$form_state) {
  drupal_write_record('simplecdn_mirrors', $form_state['values']);
  drupal_set_message(t("New CDN Mirror %name added.", array('%name' => $form_state['values']['name'])));
  simplecdn_rebuild_cache();
  $form_state['redirect'] = 'admin/settings/simplecdn/mirrors';
}

/**
 * Form to edit a CDN mirror.
 */
function simplecdn_mirror_edit($form_state, $mid = 0) {
  if (user_access('administer simplecdn')) {
    $mirror = simplecdn_mirrors($mid);

    $form['mirror'] = array(
      '#type' => 'fieldset', 
      '#title' => t('CDN Mirror Details'), 
      '#weight' => -2, 
      '#collapsible' => FALSE, 
      '#collapsed' => FALSE,
    );
    
    $form['mirror']['name'] = array(
      '#type' => 'textfield',
      '#title' => t('Name'),
      '#default_value' => $mirror['name'],
      '#required' => TRUE,
      '#size' => '20',
      '#description' => t('Unique name for the CDN mirror. Please only use alphanumeric characters, underscores (_), and hyphens (-) for mirror names.'),
    );

    $form['mirror']['url'] = array(
      '#type' => 'textfield',
      '#title' => t('Mirror URL'),
      '#default_value' => $mirror['url'],
      '#required' => TRUE,
      '#size' => '60',
      '#description' => t('The mirror URL to replace your current site URL with on enabled elements. e.g. http://www.example.com'),
    );

    $form['mid'] = array(
      '#type' => 'hidden',
      '#value' => $mid,
    );

    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Save changes to mirror'),
    );

    $form['#validate'][]  = 'simplecdn_mirror_validate';
    $form['#submit'][]    = 'simplecdn_mirror_edit_submit';

    return $form;
  }
}

/**
 * Edit a mirror.
 */
function simplecdn_mirror_edit_submit($form, &$form_state) {
  drupal_write_record('simplecdn_mirrors', $form_state['values'], 'mid');
  drupal_set_message(t("CDN Mirror %name updated.", array('%name' => $form_state['values']['name'])));
  simplecdn_rebuild_cache();
  $form_state['redirect'] = 'admin/settings/simplecdn/mirrors';
}

/**
 * Form to delete a mirror.
 */
function simplecdn_mirror_delete($form_state, $mid = NULL) {
  $mirror = simplecdn_mirrors($mid);
  if (empty($mirror)) {
    drupal_set_message(t('The specified mirror was not found.'), 'error');
    drupal_goto('admin/settings/simplecdn/mirrors');
  }

  $form = array();
  $form['mid'] = array('#type' => 'value', '#value' => $mid);
  return confirm_form(
    $form,
    t('Are you sure you want to delete the mirror %name?',
      array('%name' => $mirror['name'])
    ),
    'admin/settings/simplecdn/mirrors',
    t('This action cannot be undone.'),
    t('Delete'),  t('Cancel')
  );
}

/**
 * Delete a mirror.
 */
function simplecdn_mirror_delete_submit($form, &$form_state) {
  $mirror = simplecdn_mirrors($form_state['values']['mid']);
  db_query('DELETE FROM {simplecdn_mirrors} where mid = %d', $mirror['mid']);
  drupal_set_message(t('CDN Mirror %name was deleted.', array('%name' => $mirror['name'])));
  simplecdn_rebuild_cache();
  $form_state['redirect'] = 'admin/settings/simplecdn/mirrors';
}


/**
 * Admin settings.
 */
function simplecdn_admin() {
  $form = array();

  $form['global'] = array(
    '#type' => 'fieldset', 
    '#title' => t('Global Settings'), 
    '#weight' => -2, 
    '#collapsible' => FALSE, 
    '#collapsed' => FALSE,
  );

  $form['global']['simplecdn_site_url'] = array(
    '#type' => 'textfield',
    '#title' => t('Website URL'),
    '#default_value' => variable_get('simplecdn_site_url', 'http://'),
    '#size' => 60,
    '#maxlength' => 256,
    '#required' => TRUE,
    '#description' => t("Your website url e.g. http://www.example.com")
  );

  $form['elements'] = array(
    '#type' => 'fieldset', 
    '#title' => t('Elements'), 
    '#weight' => -1, 
    '#collapsible' => FALSE, 
    '#collapsed' => FALSE,
  );

  $mirrors = simplecdn_mirrors();
  $new_mirrors = array('none' => t("Don't use a CDN Mirror"));
  foreach($mirrors as $mirror) {
    $new_mirrors[$mirror['mid']] = t($mirror['name'].' ('.$mirror['url'].')');
  }

  foreach(simplecdn_elements() as $element) {
    $form['elements']['simplecdn_element_'.$element['eid']] = array(
      '#type' => 'select',
      '#title' => t($element['name']),
      '#default_value' => variable_get('simplecdn_element_'.$element['eid'], 'none'),
      '#options' => $new_mirrors,
    );
  }

  return system_settings_form($form);
}

/**
 * Create new CDN Mirror URL.
 */
function simplecdn_rewrite_url($url = NULL, $eid = NULL) {
  $mirror = simplecdn_mirrors(variable_get('simplecdn_element_'.$eid, NULL));

  //Check URL isn't empty
  if ($url == NULL) {
    return NULL;
  }

  //If enough variables aren't available send it back untouched
  if ($eid == NULL || $eid == 'none' || $mirror['url'] == '') {
    return $url;
  }

  //Do the URL replace
  $url = str_ireplace(variable_get('simplecdn_site_url', NULL), $mirror['url'], $url, $count);

  //Adds the domain if needed
  if($count == 0) {
    $url = $mirror['url'].$url;
  }

  return $url;
}


/** ========================================
 * PLUGINS
 */


/**
 * Invoke a hook_simplecdnapi() operation in all modules.
 *
 * @param $op
 *   A string containing the name of the simplecdnapi operation.
 *    'load' is called when an element is loaded
 *
 * @return
 *   The returned value of the invoked hooks.
 */
function simplecdn_invoke_simplecdnapi($op) {
  $results = array();
  foreach (module_implements('simplecdnapi') as $name) {
    $function = $name .'_simplecdnapi';
    $result = $function($op);
    $results[] = $result;
  }
  return $results;
}

/**
 * Return array of elements.
 */
function simplecdn_elements() {
  return simplecdn_invoke_simplecdnapi('load');
}