<?php

/**
 * @file
 * Helper function to export features overrides.
 */

/**
 * Parses the identifier into indivudal parts.
 *
 * As the keys may have a period in them, cannot use explode or similair ways.
 *
 * @param $identifier
 *   A string in the form  <comonent>.<element>.<keys> or <component>.<element>.
 * @return
 *   An array of component, element, and keys string
 * @see features_override_make_key()
 */
function features_override_parse_identifier($identifier) {
  $first_period = strpos($identifier, '.');
  $component = substr($identifier, 0, $first_period);
  if ($second_period = strpos($identifier, '.', $first_period + 1)) {
    $element = substr($identifier, $first_period + 1, $second_period - $first_period - 1);
    $keys = substr($identifier, $second_period + 1);
  }
  else {
    $element = substr($identifier, $first_period + 1);
    $keys = FALSE;
  }
  return array($component, $element, $keys);
}

/**
 * Makes a distinct string key from an array of keys.
 *
 * @param $keys
 *   An array of keys.
 * @return
 *   A string representation of the keys.
 */
function features_override_make_key($keys) {
  $return_keys = array();
  foreach ($keys as $key) {
    $return_keys[] = $key['key'];
  }
  return implode('|', $return_keys);
}

/**
 * Returns an array of keys to be ignored for various exportables
 * @param $component
 *   The component to retrieve ignore_keys from.
 */
function features_get_ignore_keys($component) {
  static $cache;
  if (!isset($cache[$component])) {
    $cache[$component] = module_invoke_all('features_override_ignore', $component);
  }
  return $cache[$component];
}

/**
 * Calculautes what overrides exist for by component/element.
 *
 * @param $component_key
 *   A component key that's defined via hook_features_api.
 * @param $element_key
 *   A key identifieing an element that's been overriden.
 * @param $reset
 *   Reset the internal cache of overrides gathered.
 * @param $all
 *   If TRUE, return all overrides, otherwise only overrides not yet in an override feature
 *  */
function features_override_get_overrides($component_key = FALSE, $element_key = FALSE, $reset = FALSE, $all = TRUE) {
  static $cache;
  if (!isset($cache) || $reset) {
    $cache = array();
    module_load_include('inc', 'features', 'features.export');
    features_include();
    foreach (features_get_components() as $component => $info) {
      if (empty($info['default_hook']) || $component == 'features_override_items' || $component == 'features_overrides' || !features_get_default_alter_hook($component) | !features_hook($component, 'features_export_render')) {
        continue;
      }

      features_include_defaults($component);
      foreach (module_implements($info['default_hook']) as $module) {
        if ($differences = array_filter(features_override_module_component_overrides($module, $component, $reset, $all))) {
          $cache[$component] = isset($cache[$component]) ? array_merge($differences, $cache[$component]) : $differences;
        }
      }
      $cache[$component] = isset($cache[$component]) ? array_filter($cache[$component]) : array();
    }
  }

  if ($component_key && $element_key) {
    return !empty($cache[$component_key][$element_key]) ? $cache[$component_key][$element_key] : array();
  }
  elseif ($component_key) {
    return !empty($cache[$component_key]) ? $cache[$component_key] : array();
  }
  return $cache;
}


/**
 * Get overrides for specific module/component.
 *
 * @param $module
 *   An enabled module to find overrides for it's components.
 * @param $component
 *   A type of component to find overrides for.
 * @param $reset
 *   Reset the internal cache of overrides gathered.
 * @param $all
 *   If TRUE, return all overrides, otherwise only overrides not yet in an override feature
 * @return
 *   An array of overrides found.
 */
function features_override_module_component_overrides($module, $component, $reset = FALSE, $all = TRUE) {
  static $cache = array();

  if (isset($cache[$module][$component])  && !$reset) {
    return $cache[$module][$component];
  }
  module_load_include('inc', 'features_override', 'features_override.hooks');
  features_include();
  features_include_defaults($component);

  // Allows overriding non-feature controlled code.
  $default_hook = features_get_default_hooks($component);
  if ($all) {
    // call hooks directly
    // could also do
    // $default = features_get_default($component, $module, FALSE, $reset);
    // but this is more efficient
    $default = module_invoke($module, $default_hook);
  }
  else {
    $default = features_get_default($component, $module, TRUE, $reset);
  }
  $normal = features_get_normal($component, $module, $reset);

  // This indicates it is likely not controlled by features, so fetch manually.
  if (!$normal) {
    $code = array_pop(features_invoke($component, 'features_export_render', $module, array_keys($default), NULL));
    if (!$code) {
      return FALSE;
    }
    else {
      $normal = eval($code);
    }
  }

  $context = array(
    'component' => $component,
    'module' => $module,
  );

  // Can't use _features_sanitize as that resets some keys.
  _features_override_sanitize($normal);
  _features_override_sanitize($default);
  // make a deep copy of data to prevent problems when removing recursion later
  $default_copy = unserialize(serialize($default)); 
  $normal_copy = unserialize(serialize($normal)); 

  $ignore_keys = features_get_ignore_keys($component);
  // remove keys to be ignored
  // doing this now allows us to better control which recursive parts are removed
  if (count($ignore_keys)) {
    _features_override_remove_ignores($default_copy, $ignore_keys);
    _features_override_remove_ignores($normal_copy, $ignore_keys);
  }
  // now remove any remaining recursion
  features_override_remove_recursion($default_copy);
  features_override_remove_recursion($normal_copy);

  $component_overrides = array();
  if ($normal && is_array($normal) || is_object($normal)) {
    foreach ($normal as $name => $properties) {
      $component_overrides[$name] = array(
        'additions' => array(),
        'deletions' => array(),
      );
      if (isset($default_copy[$name])) {
        drupal_alter('features_override_component_overrides', $default[$name], $normal_copy[$name], $context);
        _features_override_set_additions($default_copy[$name], $normal_copy[$name], $component_overrides[$name]['additions'], $ignore_keys);
        _features_override_set_deletions($default_copy[$name], $normal_copy[$name], $component_overrides[$name]['deletions'], $ignore_keys);
      }
      if (!array_filter($component_overrides[$name])) {
        $component_overrides[$name] = FALSE;
      }
    }
  }

  $cache[$module][$component] = $component_overrides;
  return $component_overrides;
}

/**
 * Sorts an array by its keys (assoc) or values (non-assoc).
 *
 * @param $array
 *   An array that needs to be sorted.
 */
function _features_override_sanitize(&$array) {
  if (is_array($array)) {
    $is_assoc = (array_keys($array) !== range(0, count($array) - 1));
    if ($is_assoc) {
      ksort($array);
    }
    else {
      sort($array);
    }
    foreach ($array as $k => $v) {
      if (is_array($v)) {
        _features_override_sanitize($array[$k]);
      }
    }
  }
}

/**
 * Helper function to set the additions between default and normal features.
 *
 * @param $default
 *   The default defination of a component.
 * @param $normal
 *   The current defination of a component.
 * @param $additions
 *   An array of currently gathered additions.
 * @param $ignore_keys
 *   Keys to ignore while processing element.
 * @param $level
 *   How many levels deep into object.
 * @param $keys
 *   The keys for this level.
 */
function _features_override_set_additions(&$default, &$normal, &$additions, $ignore_keys = array(), $level = 0, $keys = array()) {
  $object = is_object($normal);

  foreach ($normal as $key => $value) {
    if (isset($ignore_keys[$key]) && ($level == $ignore_keys[$key])) {
      continue;
    }
    if ($object) {
      if (!is_object($default) || !property_exists($default, $key) || (is_scalar($value) && ($default->$key !== $value))) {
        $_keys = array_merge($keys, array(array('type' => 'object', 'key' => $key)));
        $additions[features_override_make_key($_keys)] = array(
          'keys' => $_keys,
          'value' => $value,
          'original' => (is_scalar($value) && isset($default->$key)) ? $default->key : '',
        );
      }
      elseif (property_exists($default, $key) && ($default->$key !== $value)) {
        _features_override_set_additions($default->$key, $value, $additions, $ignore_keys, $level+1, array_merge($keys, array(array('type' => 'object', 'key' => $key))));
      }
    }
    elseif (is_array($normal)) {
      if (!is_array($default) || !array_key_exists($key, $default) || (is_scalar($value) && ($default[$key] !== $value))) {
        $_keys = array_merge($keys, array(array('type' => 'array', 'key' => $key)));
        $additions[features_override_make_key($_keys)] = array(
          'keys' => $_keys,
          'value' => $value,
          'original' => (is_scalar($value) && isset($default[$key])) ? $default[$key] : '',
        );
      }
      elseif (array_key_exists($key, $default) && (!is_null($value) && ($default[$key] !== $value))) {
        _features_override_set_additions($default[$key], $value, $additions, $ignore_keys, $level+1, array_merge($keys, array(array('type' => 'array', 'key' => $key))));
      }
    }
  }
}

/**
 * Helper function to set the deletions between default and normal features.
 *
 * @param $default
 *   The default defination of a component.
 * @param $normal
 *   The current defination of a component.
 * @param $deletions
 *   An array of currently gathered deletions.
 * @param $ignore_keys
 *   Keys to ignore while processing element.
 * @param $level
 *   How many levels deep into object.
 * @param $keys
 *   The keys for this level.
 */
function _features_override_set_deletions(&$default, &$normal, &$deletions, $ignore_keys = array(), $level = 0, $keys = array()) {
  $object = is_object($default);

  foreach ($default as $key => $value) {
    if (isset($ignore_keys[$key]) && ($level == $ignore_keys[$key])) {
      continue;
    }

    if ($object) {
      if (!property_exists($normal, $key)) {
        $_keys = array_merge($keys, array(array('type' => 'object', 'key' => $key)));
        $deletions[features_override_make_key($_keys)] = array(
          'keys' => $_keys,
        );
      }
      elseif (property_exists($normal, $key) && (is_array($value) || is_object($value))) {
        _features_override_set_deletions($value, $normal->$key, $deletions, $ignore_keys, $level+1, array_merge($keys, array(array('type' => 'object', 'key' => $key))));
      }
    }
    else {
      if (!array_key_exists($key, $normal)) {
        $_keys = array_merge($keys, array(array('type' => 'array', 'key' => $key)));
        $deletions[features_override_make_key($_keys)] = array(
          'keys' => $_keys,
        );
      }
      elseif (array_key_exists($key, $normal) && (is_array($value) || is_object($value))) {
        _features_override_set_deletions($value, $normal[$key], $deletions, $ignore_keys, $level+1, array_merge($keys, array(array('type' => 'array', 'key' => $key))));
      }
    }
  }
}

/**
 * Creates a string representation of an array of keys.
 *
 * @param $keys
 *   An array of keys with their associate types.
 *
 * @return
 *   A string representation of the keys.
 */
function features_override_export_keys($keys) {
  $line = '';
  foreach ($keys as $key) {
    if ($key['type'] == 'object') {
      $line .= "->{$key['key']}";
    }
    else {
      $line .= "['{$key['key']}']";
    }
  }
  return $line;
}

/**
 * Removes recursion from an object or array.
 *
 * @param $item
 *   An object or array passed by reference.
 */
function features_override_remove_recursion(&$item) {
  _features_override_remove_recursion($item);
  _features_override_remove_recursion_markers($item);  
}


/**
 * Helper to removes recursion from an object/array.
 *
 * @param $item
 *   An object or array passed by reference.
 */
function _features_override_remove_recursion(&$item) {
  $is_object = is_object($item);
  if ($is_object) {
    $item->{FEATURES_OVERRIDE_RECURSION_MARKER} = 1;
  }
  else {
    $item[FEATURES_OVERRIDE_RECURSION_MARKER] = 1;
  }
  foreach ($item as $key => $value) {
    if (is_array($value) || is_object($value)) {
      $remove = is_array($value) ? !empty($value[FEATURES_OVERRIDE_RECURSION_MARKER]) : !empty($value->{FEATURES_OVERRIDE_RECURSION_MARKER});
      if ($remove) {
        if ($is_object) {
          unset($item->$key);
        }
        else {
          unset($item[$key]);
        }
      }
      else {
        features_override_remove_recursion($value);
      }
    }
  }
}

/**
 * Helper to removes recursion from an object/array.
 *
 * @param $item
 *   An object or array passed by reference.
 */
function _features_override_remove_recursion_markers(&$item) {
  $is_object = is_object($item);
  foreach ($item as $key => $value) {
    if ($key === FEATURES_OVERRIDE_RECURSION_MARKER) {
      if ($is_object) {
        unset($item->$key);
      }
      else {
        unset($item[$key]);
      }
    }
    elseif (is_array($value) || is_object($value)) {
      _features_override_remove_recursion_markers($value);
    }
  }
}

/**
 * Helper to removes a set of keys an object/array.
 *
 * @param $item
 *   An object or array passed by reference.
 * @param $ignore_keys
 *   Array of keys to be ignored. Values are the level of the key. 
 * @param $level
 *   Level of key to remove.  Up to 2 levels deep because $item can still be 
 *   recursive
 */
function _features_override_remove_ignores(&$item, $ignore_keys, $level = -1) {
  $is_object = is_object($item);
  foreach ($item as $key => $value) {
    if (isset($ignore_keys[$key]) && ($ignore_keys[$key] == $level)) {
      if ($is_object) {
        unset($item->$key);
      }
      else {
        unset($item[$key]);
      }
    }
    elseif (($level < 2) && (is_array($value) || is_object($value))) {
      _features_override_remove_ignores($value, $ignore_keys, $level+1);
    }
  }
}

/**
 * Drupal-friendly var_export().
 *
 * @param $var
 *   The variable to export.
 * @param $prefix
 *   A prefix that will be added at the beginning of every lines of the output.
 * @return
 *   The variable exported in a way compatible to Drupal's coding standards.
 */
function features_override_var_export($var, $prefix = '') {
  if (is_array($var) || is_object($var)) {
    // Special causing array so calls features_override_var_export instead of
    // features_var_export.
    if (is_array($var)) {
      if (empty($var)) {
        $output = 'array()';
      }
      else {
        $output = "array(\n";
        foreach ($var as $key => $value) {
          // Using normal var_export on the key to ensure correct quoting.
          $output .= "  " . var_export($key, TRUE) . " => " . features_override_var_export($value, '  ', FALSE) . ",\n";
        }
        $output .= ')';
      }
    }
    // Objects do not export cleanily.
    else {
      if (method_exists($var, 'export')) {
        $output = $var->export();
      }
      elseif (get_class($var) === 'stdClass') {
        $output = '(object) ' . features_override_var_export((array) $var, $prefix);
      }
      elseif (!method_exists($var, '__set_state')) {
        // Ugly, but custom object with no clue how to export.without
        // __set_state class and var_export produces unusable code.
        $output = 'unserialize(' . var_export(serialize($var), TRUE) . ')';
      }
      else {
        $output = var_export($var, TRUE);
      }
    }
  }
  else {
    module_load_include('inc', 'features', 'features.export');
    $output = features_var_export($var);
  }

  if ($prefix) {
    $output = str_replace("\n", "\n$prefix", $output);
  }

  return $output;
}

/**
 * Renders the addition/change to an element.
 */
function features_override_features_export_render_addition($alter, $element, $component) {
  module_load_include('inc', 'features_override', 'features_override.hooks');
  if (features_hook($component, 'features_override_export_render_addition')) {
    return features_invoke($component, 'features_override_export_render_addition', $alter, $element);
  }
  else {
    $code = array();
    $component_start = "\$data['$element']";
    $code_line = features_override_export_keys($alter['keys']);
    $value_export = features_override_var_export($alter['value'], '    ');
    $original_export = (isset($alter['original'])) ? ' // WAS: ' . features_override_var_export($alter['original'], '    ') : '';
    $code[] = "    " . $component_start . $code_line . ' = ' . $value_export . ';' . $original_export;
    return $code;
  }
}

/**
 * Renders the deletion to an element.
 */
function features_override_features_export_render_deletion($alter, $element, $component) {
  module_load_include('inc', 'features_override', 'features_override.hooks');
  if (features_hook($component, 'features_override_export_render_deletion')) {
    return features_invoke($component, 'features_override_export_render_deletion', $alter, $element);
  }
  else {
    $code = array();
    $component_start = "\$data['$element']";
    $code_line = features_override_export_keys($alter['keys']);
    $code[] =  '    unset(' . $component_start . $code_line . ');';
    return $code;
  }
}

/**
 * Encodes a string for use as option.
 
 * @see features_dom_encode_options()
 * @param $string
 *   A string to encode.
 * @return
 *   An encoded string for use as option value.
 */
function features_override_encode_string($string) {
  $replacements = array(
    ':' => '__'. ord(':') .'__',
    '/' => '__'. ord('/') .'__',
    ',' => '__'. ord(',') .'__',
    '.' => '__'. ord('.') .'__',
    '<' => '__'. ord('<') .'__',
    '>' => '__'. ord('>') .'__',
  );
  return strtr($string, $replacements);
}
