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

namespace yii\sphinx;

use yii\base\InvalidConfigException;
use yii\base\NotSupportedException;
use yii\db\BaseActiveRecord;
use yii\db\StaleObjectException;
use yii\helpers\Inflector;
use Yii;
use yii\helpers\StringHelper;

/**
 * ActiveRecord is the base class for classes representing relational data in terms of objects.
 *
 * Warning: optimistic lock will NOT work in case of updating fields (not attributes) for the
 * runtime indexes!
 *
 * @property string $snippet Snippet value.
 * @property string $snippetSource Snippet source string. This property is read-only.
 *
 * @author Paul Klimov <klimov.paul@gmail.com>
 * @since 2.0
 */
abstract class ActiveRecord extends BaseActiveRecord
{
    /**
     * The insert operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
     */
    const OP_INSERT = 0x01;
    /**
     * The update operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
     */
    const OP_UPDATE = 0x02;
    /**
     * The delete operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
     */
    const OP_DELETE = 0x04;
    /**
     * All three operations: insert, update, delete.
     * This is a shortcut of the expression: OP_INSERT | OP_UPDATE | OP_DELETE.
     */
    const OP_ALL = 0x07;

    /**
     * @var string current snippet value for this Active Record instance.
     * It will be filled up automatically when instance found using [[Query::snippetCallback]]
     * or [[ActiveQuery::snippetByModel()]].
     */
    private $_snippet;

    /**
     * Returns the Sphinx connection used by this AR class.
     * By default, the "sphinx" application component is used as the Sphinx connection.
     * You may override this method if you want to use a different Sphinx connection.
     * @return Connection the Sphinx connection used by this AR class.
     */
    public static function getDb()
    {
        return \Yii::$app->getComponent('sphinx');
    }

    /**
     * Creates an [[ActiveQuery]] instance with a given SQL statement.
     *
     * Note that because the SQL statement is already specified, calling additional
     * query modification methods (such as `where()`, `order()`) on the created [[ActiveQuery]]
     * instance will have no effect. However, calling `with()`, `asArray()` or `indexBy()` is
     * still fine.
     *
     * Below is an example:
     *
     * ~~~
     * $customers = Article::findBySql("SELECT * FROM `idx_article` WHERE MATCH('development')")->all();
     * ~~~
     *
     * @param  string      $sql    the SQL statement to be executed
     * @param  array       $params parameters to be bound to the SQL statement during execution.
     * @return ActiveQuery the newly created [[ActiveQuery]] instance
     */
    public static function findBySql($sql, $params = [])
    {
        $query = static::createQuery();
        $query->sql = $sql;

        return $query->params($params);
    }

    /**
     * Updates the whole table using the provided attribute values and conditions.
     * For example, to change the status to be 1 for all articles which status is 2:
     *
     * ~~~
     * Article::updateAll(['status' => 1], 'status = 2');
     * ~~~
     *
     * @param  array        $attributes attribute values (name-value pairs) to be saved into the table
     * @param  string|array $condition  the conditions that will be put in the WHERE part of the UPDATE SQL.
     *                                  Please refer to [[Query::where()]] on how to specify this parameter.
     * @param  array        $params     the parameters (name => value) to be bound to the query.
     * @return integer      the number of rows updated
     */
    public static function updateAll($attributes, $condition = '', $params = [])
    {
        $command = static::getDb()->createCommand();
        $command->update(static::indexName(), $attributes, $condition, $params);

        return $command->execute();
    }

    /**
     * Deletes rows in the index using the provided conditions.
     *
     * For example, to delete all articles whose status is 3:
     *
     * ~~~
     * Article::deleteAll('status = 3');
     * ~~~
     *
     * @param  string|array $condition the conditions that will be put in the WHERE part of the DELETE SQL.
     *                                 Please refer to [[Query::where()]] on how to specify this parameter.
     * @param  array        $params    the parameters (name => value) to be bound to the query.
     * @return integer      the number of rows deleted
     */
    public static function deleteAll($condition = '', $params = [])
    {
        $command = static::getDb()->createCommand();
        $command->delete(static::indexName(), $condition, $params);

        return $command->execute();
    }

    /**
     * Creates an [[ActiveQuery]] instance.
     *
     * This method is called by [[find()]], [[findBySql()]] to start a SELECT query but also
     * by [[hasOne()]] and [[hasMany()]] to create a relational query.
     * You may override this method to return a customized query (e.g. `CustomerQuery` specified
     * written for querying `Customer` purpose.)
     *
     * You may also define default conditions that should apply to all queries unless overridden:
     *
     * ```php
     * public static function createQuery($config = [])
     * {
     *     return parent::createQuery($config)->where(['deleted' => false]);
     * }
     * ```
     *
     * Note that all queries should use [[Query::andWhere()]] and [[Query::orWhere()]] to keep the
     * default condition. Using [[Query::where()]] will override the default condition.
     *
     * @param  array       $config the configuration passed to the ActiveQuery class.
     * @return ActiveQuery the newly created [[ActiveQuery]] instance.
     */
    public static function createQuery($config = [])
    {
        $config['modelClass'] = get_called_class();

        return new ActiveQuery($config);
    }

    /**
     * Declares the name of the Sphinx index associated with this AR class.
     * By default this method returns the class name as the index name by calling [[Inflector::camel2id()]].
     * For example, 'Article' becomes 'article', and 'StockItem' becomes
     * 'stock_item'. You may override this method if the index is not named after this convention.
     * @return string the index name
     */
    public static function indexName()
    {
        return Inflector::camel2id(StringHelper::basename(get_called_class()), '_');
    }

    /**
     * Returns the schema information of the Sphinx index associated with this AR class.
     * @return IndexSchema            the schema information of the Sphinx index associated with this AR class.
     * @throws InvalidConfigException if the index for the AR class does not exist.
     */
    public static function getIndexSchema()
    {
        $schema = static::getDb()->getIndexSchema(static::indexName());
        if ($schema !== null) {
            return $schema;
        } else {
            throw new InvalidConfigException("The index does not exist: " . static::indexName());
        }
    }

    /**
     * Returns the primary key name for this AR class.
     * The default implementation will return the primary key as declared
     * in the Sphinx index, which is associated with this AR class.
     *
     * Note that an array should be returned even for a table with single primary key.
     *
     * @return string[] the primary keys of the associated Sphinx index.
     */
    public static function primaryKey()
    {
        return [static::getIndexSchema()->primaryKey];
    }

    /**
     * Builds a snippet from provided data and query, using specified index settings.
     * @param  string|array $source  is the source data to extract a snippet from.
     *                               It could be either a single string or array of strings.
     * @param  string       $match   the full-text query to build snippets for.
     * @param  array        $options list of options in format: optionName => optionValue
     * @return string|array built snippet in case "source" is a string, list of built snippets
     *                              in case "source" is an array.
     */
    public static function callSnippets($source, $match, $options = [])
    {
        $command = static::getDb()->createCommand();
        $command->callSnippets(static::indexName(), $source, $match, $options);
        if (is_array($source)) {
            return $command->queryColumn();
        } else {
            return $command->queryScalar();
        }
    }

    /**
     * Returns tokenized and normalized forms of the keywords, and, optionally, keyword statistics.
     * @param  string  $text           the text to break down to keywords.
     * @param  boolean $fetchStatistic whether to return document and hit occurrence statistics
     * @return array   keywords and statistics
     */
    public static function callKeywords($text, $fetchStatistic = false)
    {
        $command = static::getDb()->createCommand();
        $command->callKeywords(static::indexName(), $text, $fetchStatistic);

        return $command->queryAll();
    }

    /**
     * @param string $snippet
     */
    public function setSnippet($snippet)
    {
        $this->_snippet = $snippet;
    }

    /**
     * Returns current snippet value or generates new one from given match.
     * @param  string $match   snippet source query
     * @param  array  $options list of options in format: optionName => optionValue
     * @return string snippet value
     */
    public function getSnippet($match = null, $options = [])
    {
        if ($match !== null) {
            $this->_snippet = $this->fetchSnippet($match, $options);
        }

        return $this->_snippet;
    }

    /**
     * Builds up the snippet value from the given query.
     * @param  string $match   the full-text query to build snippets for.
     * @param  array  $options list of options in format: optionName => optionValue
     * @return string snippet value.
     */
    protected function fetchSnippet($match, $options = [])
    {
        return static::callSnippets($this->getSnippetSource(), $match, $options);
    }

    /**
     * Returns the string, which should be used as a source to create snippet for this
     * Active Record instance.
     * Child classes must implement this method to return the actual snippet source text.
     * For example:
     * ~~~
     * public function getSnippetSource()
     * {
     *     return $this->snippetSourceRelation->content;
     * }
     * ~~~
     * @return string                          snippet source string.
     * @throws \yii\base\NotSupportedException if this is not supported by the Active Record class
     */
    public function getSnippetSource()
    {
        throw new NotSupportedException($this->className() . ' does not provide snippet source.');
    }

    /**
     * Declares which operations should be performed within a transaction in different scenarios.
     * The supported DB operations are: [[OP_INSERT]], [[OP_UPDATE]] and [[OP_DELETE]],
     * which correspond to the [[insert()]], [[update()]] and [[delete()]] methods, respectively.
     * By default, these methods are NOT enclosed in a transaction.
     *
     * In some scenarios, to ensure data consistency, you may want to enclose some or all of them
     * in transactions. You can do so by overriding this method and returning the operations
     * that need to be transactional. For example,
     *
     * ~~~
     * return [
     *     'admin' => self::OP_INSERT,
     *     'api' => self::OP_INSERT | self::OP_UPDATE | self::OP_DELETE,
     *     // the above is equivalent to the following:
     *     // 'api' => self::OP_ALL,
     *
     * ];
     * ~~~
     *
     * The above declaration specifies that in the "admin" scenario, the insert operation ([[insert()]])
     * should be done in a transaction; and in the "api" scenario, all the operations should be done
     * in a transaction.
     *
     * @return array the declarations of transactional operations. The array keys are scenarios names,
     *               and the array values are the corresponding transaction operations.
     */
    public function transactions()
    {
        return [];
    }

    /**
     * Returns the list of all attribute names of the model.
     * The default implementation will return all column names of the table associated with this AR class.
     * @return array list of attribute names.
     */
    public function attributes()
    {
        return array_keys(static::getIndexSchema()->columns);
    }

    /**
     * Inserts a row into the associated Sphinx index 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 index. 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 [[changedAttributes|changed attribute values]] will be inserted.
     *
     * For example, to insert an article record:
     *
     * ~~~
     * $article = new Article;
     * $article->id = $id;
     * $article->genre_id = $genreId;
     * $article->content = $content;
     * $article->insert();
     * ~~~
     *
     * @param  boolean    $runValidation whether to perform validation before saving the record.
     *                                   If the validation fails, the record will not be inserted.
     * @param  array      $attributes    list of attributes that need to be saved. Defaults to null,
     *                                   meaning all attributes that are loaded from index will be saved.
     * @return boolean    whether the attributes are valid and the record is inserted successfully.
     * @throws \Exception in case insert failed.
     */
    public function insert($runValidation = true, $attributes = null)
    {
        if ($runValidation && !$this->validate($attributes)) {
            return false;
        }
        $db = static::getDb();
        if ($this->isTransactional(self::OP_INSERT) && $db->getTransaction() === null) {
            $transaction = $db->beginTransaction();
            try {
                $result = $this->insertInternal($attributes);
                if ($result === false) {
                    $transaction->rollBack();
                } else {
                    $transaction->commit();
                }
            } catch (\Exception $e) {
                $transaction->rollBack();
                throw $e;
            }
        } else {
            $result = $this->insertInternal($attributes);
        }

        return $result;
    }

    /**
     * @see ActiveRecord::insert()
     */
    private function insertInternal($attributes = null)
    {
        if (!$this->beforeSave(true)) {
            return false;
        }
        $values = $this->getDirtyAttributes($attributes);
        if (empty($values)) {
            foreach ($this->getPrimaryKey(true) as $key => $value) {
                $values[$key] = $value;
            }
        }
        $db = static::getDb();
        $command = $db->createCommand()->insert($this->indexName(), $values);
        if (!$command->execute()) {
            return false;
        }
        foreach ($values as $name => $value) {
            $this->setOldAttribute($name, $value);
        }
        $this->afterSave(true);

        return true;
    }

    /**
     * Saves the changes to this active record into the associated Sphinx index.
     *
     * 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. save the record into index. 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_UPDATE]], [[EVENT_AFTER_UPDATE]] and [[EVENT_AFTER_VALIDATE]]
     * will be raised by the corresponding methods.
     *
     * Only the [[changedAttributes|changed attribute values]] will be saved into database.
     *
     * For example, to update an article record:
     *
     * ~~~
     * $article = Article::find(['id' => $id]);
     * $article->genre_id = $genreId;
     * $article->group_id = $groupId;
     * $article->update();
     * ~~~
     *
     * Note that it is possible the update does not affect any row in the table.
     * In this case, this method will return 0. For this reason, you should use the following
     * code to check if update() is successful or not:
     *
     * ~~~
     * if ($this->update() !== false) {
     *     // update successful
     * } else {
     *     // update failed
     * }
     * ~~~
     *
     * @param  boolean              $runValidation whether to perform validation before saving the record.
     *                                             If the validation fails, the record will not be inserted into the database.
     * @param  array                $attributes    list of attributes that need to be saved. Defaults to null,
     *                                             meaning all attributes that are loaded from DB will be saved.
     * @return integer|boolean      the number of rows affected, or false if validation fails
     *                                            or [[beforeSave()]] stops the updating process.
     * @throws StaleObjectException if [[optimisticLock|optimistic locking]] is enabled and the data
     *                                            being updated is outdated.
     * @throws \Exception           in case update failed.
     */
    public function update($runValidation = true, $attributes = null)
    {
        if ($runValidation && !$this->validate($attributes)) {
            return false;
        }
        $db = static::getDb();
        if ($this->isTransactional(self::OP_UPDATE) && $db->getTransaction() === null) {
            $transaction = $db->beginTransaction();
            try {
                $result = $this->updateInternal($attributes);
                if ($result === false) {
                    $transaction->rollBack();
                } else {
                    $transaction->commit();
                }
            } catch (\Exception $e) {
                $transaction->rollBack();
                throw $e;
            }
        } else {
            $result = $this->updateInternal($attributes);
        }

        return $result;
    }

    /**
     * @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;
        }

        // Replace is supported only by runtime indexes and necessary only for field update
        $useReplace = false;
        $indexSchema = $this->getIndexSchema();
        if ($this->getIndexSchema()->isRuntime) {
            foreach ($values as $name => $value) {
                $columnSchema = $indexSchema->getColumn($name);
                if ($columnSchema->isField) {
                    $useReplace = true;
                    break;
                }
            }
        }

        if ($useReplace) {
            $values = array_merge($values, $this->getOldPrimaryKey(true));
            $command = static::getDb()->createCommand();
            $command->replace(static::indexName(), $values);
            // We do not check the return value of replace because it's possible
            // that the REPLACE statement doesn't change anything and thus returns 0.
            $rows = $command->execute();
        } else {
            $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 updateAll() because it's possible
            // that the UPDATE statement doesn't change anything and thus returns 0.
            $rows = $this->updateAll($values, $condition);

            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 index entry corresponding to this active record.
     *
     * 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 record from the index;
     * 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 rows deleted, or false if the deletion is unsuccessful for some reason.
     *                              Note that it is possible the number of rows 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()
    {
        $db = static::getDb();
        $transaction = $this->isTransactional(self::OP_DELETE) && $db->getTransaction() === null ? $db->beginTransaction() : null;
        try {
            $result = false;
            if ($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 = $this->deleteAll($condition);
                if ($lock !== null && !$result) {
                    throw new StaleObjectException('The object being deleted is outdated.');
                }
                $this->setOldAttributes(null);
                $this->afterDelete();
            }
            if ($transaction !== null) {
                if ($result === false) {
                    $transaction->rollBack();
                } else {
                    $transaction->commit();
                }
            }
        } catch (\Exception $e) {
            if ($transaction !== null) {
                $transaction->rollBack();
            }
            throw $e;
        }

        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 index 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 $record record to compare to
     * @return boolean      whether the two active records refer to the same row in the same index.
     */
    public function equals($record)
    {
        if ($this->isNewRecord || $record->isNewRecord) {
            return false;
        }

        return $this->indexName() === $record->indexName() && $this->getPrimaryKey() === $record->getPrimaryKey();
    }

    /**
     * @inheritdoc
     */
    public static function populateRecord($record, $row)
    {
        $columns = static::getIndexSchema()->columns;
        foreach ($row as $name => $value) {
            if (isset($columns[$name]) && $columns[$name]->isMva) {
                $row[$name] = explode(',', $value);
            }
        }
        parent::populateRecord($record, $row);
    }

    /**
     * Returns a value indicating whether the specified operation is transactional in the current [[scenario]].
     * @param  integer $operation the operation to check. Possible values are [[OP_INSERT]], [[OP_UPDATE]] and [[OP_DELETE]].
     * @return boolean whether the specified operation is transactional in the current [[scenario]].
     */
    public function isTransactional($operation)
    {
        $scenario = $this->getScenario();
        $transactions = $this->transactions();

        return isset($transactions[$scenario]) && ($transactions[$scenario] & $operation);
    }
}
