<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\mongo;

use yii\base\InvalidConfigException;
use yii\base\InvalidParamException;
use yii\db\BaseActiveRecord;
use yii\base\UnknownMethodException;
use yii\db\StaleObjectException;
use yii\helpers\Inflector;
use yii\helpers\StringHelper;

/**
 * ActiveRecord is the base class for classes representing Mongo documents in terms of objects.
 *
 * @author Paul Klimov <klimov.paul@gmail.com>
 * @since 2.0
 */
abstract class ActiveRecord extends BaseActiveRecord
{
	/**
	 * Returns the Mongo connection used by this AR class.
	 * By default, the "mongo" application component is used as the Mongo connection.
	 * You may override this method if you want to use a different database connection.
	 * @return Connection the database connection used by this AR class.
	 */
	public static function getDb()
	{
		return \Yii::$app->getComponent('mongo');
	}

	/**
	 * Updates all documents in the collection using the provided attribute values and conditions.
	 * For example, to change the status to be 1 for all customers whose status is 2:
	 *
	 * ~~~
	 * Customer::updateAll(['status' => 1], ['status' = 2]);
	 * ~~~
	 *
	 * @param array $attributes attribute values (name-value pairs) to be saved into the collection
	 * @param array $condition description of the objects to update.
	 * Please refer to [[Query::where()]] on how to specify this parameter.
	 * @param array $options list of options in format: optionName => optionValue.
	 * @return integer the number of documents updated.
	 */
	public static function updateAll($attributes, $condition = [], $options = [])
	{
		return static::getCollection()->update($condition, $attributes, $options);
	}

	/**
	 * Updates all documents in the collection using the provided counter changes and conditions.
	 * For example, to increment all customers' age by 1,
	 *
	 * ~~~
	 * Customer::updateAllCounters(['age' => 1]);
	 * ~~~
	 *
	 * @param array $counters the counters to be updated (attribute name => increment value).
	 * Use negative values if you want to decrement the counters.
	 * @param array $condition description of the objects to update.
	 * Please refer to [[Query::where()]] on how to specify this parameter.
	 * @param array $options list of options in format: optionName => optionValue.
	 * @return integer the number of documents updated.
	 */
	public static function updateAllCounters($counters, $condition = [], $options = [])
	{
		return static::getCollection()->update($condition, ['$inc' => $counters], $options);
	}

	/**
	 * Deletes documents in the collection using the provided conditions.
	 * WARNING: If you do not specify any condition, this method will delete documents rows in the collection.
	 *
	 * For example, to delete all customers whose status is 3:
	 *
	 * ~~~
	 * Customer::deleteAll('status = 3');
	 * ~~~
	 *
	 * @param array $condition description of the objects to delete.
	 * Please refer to [[Query::where()]] on how to specify this parameter.
	 * @param array $options list of options in format: optionName => optionValue.
	 * @return integer the number of documents deleted.
	 */
	public static function deleteAll($condition = [], $options = [])
	{
		$options['w'] = 1;
		if (!array_key_exists('multiple', $options)) {
			$options['multiple'] = true;
		}
		return static::getCollection()->remove($condition, $options);
	}

	/**
	 * Creates an [[ActiveQuery]] instance.
	 * This method is called by [[find()]] to start a "find" command.
	 * You may override this method to return a customized query (e.g. `CustomerQuery` specified
	 * written for querying `Customer` purpose.)
	 * @return ActiveQuery the newly created [[ActiveQuery]] instance.
	 */
	public static function createQuery()
	{
		return new ActiveQuery(['modelClass' => get_called_class()]);
	}

	/**
	 * Declares the name of the Mongo collection associated with this AR class.
	 * Collection name can be either a string or array:
	 *  - if string considered as the name of the collection inside the default database.
	 *  - if array - first element considered as the name of the database, second - as
	 * name of collection inside that database
	 * By default this method returns the class name as the collection name by calling [[Inflector::camel2id()]].
	 * For example, 'Customer' becomes 'customer', and 'OrderItem' becomes
	 * 'order_item'. You may override this method if the table is not named after this convention.
	 * @return string|array the collection name
	 */
	public static function collectionName()
	{
		return Inflector::camel2id(StringHelper::basename(get_called_class()), '_');
	}

	/**
	 * Return the Mongo collection instance for this AR class.
	 * @return Collection collection instance.
	 */
	public static function getCollection()
	{
		return static::getDb()->getCollection(static::collectionName());
	}

	/**
	 * Returns the primary key name(s) for this AR class.
	 * The default implementation will return ['_id'].
	 *
	 * Note that an array should be returned even for a collection with single primary key.
	 *
	 * @return string[] the primary keys of the associated Mongo collection.
	 */
	public static function primaryKey()
	{
		return ['_id'];
	}

	/**
	 * Creates an [[ActiveRelation]] instance.
	 * This method is called by [[hasOne()]] and [[hasMany()]] to create a relation instance.
	 * You may override this method to return a customized relation.
	 * @param array $config the configuration passed to the ActiveRelation class.
	 * @return ActiveRelation the newly created [[ActiveRelation]] instance.
	 */
	public static function createActiveRelation($config = [])
	{
		return new ActiveRelation($config);
	}

	/**
	 * Returns the list of all attribute names of the model.
	 * This method must be overridden by child classes to define available attributes.
	 * Note: primary key attribute "_id" should be always present in returned array.
	 * For example:
	 * ~~~
	 * public function attributes()
	 * {
	 *     return ['_id', 'name', 'address', 'status'];
	 * }
	 * ~~~
	 * @return array list of attribute names.
	 */
	public function attributes()
	{
		throw new InvalidConfigException('The attributes() method of mongo ActiveRecord has to be implemented by child classes.');
	}

	/**
	 * Inserts a row into the associated Mongo collection using the attribute values of this record.
	 *
	 * This method performs the following steps in order:
	 *
	 * 1. call [[beforeValidate()]] when `$runValidation` is true. If validation
	 *    fails, it will skip the rest of the steps;
	 * 2. call [[afterValidate()]] when `$runValidation` is true.
	 * 3. call [[beforeSave()]]. If the method returns false, it will skip the
	 *    rest of the steps;
	 * 4. insert the record into collection. If this fails, it will skip the rest of the steps;
	 * 5. call [[afterSave()]];
	 *
	 * In the above step 1, 2, 3 and 5, events [[EVENT_BEFORE_VALIDATE]],
	 * [[EVENT_BEFORE_INSERT]], [[EVENT_AFTER_INSERT]] and [[EVENT_AFTER_VALIDATE]]
	 * will be raised by the corresponding methods.
	 *
	 * Only the [[dirtyAttributes|changed attribute values]] will be inserted into database.
	 *
	 * If the primary key  is null during insertion, it will be populated with the actual
	 * value after insertion.
	 *
	 * For example, to insert a customer record:
	 *
	 * ~~~
	 * $customer = new Customer;
	 * $customer->name = $name;
	 * $customer->email = $email;
	 * $customer->insert();
	 * ~~~
	 *
	 * @param boolean $runValidation whether to perform validation before saving the record.
	 * If the validation fails, the record will not be inserted into the collection.
	 * @param array $attributes list of attributes that need to be saved. Defaults to null,
	 * meaning all attributes that are loaded will be saved.
	 * @return boolean whether the attributes are valid and the record is inserted successfully.
	 * @throws \Exception in case insert failed.
	 */
	public function insert($runValidation = true, $attributes = null)
	{
		if ($runValidation && !$this->validate($attributes)) {
			return false;
		}
		$result = $this->insertInternal($attributes);
		return $result;
	}

	/**
	 * @see ActiveRecord::insert()
	 */
	protected function insertInternal($attributes = null)
	{
		if (!$this->beforeSave(true)) {
			return false;
		}
		$values = $this->getDirtyAttributes($attributes);
		if (empty($values)) {
			$currentAttributes = $this->getAttributes();
			foreach ($this->primaryKey() as $key) {
				$values[$key] = isset($currentAttributes[$key]) ? $currentAttributes[$key] : null;
			}
		}
		$collection = static::getCollection();
		$newId = $collection->insert($values);
		$this->setAttribute('_id', $newId);
		foreach ($values as $name => $value) {
			$this->setOldAttribute($name, $value);
		}
		$this->afterSave(true);
		return true;
	}

	/**
	 * @see CActiveRecord::update()
	 * @throws StaleObjectException
	 */
	protected function updateInternal($attributes = null)
	{
		if (!$this->beforeSave(false)) {
			return false;
		}
		$values = $this->getDirtyAttributes($attributes);
		if (empty($values)) {
			$this->afterSave(false);
			return 0;
		}
		$condition = $this->getOldPrimaryKey(true);
		$lock = $this->optimisticLock();
		if ($lock !== null) {
			if (!isset($values[$lock])) {
				$values[$lock] = $this->$lock + 1;
			}
			$condition[$lock] = $this->$lock;
		}
		// We do not check the return value of update() because it's possible
		// that it doesn't change anything and thus returns 0.
		$rows = static::getCollection()->update($condition, $values);

		if ($lock !== null && !$rows) {
			throw new StaleObjectException('The object being updated is outdated.');
		}

		foreach ($values as $name => $value) {
			$this->setOldAttribute($name, $this->getAttribute($name));
		}
		$this->afterSave(false);
		return $rows;
	}

	/**
	 * Deletes the document corresponding to this active record from the collection.
	 *
	 * This method performs the following steps in order:
	 *
	 * 1. call [[beforeDelete()]]. If the method returns false, it will skip the
	 *    rest of the steps;
	 * 2. delete the document from the collection;
	 * 3. call [[afterDelete()]].
	 *
	 * In the above step 1 and 3, events named [[EVENT_BEFORE_DELETE]] and [[EVENT_AFTER_DELETE]]
	 * will be raised by the corresponding methods.
	 *
	 * @return integer|boolean the number of documents deleted, or false if the deletion is unsuccessful for some reason.
	 * Note that it is possible the number of documents deleted is 0, even though the deletion execution is successful.
	 * @throws StaleObjectException if [[optimisticLock|optimistic locking]] is enabled and the data
	 * being deleted is outdated.
	 * @throws \Exception in case delete failed.
	 */
	public function delete()
	{
		$result = false;
		if ($this->beforeDelete()) {
			// we do not check the return value of deleteAll() because it's possible
			// the record is already deleted in the database and thus the method will return 0
			$condition = $this->getOldPrimaryKey(true);
			$lock = $this->optimisticLock();
			if ($lock !== null) {
				$condition[$lock] = $this->$lock;
			}
			$result = static::getCollection()->remove($condition);
			if ($lock !== null && !$result) {
				throw new StaleObjectException('The object being deleted is outdated.');
			}
			$this->setOldAttributes(null);
			$this->afterDelete();
		}
		return $result;
	}

	/**
	 * Returns a value indicating whether the given active record is the same as the current one.
	 * The comparison is made by comparing the table names and the primary key values of the two active records.
	 * If one of the records [[isNewRecord|is new]] they are also considered not equal.
	 * @param ActiveRecord $record record to compare to
	 * @return boolean whether the two active records refer to the same row in the same Mongo collection.
	 */
	public function equals($record)
	{
		if ($this->isNewRecord || $record->isNewRecord) {
			return false;
		}
		return $this->collectionName() === $record->collectionName() && $this->getPrimaryKey() === $record->getPrimaryKey();
	}
}