<?php
/**
 * @file
 * Hooks and API functions for Data Node module.
 */

/**
 * Implementation of hook_views_api().
 */
function data_node_views_api() {
  return array(
    'api' => '2.0',
    'path' => drupal_get_path('module', 'data_node') .'/views',
  );
}

/**
 * Implementation of hook_theme().
 */
function data_node_theme() {
  return array(
    'data_node_label' => array(
      'arguments' => array('table' => NULL, 'id' => NULL, 'nid' => NULL, 'title' => NULL),
      'file' => 'data_node.theme.inc',
    ),
    'data_node_active_form' => array(
      'arguments' => array('form' => array()),
      'file' => 'data_node.theme.inc',
    ),
  );
}

/**
 * Implementation of hook_block().
 */
function data_node_block($op = 'list', $delta = 0) {
  switch ($op) {
    case 'list':
      $blocks = array();
      $tables = data_get_all_tables();
      foreach ($tables as $table) {
        $meta = $table->get('meta');
        if (!empty($meta['data_node']['content_type'])) {
          $blocks[$table->get('name')]['info'] = t('Data node: Active node form for @table', array('@table' => $table->get('title')));
        }
      }
      return $blocks;
    case 'view':
      if (user_access('manage data relations') && $table = data_get_table($delta)) {
        // Grab the node type name
        $meta = $table->get('meta');
        $names = node_get_types('names');
        $type_name = check_plain($names[$meta['data_node']['content_type']]);

        return array(
          'subject' => t('Active !type', array('!type' => $type_name)),
          'content' => drupal_get_form('data_node_active_form', $table),
         );
      }
  }
}

/**
 * Implementation of hook_menu().
 */
function data_node_menu() {
  $items = array();
  $items['data-node/add/%data_ui_table/%/%/%'] = array(
    'page callback' => 'data_node_add_page',
    'page arguments' => array(2, 3, 4, 5),
    'access callback' => 'user_access',
    'access arguments' => array('manage data relations'),
    'type' => MENU_CALLBACK,
    );
  $items['data-node/remove/%data_ui_table/%/%/%'] = array(
    'page callback' => 'data_node_remove_page',
    'page arguments' => array(2, 3, 4, 5),
    'access callback' => 'user_access',
    'access arguments' => array('manage data relations'),
    'type' => MENU_CALLBACK,
    );
  $items['data-node/active/%data_ui_table/%'] = array(
    'page callback' => 'data_node_active_page',
    'page arguments' => array(2, 3),
    'access callback' => 'user_access',
    'access arguments' => array('manage data relations'),
    'type' => MENU_CALLBACK,
    );
  $items['admin/build/data/edit/%data_ui_table/node'] = array(
    'title' => 'Relate to nodes',
    'description' => 'Administer data tables.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('data_node_settings_form', 4),
    'file' => 'data_node.admin.inc',
    'access arguments' => array('administer data tables'),
    'type' => MENU_LOCAL_TASK,
  );
  return $items;
}

/**
 * Implementation of hook_perm().
 */
function data_node_perm() {
  return array('edit data node relations');
}

/**
 * Form callback for setting the active node.
 */
function data_node_active_form(&$form_state, $table) {
  $form = array(
    '#attributes' => array('class' => 'data-node-active-form'),
    '#table' => $table,
    '#theme' => 'data_node_active_form',

    // These three are here to keep JS from doing reconstructive URL surgery.
    'ajax_url' => array(
      '#type' => 'hidden',
      '#value' => url('data-node/active/' . $table->get('name')),
      '#attributes' => array('class' => 'data-node-ajax-url'),
    ),
    'add_url' => array(
      '#type' => 'hidden',
      '#value' => url('data-node/add/' . $table->get('name')),
      '#attributes' => array('class' => 'data-node-add-url'),
    ),
    'remove_url' => array(
      '#type' => 'hidden',
      '#value' => url('data-node/remove/' . $table->get('name')),
      '#attributes' => array('class' => 'data-node-remove-url'),
    ),
  );

  $nodes = array(0 => '--'. t('Select') .'--');
  $nodes += data_node_get_nodes($table);

  // Grab the node type name and provide a creation option
  $meta = $table->get('meta');
  $names = node_get_types('names');
  $type_name = check_plain($names[$meta['data_node']['content_type']]);
  if (node_access('create', $meta['data_node']['content_type'])) {
    $nodes['new'] = '< '. t('New !type', array('!type' => $type_name)) .' >';
  }

  $form['nid'] = array(
    '#type' => 'select',
    '#title' => t('Active !type', array('!type' => $type_name)),
    '#options' => $nodes,
    '#default_value' => data_node_get_active($table->get('name')),
  );

  if (node_access('create', $meta['data_node']['content_type'])) {
    $form['new'] = array('#tree' => FALSE);
    $form['new']['type'] = array(
      '#type' => 'value',
      '#value' => $meta['data_node']['content_type'],
    );
    $form['new']['title'] = array(
      '#type' => 'textfield',
      '#size' => 20,
    );
    $form['new']['create'] = array(
      '#type' => 'submit',
      '#value' => t('Create'),
      '#submit' => array('data_node_active_form_create_submit'),
    );
  }

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

/**
 * Submit handler for form.
 */
function data_node_active_form_submit($form, &$form_state) {
  data_node_set_active($form['#table']->get('name'), $form_state['values']['nid']);

  // Redirect ourselves because '#redirect' does not support queries.
  $query = array();
  foreach ($_GET as $k => $v) {
    if ($k != 'q') {
      $query[] = "$k=$v";
    }
  }
  drupal_goto($_GET['q'], implode('&', $query));
}

/**
 * Create submit handler for form.
 */
function data_node_active_form_create_submit($form, &$form_state) {
  $title = trim($form_state['values']['title']);
  if (!empty($title)) {
    global $user;
    $node = new stdClass();
    $node->uid = $user->uid;
    $node->title = $title;
    $node->type = $form_state['values']['type'];
    $node->body = '';
    foreach (variable_get('node_options_'. $node->type, array('status')) as $key) {
      $node->{$key} = 1;
    }
    node_save($node);

    data_node_set_active($form['#table']->get('name'), $node->nid);
  }

  // Redirect ourselves because '#redirect' does not support queries.
  $query = array();
  foreach ($_GET as $k => $v) {
    if ($k != 'q') {
      $query[] = "$k=$v";
    }
  }
  drupal_goto($_GET['q'], implode('&', $query));
}

/**
 * Page callback for adding.
 *
 * @todo: add tokenizing drupal_valid_token/drupal_get_token to prevent XSS
 */
function data_node_add_page($table, $id, $nid, $token) {
  if (drupal_valid_token($token, _data_node_hash($table, $id, $nid))) {
    data_node_remove($table, $id, $nid);
    data_node_add($table, $id, $nid);
  }
  // Handle AJAX requests
  if (isset($_GET['ajax'])) {
    $response = array(
      'status' => TRUE,
      'table' => $table->get('name'),
      'id' => $id,
      'nid' => $nid,
      'labels' => data_node_render_labels($table, $id),

      'add_link' => data_node_render_remove_link($table, $id, $nid),
      'remove_link' => data_node_render_add_link($table, $id, $nid),
    );
    drupal_json($response);
    exit;
  }
  drupal_goto($_GET['q']);
}

/**
 * Page callback for setting the active node.
 */
function data_node_active_page($table, $nid) {
  data_node_set_active($table->get('name'), $nid);
  // Handle AJAX requests
  if (isset($_GET['ajax'])) {
    // Generate new add/remove links to replace stale ones.
    $stale = isset($_GET['stale']) ?  explode('-', $_GET['stale']) : array();
    $refresh = array();
    foreach ($stale as $id) {
      $node_list = data_node_get_nids($table, $id);
      $refresh[$id] = in_array($nid, $node_list) ? data_node_render_remove_link($table, $id, $nid) : data_node_render_add_link($table, $id, $nid);
    }
    $response = array(
      'status' => TRUE,
      'table' => $table->get('name'),
      'nid' => $nid,
      'refresh' => $refresh,
    );
    drupal_json($response);
    exit;
  }
  drupal_goto($_GET['q']);
}

/**
 * Page callback for removing.
 *
 * @todo: add tokenizing drupal_valid_token/drupal_get_token to prevent XSS
 */
function data_node_remove_page($table, $id, $nid, $token) {
  if (drupal_valid_token($token, _data_node_hash($table, $id, $nid))) {
    data_node_remove($table, $id, $nid);
  }
  // Handle AJAX requests
  if (isset($_GET['ajax'])) {
    $response = array(
      'status' => TRUE,
      'table' => $table->get('name'),
      'id' => $id,
      'nid' => $nid,
      'labels' => data_node_render_labels($table, $id),

      'add_link' => data_node_render_remove_link($table, $id, $nid),
      'remove_link' => data_node_render_add_link($table, $id, $nid),
    );
    drupal_json($response);
    exit;
  }
  drupal_goto($_GET['q']);
}

/**
 * Add a relationship between a data table and a node.
 */
function data_node_add($table, $id, $nid) {
  $save = array(
    'data_table_name' => $table->get('name'),
    'id' => $id,
    'nid' => $nid,
  );
  return drupal_write_record('data_table_node', $save);
}

/**
 * Get the nids for a given record.
 */
function data_node_get_nids($table, $id) {
  $list = array();
  $result = db_query("SELECT nid FROM {data_table_node} WHERE data_table_name = '%s' AND id = %d", $table->get('name'), $id);
  while ($row = db_fetch_object($result)) {
    $list[] = $row->nid;
  }
  return $list;
}

/**
 * Remove a relationship between a data table and a node.
 */
function data_node_remove($table, $id, $nid) {
  db_query("DELETE FROM {data_table_node} WHERE data_table_name = '%s' AND id = %d AND nid = %d", $table->get('name'), $id, $nid);
}

/**
 * Get all available nodes for a specific table.
 */
function data_node_get_nodes($table) {
  $nodes = array();
  $meta = $table->get('meta');
  if ($meta['data_node']['content_type']) {
    $result = db_query("SELECT nid, title FROM {node} WHERE type = '%s' ORDER BY title ASC", $meta['data_node']['content_type']);
    while ($node = db_fetch_object($result)) {
      $nodes[$node->nid] = $node->title;
    }
  }
  return $nodes;
}

/**
 * Set a specific node as the active node. This is used for the collection workflow.
 */
function data_node_set_active($table_name, $nid) {
  $_SESSION['data_node_active'][$table_name] = $nid;
}

/**
 * Get a the current active node. This is used for the collection workflow.
 */
function data_node_get_active($table_name) {
  return $_SESSION['data_node_active'][$table_name];
}

/**
 * Create a simple hash of a table name, an id and a nid.
 */
function _data_node_hash($table, $id, $nid) {
  return $table->get('name') . $id . $nid;
}

/**
 * Static cache node titles to avoid unnecessary node loading.
 */
function _data_node_get_title($nid) {
  static $nodes = array();
  if (!isset($nodes[$nid])) {
    $nodes[$nid] = check_plain(db_result(db_query("SELECT title FROM {node} WHERE nid = %d", $nid)));
  }
  return isset($nodes[$nid]) ? $nodes[$nid] : NULL;
}

/**
 * Generate the path for a remove link for an item/node pair.
 */
function data_node_remove_path($table, $id, $nid) {
  $token = drupal_get_token(_data_node_hash($table, $id, $nid));
  $table_name = $table->get('name');
  return "data-node/remove/{$table_name}/$id/$nid/$token";
}

/**
 * Generate the path for an add link for an item/node pair.
 */
function data_node_add_path($table, $id, $nid) {
  $token = drupal_get_token(_data_node_hash($table, $id, $nid));
  $table_name = $table->get('name');
  return "data-node/add/{$table_name}/$id/$nid/$token";
}

/**
 * Render node-data labels for a given item.
 */
function data_node_render_labels($table, $id) {
  $nids = data_node_get_nids($table, $id);
  foreach ($nids as $nid) {
    $title = _data_node_get_title($nid);;
    $output .= theme('data_node_label', $table, $id, $nid, $title);
  }
  $table_name = $table->get('name');
  $class = "data_node_labels-{$table_name}-{$id}";
  return "<div class='{$class} clear-block'>{$output}</div>";
}

/**
 * Render a placeholder when there are no active nodes that can be replaced via AJAX.
 */
function data_node_render_placeholder_link($table, $id) {
  drupal_add_css(drupal_get_path('module', 'data_node') . '/data_node.css');
  drupal_add_js(drupal_get_path('module', 'data_node') . '/data_node.js');
  $table_name = $table->get('name');
  return "<span class='data-node-placeholder data_node_link-{$table_name}-{$id}-0'></span>";
}

/**
 * Render an add link for a given item..
 */
function data_node_render_add_link($table, $id, $nid) {
  drupal_add_css(drupal_get_path('module', 'data_node') . '/data_node.css');
  drupal_add_js(drupal_get_path('module', 'data_node') . '/data_node.js');

  $title = _data_node_get_title($nid);
  $table_name = $table->get('name');
  $class = "data_node_link-{$table_name}-{$id}-{$nid}";
  return l(t('Add to !title', array('!title' => $title)), data_node_add_path($table, $id, $nid), array('attributes' => array('class' => "data-node-add $class"), 'query' => drupal_get_destination()));
}

/**
 * Render a remove link for a given item.
 */
function data_node_render_remove_link($table, $id, $nid) {
  drupal_add_css(drupal_get_path('module', 'data_node') . '/data_node.css');
  drupal_add_js(drupal_get_path('module', 'data_node') . '/data_node.js');

  $title = _data_node_get_title($nid);
  $table_name = $table->get('name');
  $class = "data_node_link-{$table_name}-{$id}-{$nid}";
  return l(t('Remove from !title', array('!title' => $title)), data_node_remove_path($table, $id, $nid), array('attributes' => array('class' => "data-node-remove $class"), 'query' => drupal_get_destination()));
}