<?php
// $Id: panels.module,v 1.10.4.16 2007-06-01 02:41:49 merlinofchaos Exp $

function panels_help($section = NULL) {
  
}
    /**
     * FIXME: needs to be with the layout piece that requires it.
     * farm out menu items to layouts.
     */
function panels_menu($may_cache) {
  if ($may_cache) {
    $items[] = array(
      'path' => 'panels/node/autocomplete',
      'title' => t('Autocomplete node'),
      'callback' => 'panels_node_autocomplete',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK
    );
    $items[] = array(
      'path' => 'panels/ajax',
      'title' => t('ajax'),
      'callback' => 'panels_ajax',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK
    );
    $items[] = array(
      'path' => 'panels/ajax/add-content',
      'title' => t('ajax'),
      'callback' => 'panels_ajax_add_content',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK
    );
    $items[] = array(
      'path' => 'panels/ajax/add-config',
      'title' => t('ajax'),
      'callback' => 'panels_ajax_add_config',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK
    );
    $items[] = array(
      'path' => 'panels/ajax/configure',
      'title' => t('ajax'),
      'callback' => 'panels_ajax_configure',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK
    );
  }
  return $items;
}

/**
 * panels path helper function
 */
function panels_get_path($file, $base_path = false, $module = 'panels') {
  if ($base_path) {
    $output = base_path();
  }
  return $output . drupal_get_path('module', $module) . '/' . $file;
}

// ---------------------------------------------------------------------------
// panels custom image button

/**
 * Custom form element to do our nice images.
 */
function panels_elements() {
  $type['panels_imagebutton'] = array('#input' => TRUE, '#button_type' => 'submit',);
  return $type;
}

/**
 * Theme our image button.
 */
function theme_panels_imagebutton($element) {
  return '<input type="image" ' . 
    'class="form-' . $element['#button_type'] . ' ' . $element['#class'] . '" ' . 
    'name="'. $element['#name'] .'" ' .
    'value="'. check_plain($element['#default_value']) .'" ' . 
    'id="' . $element['#id'] . '" ' .
    drupal_attributes($element['#attributes']) . 
    ' src="' . $element['#image'] . '" ' .
    'alt="' . $element['#title'] . '" ' .
    'title="' . $element['#title'] . '" ' .
    "/>\n";
}

function panels_imagebutton_value() {
  // null function guarantees default_value doesn't get moved to #value.
}

/**
 * Add a single button to a form.
 */
function panels_add_button($image, $name, $text, $class, $id = NULL) {
  return array(
    '#type' => 'panels_imagebutton',
    '#image' => panels_get_path('images/' . $image, true),
    '#title' => $text,
    '#default_value' => $name,
    '#class' => $class,
    '#id' => $id,
  );
}

// ---------------------------------------------------------------------------
// session handling stuff for display editing

function panels_cache_get($did) {
  static $cache = array();
  if (!array_key_exists($did, $cache)) {
    $data = cache_get(session_id() . ':' . $did, 'cache');
    $cache[$did] = unserialize($data->data);
  }
  return $cache[$did];
}

function panels_cache_set($did, $cache) {
  cache_set(session_id() . ':' . $did, 'cache', serialize($cache), time() + 86400);
}

function panels_cache_clear($did) {
  cache_clear_all(session_id() . ':' . $did, 'cache');
}

// non-session globals
function panels_set($var, $value = NULL) {
  static $vars = array();
  if ($value !== NULL) {
    $vars[$var] = $value;
  }
  return $vars[$var];
}

function panels_get($var) {
  return panels_set($var);
}

// ---------------------------------------------------------------------------
// panels display editing

/**
 * Main API entry point to edit a panel display.
 */
function panels_edit($display, $destination, $content_types = NULL) {
  $did = $display->did;
  if (!$did) {
    $display->did = $did = 'new';
  }

  if (!empty($_POST) && is_object($cache = panels_cache_get($did))) {
    $display = $cache->display;
  }
  else {
    panels_cache_clear($did);
    $cache = new stdClass();
    $cache->display = $display;
    $cache->highest = 0;
    $cache->content_types = $content_types;
    panels_cache_set($did, $cache);
  }

  $output = drupal_get_form('panels_edit_display', $display, $destination);
  $hidden = theme('panels_hidden');
  return $output . $hidden;
}

function panels_edit_display($display, $destination) {
  $form['did'] = array(
    '#type' => 'hidden',
    '#value' => $display->did,
    '#id' => 'panel-did',
  );

  $form['op'] = array(
    '#type' => 'hidden',
    '#id' => 'panel-op',
  );

  $form['panels_display'] = array(
    '#type' => 'value',
    '#value' => $display
  );

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

  $form['button']['#tree'] = TRUE;
  foreach ($display->content as $pid => $panel) {
    $form['button'][$pid]['#tree'] = TRUE;
    $form['button'][$pid]['configure'] = panels_add_button('configure.gif', t('Configure'), t('Configure this pane'), 'pane-configure');
    $form['button'][$pid]['delete'] = panels_add_button('close.gif', t('Delete'), t('Remove this pane'), 'pane-delete');
  }

  $layout = panels_get_layout($display->layout);
  foreach ($layout['panels'] as $id => $name) {
    $form['panels'][$id]['add'] = panels_add_button('add.gif', t('Add content'), t('Add content to this panel'), 'pane-add', "pane-add-$id");
  }

  $form['panel'] = array('#tree' => TRUE);
  $form['panel']['pane'] = array('#tree' => TRUE);
  foreach ($layout['panels'] as $panel_id => $title) {
    $form['panel']['pane'][$panel_id] = array(
      '#type' => 'hidden',
      '#default_value' => implode(',', (array) $display->panels[$panel_id]),
    );
  }
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
    '#id' => 'panels-dnd-save',
  );  
  $form['cancel'] = array(
    '#type' => 'submit',
    '#value' => t('Cancel'),
  );  

  $form['hide'] = array(
    '#prefix' => '<span id="panels-js-only">',
    '#suffix' => '</span>',
  );

  $form['hide']['hide-all'] = array(
    '#type' => 'submit',
    '#value' => t('Hide all'),
    '#id' => 'panels-hide-all',
  );  

  $form['hide']['show-all'] = array(
    '#type' => 'submit',
    '#value' => t('Show all'),
    '#id' => 'panels-show-all',
  );  
  
  if ($submit) {
    // The caller wants their own submit.
    $form['#submit'] = array($submit => array());
  }
  return $form;
}

function theme_panels_edit_display($form) {
  _panels_js_files();
  $display = $form['panels_display']['#value'];
  $layout = panels_get_layout($display->layout);
  $save_buttons = drupal_render($form['submit']) . drupal_render($form['cancel']);

  foreach ($layout['panels'] as $panel_id => $title) {
    foreach ((array) $display->panels[$panel_id] as $pid) {
      $pane = $display->content[$pid];
      $left_buttons = NULL;
      $buttons = drupal_render($form['button'][$pid]['configure']);
      $buttons .= drupal_render($form['button'][$pid]['delete']);
      $content[$pane->panel] .= panels_show_pane($pane, $left_buttons, $buttons);
    }
    $content[$panel_id] = theme('panels_panel_dnd', $content[$panel_id], $panel_id, $title, drupal_render($form['panels'][$panel_id]['add']));
  }
  $output .= drupal_render($form);
  $output .= theme('panels_dnd', panels_render_layout($layout, $content));
  $output .= $save_buttons;
  return $output;
}

function panels_edit_display_submit($form_id, $form_values) {
  $display = $form_values['panels_display'];
  if ($form_values['op'] == t('Save')) {
    $old_content = $display->content;
    $display->content = array();

    foreach ($form_values['panel']['pane'] as $panel_id => $panes) {
      $display->panels[$panel_id] = array();
      if ($panes) {
        $pids = explode(',', $panes);
        foreach ($pids as $pid) {
          if ($old_content[$pid]) {
            $display->panels[$panel_id][] = $pid;
            $old_content[$pid]->panel = $panel_id;
            $display->content[$pid] = $old_content[$pid];
          }
        }
      }
    }
    drupal_set_message(t('Panel content has been updated.'));
    panels_save_display($display);
  }

  panels_cache_clear($display->did);
  return $form_values['destination'];
}

/**
 * Shortcut to the panels layout editor
 */
function panels_edit_layout($display, $finish, $destination) {
  return drupal_get_form('panels_choose_layout', $display, $finish, $destination);
}
/**
 * Form to change the layout of a display.
 */
function panels_choose_layout($display, $finish, $destination) {
  $layouts = panels_get_layouts();

  foreach ($layouts as $id => $layout) {
    $options[$id] = panels_print_layout_icon($id, $layout, check_plain($layout['title']));
  }
  $form['layout'] = array(
    '#type' => 'radios',
    '#title' => t('Choose layout'),
    '#options' => $options,
    '#default_value' => $display->layout,
  );

  $form['clearer'] = array(
    '#value' => '<div style="clear: both;"></div>',
  );

  $form['variables'] = array(
    '#type' => 'value',
    '#value' => array($display, $finish, $destination),
  );

  if ($_POST['op'] && $_POST['op'] != t('Back') && $display->content) {
    $form['#post'] = $_POST;
    $form = form_builder('panels_choose_layout', $form);
    unset($form['#post']);
    $form['layout']['#type'] = 'hidden';
    panels_change_layout($form, $display, $form['layout']['#value']);
  }

  if (($_POST['op'] && $_POST['op'] != t('Back')) || !$display->content) {
    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => $finish,
    );
  }
  else { 
    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Next'),
    );
  }
  
  $form['#token'] = FALSE; // no token please
  return $form;
}

function panels_choose_layout_submit($form_id, $form_values) {
  list($display, $finish, $destination) = $form_values['variables'];
  $new_layout_id = $form_values['layout'];
  if ($form_values['op'] == $finish) {
    foreach ($form_values['old'] as $id => $new_id) {
      $content[$new_id] = (array) $content[$new_id] + $display->panels[$id];
      foreach($content[$new_id] as $pid) {
        $display->content[$pid]->panel = $new_id;
      }
    }

    $display->panels = $content;
    $display->layout = $new_layout_id;

    // save it back to our session.
    panels_save_display($display);
    return $destination;
  }

  return FALSE;
}

function panels_change_layout(&$form, $display, $new_layout_id) {
  $new_layout = panels_get_layout($new_layout_id);

  $options = $new_layout['panels'];
  $keys = array_keys($options);
  $default = $options[0];

  $old_layout = panels_get_layout($display->layout);

  $form['container'] = array(
    '#prefix' => '<div class="change-layout-display">',
    '#suffix' => '</div>',
  );

  $form['container']['old_layout'] = array(
    '#value' => panels_print_layout_icon($display->layout, $old_layout, check_plain($old_layout['title'])),
  );
  
  $form['container']['right_arrow'] = array(
    '#value' => theme('image', drupal_get_path('module', 'panels') . '/images/go-right.png'),
  );
  $form['container']['new_layout'] = array(
    '#value' => panels_print_layout_icon($new_layout_id, $new_layout, check_plain($new_layout['title'])),
  );

  $form['container-clearer'] = array(
    '#value' => '<div style="clear: both;"></div>',
  );

  $form['old'] = array(
    '#tree' => true,
  );

  foreach ($display->panels as $id => $content) {
    $form['old'][$id] = array(
      '#type' => 'select',
      '#title' => t('Move content in @layout to', array('@layout' => $old_layout['panels'][$id])),
      '#options' => $options,
      '#default_value' => array_key_exists($id, $options) ? $id : $default,
    );
  }

  $form['back'] = array(
    '#type' => 'submit',
    '#value' => t('Back'),
  );
  return $form;
}

// ------------------------------------------------------------------
// Functions to provide information about a content type

function panels_ct_function($type, $name) {
  if (is_object($type)) {
    $content_type = $type;
  }
  else {
    $content_type = panels_get_content_type($type);
  }

  $function = $content_type[$name];
  if (function_exists($function)) {
    return $function; 
  }
}  

function panels_ct_get_content($type, $conf, $args, $context, $incoming_content) {
  if ($function = panels_ct_function($type, 'render callback')) {
    return $function($conf, $args, $context, $incoming_content); 
  }
}

function panels_ct_get_title($type, $conf) {
  if ($function = panels_ct_function($type, 'title callback')) {
    return $function($conf); 
  }
}

function panels_ct_get_add_form($type, $id, $parents) {
  if ($function = panels_ct_function($type, 'add callback')) {
    return $function($id, $parents); 
  }
}

function panels_ct_get_edit_form($type, $conf, $parents) {
  if ($function = panels_ct_function($type, 'edit callback')) {
    return $function($conf, $parents); 
  }
}

function panels_ct_validate_form($type, $form, $form_values) {
  if ($function = panels_ct_function($type, 'validate callback')) {
    return $function($form, $form_values); 
  }
}

function panels_ct_get_types($type) {
  if (is_array($type)) {
    $content_type = $type;
  }
  else {
    $content_type = panels_get_content_type($type);
  }

  $function = $content_type['content_types'];
  if (is_array($function)) {
    return $function;
  }

  if (function_exists($function)) {
    return $function($conf); 
  }
}

/**
 * Get an array of all available content types that can be fed into the
 * display editor for the add content list.
 */
function panels_get_available_content_types($context = NULL, $has_content = FALSE) {
  $content_types = panels_get_content_types();
  uasort($content_types, 'panels_title_sort');
  $available = array();

  foreach ($content_types as $id => $type) {
    // exclude items that require content if we're saying we don't
    // provide it.
    if (!empty($type['requires content']) && !$has_content) {
      continue;
    }

    // Check to see if the content type can be used in this context.
    if (!isset($type['required context']) || 
        (is_array($type['required_context']) &&
           in_array($context, $type['required_context'])) ||
        ($type['required_context'] == $context)) {
      $available[$id] = panels_ct_get_types($type);
    }
  }
  return $available;
}

// ------------------------------------------------------------------
// Functions to provide information about a panel or part of a panel.

function panels_get_pane_content($pane, $args = array(), $context = NULL, $incoming_content = '') {
  if (!$context) {
    $context = new panels_context;
  }
  if (!$incoming_content === '') {
    $incoming_content = t('Incoming content will be displayed here.');
  }

  return panels_ct_get_content($pane->type, $pane->configuration, $args, $context, $incoming_content);
}

function panels_get_pane_title($pane) {
  return panels_ct_get_title($pane->type, $pane->configuration);
}

function panels_get_pane_edit_form($pane, $parents) {
  return panels_ct_get_edit_form($pane->type, $pane->configuration, $parents);
}

function panels_show_pane($pane, $left_buttons, $buttons, $skin = TRUE) {
  $block = panels_get_pane_content($pane);
  $title = panels_get_pane_title($pane);

  $output = theme('panels_pane_dnd', $block, $pane->pid, $title, $left_buttons, $buttons);
  if ($skin) {
    $output = '<div class="panel-pane" id="panel-pane-' . $pane->pid . '">' . $output . '</div>';
  }
  return $output;
}

// ---------------------------------------------------------------------------
// panels ajax stuff (part of editing)

/**
 * Simple render function to make sure output is what we want.
 */
function panels_ajax_render($output = NULL, $title = NULL) {
  if (!is_object($output)) {
    $temp = new stdClass();
    $temp->output = $output;
    $temp->type = 'display';
    $temp->title = $title;
    $output = $temp;
  }
  if (!$output->output || !$output->type) {
    $output->output = t('The input was invalid');
    $output->type = 'display';
    $output->title = t('Error');
  }
  print drupal_to_js($output);
  exit;
}

/**
 * entry point into all the ajax stuff
 */
function panels_ajax($op = NULL, $did = NULL, $pid = NULL) {
  switch ($op) {
    case 'submit-form':
      if ((is_numeric($did) || $did == 'new') && $cache = panels_cache_get($did)) {
        $output = panels_edit_submit_subform($cache->display);
      }
      break;
  }      

  panels_ajax_render($output);
}

function panels_ajax_add_content($did = NULL, $panel_id = NULL) {
  if ((is_numeric($did) || $did == 'new') && $cache = panels_cache_get($did)) {
    $display = $cache->display;
    $layout = panels_get_layout($display->layout);
    if ($layout && array_key_exists($panel_id, $layout['panels'])) {
      $output->output = panels_add_content($cache, $panel_id);
      $output->type = 'display';
      $output->title = t('Add content to !s', array('!s' => $layout['panels'][$panel_id]));
    }
  }
  panels_ajax_render($output);
}

function panels_add_content($cache, $panel_id) {
  $return->type = 'display';
  $return->title = t('Choose type');
  panels_set('return', $return);

  if (!isset($cache->content_types)) {
    $cache->content_types = panels_get_available_content_types();
  }

  foreach ($cache->content_types as $id => $types) {
    if (is_array($types)) {
      foreach ($types as $content_id => $info) {
        if (isset($info['icon'])) {
          $icon = $info['icon'];
          if (isset($info['path'])) {
            $path = $info['path'];
          }
          else {
            $path = panels_get_path("content_types/$id");
          }
        }
        else {
          $icon = 'no-icon.png';
          $path = panels_get_path('images');
        }
        $title = filter_xss_admin($info['title']);
        if (isset($info['description'])) {
          $description = $info['description'];
        }
        else {
          $description = $title;
        }
        $output .= '<div class="content-type-button">';
        $link_text = theme('image', $path . '/' . $icon, $description, $description);
        $output .= l($link_text, 'javascript: void()', array('class' => 'panels-modal-add-config', 'id' => $id . '-' . $panel_id . '-' . $content_id), NULL, NULL, NULL, TRUE);
        $output .= "<div>$title</div>";
        $output .= '</div>';
      }
    }
  }
  if (!$output) {
    $output = t('There are no content types you may add to this display.');
  }
  return $output;
}


function panels_ajax_add_config($did = NULL, $pid = NULL) {
  if ((is_numeric($did) || $did == 'new') && $cache = panels_cache_get($did)) {
    $display = $cache->display;
    list($content_type_id, $panel_id, $type) = explode('-', $pid, 3);
    $conf = panels_ct_get_add_form($content_type_id, $type, array('configuration'));
    $types = panels_ct_get_types($content_type_id);
    $title = $types[$type]['title'];

    $cache->add_config = array($content_type_id, $conf, $panel_id, $title);
    panels_cache_set($display->did, $cache);

    $text = drupal_get_form('panels_add_content_config_form', $cache, $content_type_id, $conf, $panel_id, $title);
    $output = panels_get('return');
    $output->output = $text;
  }      
  panels_ajax_render($output);
}

function panels_add_content_config_form($display, $content_type_id = NULL, $conf = NULL, $panel_id = NULL, $title = NULL) {
  if (empty($content_type_id)) {
    $cache = panels_cache_get($display->did);
    if (isset($cache->add_config)) {
      list($content_type_id, $conf, $panel_id, $title) = $cache->add_config;
    }
  }

  $form['start_form'] = array('#value' => '<div class="modal-form">');

  $form['did'] = array(
    '#type' => 'value',
    '#value' => $display->did,
  );

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

  $form['panel'] = array(
    '#type' => 'value',
    '#value' => $panel_id,
  );

  $form['configuration'] = $conf;
  $form['configuration']['#tree'] = TRUE;
  
  $form['end_form'] = array('#value' => '</div>');

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

  $return->type = 'display';
  $return->title = t('Configure !s', array('!s' => $title));
  panels_set('return', $return);
  return $form;
}

function panels_add_content_config_form_validate($form_id, $form_values, $form) {
  panels_ct_validate_form($form_values['type'], $form['configuration'], $form_values['configuration']);
}

function panels_add_content_config_form_submit($form_id, $form) {
  $cache = panels_cache_get($form['did']);

  // keep an incrementing counter, add the data to the display.
  $pid = ++$cache->highest;
  $form['pid'] = "new-$pid";

  $cache->display->content[$form['pid']] = (object) $form;
  $cache->display->panels[$form['panel']][] = $form['pid'];

  panels_cache_set($form['did'], $cache);
  $return->type = 'add';
  $return->area = $form['panel'];
  $return->id = $form['pid'];

  // we need to fake the buttons a little.
  $buttons['configure'] = panels_add_button('configure.gif', t('Configure'), t('Configure this pane'), 'pane-configure');
  $buttons['configure']['#parents'] = array('button', $form['pid'], 'configure');

  $buttons['delete'] = panels_add_button('close.gif', t('Delete'), t('Remove this pane'), 'pane-delete');
  $buttons['delete']['#parents'] = array('button', $form['pid'], 'delete');
  
  $buttons = form_builder('dummy', $buttons);
  $return->output = panels_show_pane($cache->display->content[$form['pid']], NULL, drupal_render($buttons));

  panels_set('return', $return);
  return FALSE;
}

function panels_ajax_configure($did = NULL, $pid = NULL) {
  if ((is_numeric($did) || $did == 'new') && $cache = panels_cache_get($did)) {
    $text = drupal_get_form('panels_edit_pane_config_form', $cache->display, $pid);
    $output = panels_get('return');
    $output->output = $text;
  }
  panels_ajax_render($output);
}

function panels_edit_pane_config_form($display, $pid = NULL) {
  $cache = panels_cache_get($display->did);
  if ($pid === NULL) {
    if (isset($cache->pid)) {
      $pid = $cache->pid;
    }
    else {
      return array();
    }
  }
  else {
    $cache->pid = $pid;
    panels_cache_set($display->did, $cache);
  }

  $pane = $display->content[$pid];

  $form['start_form'] = array('#value' => '<div class="modal-form">');

  $form['did'] = array(
    '#type' => 'value',
    '#value' => $display->did,
  );

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

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

  $return->title = t('Configure !s', array('!s' => panels_get_pane_title($pane)));
  $form['configuration'] = panels_get_pane_edit_form($pane, array('configuration'));
  $form['configuration']['#tree'] = true;

  $return->type = 'display';
  panels_set('return', $return);
  
  $form['end_form'] = array('#value' => '</div>');

  $form['next'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );
  return $form;
}

function panels_edit_pane_config_form_submit($form_id, $form) {
  // save the new configuration.
  $cache = panels_cache_get($form['did']);
  $cache->display->content[$form['pid']]->configuration = $form['configuration'];
  panels_cache_set($form['did'], $cache);

  $return->type = 'replace';
  $return->id = $form['pid'];

  $block = panels_get_pane_content($cache->display->content[$form['pid']]);
  if (!$block->subject) {
    $block->subject = t('No title');
  }

  $return->output = theme('panels_pane', $block, $cache->display);

  panels_set('return', $return);
  return FALSE;
}
 
function panels_edit_submit_subform($display) {
  $valid_forms = array('panels_add_content_config_form', 'panels_edit_pane_config_form');
  $form_id = $_POST['form_id'];
  if (!in_array($form_id, $valid_forms)) {
    return panels_ajax_render();
  }

  // TODO: protect form_id to make sure it can only get panels forms.
  $output = drupal_get_form($form_id, $display);

  $next = panels_get('next');

  if ($next) {
    $output = drupal_get_form($next['form'], $display, $next['data']);
    $return = panels_get('return');
    if (!$return->output) {
      $return->output = $output;
    }
  }
  else {
    if (!($return = panels_get('return'))) {
      $return->type = 'display';
      $return->output = $output;
    }
    else if ($return->type == 'display' && !$return->output) {
      $return->output = $output;
    }
  }

  if ($return->type == 'display') {
    $return->output = theme('status_messages') . $return->output;
  }
  return $return;
}

// End of ajax functions
// ---------------------

/* TODO: Integrate this back in */
/*
function panels_edit_display_validate($form_id, $form_values, $form) {
  foreach ($form_values['content'] as $area => $content) {
    foreach ($content as $id => $item) {
      if (is_numeric($id)) {
        panels_ct_validate($item['type'], $item['configuration'], $form['content'][$area][$id]['configuration']);
      }
    }
  }
}
*/
/**
 * move an item in an array to the top
 */
function panels_move_top(&$array, &$position) {
  $value = $array[$position];
  unset($array[$position]);
  array_unshift($array, $value);
  // reindex the array now
  $array = array_values($array);
}

/**
 * move an item in an array to the bottom
 */
function panels_move_bottom(&$array, &$position) {
  $value = $array[$position];
  unset($array[$position]);
  $array[] = $value;
  // reindex the array now
  $array = array_values($array);
}

/**
 * move an item in an array up one position
 */
function panels_move_up(&$array, &$position) {
  $value = $array[$position];
  $array[$position] = $array[$position - 1];
  $array[$position - 1] = $value;
}

/**
 * move an item in an array up one position
 */
function panels_move_down(&$array, &$position) {
  $value = $array[$position];
  $array[$position] = $array[$position + 1];
  $array[$position + 1] = $value;
}

/**
 * Remove an item from an array
 */
function panels_move_delete(&$array, &$position) {
  unset($array[$position]);
  // reindex the array now
  $array = array_values($array);
}

// ---------------------------------------------------------------------------
// panels database functions

class panels_display {
  var $args = array();
  var $incoming_content = NULL;
  var $context = NULL;
  var $css_id = NULL;

  function panels_display($context = NULL) {
    if (!isset($context)) {
      $this->context = new panels_context();
    }
  }
}

function panels_new_display($context = NULL) {
  $display = new panels_display($context);
  $display->did = 'new';
  return $display;
}

function panels_load_display($did, $context = NULL) {
  $display = new panels_display($context);

  $obj = db_fetch_array(db_query("SELECT * FROM {panels_display} WHERE did = %d", $did));
  foreach ($obj as $key => $value) {
    $display->$key = $value;
  }
  if (!$display) {
    return NULL;
  }
  $result = db_query("SELECT * FROM {panels_pane} WHERE did = %d ORDER BY panel, position", $did);
  $display->panels = $display->content = array();
  while ($pane = db_fetch_object($result)) {
    $pane->configuration = unserialize($pane->configuration);
    $display->panels[$pane->panel][] = $pane->pid;
    $display->content[$pane->pid] = $pane;
  }
  return $display;
}

function panels_save_display(&$display) {
  if ($display->did && $display->did != 'new') {
    db_query("UPDATE {panels_display} SET layout = '%s' WHERE did = %d", $display->layout, $display->did);
    db_query("DELETE FROM {panels_pane} WHERE did = %d", $display->did);
  }
  else {
    $display->did = db_next_id("{panels_display}_id");
    db_query("INSERT INTO {panels_display} (did, layout) VALUES (%d, '%s')", $display->did, $display->layout);
  }

  // update all the panes
  foreach ($display->panels as $id => $panes) {
    $position = 0;
    $new_panes = array();
    foreach ((array) $panes as $pid) {
      $pane = $display->content[$pid];
      $pane->position = $position++;
      if (!is_numeric($pid)) {
        unset($display->content[$pid]);
        $pane->pid = db_next_id("{panels_pane}_pid");
      }
      db_query("INSERT INTO {panels_pane} (pid, did, panel, type, configuration, position) VALUES (%d, %d, '%s', '%s', '%s', %d)", $pane->pid, $display->did, $pane->panel, $pane->type, serialize($pane->configuration), $pane->position);
      // and put it back so our pids and positions can be used
      $display->content[$pid] = $pane;
      $new_panes[] = $pid;
    }
    $display->panels[$id] = $panes;
  }

  return $display; // to be nice, even tho we have a reference.
}

function panels_delete_display($display) {
  db_query("DELETE FROM {panels_display} WHERE did = %d", $display->did);
  db_query("DELETE FROM {panels_pane} WHERE did = %d", $display->did);
}

/**
 * For external use: Given a layout ID and a $content array, return the
 * panel display.
 */
function panels_print_layout($id, $content) {
  $layout = panels_get_layout($id);
  if (!$layout) {
    return;
  }
  
  return panels_render_layout($layout, $content);
}

/**
 * Given a full layout structure and a content array, render a panel display.
 */
function panels_render_layout($layout, $content, $css_id = NULL) {
  $output = theme($layout['theme'], check_plain($css_id), $content);

  if ($output) {
    if (file_exists(path_to_theme() . '/' . $layout['css'])) {
      drupal_add_css(path_to_theme() . '/' . $layout['css']);
    }
    else {
      drupal_add_css(panels_get_path($layout['css'], false, $layout['module']));
    }
  }
  return $output;
}

class panels_context {
  var $type = NULL;
  var $data = NULL;

  function panels_context($type = 'none', $data = NULL) {
    $this->type = $type;
    $this->data = $data;
  }
}

function panels_sanitize_display(&$display) {
  if (!isset($display->args)) {
    $display->args = array();
  }

  if (!isset($display->incoming_content)) {
    $display->incoming_content = NULL;
  }

  if (!isset($display->context)) {
    $display->context = new panels_context();
  }

  if (!isset($display->css_id)) {
    $display->css_id = NULL;
  }
}

/**
 * Render a display by loading the content into an appropriate
 * array and then passing through to panels_render_layout. 
 *
 * if $incoming_content is NULL, default content will be applied. Use 
 * an empty string to indicate no content.
 */
function panels_render_display(&$display) {
  $layout = panels_get_layout($display->layout);
  
  if (!$layout) {
    return NULL;
  }

  panels_sanitize_display($display);

  foreach ($display->content as $pid => $pane) {
    if ($result = panels_get_pane_content($pane, $display->args, $display->context, $display->incoming_content)) {
      if (!empty($content[$pane->panel])) {
        $content[$pane->panel] .= theme('panels_separator', $display);
      }
      $content[$pane->panel] .= theme('panels_pane', $result, $display); 
    }
  }

  $output = panels_render_layout($layout, $content, $display->css_id);
  return $output;
}

// ---------------------------------------------------------------------------
// panels data loading

function panels_load_includes($directory, $callback, $file = NULL) {
  // Load all our module 'on behalfs'.
  $path = panels_get_path($directory);
  $files = drupal_system_listing("$file" . '.inc$', $path, 'name', 0);
  foreach($files as $file) {
    require_once('./' . $file->filename);
  }
  $output = module_invoke_all($callback);
  foreach ($files as $file) {
    $function = 'panels_' . $file->name . '_' . $callback;
    if (function_exists($function)) {
      $result = $function();
      if (isset($result) && is_array($result)) {
        $output = array_merge($output, $result);
      }
    }
  }
  return $output;
}

function panels_get_layout($layout) {
  return panels_get_layouts($layout);
}

function panels_get_layouts($layout = NULL) {
  static $layouts = array();
  static $all_layouts = FALSE;

  if (!$all_layouts) {
    if (!$layout) {
      $layouts = panels_load_includes('layouts', 'panels_layouts');
      $all_layouts = TRUE;
    }
    else if (!array_key_exists($layout, $layouts)) {
      $temp_layouts = panels_load_includes('layouts', 'panels_layouts', $layout);
      if (isset($temp_layouts[$layout])) {
        $layouts[$layout] = $temp_layouts[$layout];
      }
    }
  }
  if ($layout) {
    return isset($layouts[$layout]) ? $layouts[$layout] : NULL;
  }
  return $layouts;
}

function panels_get_content_type($content_type) {
  return panels_get_content_types($content_type);
}

function panels_get_content_types($content_type = NULL) {
  static $content_types = array();
  static $all_content_types = FALSE;

  if (!$all_content_types) {
    if (!$content_type) {
      $content_types = panels_load_includes('content_types', 'panels_content_types');
      $all_content_types = TRUE;
    }
    else if (!array_key_exists($content_type, $content_types)) {
      $temp_content_types = panels_load_includes('content_types', 'panels_content_types', $content_type);
      if (isset($temp_content_types[$content_type])) {
        $content_types[$content_type] = $temp_content_types[$content_type];
      }
    }
  }
  if ($content_type) {
    return isset($content_types[$content_type]) ? $content_types[$content_type] : NULL;
  }
  return $content_types;
}

/**
 * Includes required JavaScript libraries:
 * jQuery, iutil, idrag, idrop, isortables
 * In addition to panels.js.
 */
function _panels_js_files() {
  // while we don't use this directly some of our forms do.
  drupal_add_js('misc/collapse.js');
  drupal_add_js('misc/autocomplete.js');

  drupal_add_js(panels_get_path('js/lib/dimensions.js'));
  drupal_add_js(panels_get_path('js/lib/mc.js'));
  drupal_add_js(panels_get_path('js/lib/form.js'));
  drupal_add_js(array('panelsAjaxURL' => url('panels/ajax', NULL, NULL, TRUE)), 'setting');
  drupal_add_js(panels_get_path('js/display_editor.js'));
  drupal_add_css(panels_get_path('css/panels_dnd.css'));
  drupal_add_css(panels_get_path('css/panels_admin.css'));
}

// ---------------------------------------------------------------------------
// Panels theming functions

function theme_panels_dnd($content) {
  $output = "<div class=\"panels-dnd\" id=\"panels-dnd-main\">$content</div>";
  return $output;
}

function theme_panels_panel_dnd($content, $area, $label, $footer) {
  return "<div class=\"panels-display\" id=\"panel-pane-$area\">$footer<h2 class=\"label\">$label</h2>$content</div>";
}

function theme_panels_pane_dnd($block, $id, $label, $left_buttons = NULL, $buttons = NULL) {
  if (!$block->subject) {
    $block->subject = t('No title');
  }
  static $count = 0;
  $output .= "<div class=\"grabber\">";
  if ($buttons) {
    $output .= "<span class='buttons'>$buttons</span>";
  }
  if ($left_buttons) {
    $output .= "<span class='left_buttons'>$left_buttons</span>";
  }
  $output .= "<span class=\"text\">$label</span></div>";
  $output .= '<div class="panel-pane-collapsible">';
  $output .= theme('panels_pane_collapsible', $block);
  $output .= '</div>';
  return $output;
}

function theme_panels_pane($block, $display) {
  $output = '<div class="panel-pane">';
  $output .= theme('block', $block);
  $output .= '</div>';
  return $output;
}

function theme_panels_pane_collapsible($block) {
  $output .= '<h2 class="title">' . $block->subject . '</h2>';
  $output .= '<div class="content">' . filter_xss_admin($block->content) . '</div>';
  return $output;
}

function theme_panels_separator($display) {
  return '<div class="panel-separator"></div>';
}

/**
 * Print the layout link. Sends out to a theme function.
 */
function panels_print_layout_link($id, $layout, $link) {
  drupal_add_css(panels_get_path('css/panels_admin.css'));
  $file = panels_get_path($layout['icon'], false, $layout['module']);
  $image = l(theme('image', $file), $link, NULL, NULL, NULL, NULL, TRUE);
  $title = l($layout['title'], $link);
  return theme('panels_layout_link', $title, $id, $image, $link);
}

function panels_print_layout_icon($id, $layout, $title = NULL) {
  drupal_add_css(panels_get_path('css/panels_admin.css'));
  $file = panels_get_path($layout['icon'], false, $layout['module']);
  return theme('panels_layout_icon', $id, theme('image', $file), $title);
}

/**
 * Theme the layout link image
 */
function theme_panels_layout_link($title, $id, $image, $link) {
  $output .= '<div class="layout-link">';
  $output .= $image;
  $output .= '<div>' . $title . '</div>';
  $output .= '</div>';
  return $output;
}

/**
 * Theme the layout icon image
 */
function theme_panels_layout_icon($id, $image, $title = NULL) {
  $output .= '<div class="layout-icon">';
  $output .= $image;
  if ($title) {
    $output .= '<div class="caption">' . $title . '</div>';
  }
  $output .= '</div>';
  return $output;
}

/**
 * This is separate because it must be outside the <form> to work, and
 * everything in the form theme is inside the form.
 */
function theme_panels_hidden() {
  // TODO: Move this to a theme function.
  $close_text = t('Close Window');
  $close_image = theme('image', panels_get_path('images/close.gif'), t('Close window'), t('Close window'));
  $throbber_image = theme('image', panels_get_path('images/throbber.gif'), t('Loading...'), t('Loading'));
  $output = <<<EOF
<div class="panels-hidden">\n
  <div id="panels-modal">\n
    <div class="panels-modal-content">\n
       <div class="modal-header">\n
         <a class="close" href="#">$close_text $close_image</a>\n
         <span class="modal-title">&nbsp;</span>\n
       </div>\n
       <div class="modal-content">\n
       </div>\n
    </div>\n
  </div>\n
  <div id="panels-throbber">\n
    <div class="panels-throbber-wrapper">
      $throbber_image\n
    </div>
  </div>\n
</div>\n
EOF;

  return $output;
}

/**
 * Helper function for autocompletion of node titles.
 * This is mostly stolen from clipper.
 */
function panels_node_autocomplete($string) {
  if ($string != '') { // if there are node_types passed, we'll use those in a MySQL IN query.
    $result = db_query_range(db_rewrite_sql('SELECT n.title, u.name FROM {node} n INNER JOIN {users} u ON u.uid = n.uid WHERE LOWER(title) LIKE LOWER("%%%s%%")'), $string, 0, 10);
    $prefix = count($array) ? implode(', ', $array) .', ' : '';

    $matches = array();
    while ($node = db_fetch_object($result)) {
      $n = $node->title;
      // Commas and quotes in terms are special cases, so encode 'em.
      if (preg_match('/,/', $node->title) || preg_match('/"/', $node->title)) {
        $n = '"'. preg_replace('/"/', '""', $node->title) .'"';
      }
      $matches[$prefix . $n] = '<span class="autocomplete_title">'. check_plain($node->title) .'</span> <span class="autocomplete_user">('. t('by %user', array('%user' => check_plain($node->name))) .')</span>';
    }
    print drupal_to_js($matches);
    exit();
  }
}

/**
 * function for uasort to do title sorting.
 */
function panels_title_sort($a, $b) {
  if (!isset($a['weight'])) {
    $a['weight'] = 0;
  }
  if (!isset($b['weight'])) {
    $b['weight'] = 0;
  }
  if (!isset($a['title'])) {
    $a['title'] = NULL;
  }
  if (!isset($b['title'])) {
    $b['title'] = NULL;
  }
  if ($a['weight'] == $b['weight']) {
    if ($a['title'] < $b['title']) {
      return -1;
    }
    else if (drupal_strtolower($a['title']) > drupal_strtolower($b['title'])) {
      return 1;
    }
    else {
      return 0;
    }
  }
  return ($a['weight'] < $b['weight']) ? -1 : 1;
}