/**
 * Implements hook_theme().
 */
function uc_varprice_theme() {
  return array(
    'varprice_qty' => array(
      'render element' => 'form',
    ),
  );
}

/**
 * Implements hook_form_alter().
 *
 * Summary of alterations:
 * 1) Alters the product feature add form to restrict multiple Variable Price
 *      features from being added to a single product.
 * 2) Alters the add to cart form for variable priced products.
 * 3) Disable the appropriate Qty. fields on the cart view form.
 * 4) Alter the product class form to set default donations.
 */
function uc_varprice_form_alter(&$form, &$form_state, $form_id) {
  // 1) Alter the product feature add form.
  if ($form_id == 'uc_product_feature_add_form') {
    // If a Variable Price feature has already been added to this product...
    if (db_query("SELECT COUNT(*) FROM {uc_product_features} WHERE nid = :nid AND fid = :fid", array(':nid' => arg(1), ':fid' => 'varprice'))->fetchField()) {
      // Remove Variable Price from the available list of features to add.
      unset($form['feature']['#options']['varprice']);
    }
  }

  // 2) Alter the add to cart form.
  if (strpos($form_id, 'uc_product_add_to_cart_form_') === 0) {
    $data = uc_varprice_product_load($form['nid']['#value']);

    if ($data) {
      $description = array();

      if (!empty($data->price_minimum)) {
        $description[] = t('Minimum: @price', array('@price' => uc_currency_format($data->price_minimum)));
      }
      if (!empty($data->price_maximum)) {
        $description[] = t('Maximum: @price', array('@price' => uc_currency_format($data->price_maximum)));
      }

      // Add the amount textfield to the add to cart form.
      $form['varprice'] = array(
        '#type' => 'textfield',
        '#title' => $data && !empty($data->amount_title) ? $data->amount_title : t('Amount'),
        '#description' => implode('<br />', $description),
        '#default_value' => $data ? $data->price_default : variable_get('uc_varprice_global_default', '0'),
        '#size' => 8,
        '#weight' => -5,
        '#field_prefix' => variable_get('uc_sign_after_amount', FALSE) ? '' : variable_get('uc_currency_sign', '$'),
        '#field_suffix' => variable_get('uc_sign_after_amount', FALSE) ? variable_get('uc_currency_sign', '$') : '',
      );
    }
  }

  // 3) Disable the appropriate Qty. fields on the cart view form.
  if ($form_id == 'uc_cart_view_form') {
    for ($i = 0, $j = count(uc_cart_get_contents()); $i < $j; $i++) {
      $data = unserialize($form['items'][$i]['data']['#value']);

      // If this item has a quantity restriction on it...
      if (isset($data['varprice']) && $data['varprice'] > 0) {
        $form['items'][$i]['qty']['#type'] = 'value';
        $form['items'][$i]['qty']['#theme'] = 'varprice_qty';
      }
    }
  }

  // 4) Alter the product class form to set default donations.
  if ($form_id == 'uc_product_class_form') {
    // Add some helper JS to the form.
    drupal_add_js(drupal_get_path('module', 'uc_varprice') . '/uc_varprice.js');

    $data = FALSE;
    if (!empty($form['pcid']['#value'])) {
      $class_defaults = variable_get('ucvp_class_def_' . $form['pcid']['#value'], array());
      if (!empty($class_defaults)) {
        $data = (object) unserialize($class_defaults);
      }
    }

    $form['varprice'] = array(
      '#type' => 'fieldset',
      '#title' => t('Default Variable Price product feature'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => 5,
    );
    $form['varprice']['default_varprice'] = array(
      '#type' => 'checkbox',
      '#title' => t('Check this box to add a default product feature to every product of this class using these settings.'),
      '#default_value' => $data === FALSE ? FALSE : TRUE,
    );
    $form['varprice'] += _uc_varprice_feature_form($data);

    $form['#submit'][] = 'uc_varprice_product_class_submit';

    $form['submit']['#weight'] = 10;
  }
}

/**
 * Submit handler for the product class form for default Variable Price features.
 */
function uc_varprice_product_class_submit($form, &$form_state) {
  if ($form_state['values']['default_varprice']) {
    $data = array(
      'price_default' => $form_state['values']['price_default'],
      'price_minimum' => $form_state['values']['price_minimum'],
      'price_maximum' => $form_state['values']['price_maximum'],
      'override_add_to_cart_title' => $form_state['values']['override_add_to_cart_title'],
      'add_to_cart_title' => $form_state['values']['override_add_to_cart_title'] ? $form_state['values']['add_to_cart_title'] : '',
      'override_amount_title' => $form_state['values']['override_amount_title'],
      'amount_title' => $form_state['values']['override_amount_title'] ? $form_state['values']['amount_title'] : '',
    );

    variable_set('ucvp_class_def_' . $form_state['values']['pcid'], serialize($data));
  }
  else {
    variable_del('ucvp_class_def_' . $form_state['values']['pcid']);
  }
}

/**
 * Implements hook_node_view().
 * Summary of alterations:
 * 1) Removes price displays from variable priced product nodes.
 * 2) Inserts Variable Price product feature on product node creation.
 */
function uc_varprice_node_view($node, $view_mode = 'full') {
  // If this node has a variable price product feature...
  if (db_query("SELECT pfid FROM {uc_product_features} WHERE fid = :fid AND nid = :nid", array(':fid' => 'varprice', ':nid' => $node->nid))->fetchField()) {
    // Hide all the prices from display.
    $node->content['cost']['#access'] = FALSE;
    $node->content['list_price']['#access'] = FALSE;
    $node->content['sell_price']['#access'] = FALSE;
    $node->content['display_price']['#access'] = FALSE;
  }
}

/**
 * Implements hook_node_insert().
 */
function uc_varprice_node_insert($node) {
  if (uc_product_is_product($node)) {
    $data = variable_get('ucvp_class_def_' . $node->type, array());

    // If the product class has a default Variable Price product feature...
    if ($data) {
      // Prepare the data as if it were from a form submission.
      $data = unserialize($data);
      $data['nid'] = $node->nid;
      $data['pfid'] = '';
      $form_state = array('values' => $data);

      // Add the feature to the product by spoofing the normal form submission.
      uc_varprice_feature_form_submit(array(), $form_state);
    }
  }
}

/**
 * Implements hook_uc_add_to_cart_data().
 */
function uc_varprice_uc_add_to_cart_data($form_values) {
  // Store the customer entered price in the product's data array.
  if (!empty($form_values['varprice'])) {
    return array('varprice' => $form_values['varprice'], 'uniqid' => uniqid());
  }
}

/**
 * Implements hook_uc_add_to_cart().
 */
function uc_varprice_uc_add_to_cart($nid, $qty, $data) {
  $result = array();

  // If there is Variable Price data for this product...
  if (isset($data['varprice'])) {
    $message = '';

    // Load the product feature data.
    $vp_data = uc_varprice_product_load($nid);

    // Fail if the customer failed to enter a price.
    if (empty($data['varprice']) || $data['varprice'] == 0) {
      $message = t('You must specify a price.');
    }
    // Fail if the customer entered a price lower than the minimum.
    elseif (!empty($vp_data->price_minimum) && $data['varprice'] < $vp_data->price_minimum) {
      $message = t('You must specify an amount greater than or equal to @price.', array('@price' => uc_currency_format($vp_data->price_minimum)));
    }
    // Fail if the customer entered a price above the maximum.
    elseif (!empty($vp_data->price_maximum) && $data['varprice'] > $vp_data->price_maximum) {
      $message = t('You must specify an amount less than or equal to @price.', array('@price' => uc_currency_format($vp_data->price_maximum)));
    }

    // If an error message was set, return the failure notification.
    if (!empty($message)) {
      return array(array('success' => FALSE, 'message' => $message, 'silent' => FALSE));
    }
  }
}

/**
 * Implements hook_uc_product_alter().
 */
function uc_varprice_uc_product_alter($item) {
  // If the product has a variable price set...
  if (!empty($item->data['varprice'])) {
    // Update the cart item's price to the entered price value.
    $item->display_price = $item->price = $item->data['varprice'];
  }
}

/**
 * Implements hook_uc_product_feature().
 */
function uc_varprice_uc_product_feature() {
  $features = array();

  $features[] = array(
    'id' => 'varprice',
    'title' => t('Variable price'),
    'callback' => 'uc_varprice_feature_form',
    'delete' => 'uc_varprice_feature_delete',
    'settings' => 'uc_varprice_settings',
    'multiple' => FALSE,
  );

  return $features;
}

/**
 * Adds settings to the product features form for UC Variable Price.
 */
function uc_varprice_settings() {
  $form = array();

  $form['uc_varprice_global_default'] = array(
    '#title' => t('Global default price'),
    '#type' => 'textfield',
    '#size' => 8,
    '#description' => t('The global default price for variable priced products; may be overridden at the product class or product level.'),
    '#default_value' => variable_get('uc_varprice_global_default', '0'),
    '#field_prefix' => variable_get('uc_sign_after_amount', FALSE) ? '' : variable_get('uc_currency_sign', '$'),
    '#field_suffix' => variable_get('uc_sign_after_amount', FALSE) ? variable_get('uc_currency_sign', '$') : '',
  );

  return $form;
}

/**
 * Settings form for individual Variable Price product features.
 */
function uc_varprice_feature_form($form, &$form_state, $node, $feature) {
  // Add some helper JS to the form.
  drupal_add_js(drupal_get_path('module', 'uc_varprice') . '/uc_varprice.js');

  // Load the Variable Price data specific to this product.
  if (!empty($feature)) {
    $varprice_feature = db_query('SELECT * FROM {uc_varprice_products} WHERE pfid = :pfid', array(':pfid' => $feature['pfid']))->fetchObject();
  }
  else {
    $varprice_feature = new stdClass();
    $varprice_feature->pfid = NULL;
    $varprice_feature->price_default = variable_get('uc_varprice_global_default', '0');
    $varprice_feature->price_minimum = '';
    $varprice_feature->price_maximum = '';
    $varprice_feature->add_to_cart_title = t('Add to cart');
    $varprice_feature->amount_title = t('Amount');
  }

  $form['nid'] = array(
    '#type' => 'value',
    '#value' => $node->nid,
  );
  $form['pfid'] = array(
    '#type' => 'value',
    '#value' => $varprice_feature ? $varprice_feature->pfid : '',
  );

  $form += _uc_varprice_feature_form($varprice_feature);

  return $form;
}

function _uc_varprice_feature_form($varprice_feature = FALSE) {
  $form = array();

  $form['prices'] = array(
    '#type' => 'fieldset',
    '#title' => t('Price settings'),
  );
  $form['prices']['price_default'] = array(
    '#type' => 'textfield',
    '#title' => t('Default price'),
    '#size' => 8,
    '#description' => t('The default price for this variable priced products.'),
    '#default_value' => $varprice_feature ? $varprice_feature->price_default : variable_get('uc_varprice_global_default', '0'),
    '#field_prefix' => variable_get('uc_sign_after_amount', FALSE) ? '' : variable_get('uc_currency_sign', '$'),
    '#field_suffix' => variable_get('uc_sign_after_amount', FALSE) ? variable_get('uc_currency_sign', '$') : '',
  );
  $form['prices']['price_minimum'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum price'),
    '#size' => 8,
    '#description' => t('The minimum price required for this product to be added to the cart.<br />Leave blank for no minimum.'),
    '#default_value' => $varprice_feature ? $varprice_feature->price_minimum : '',
    '#field_prefix' => variable_get('uc_sign_after_amount', FALSE) ? '' : variable_get('uc_currency_sign', '$'),
    '#field_suffix' => variable_get('uc_sign_after_amount', FALSE) ? variable_get('uc_currency_sign', '$') : '',
  );
  $form['prices']['price_maximum'] = array(
    '#type' => 'textfield',
    '#title' => t('Maximum price'),
    '#size' => 8,
    '#description' => t('The maximum price allowed for this product to be added to the cart.<br />Leave blank for no maximum.'),
    '#default_value' => $varprice_feature ? $varprice_feature->price_maximum : '',
    '#field_prefix' => variable_get('uc_sign_after_amount', FALSE) ? '' : variable_get('uc_currency_sign', '$'),
    '#field_suffix' => variable_get('uc_sign_after_amount', FALSE) ? variable_get('uc_currency_sign', '$') : '',
  );

  $form['titles'] = array(
    '#type' => 'fieldset',
    '#title' => t('Add to cart form element titles'),
    '#description' => t('Use these settings to adjust the normal titles of add to cart form elements for variable priced products.'),
  );
  $form['titles']['override_add_to_cart_title'] = array(
    '#type' => 'checkbox',
    '#title' => t('Override the title of the add to cart button.'),
    '#description' => t('Defaults to <em>Add to cart</em>. For multilingual sites, use <a href="!url">String Overrides</a> instead.', array('!url' => url('http://drupal.org/project/stringoverrides', array('absolute' => TRUE)))),
    '#default_value' => $varprice_feature ? !empty($varprice_feature->add_to_cart_title) : FALSE,
    '#attributes' => array('class' => array('override-checkbox')),
  );
  $form['titles']['add_to_cart_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Add to cart button title'),
    '#default_value' => $varprice_feature && !empty($varprice_feature->add_to_cart_title) ? $varprice_feature->add_to_cart_title : t('Add to cart'),
  );
  $form['titles']['override_amount_title'] = array(
    '#type' => 'checkbox',
    '#title' => t('Override the title of the amount field for the price on the add to cart form.'),
    '#description' => t('Defaults to <em>Amount</em>. For multilingual sites, use <a href="!url">String Overrides</a> instead.', array('!url' => url('http://drupal.org/project/stringoverrides', array('absolute' => TRUE)))),
    '#default_value' => $varprice_feature ? !empty($varprice_feature->amount_title) : FALSE,
    '#attributes' => array('class' => array('override-checkbox')),
  );
  $form['titles']['amount_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Amount field title'),
    '#default_value' => $varprice_feature && !empty($varprice_feature->amount_title) ? $varprice_feature->amount_title : t('Amount'),
  );

  return $form;
}

/**
 * Creates the varprice feature in the database.
 */
function uc_varprice_feature_form_submit($form, &$form_state) {
  // Build an array of Variable Price data from the form submission.
  $vp_data = array(
    'pfid' => $form_state['values']['pfid'],
    'price_default' => $form_state['values']['price_default'],
    'price_minimum' => $form_state['values']['price_minimum'],
    'price_maximum' => $form_state['values']['price_maximum'],
    'add_to_cart_title' => $form_state['values']['override_add_to_cart_title'] ? $form_state['values']['add_to_cart_title'] : '',
    'amount_title' => $form_state['values']['override_amount_title'] ? $form_state['values']['amount_title'] : '',
  );

  // Build the product feature description.
  $description = array(
    t('Customers can specify a price for this product.'),
    t('<b>Default price:</b> @price', array('@price' => uc_currency_format($vp_data['price_default']))),
  );
  if (!empty($vp_data['price_minimum'])) {
    $description[] = t('<b>Minimum price:</b> @price', array('@price' => uc_currency_format($vp_data['price_minimum'])));
  }
  if (!empty($vp_data['price_maximum'])) {
    $description[] = t('<b>Maximum price:</b> @price', array('@price' => uc_currency_format($vp_data['price_maximum'])));
  }
  if (!empty($vp_data['add_to_cart_title'])) {
    $description[] = t('<b>Add to cart title:</b> @title', array('@title' => $vp_data['add_to_cart_title']));
  }
  if (!empty($vp_data['amount_title'])) {
    $description[] = t('<b>Amount field title:</b> @title', array('@title' => $vp_data['amount_title']));
  }

  // Save the basic product feature data.
  $data = array(
    'pfid' => $vp_data['pfid'],
    'nid' => $form_state['values']['nid'],
    'fid' => 'varprice',
    'description' => implode('<br />', $description),
  );

  $form_state['redirect'] = uc_product_feature_save($data);

  $vp_data['pfid'] = $data['pfid'];

  // Insert or update the data in the Variable Price products table.
  $key = array();
  if ($vpid = _uc_varprice_get_vpid($vp_data['pfid'])) {
    $key = 'vpid';
    $vp_data['vpid'] = $vpid;
  }

  drupal_write_record('uc_varprice_products', $vp_data, $key);
}

/**
 * Variable Price product feature delete function.
 */
function uc_varprice_feature_delete($feature) {
  db_delete('uc_varprice_products')
    ->condition('pfid', $feature['pfid'])
    ->execute();
}

// Load the product feature data for a given node.
/**
 * @todo Please document this function.
 * @see http://drupal.org/node/1354
 */
function uc_varprice_product_load($nid) {
  return db_query('SELECT vp.* FROM {uc_product_features} AS pf
                   LEFT JOIN {uc_varprice_products} AS vp ON pf.pfid = vp.pfid
                   WHERE pf.fid = :pf_fid AND pf.nid = :pf_nid',
                  array(':pf_fid' => 'varprice', ':pf_nid' => $nid))->fetchObject();
}

/**
 * Theme the Qty. field for products in the shopping cart with variable prices.
 */
function theme_varprice_qty($variables) {
  $element = $variables['form'];
  return $element['#default_value'];
}

/**
 * Gets a uc_varprice id from a product feature id.
 */
function _uc_varprice_get_vpid($pfid) {
  return db_query('SELECT vpid FROM {uc_varprice_products} WHERE pfid = :pfid', array(':pfid' => $pfid))->fetchField();
}