<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         CakePHP(tm) v 3.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\View\Form;

use Cake\Network\Request;
use Cake\Utility\Hash;

/**
 * Provides a basic array based context provider for FormHelper
 * this adapter is useful in testing or when you have forms backed by
 * by simple array data structures.
 *
 * Important keys:
 *
 * - `defaults` The default values for fields. These values
 *   will be used when there is no request data set. Data should be nested following
 *   the dot separated paths you access your fields with.
 * - `required` A nested array of fields, relationships and boolean
 *   flags to indicate a field is required.
 * - `schema` An array of data that emulate the column structures that
 *   Cake\Database\Schema\Table uses. This array allows you to control
 *   the inferred type for fields and allows auto generation of attributes
 *   like maxlength, step and other HTML attributes.
 * - `errors` An array of validation errors. Errors should be nested following
 *   the dot separated paths you access your fields with.
 */
class ArrayContext {

/**
 * The request object.
 *
 * @var Cake\Network\Request
 */
	protected $_request;

/**
 * Context data for this object.
 *
 * @var array
 */
	protected $_context;

/**
 * Constructor.
 *
 * @param Cake\Network\Request
 * @param array
 */
	public function __construct(Request $request, array $context) {
		$this->_request = $request;
		$context += [
			'schema' => [],
			'required' => [],
			'defaults' => [],
			'errors' => [],
		];
		$this->_context = $context;
	}

/**
 * Get the current value for a given field.
 *
 * This method will coalesce the current request data and the 'defaults'
 * array.
 *
 * @param string $field A dot separated path to the field a value
 *   is needed for.
 * @return mixed
 */
	public function val($field) {
		$val = $this->_request->data($field);
		if ($val !== null) {
			return $val;
		}
		if (empty($this->_context['defaults']) || !is_array($this->_context['defaults'])) {
			return null;
		}
		return Hash::get($this->_context['defaults'], $field);
	}

/**
 * Check if a given field is 'required'.
 *
 * In this context class, this is simply defined by the 'required' array.
 *
 * @param string $field A dot separated path to check required-ness for.
 * @return boolean
 */
	public function isRequired($field) {
		if (!is_array($this->_context['required'])) {
			return false;
		}
		$required = Hash::get($this->_context['required'], $field);
		return (bool)$required;
	}

/**
 * Get the abstract field type for a given field name.
 *
 * @param string $field A dot separated path to get a schema type for.
 * @return string An abstract data type.
 * @see Cake\Database\Type
 */
	public function type($field) {
		if (!is_array($this->_context['schema'])) {
			return false;
		}
		$schema = Hash::get($this->_context['schema'], $field);
		return isset($schema['type']) ? $schema['type'] : null;
	}

/**
 * Get an associative array of other attributes for a field name.
 *
 * @param string $field A dot separated path to get a additional data on.
 * @return array An array of data describing the additional attributes on a field.
 */
	public function attributes($field) {
		if (!is_array($this->_context['schema'])) {
			return [];
		}
		$schema = Hash::get($this->_context['schema'], $field);
		$whitelist = ['length' => null, 'precision' => null];
		return array_intersect_key($schema, $whitelist);
	}

/**
 * Check whether or not a field has an error attached to it
 *
 * @param string $field A dot separated path to check errors on.
 * @return boolean Returns true if the errors for the field are not empty.
 */
	public function hasError($field) {
		if (empty($this->_context['errors'])) {
			return false;
		}
		return (bool)Hash::check($this->_context['errors'], $field);
	}

/**
 * Get the errors for a given field
 *
 * @param string $field A dot separated path to check errors on.
 * @return mixed Either a string or an array of errors. Null
 *  will be returned when the field path is undefined.
 */
	public function error($field) {
		if (empty($this->_context['errors'])) {
			return null;
		}
		return Hash::get($this->_context['errors'], $field);
	}

}