<?php

/**
 * EMongoMigration is designed to be used together with the "yiic migratemongo" command.
 *
 * It provides a set of convenient methods for manipulating database data.
 * For example, the {@link insert} method can be used to easily insert data into
 * a mongo collection; the {@link createCollection} method can be used to create a new collection.
 * Compared with the same methods in {@link MongoCollection}, these methods will display extra
 * information showing the method parameters and execution time, which may be useful when
 * applying migrations.
 */
abstract class EMongoMigration extends CComponent
{
	/**
	 *
	 * @var string global collection name to be used for every mongodb operation 
	 * Can also be set dynamically
	 * @see setCollectionName
	 * @see getCollectionName
	 */
	protected $collectionName;
	
	/**
	 * The name of the database 
	 * Used by set/getDbConnection()
	 * @var EMongoClient
	 */
	private $_db;
	
	/**
	 * Creates a collection.
	 * @param string $name The name of the collection.
	 * @param array $options Options (name=>value) for the operation. See {@link MongoDB::createCollection} for more details.
	 */
	public function createCollection($name, $options = array())
	{
		echo "    > creating collection $name ...";
		$time = microtime(true);
		
		if(version_compare(phpversion('mongo'), '1.4.0', '<')){
			$options ['capped'] = isset($options['capped']) ? $options['capped'] : false;
			$options ['size'] = isset($options['size']) ? $options['size'] : 0;
			$options ['max'] = isset($options['max']) ? $options['max'] : 0;
			$this->getDbConnection()->getDB()->createCollection($name, $options['capped'], $options['size'], $options['max']);
		}else{
			$this->getDbConnection()->getDB()->createCollection($name, $options);
		}
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Deletes an index from this collection.
	 * 
	 * @param array $keys Deletes one or multiple indices from name
	 */
	public function deleteIndex($keys)
	{
		echo "    > deleteIndex ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->deleteIndex($keys);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Deletes all indexes from current collection.
	 */
	public function deleteIndexes()
	{
		echo "    > deleteIndexes ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->deleteIndexes();
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * This method contains the logic to be executed when removing this migration.
	 * Child classes may override this method if the corresponding migrations can be removed.
	 * @return boolean Returning false means, the migration will not be applied.
	 */
	public function down()
	{
	}
	
	/**
	 * Drops the current collection.
	 */
	public function drop()
	{
		echo "    > drop collection {$this->getCollectionName()} ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->drop();
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Drops the current collection.
	 */
	public function dropCollection()
	{
		echo "    > dropping collection {$this->getCollectionName()}...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->drop();
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	private function indexList($array)
	{
		$ret = '';
		foreach($array as $key => $order){
			$ret .= $key . ' (' . ($order == - 1 ? 'desc' : 'asc') . '), ';
		}
		return substr($ret, 0, strlen($ret) - 2);
	}
	
	/**
	 * Creates an index on the given field(s), or does nothing if the index already exists.
	 * 
	 * @param mixed $keys
	 * An array of fields by which to sort the index on. Each element in the array has as key the field name, 
	 * and as value either 1 for ascending sort, or -1 for descending sort.
	 * @param array $options
	 * Options (name=>value) for the save operation. See {@link MongoCollection::ensureIndex} for more details.
	 */
	public function ensureIndex($keys, $options = array())
	{
		echo "    > creating index for fields " . $this->indexList ( $keys ) . " ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->ensureIndex($keys, $options);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Runs JavaScript code on the database server.
	 * 
	 * @param mixed $code @link MongoCode or string to execute.
	 * @param array $args Arguments to be passed to code.
	 */
	public function execute($code, $args = array())
	{
		echo "    > execute command: $code ...";
		$time = microtime(true);
		$this->getDbConnection()->getDB()->execute($code, $args);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 *
	 * @return string The current selected collection
	 */
	public function getCollectionName()
	{
		if($this->collectionName === null){
			throw new CException(
				Yii::t(
					'yii', 
					'You need to set a collection first in order to execute mongodb operations'
				)
			);
		}
		return $this->collectionName;
	}
	
	/**
	 *
	 * @param string $collectionName Name of the connection on which mongodb operations are applied to
	 */
	public function setCollectionName($collectionName)
	{
		echo "    > switching to collecton {$collectionName}.\n";
		$this->collectionName = $collectionName;
	}
	
	/**
	 * Returns the currently active database connection.
	 * By default, the 'db' application component will be returned and activated.
	 * You can call {@link setDbConnection} to switch to a different database connection.
	 * Methods such as {@link insert}, {@link createCollection} will use this database connection
	 * to perform DB queries.
	 * 
	 * @throws CException if "db" application component is not configured
	 * @return EMongoClient the currently active mongodb connection
	 */
	public function getDbConnection()
	{
		if($this->_db === null){
			$this->_db = Yii::app ()->getComponent('mongodb');
			if(!$this->_db instanceof EMongoClient){
				throw new CException(Yii::t('yii', 'The "db" application component must be configured to be a EMongoClient object.'));
			}
		}
		return $this->_db;
	}
	
	/**
	 * Inserts a document into current collection.
	 * 
	 * @param mixed $a An array or object. If an object is used, it may not have protected or private properties.
	 * @param array $options Options (name=>value) for the insert operation. See {@link MongoCollection::insert} for more details.
	 */
	public function insert($a, $options = array())
	{
		echo "    > insert document ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->insert($a, $options);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Deletes a document from current collection.
	 * 
	 * @param array $criteria Description of records to remove.
	 * @param array $options Options (name=>value) for the remove operation. See {@link MongoCollection::remove} for more details.
	 */
	public function remove($criteria, $options = array())
	{
		echo "    > remove document ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->remove($criteria, $options);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Saves a document into current collection.
	 * 
	 * @param mixed $a Array or object to save. If an object is used, it may not have protected or private properties.
	 * @param array $options Options (name=>value) for the save operation. See {@link MongoCollection::save} for more details.
	 */
	public function save($a, $options = array())
	{
		echo "    > save document ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->save($a, $options);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
	
	/**
	 * Sets the currently active database connection.
	 * The database connection will be used by the methods such as {@link insert}, {@link createCollection}.
	 * 
	 * @param EMongoClient $db the database connection component
	 */
	public function setDbConnection($db)
	{
		$this->_db = $db;
	}
	
	/**
	 * This method contains the logic to be executed when applying this migration.
	 * Child classes may implement this method to provide actual migration logic.
	 * 
	 * @return boolean Returning false means, the migration will not be applied.
	 */
	public function up()
	{
	}
	
	/**
	 * Updates a document within the current collection.
	 * 
	 * @param array $criteria Description of the objects to update.
	 * @param array $options Options (name=>value) for the update operation. See {@link MongoCollection::update} for more details.
	 */
	public function update($criteria, $new_object, $options = array())
	{
		echo "    > update document ...";
		$time = microtime(true);
		$this->getDbConnection()->{$this->getCollectionName()}->update($criteria, $new_object, $options);
		echo " done (time: " . sprintf('%.3f', microtime(true) - $time) . "s)\n";
	}
}