<?php
// $Id: uc_cart_links.module,v 1.1.2.6 2010-08-11 18:15:57 islandusurper Exp $

/**
 * @file
 * Allows store owners to create links to add products to carts and send
 * customers on to checkout.
 *
 * Development sponsored by the Ubercart project.  http://www.ubercart.org
 */


/*******************************************************************************
 * Hook Functions (Drupal)
 ******************************************************************************/

/**
 * Implementation of hook_menu().
 */
function uc_cart_links_menu($may_cache) {
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/store/settings/cart_links',
      'title' => t('Cart links settings'),
      'description' => t('Configure and craft special product add to cart links.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('uc_cart_links_settings_form'),
      'access' => user_access('administer cart links'),
      'type' => MENU_NORMAL_ITEM,
    );
    $items[] = array(
      'path' => 'admin/store/reports/cart_links',
      'title' => t('Cart links clicks'),
      'description' => t('Track clicks through cart links.'),
      'callback' => 'uc_cart_links_report',
      'access' => user_access('view cart links report'),
      'type' => MENU_NORMAL_ITEM,
    );
    $items[] = array(
      'path' => 'admin/store/help/cart_links',
      'title' => t('Creating cart links'),
      'description' => t('Learn how to create cart links for your products.'),
      'callback' => 'uc_cart_links_creation_help',
      'access' => user_access('administer store'),
      'type' => MENU_NORMAL_ITEM,
    );
  }
  else {
    $items[] = array(
      'path' => 'cart/add/'. arg(2),
      'title' => t('Add to cart'),
      'callback' => 'uc_cart_links_process',
      'callback arguments' => array(arg(2)),
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK,
    );

  }

  return $items;
}

/**
 * Implementation of hook_perm().
 */
function uc_cart_links_perm() {
  return array('administer cart links', 'view cart links report');
}

/**
 * Implementation of hook_add_to_cart().
 */
function uc_cart_links_add_to_cart($nid, $qty, $data) {
  if (user_access('administer cart links') &&
      variable_get('uc_cart_links_add_show', TRUE)) {
    $cart_link = 'p'. $nid .'_q'. $qty;
    if (!empty($data['attributes'])) {
      foreach ($data['attributes'] as $attribute => $option) {
        $cart_link .= '_a'. $attribute .'o'. $option;
      }
    }
    drupal_set_message(t('Cart link product action: @cart_link', array('@cart_link' => $cart_link)));
  }
}


/*******************************************************************************
 * Callback Functions, Forms, and Tables
 ******************************************************************************/

function uc_cart_links_settings_form() {
  $form['instructions'] = array(
    '#value' => '<div>'. t('<a href="!url">View the help page</a> to learn how to create cart links.', array('!url' => url('admin/store/help/cart_links'))) .'</div>',
  );

  $form['uc_cart_links_add_show'] = array(
    '#type' => 'checkbox',
    '#title' => t('Display the cart link product action when you add a product to your cart.'),
    '#default_value' => variable_get('uc_cart_links_add_show', TRUE),
  );
  $form['uc_cart_links_track'] = array(
    '#type' => 'checkbox',
    '#title' => t('Track clicks through cart links that specify tracking IDs.'),
    '#default_value' => variable_get('uc_cart_links_track', TRUE),
  );
  $form['uc_cart_links_messages'] = array(
    '#type' => 'textarea',
    '#title' => t('Cart links messages'),
    '#description' => t('Enter in messages available to the cart links API for display through a link. Separate messages with a line break.<br />Messages should have a numeric key and text value. Example: 1337|Message text.'),
    '#default_value' => variable_get('uc_cart_links_messages', ''),
  );
  $form['uc_cart_links_restrictions'] = array(
    '#type' => 'textarea',
    '#title' => t('Cart links restrictions'),
    '#description' => t('To restrict what cart links may be used on your site, enter valid cart links in this textbox.  Separate links with a line break. Leave blank to permit any cart link.'),
    '#default_value' => variable_get('uc_cart_links_restrictions', ''),
  );
  $form['uc_cart_links_invalid_page'] = array(
    '#type' => 'textfield',
    '#title' => t('Invalid link redirect page'),
    '#description' => t('Enter the URL to redirect to when an invalid cart link is used.'),
    '#default_value' => variable_get('uc_cart_links_invalid_page', ''),
    '#size' => 32,
    '#field_prefix' => url(NULL, NULL, NULL, TRUE) . (variable_get('clean_url', 0) ? '' : '?q='),
  );

  return system_settings_form($form);
}

// Displays the cart links report.
function uc_cart_links_report() {
  $header = array(
    array('data' => t('ID'), 'field' => 'cart_link_id'),
    array('data' => t('Clicks'), 'field' => 'clicks'),
    array('data' => t('Last click'), 'field' => 'last_click', 'sort' => 'desc'),
  );

  $rows = array();
  $result = pager_query("SELECT * FROM {uc_cart_link_clicks}". tablesort_sql($header), 25, 1);
  while ($data = db_fetch_object($result)) {
    $rows[] = array(
      check_plain($data->cart_link_id),
      $data->clicks,
      format_date($data->last_click, 'short'),
    );
  }

  if (empty($rows)) {
    $rows[] = array(
      array('data' => t('No cart links have been tracked yet.'), 'colspan' => 3),
    );
  }

  return theme('table', $header, $rows) . theme('pager', array(), 25, 1);
}

// Processes a cart link to fiddle with the cart and redirect the user.
function uc_cart_links_process($arg1) {
  $messages = array();

  // Fail if the link is restricted.
  $data = variable_get('uc_cart_links_restrictions', '');
  if (!empty($data)) {
    $restrictions = explode("\n", variable_get('uc_cart_links_restrictions', ''));
    if (!empty($restrictions) && !in_array($arg1, $restrictions)) {
      $url = variable_get('uc_cart_links_invalid_page', '');
      if (empty($url)) {
        $url = '<front>';
      }
      unset($_REQUEST['destination']);
      drupal_goto($url);
    }
  }

  // Split apart the cart link on the -.
  $actions = explode('-', strtolower($arg1));

  foreach ($actions as $action) {
    switch (substr($action, 0, 1)) {
      // Set the ID of the cart link.
      case 'i':
        $id = substr($action, 1);
        break;

      // Add a product to the cart.
      case 'p':
        // Set the default product variables.
        $p = array('nid' => 0, 'qty' => 1, 'data' => array());
        $msg = TRUE;

        // Parse the product action to adjust the product variables.
        $parts = explode('_', $action);
        foreach ($parts as $part) {
          switch (substr($part, 0, 1)) {
            // Set the product node ID: p23
            case 'p':
              $p['nid'] = intval(substr($part, 1));
              break;
            // Set the quantity to add to cart: q2
            case 'q':
              $p['qty'] = intval(substr($part, 1));
              break;
            // Set an attribute/option for the product: a3o6
            case 'a':
              $attribute = intval(substr($part, 1, strpos($part, 'o') - 1));
              $option = intval(substr($part, strpos($part, 'o') + 1));
              $p['attributes'][$attribute] = (string) $option;
              break;
            // Suppress the add to cart message: m0
            case 'm':
              $msg = intval(substr($part, 1)) == 1 ? TRUE : FALSE;
              break;
          }
        }

        // Add the item to the cart, suppressing the default redirect.
        if ($p['nid'] > 0 && $p['qty'] > 0) {
          $node = node_load(array('nid' => $p['nid']));
          if ($node->status) {
            uc_cart_add_item($p['nid'], $p['qty'], $p['data'] + module_invoke_all('add_to_cart_data', $p), NULL, $msg, FALSE);
          }
          else {
            watchdog('uc_cart_link', t('Cart link on %url tried to add an unpublished product to the cart.', array('%url' => uc_referer_uri())), WATCHDOG_ERROR);
          }
        }
        break;

      // Display a pre-configured message.
      case 'm':
        // Load the messages if they haven't been loaded yet.
        if (empty($messages)) {
          $data = explode("\n", variable_get('uc_cart_links_messages', ''));
          foreach ($data as $message) {
            $mdata = explode('|', $message);
            $messages[$mdata[0]] = $mdata[1];
          }
        }

        // Parse the message key and display it if it exists.
        $mkey = intval(substr($action, 1));
        if (!empty($messages[$mkey])) {
          drupal_set_message($messages[$mkey]);
        }
        break;
    }
  }

  if (variable_get('uc_cart_links_track', TRUE)) {
    $exists = db_result(db_query("SELECT clicks FROM {uc_cart_link_clicks} WHERE cart_link_id = '%s'", $id));
    if (intval($exists) == 0) {
      db_query("INSERT INTO {uc_cart_link_clicks} (cart_link_id, clicks, last_click) VALUES ('%s', 1, %d)", $id, time());
    }
    else {
      db_query("UPDATE {uc_cart_link_clicks} SET clicks = clicks + 1, last_click = %d WHERE cart_link_id = '%s'", time(), $id);
    }
  }

  drupal_goto();
}

function uc_cart_links_creation_help() {
  $items = array(
    t('The cart link should be /cart/add/cart_link_content.'),
    t('Chain together as many actions as you want with dashes.'),
    t('Do not put any spaces or use dashes in any action arguments.'),
    t('Use the table below to learn about actions and their arguments.'),
    t('Arguments come directly after their action letters.'),
    t('Specify the redirection by adding ?destination=url where url is the page to go to.'),
  );
  $header = array(t('Action'), t('Description'), t('Argument'));
  $rows = array(
    array('i', t('Sets the ID of the cart link.'), t('A custom text ID for the link.')),
    array('e', t("Empties the customer's cart."), t('None.')),
    array('m', t('Displays a preset message to the customer.'), t('A message ID.')),
    array('p', t('Adds a product to the cart.'), t('A product string using the rules below...')),
  );
  $items2 = array(
    t("You must at least specify a node ID immediately after the 'p'."),
    t('Add additional specifications separated by underscores.'),
    t('Specify the quantity with q followed by the number to add.'),
    t('Specify attributes/options using a#o#, replacing # with the ID of the attribute and option.'),
    t('Turn off the add to cart message with m0.'),
  );

  $output = '<div>'. t('There is currently no user interface for creating cart links, but this section includes some basic instructions.<br />Cart links are simple to form using a few actions and arguments with the following rules:')
           .'<p>'. theme('item_list', $items) .'</p><p>'. theme('table', $header, $rows) .'</p><p>'. theme('item_list', $items2) .'</p><p>'. t('<b>Example:</b> /cart/add/e-p1_q5-imonday_special?destination=cart<br /><br />This example will empty the cart, add 5 of product 1 to the cart, track clicks with the ID "monday_special", and redirect the user to the cart. To use this on your site, simply create an HTML link to the URL you create:')
           .'</p><p>&lt;a href="http://www.example.com/cart/add/e-p1_q5-imonday_special?destination=cart">'. t('Link text.') .'&lt;/a></p></div>';

  return $output;
}