<?php
/**
 * Manages a set of database fixtures for {@link DataObject} records
 * as well as raw database table rows.
 *
 * Delegates creation of objects to {@link FixtureBlueprint},
 * which can implement class- and use-case specific fixture setup.
 *
 * Supports referencing model relations through a specialized syntax:
 * <code>
 * $factory = new FixtureFactory();
 * $relatedObj = $factory->createObject(
 * 	'MyRelatedClass', 
 * 	'relation1'
 * );
 * $obj = $factory->createObject(
 * 	'MyClass', 
 * 	'object1'
 * 	array('MyRelationName' => '=>MyRelatedClass.relation1')
 * );
 * </code>
 * Relation loading is order dependant.
 *
 * @package framework
 * @subpackage core
 */
class FixtureFactory {
	
	/**
	 * @var array Array of fixture items, keyed by class and unique identifier,
	 * with values being the generated database ID. Does not store object instances.
	 */
	protected $fixtures = array();

	/**
	 * @var array Callbacks
	 */
	protected $blueprints = array();

	/**
	 * @param String $name Unique name for this blueprint
	 * @param array|FixtureBlueprint $defaults Array of default values, or a blueprint instance
	 */
	public function define($name, $defaults = array()) {
		if($defaults instanceof FixtureBlueprint) {
			$this->blueprints[$name] = $defaults;
		} else {
			$class = $name;
			$this->blueprints[$name] = Injector::inst()->create(
				'FixtureBlueprint', $name, $class, $defaults
			);
		}
		
		return $this;
	}

	/**
	 * Writes the fixture into the database using DataObjects
	 *
	 * @param String $name Name of the {@link FixtureBlueprint} to use, 
	 *                     usually a DataObject subclass.
	 * @param String $identifier Unique identifier for this fixture type
	 * @param Array $data Map of properties. Overrides default data.
	 * @return DataObject
	 */
	public function createObject($name, $identifier, $data = null) {
		if(!isset($this->blueprints[$name])) {
			$this->blueprints[$name] = new FixtureBlueprint($name);
		}
		$blueprint = $this->blueprints[$name];
		$obj = $blueprint->createObject($identifier, $data, $this->fixtures);
		$class = $blueprint->getClass();

		if(!isset($this->fixtures[$class])) {
			$this->fixtures[$class] = array();
		}
		$this->fixtures[$class][$identifier] = $obj->ID;

		return $obj;
	}
	
	/**
	 * Writes the fixture into the database directly using a database manipulation.
	 * Does not use blueprints. Only supports tables with a primary key.
	 *
	 * @param String $table Existing database table name
	 * @param String $identifier Unique identifier for this fixture type
	 * @param Array $data Map of properties
	 * @return Int Database identifier
	 */
	public function createRaw($table, $identifier, $data) {
		$fields = array();
		foreach($data as $fieldName => $fieldVal) {
			$fields["\"$fieldName\""] = $this->parseValue($fieldVal);
		}
		$insert = new SQLInsert($table, $fields);
		$insert->execute();
		$id = DB::get_generated_id($table);
		$this->fixtures[$table][$identifier] = $id;

		return $id;
	}

	/**
	 * Get the ID of an object from the fixture.
	 * @param $className The data class, as specified in your fixture file.  Parent classes won't work
	 * @param $identifier The identifier string, as provided in your fixture file
	 */
	public function getId($class, $identifier) {
		if(isset($this->fixtures[$class][$identifier])) {
			return $this->fixtures[$class][$identifier];
		} else {
			return false;
		}
	}
	
	/**
	 * Return all of the IDs in the fixture of a particular class name.
	 * 
	 * @return A map of fixture-identifier => object-id
	 */
	public function getIds($class) {
		if(isset($this->fixtures[$class])) {
			return $this->fixtures[$class];
		} else {
			return false;
		}
	}

	/**
	 * @param String 
	 * @param String $identifier
	 * @param Int $databaseId
	 */
	public function setId($class, $identifier, $databaseId) {
		$this->fixtures[$class][$identifier] = $databaseId;
		return $this;
	}

	/**
	 * Get an object from the fixture.
	 * 
	 * @param $class The data class, as specified in your fixture file.  Parent classes won't work
	 * @param $identifier The identifier string, as provided in your fixture file
	 */
	public function get($class, $identifier) {
		$id = $this->getId($class, $identifier);
		if($id) return DataObject::get_by_id($class, $id);
	}

	/**
	 * @return Array Map of class names, containing a map of in-memory identifiers
	 * mapped to database identifiers.
	 */
	public function getFixtures() {
		return $this->fixtures;
	}

	/**
	 * Remove all fixtures previously defined through {@link createObject()}
	 * or {@link createRaw()}, both from the internal fixture mapping and the database.
	 * If the $class argument is set, limit clearing to items of this class.
	 * 
	 * @param String $class
	 */
	public function clear($limitToClass = null) {
		$classes = ($limitToClass) ? array($limitToClass) : array_keys($this->fixtures);
		foreach($classes as $class) {
			$ids = $this->fixtures[$class];
			foreach($ids as $id => $dbId) {
				if(class_exists($class)) {
					$class::get()->byId($dbId)->delete();
				} else {
					$table = $class;
					$delete = new SQLDelete("\"$table\"", array(
						"\"$table\".\"ID\"" => $dbId
					));
					$delete->execute();
				}

				unset($this->fixtures[$class][$id]);
			}
		}
	}

	/**
	 * @return Array Of {@link FixtureBlueprint} instances
	 */
	public function getBlueprints() {
		return $this->blueprints;
	}

	/**
	 * @param String $name
	 * @return FixtureBlueprint
	 */
	public function getBlueprint($name) {
		return (isset($this->blueprints[$name])) ? $this->blueprints[$name] : false;
	}

	/**
	 * Parse a value from a fixture file.  If it starts with => 
	 * it will get an ID from the fixture dictionary
	 *
	 * @param String $fieldVal
	 * @return String Fixture database ID, or the original value
	 */
	protected function parseValue($value) {
		if(substr($value,0,2) == '=>') {
			// Parse a dictionary reference - used to set foreign keys
			list($class, $identifier) = explode('.', substr($value,2), 2);

			if($this->fixtures && !isset($this->fixtures[$class][$identifier])) {
				throw new InvalidArgumentException(sprintf(
					'No fixture definitions found for "%s"',
					$value
				));
			}

			return $this->fixtures[$class][$identifier];
		} else {
			// Regular field value setting
			return $value;
		}
	}
	
}