<?php
  
  /**
  * ownCloud - App Framework
  *
  * @author Bernhard Posselt
  * @copyright 2012 Bernhard Posselt dev@bernhard-posselt.com
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
  * License as published by the Free Software Foundation; either
  * version 3 of the License, or any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
  *
  * You should have received a copy of the GNU Affero General Public
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
  
  namespace OCP\AppFramework\Db;
  
  
  /**
   * @method integer getId()
   * @method void setId(integer $id)
   */
  abstract class Entity {
  
  	public $id;
  
  	private $_updatedFields = array();
  	private $_fieldTypes = array('id' => 'integer');
  
  
  	/**
  	 * Simple alternative constructor for building entities from a request
  	 * @param array $params the array which was obtained via $this->params('key')
  	 * in the controller
  	 * @return Entity
  	 */
  	public static function fromParams(array $params) {
  		$instance = new static();
  
  		foreach($params as $key => $value) {
  			$method = 'set' . ucfirst($key);
  			$instance->$method($value);
  		}
  
  		return $instance;
  	}
  
  
  	/**
  	 * Maps the keys of the row array to the attributes
  	 * @param array $row the row to map onto the entity
  	 */
  	public static function fromRow(array $row){
  		$instance = new static();
  
  		foreach($row as $key => $value){
  			$prop = ucfirst($instance->columnToProperty($key));
  			$setter = 'set' . $prop;
  			$instance->$setter($value);
  		}
  
  		$instance->resetUpdatedFields();
  
  		return $instance;
  	}
  
  
  	/**
  	 * @return an array with attribute and type
  	 */
  	public function getFieldTypes() {
  		return $this->_fieldTypes;
  	}
  
  	
  	/**
  	 * Marks the entity as clean needed for setting the id after the insertion
  	 */
  	public function resetUpdatedFields(){
  		$this->_updatedFields = array();
  	}
  
  
  	protected function setter($name, $args) {
  		// setters should only work for existing attributes
  		if(property_exists($this, $name)){
  			if($this->$name === $args[0]) {
  				return;
  			}
  			$this->markFieldUpdated($name);
  
  			// if type definition exists, cast to correct type
  			if($args[0] !== null && array_key_exists($name, $this->_fieldTypes)) {
  				settype($args[0], $this->_fieldTypes[$name]);
  			}
  			$this->$name = $args[0];
  
  		} else {
  			throw new \BadFunctionCallException($name . 
  				' is not a valid attribute');
  		}
  	}
  
  
  	protected function getter($name) {
  		// getters should only work for existing attributes
  		if(property_exists($this, $name)){
  			return $this->$name;
  		} else {
  			throw new \BadFunctionCallException($name . 
  				' is not a valid attribute');
  		}
  	}
  
  
  	/**
  	 * Each time a setter is called, push the part after set
  	 * into an array: for instance setId will save Id in the 
  	 * updated fields array so it can be easily used to create the
  	 * getter method
  	 */
  	public function __call($methodName, $args){
  		$attr = lcfirst( substr($methodName, 3) );
  
  		if(strpos($methodName, 'set') === 0){
  			$this->setter($attr, $args);
  		} elseif(strpos($methodName, 'get') === 0) {
  			return $this->getter($attr);
  		} else {
  			throw new \BadFunctionCallException($methodName . 
  					' does not exist');
  		}
  
  	}
  
  
  	/**
  	 * Mark am attribute as updated
  	 * @param string $attribute the name of the attribute
  	 */
  	protected function markFieldUpdated($attribute){
  		$this->_updatedFields[$attribute] = true;
  	}
  
  
  	/**
  	 * Transform a database columnname to a property 
  	 * @param string $columnName the name of the column
  	 * @return string the property name
  	 */
  	public function columnToProperty($columnName){
  		$parts = explode('_', $columnName);
  		$property = null;
  
  		foreach($parts as $part){
  			if($property === null){
  				$property = $part;
  			} else {
  				$property .= ucfirst($part);
  			}
  		}
  
  		return $property;
  	}
  
  
  	/**
  	 * Transform a property to a database column name
  	 * @param string $property the name of the property
  	 * @return string the column name
  	 */
  	public function propertyToColumn($property){
  		$parts = preg_split('/(?=[A-Z])/', $property);
  		$column = null;
  
  		foreach($parts as $part){
  			if($column === null){
  				$column = $part;
  			} else {
  				$column .= '_' . lcfirst($part);
  			}
  		}
  
  		return $column;
  	}
  
  
  	/**
  	 * @return array array of updated fields for update query
  	 */
  	public function getUpdatedFields(){
  		return $this->_updatedFields;
  	}
  
  
  	/**
  	 * Adds type information for a field so that its automatically casted to
  	 * that value once its being returned from the database
  	 * @param string $fieldName the name of the attribute
  	 * @param string $type the type which will be used to call settype()
  	 */
  	protected function addType($fieldName, $type){
  		$this->_fieldTypes[$fieldName] = $type;
  	}
  
  
  	/**
  	 * Slugify the value of a given attribute
  	 * Warning: This doesn't result in a unique value
  	 * @param string $attributeName the name of the attribute, which value should be slugified
  	 * @return string slugified value
  	 */
  	public function slugify($attributeName){
  		// toSlug should only work for existing attributes
  		if(property_exists($this, $attributeName)){
  			$value = $this->$attributeName;
  			// replace everything except alphanumeric with a single '-'
  			$value = preg_replace('/[^A-Za-z0-9]+/', '-', $value);
  			$value = strtolower($value);
  			// trim '-'
  			return trim($value, '-');
  		} else {
  			throw new \BadFunctionCallException($attributeName .
  				' is not a valid attribute');
  		}
  	}
  
  }