<?php

/**
 * @file
 * Field handler to present a form field to change quantity of a line item. It's
 * a dummy handler, most part of the implementation is done via post render
 * hook.
 */

/**
 * Field handler to present a field to change quantity of a line item.
 */
class commerce_line_item_handler_field_edit_quantity extends views_handler_field {

  function construct() {
    parent::construct();
    $this->additional_fields['line_item_id'] = 'line_item_id';
    $this->additional_fields['quantity'] = 'quantity';

    // Set real_field in order to make it generate a field_alias.
    $this->real_field = 'quantity';
  }

  function render($values) {
    return '<!--form-item-' . $this->options['id'] . '--' . $this->view->row_index . '-->';
  }

  /**
   * Returns the form which replaces the placeholder from render().
   */
  function views_form(&$form, &$form_state) {
    // The view is empty, abort.
    if (empty($this->view->result)) {
      return;
    }

    $form[$this->options['id']] = array(
      '#tree' => TRUE,
    );
    // At this point, the query has already been run, so we can access the results
    // in order to get the base key value (for example, nid for nodes).
    foreach ($this->view->result as $row_id => $row) {
      $line_item_id = $this->get_value($row, 'line_item_id');
      $quantity = $this->get_value($row, 'quantity');

      $form[$this->options['id']][$row_id] = array(
        '#type' => 'textfield',
        '#datatype' => 'integer',
        '#default_value' => round($quantity),
        '#size' => 4,
        // The line item database schema limits the quantity to 8 numerals for
        // integer quantities. For fractional quantities, we'd support decimal
        // places, but without knowing if a site supports them or not, the
        // safest option for this field's supported input length is 8; but a
        // malicious user could still create a problem insert by using the max
        // quantity on a price so it breaks the total allowed amount. If a site
        // has been customized to support larger quantity values, this property
        // can still be overridden via a form alter.
        '#maxlength' => 6,
        '#line_item_id' => $line_item_id,
        '#attributes' => array(
          'title' => $this->options['label'],
        ),
      );
    }
  }

  function views_form_validate($form, &$form_state) {
    $field_name = $this->options['id'];
    foreach (element_children($form[$field_name]) as $row_id) {
      // Ensure the quantity is actually a numeric value.
      if (!is_numeric($form_state['values'][$field_name][$row_id]) || $form_state['values'][$field_name][$row_id] < 0) {
        form_set_error($field_name . '][' . $row_id, t('You must specify a positive number for the quantity'));
      }

      // If the custom data type attribute of the quantity element is integer,
      // ensure we only accept whole number values.
      if ($form[$field_name][$row_id]['#datatype'] == 'integer' &&
        (int) $form_state['values'][$field_name][$row_id] != $form_state['values'][$field_name][$row_id]) {
        form_set_error($field_name . '][' . $row_id, t('You must specify a whole number for the quantity.'));
      }
    }
  }

  function views_form_submit($form, &$form_state) {
    $field_name = $this->options['id'];
    $deleted_line_items = array();
    $updated_line_items = array();

    foreach (element_children($form[$field_name]) as $row_id) {
      $line_item_id = $form[$field_name][$row_id]['#line_item_id'];

      // If the line item hasn't been deleted...
      if ($line_item = commerce_line_item_load($line_item_id)) {
        $form_quantity = $form_state['values'][$field_name][$row_id];

        // If the quantity on the form is different...
        if ($form_quantity != $line_item->quantity) {
          // If the quantity specified is 0, flag the line item for deletion.
          if ($form_quantity == 0) {
            $deleted_line_items[] = $line_item_id;
          }
          else {
            // Otherwise queue the line item quantity update.
            $updated_line_items[$line_item_id] = $form_quantity;
          }
        }
      }
    }

    // Process the deletes first.
    if (!empty($deleted_line_items)) {
      $order = commerce_order_load($form_state['order']->order_id);
      foreach ($deleted_line_items as $line_item_id) {
        $order = commerce_cart_order_product_line_item_delete($order, $line_item_id, TRUE);
      }
      commerce_order_save($order);
    }

    // Then process the quantity updates.
    foreach ($updated_line_items as $line_item_id => $quantity) {
      // Load the line item and update it.
      $line_item = commerce_line_item_load($line_item_id);
      $line_item->quantity = $quantity;
      commerce_line_item_save($line_item);
    }
  }
}
