<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\ORM;

use ArrayObject;
use Cake\Database\ExpressionInterface;
use Cake\Database\Query as DatabaseQuery;
use Cake\Database\ValueBinder;
use Cake\Datasource\QueryInterface;
use Cake\Datasource\QueryTrait;
use JsonSerializable;
use RuntimeException;

/**
 * Extends the base Query class to provide new methods related to association
 * loading, automatic fields selection, automatic type casting and to wrap results
 * into a specific iterator that will be responsible for hydrating results if
 * required.
 *
 */
class Query extends DatabaseQuery implements JsonSerializable, QueryInterface
{

    use QueryTrait {
        cache as private _cache;
        all as private _all;
        _decorateResults as private _applyDecorators;
        __call as private _call;
    }

    /**
     * Indicates that the operation should append to the list
     *
     * @var int
     */
    const APPEND = 0;

    /**
     * Indicates that the operation should prepend to the list
     *
     * @var int
     */
    const PREPEND = 1;

    /**
     * Indicates that the operation should overwrite the list
     *
     * @var bool
     */
    const OVERWRITE = true;

    /**
     * Whether the user select any fields before being executed, this is used
     * to determined if any fields should be automatically be selected.
     *
     * @var bool
     */
    protected $_hasFields;

    /**
     * Tracks whether or not the original query should include
     * fields from the top level table.
     *
     * @var bool
     */
    protected $_autoFields;

    /**
     * Whether to hydrate results into entity objects
     *
     * @var bool
     */
    protected $_hydrate = true;

    /**
     * A callable function that can be used to calculate the total amount of
     * records this query will match when not using `limit`
     *
     * @var callable
     */
    protected $_counter;

    /**
     * Instance of a class responsible for storing association containments and
     * for eager loading them when this query is executed
     *
     * @var \Cake\ORM\EagerLoader
     */
    protected $_eagerLoader;

    /**
     * True if the beforeFind event has already been triggered for this query
     *
     * @var bool
     */
    protected $_beforeFindFired = false;

    /**
     * The COUNT(*) for the query.
     *
     * When set, count query execution will be bypassed.
     *
     * @var int
     */
    protected $_resultsCount;

    /**
     * Constructor
     *
     * @param \Cake\Database\Connection $connection The connection object
     * @param \Cake\ORM\Table $table The table this query is starting on
     */
    public function __construct($connection, $table)
    {
        parent::__construct($connection);
        $this->repository($table);

        if ($this->_repository) {
            $this->addDefaultTypes($this->_repository);
        }
    }

    /**
     * {@inheritDoc}
     *
     * If you pass an instance of a `Cake\ORM\Table` or `Cake\ORM\Association` class,
     * all the fields in the schema of the table or the association will be added to
     * the select clause.
     *
     * @param array|ExpressionInterface|string|\Cake\ORM\Table|\Cake\ORM\Association $fields fields
     * to be added to the list.
     * @param bool $overwrite whether to reset fields with passed list or not
     */
    public function select($fields = [], $overwrite = false)
    {
        if ($fields instanceof Association) {
            $fields = $fields->target();
        }

        if ($fields instanceof Table) {
            $fields = $this->aliasFields($fields->schema()->columns(), $fields->alias());
        }

        return parent::select($fields, $overwrite);
    }

    /**
     * Hints this object to associate the correct types when casting conditions
     * for the database. This is done by extracting the field types from the schema
     * associated to the passed table object. This prevents the user from repeating
     * himself when specifying conditions.
     *
     * This method returns the same query object for chaining.
     *
     * @param \Cake\ORM\Table $table The table to pull types from
     * @return $this
     */
    public function addDefaultTypes(Table $table)
    {
        $alias = $table->alias();
        $map = $table->schema()->typeMap();
        $fields = [];
        foreach ($map as $f => $type) {
            $fields[$f] = $fields[$alias . '.' . $f] = $type;
        }
        $this->typeMap()->addDefaults($fields);

        return $this;
    }

    /**
     * Sets the instance of the eager loader class to use for loading associations
     * and storing containments. If called with no arguments, it will return the
     * currently configured instance.
     *
     * @param \Cake\ORM\EagerLoader $instance The eager loader to use. Pass null
     *   to get the current eagerloader.
     * @return \Cake\ORM\EagerLoader|$this
     */
    public function eagerLoader(EagerLoader $instance = null)
    {
        if ($instance === null) {
            if ($this->_eagerLoader === null) {
                $this->_eagerLoader = new EagerLoader;
            }
            return $this->_eagerLoader;
        }
        $this->_eagerLoader = $instance;
        return $this;
    }

    /**
     * Sets the list of associations that should be eagerly loaded along with this
     * query. The list of associated tables passed must have been previously set as
     * associations using the Table API.
     *
     * ### Example:
     *
     * ```
     *  // Bring articles' author information
     *  $query->contain('Author');
     *
     *  // Also bring the category and tags associated to each article
     *  $query->contain(['Category', 'Tag']);
     * ```
     *
     * Associations can be arbitrarily nested using dot notation or nested arrays,
     * this allows this object to calculate joins or any additional queries that
     * must be executed to bring the required associated data.
     *
     * ### Example:
     *
     * ```
     *  // Eager load the product info, and for each product load other 2 associations
     *  $query->contain(['Product' => ['Manufacturer', 'Distributor']);
     *
     *  // Which is equivalent to calling
     *  $query->contain(['Products.Manufactures', 'Products.Distributors']);
     *
     *  // For an author query, load his region, state and country
     *  $query->contain('Regions.States.Countries');
     * ```
     *
     * It is possible to control the conditions and fields selected for each of the
     * contained associations:
     *
     * ### Example:
     *
     * ```
     *  $query->contain(['Tags' => function ($q) {
     *      return $q->where(['Tags.is_popular' => true]);
     *  }]);
     *
     *  $query->contain(['Products.Manufactures' => function ($q) {
     *      return $q->select(['name'])->where(['Manufactures.active' => true]);
     *  }]);
     * ```
     *
     * Each association might define special options when eager loaded, the allowed
     * options that can be set per association are:
     *
     * - foreignKey: Used to set a different field to match both tables, if set to false
     *   no join conditions will be generated automatically. `false` can only be used on
     *   joinable associations and cannot be used with hasMany or belongsToMany associations.
     * - fields: An array with the fields that should be fetched from the association
     * - queryBuilder: Equivalent to passing a callable instead of an options array
     *
     * ### Example:
     *
     * ```
     * // Set options for the hasMany articles that will be eagerly loaded for an author
     * $query->contain([
     *   'Articles' => [
     *     'fields' => ['title', 'author_id']
     *   ]
     * ]);
     * ```
     *
     * When containing associations, it is important to include foreign key columns.
     * Failing to do so will trigger exceptions.
     *
     * ```
     * // Use special join conditions for getting an Articles's belongsTo 'authors'
     * $query->contain([
     *   'Authors' => [
     *     'foreignKey' => false,
     *     'queryBuilder' => function ($q) {
     *       return $q->where(...); // Add full filtering conditions
     *     }
     *   ]
     * ]);
     * ```
     *
     * If called with no arguments, this function will return an array with
     * with the list of previously configured associations to be contained in the
     * result.
     *
     * If called with an empty first argument and $override is set to true, the
     * previous list will be emptied.
     *
     * @param array|string $associations list of table aliases to be queried
     * @param bool $override whether override previous list with the one passed
     * defaults to merging previous list with the new one.
     * @return array|$this
     */
    public function contain($associations = null, $override = false)
    {
        $loader = $this->eagerLoader();
        if ($override === true) {
            $loader->clearContain();
            $this->_dirty();
        }

        if ($associations === null) {
            return $loader->contain();
        }

        $result = $loader->contain($associations);
        $this->_addAssociationsToTypeMap($this->repository(), $this->typeMap(), $result);
        return $this;
    }

    /**
     * Used to recursively add contained association column types to
     * the query.
     *
     * @param \Cake\ORM\Table $table The table instance to pluck associations from.
     * @param \Cake\Database\TypeMap $typeMap The typemap to check for columns in.
     *   This typemap is indirectly mutated via Cake\ORM\Query::addDefaultTypes()
     * @param array $associations The nested tree of associations to walk.
     * @return void
     */
    protected function _addAssociationsToTypeMap($table, $typeMap, $associations)
    {
        foreach ($associations as $name => $nested) {
            $association = $table->association($name);
            if (!$association) {
                continue;
            }
            $target = $association->target();
            $primary = (array)$target->primaryKey();
            if (empty($primary) || $typeMap->type($target->aliasField($primary[0])) === null) {
                $this->addDefaultTypes($target);
            }
            if (!empty($nested)) {
                $this->_addAssociationsToTypeMap($target, $typeMap, $nested);
            }
        }
    }

    /**
     * Adds filtering conditions to this query to only bring rows that have a relation
     * to another from an associated table, based on conditions in the associated table.
     *
     * This function will add entries in the `contain` graph.
     *
     * ### Example:
     *
     * ```
     *  // Bring only articles that were tagged with 'cake'
     *  $query->matching('Tags', function ($q) {
     *      return $q->where(['name' => 'cake']);
     *  );
     * ```
     *
     * It is possible to filter by deep associations by using dot notation:
     *
     * ### Example:
     *
     * ```
     *  // Bring only articles that were commented by 'markstory'
     *  $query->matching('Comments.Users', function ($q) {
     *      return $q->where(['username' => 'markstory']);
     *  );
     * ```
     *
     * As this function will create `INNER JOIN`, you might want to consider
     * calling `distinct` on this query as you might get duplicate rows if
     * your conditions don't filter them already. This might be the case, for example,
     * of the same user commenting more than once in the same article.
     *
     * ### Example:
     *
     * ```
     *  // Bring unique articles that were commented by 'markstory'
     *  $query->distinct(['Articles.id'])
     *  ->matching('Comments.Users', function ($q) {
     *      return $q->where(['username' => 'markstory']);
     *  );
     * ```
     *
     * Please note that the query passed to the closure will only accept calling
     * `select`, `where`, `andWhere` and `orWhere` on it. If you wish to
     * add more complex clauses you can do it directly in the main query.
     *
     * @param string $assoc The association to filter by
     * @param callable $builder a function that will receive a pre-made query object
     * that can be used to add custom conditions or selecting some fields
     * @return $this
     */
    public function matching($assoc, callable $builder = null)
    {
        $this->eagerLoader()->matching($assoc, $builder);
        $this->_dirty();
        return $this;
    }

    /**
     * Creates a LEFT JOIN with the passed association table while preserving
     * the foreign key matching and the custom conditions that were originally set
     * for it.
     *
     * This function will add entries in the `contain` graph.
     *
     * ### Example:
     *
     * ```
     *  // Get the count of articles per user
     *  $usersQuery
     *      ->select(['total_articles' => $query->func()->count('Articles.id')])
     *      ->leftJoinWith('Articles')
     *      ->group(['Users.id'])
     *      ->autoFields(true);
     * ```
     *
     * You can also customize the conditions passed to the LEFT JOIN:
     *
     * ```
     *  // Get the count of articles per user with at least 5 votes
     *  $usersQuery
     *      ->select(['total_articles' => $query->func()->count('Articles.id')])
     *      ->leftJoinWith('Articles', function ($q) {
     *          return $q->where(['Articles.votes >=' => 5]);
     *      })
     *      ->group(['Users.id'])
     *      ->autoFields(true);
     * ```
     *
     * This will create the following SQL:
     *
     * ```
     *  SELECT COUNT(Articles.id) AS total_articles, Users.*
     *  FROM users Users
     *  LEFT JOIN articles Articles ON Articles.user_id = Users.id AND Articles.votes >= 5
     *  GROUP BY USers.id
     * ```
     *
     * It is possible to left join deep associations by using dot notation
     *
     * ### Example:
     *
     * ```
     *  // Total comments in articles by 'markstory'
     *  $query
     *   ->select(['total_comments' => $query->func()->count('Comments.id')])
     *   ->leftJoinWith('Comments.Users', function ($q) {
     *      return $q->where(['username' => 'markstory']);
     *  )
     *  ->group(['Users.id']);
     * ```
     *
     * Please note that the query passed to the closure will only accept calling
     * `select`, `where`, `andWhere` and `orWhere` on it. If you wish to
     * add more complex clauses you can do it directly in the main query.
     *
     * @param string $assoc The association to join with
     * @param callable $builder a function that will receive a pre-made query object
     * that can be used to add custom conditions or selecting some fields
     * @return $this
     */
    public function leftJoinWith($assoc, callable $builder = null)
    {
        $this->eagerLoader()->matching($assoc, $builder, [
            'joinType' => 'LEFT',
            'fields' => false
        ]);
        $this->_dirty();
        return $this;
    }

    /**
     * Creates an INNER JOIN with the passed association table while preserving
     * the foreign key matching and the custom conditions that were originally set
     * for it.
     *
     * This function will add entries in the `contain` graph.
     *
     * ### Example:
     *
     * ```
     *  // Bring only articles that were tagged with 'cake'
     *  $query->innerJoinWith('Tags', function ($q) {
     *      return $q->where(['name' => 'cake']);
     *  );
     * ```
     *
     * This will create the following SQL:
     *
     * ```
     *  SELECT Articles.*
     *  FROM articles Articles
     *  INNER JOIN tags Tags ON Tags.name = 'cake'
     *  INNER JOIN articles_tags ArticlesTags ON ArticlesTags.tag_id = Tags.id
     *    AND ArticlesTags.articles_id = Articles.id
     * ```
     *
     * This function works the same as `matching()` with the difference that it
     * will select no fields from the association.
     *
     * @param string $assoc The association to join with
     * @param callable $builder a function that will receive a pre-made query object
     * that can be used to add custom conditions or selecting some fields
     * @return $this
     * @see \Cake\ORM\Query::matching()
     */
    public function innerJoinWith($assoc, callable $builder = null)
    {
        $this->eagerLoader()->matching($assoc, $builder, [
            'joinType' => 'INNER',
            'fields' => false
        ]);
        $this->_dirty();
        return $this;
    }

    /**
     * Adds filtering conditions to this query to only bring rows that have no match
     * to another from an associated table, based on conditions in the associated table.
     *
     * This function will add entries in the `contain` graph.
     *
     * ### Example:
     *
     * ```
     *  // Bring only articles that were not tagged with 'cake'
     *  $query->notMatching('Tags', function ($q) {
     *      return $q->where(['name' => 'cake']);
     *  );
     * ```
     *
     * It is possible to filter by deep associations by using dot notation:
     *
     * ### Example:
     *
     * ```
     *  // Bring only articles that weren't commented by 'markstory'
     *  $query->notMatching('Comments.Users', function ($q) {
     *      return $q->where(['username' => 'markstory']);
     *  );
     * ```
     *
     * As this function will create a `LEFT JOIN`, you might want to consider
     * calling `distinct` on this query as you might get duplicate rows if
     * your conditions don't filter them already. This might be the case, for example,
     * of the same article having multiple comments.
     *
     * ### Example:
     *
     * ```
     *  // Bring unique articles that were commented by 'markstory'
     *  $query->distinct(['Articles.id'])
     *  ->notMatching('Comments.Users', function ($q) {
     *      return $q->where(['username' => 'markstory']);
     *  );
     * ```
     *
     * Please note that the query passed to the closure will only accept calling
     * `select`, `where`, `andWhere` and `orWhere` on it. If you wish to
     * add more complex clauses you can do it directly in the main query.
     *
     * @param string $assoc The association to filter by
     * @param callable $builder a function that will receive a pre-made query object
     * that can be used to add custom conditions or selecting some fields
     * @return $this
     */
    public function notMatching($assoc, callable $builder = null)
    {
        $this->eagerLoader()->matching($assoc, $builder, [
            'joinType' => 'LEFT',
            'fields' => false,
            'negateMatch' => true
        ]);
        $this->_dirty();
        return $this;
    }

    /**
     * {@inheritDoc}
     *
     * Populates or adds parts to current query clauses using an array.
     * This is handy for passing all query clauses at once. The option array accepts:
     *
     * - fields: Maps to the select method
     * - conditions: Maps to the where method
     * - limit: Maps to the limit method
     * - order: Maps to the order method
     * - offset: Maps to the offset method
     * - group: Maps to the group method
     * - having: Maps to the having method
     * - contain: Maps to the contain options for eager loading
     * - join: Maps to the join method
     * - page: Maps to the page method
     *
     * ### Example:
     *
     * ```
     * $query->applyOptions([
     *   'fields' => ['id', 'name'],
     *   'conditions' => [
     *     'created >=' => '2013-01-01'
     *   ],
     *   'limit' => 10
     * ]);
     * ```
     *
     * Is equivalent to:
     *
     * ```
     *  $query
     *  ->select(['id', 'name'])
     *  ->where(['created >=' => '2013-01-01'])
     *  ->limit(10)
     * ```
     */
    public function applyOptions(array $options)
    {
        $valid = [
            'fields' => 'select',
            'conditions' => 'where',
            'join' => 'join',
            'order' => 'order',
            'limit' => 'limit',
            'offset' => 'offset',
            'group' => 'group',
            'having' => 'having',
            'contain' => 'contain',
            'page' => 'page',
        ];

        ksort($options);
        foreach ($options as $option => $values) {
            if (isset($valid[$option], $values)) {
                $this->{$valid[$option]}($values);
            } else {
                $this->_options[$option] = $values;
            }
        }

        return $this;
    }

    /**
     * Creates a copy of this current query, triggers beforeFind and resets some state.
     *
     * The following state will be cleared:
     *
     * - autoFields
     * - limit
     * - offset
     * - map/reduce functions
     * - result formatters
     * - order
     * - containments
     *
     * This method creates query clones that are useful when working with subqueries.
     *
     * @return \Cake\ORM\Query
     */
    public function cleanCopy()
    {
        $clone = clone $this;
        $clone->triggerBeforeFind();
        $clone->autoFields(false);
        $clone->limit(null);
        $clone->order([], true);
        $clone->offset(null);
        $clone->mapReduce(null, null, true);
        $clone->formatResults(null, true);
        return $clone;
    }

    /**
     * Object clone hook.
     *
     * Destroys the clones inner iterator and clones the value binder, and eagerloader instances.
     *
     * @return void
     */
    public function __clone()
    {
        parent::__clone();
        if ($this->_eagerLoader) {
            $this->_eagerLoader = clone $this->_eagerLoader;
        }
    }

    /**
     * {@inheritDoc}
     *
     * Returns the COUNT(*) for the query. If the query has not been
     * modified, and the count has already been performed the cached
     * value is returned
     */
    public function count()
    {
        if ($this->_resultsCount === null) {
            $this->_resultsCount = $this->_performCount();
        }

        return $this->_resultsCount;
    }

    /**
     * Performs and returns the COUNT(*) for the query.
     *
     * @return int
     */
    protected function _performCount()
    {
        $query = $this->cleanCopy();
        $counter = $this->_counter;
        if ($counter) {
            $query->counter(null);
            return (int)$counter($query);
        }

        $complex = (
            $query->clause('distinct') ||
            count($query->clause('group')) ||
            count($query->clause('union')) ||
            $query->clause('having')
        );

        if (!$complex) {
            // Expression fields could have bound parameters.
            foreach ($query->clause('select') as $field) {
                if ($field instanceof ExpressionInterface) {
                    $complex = true;
                    break;
                }
            }
        }

        if (!$complex && $this->_valueBinder !== null) {
            $order = $this->clause('order');
            $complex = $order === null ? false : $order->hasNestedExpression();
        }

        $count = ['count' => $query->func()->count('*')];

        if (!$complex) {
            $query->eagerLoader()->autoFields(false);
            $statement = $query
                ->select($count, true)
                ->autoFields(false)
                ->execute();
        } else {
            $statement = $this->connection()->newQuery()
                ->select($count)
                ->from(['count_source' => $query])
                ->execute();
        }

        $result = $statement->fetch('assoc')['count'];
        $statement->closeCursor();
        return (int)$result;
    }

    /**
     * Registers a callable function that will be executed when the `count` method in
     * this query is called. The return value for the function will be set as the
     * return value of the `count` method.
     *
     * This is particularly useful when you need to optimize a query for returning the
     * count, for example removing unnecessary joins, removing group by or just return
     * an estimated number of rows.
     *
     * The callback will receive as first argument a clone of this query and not this
     * query itself.
     *
     * If the first param is a null value, the built-in counter function will be called
     * instead
     *
     * @param callable|null $counter The counter value
     * @return $this
     */
    public function counter($counter)
    {
        $this->_counter = $counter;
        return $this;
    }

    /**
     * Toggle hydrating entities.
     *
     * If set to false array results will be returned
     *
     * @param bool|null $enable Use a boolean to set the hydration mode.
     *   Null will fetch the current hydration mode.
     * @return bool|$this A boolean when reading, and $this when setting the mode.
     */
    public function hydrate($enable = null)
    {
        if ($enable === null) {
            return $this->_hydrate;
        }

        $this->_dirty();
        $this->_hydrate = (bool)$enable;
        return $this;
    }

    /**
     * {@inheritDoc}
     *
     * @return $this
     * @throws \RuntimeException When you attempt to cache a non-select query.
     */
    public function cache($key, $config = 'default')
    {
        if ($this->_type !== 'select' && $this->_type !== null) {
            throw new RuntimeException('You cannot cache the results of non-select queries.');
        }
        return $this->_cache($key, $config);
    }

    /**
     * {@inheritDoc}
     *
     * @throws \RuntimeException if this method is called on a non-select Query.
     */
    public function all()
    {
        if ($this->_type !== 'select' && $this->_type !== null) {
            throw new RuntimeException(
                'You cannot call all() on a non-select query. Use execute() instead.'
            );
        }
        return $this->_all();
    }

    /**
     * Trigger the beforeFind event on the query's repository object.
     *
     * Will not trigger more than once, and only for select queries.
     *
     * @return void
     */
    public function triggerBeforeFind()
    {
        if (!$this->_beforeFindFired && $this->_type === 'select') {
            $table = $this->repository();
            $this->_beforeFindFired = true;
            $table->dispatchEvent('Model.beforeFind', [
                $this,
                new ArrayObject($this->_options),
                !$this->eagerLoaded()
            ]);
        }
    }

    /**
     * {@inheritDoc}
     */
    public function sql(ValueBinder $binder = null)
    {
        $this->triggerBeforeFind();

        $this->_transformQuery();
        $sql = parent::sql($binder);
        return $sql;
    }

    /**
     * Executes this query and returns a ResultSet object containing the results.
     * This will also setup the correct statement class in order to eager load deep
     * associations.
     *
     * @return \Cake\ORM\ResultSet
     */
    protected function _execute()
    {
        $this->triggerBeforeFind();
        if ($this->_results) {
            $decorator = $this->_decoratorClass();
            return new $decorator($this->_results);
        }
        $statement = $this->eagerLoader()->loadExternal($this, $this->execute());
        return new ResultSet($this, $statement);
    }

    /**
     * Applies some defaults to the query object before it is executed.
     *
     * Specifically add the FROM clause, adds default table fields if none are
     * specified and applies the joins required to eager load associations defined
     * using `contain`
     *
     * @see \Cake\Database\Query::execute()
     * @return void
     */
    protected function _transformQuery()
    {
        if (!$this->_dirty) {
            return;
        }

        if ($this->_type === 'select') {
            if (empty($this->_parts['from'])) {
                $this->from([$this->_repository->alias() => $this->_repository->table()]);
            }
            $this->_addDefaultFields();
            $this->eagerLoader()->attachAssociations($this, $this->_repository, !$this->_hasFields);
        }
    }

    /**
     * Inspects if there are any set fields for selecting, otherwise adds all
     * the fields for the default table.
     *
     * @return void
     */
    protected function _addDefaultFields()
    {
        $select = $this->clause('select');
        $this->_hasFields = true;

        if (!count($select) || $this->_autoFields === true) {
            $this->_hasFields = false;
            $this->select($this->repository()->schema()->columns());
            $select = $this->clause('select');
        }

        $aliased = $this->aliasFields($select, $this->repository()->alias());
        $this->select($aliased, true);
    }

    /**
     * {@inheritDoc}
     *
     * @see \Cake\ORM\Table::find()
     */
    public function find($finder, array $options = [])
    {
        return $this->repository()->callFinder($finder, $this, $options);
    }

    /**
     * Marks a query as dirty, removing any preprocessed information
     * from in memory caching such as previous results
     *
     * @return void
     */
    protected function _dirty()
    {
        $this->_results = null;
        $this->_resultsCount = null;
        parent::_dirty();
    }

    /**
     * Create an update query.
     *
     * This changes the query type to be 'update'.
     * Can be combined with set() and where() methods to create update queries.
     *
     * @param string|null $table Unused parameter.
     * @return $this
     */
    public function update($table = null)
    {
        $table = $table ?: $this->repository()->table();
        return parent::update($table);
    }

    /**
     * Create a delete query.
     *
     * This changes the query type to be 'delete'.
     * Can be combined with the where() method to create delete queries.
     *
     * @param string|null $table Unused parameter.
     * @return $this
     */
    public function delete($table = null)
    {
        $repo = $this->repository();
        $this->from([$repo->alias() => $repo->table()]);
        return parent::delete();
    }

    /**
     * Create an insert query.
     *
     * This changes the query type to be 'insert'.
     * Note calling this method will reset any data previously set
     * with Query::values()
     *
     * Can be combined with the where() method to create delete queries.
     *
     * @param array $columns The columns to insert into.
     * @param array $types A map between columns & their datatypes.
     * @return $this
     */
    public function insert(array $columns, array $types = [])
    {
        $table = $this->repository()->table();
        $this->into($table);
        return parent::insert($columns, $types);
    }

    /**
     * {@inheritDoc}
     *
     * @throws \BadMethodCallException if the method is called for a non-select query
     */
    public function __call($method, $arguments)
    {
        if ($this->type() === 'select') {
            return $this->_call($method, $arguments);
        }

        throw new \BadMethodCallException(
            sprintf('Cannot call method "%s" on a "%s" query', $method, $this->type())
        );
    }

    /**
     * {@inheritDoc}
     */
    public function __debugInfo()
    {
        $eagerLoader = $this->eagerLoader();
        return parent::__debugInfo() + [
            'hydrate' => $this->_hydrate,
            'buffered' => $this->_useBufferedResults,
            'formatters' => count($this->_formatters),
            'mapReducers' => count($this->_mapReduce),
            'contain' => $eagerLoader ? $eagerLoader->contain() : [],
            'matching' => $eagerLoader ? $eagerLoader->matching() : [],
            'extraOptions' => $this->_options,
            'repository' => $this->_repository
        ];
    }

    /**
     * Executes the query and converts the result set into JSON.
     *
     * Part of JsonSerializable interface.
     *
     * @return \Cake\Datasource\ResultSetInterface The data to convert to JSON.
     */
    public function jsonSerialize()
    {
        return $this->all();
    }

    /**
     * Get/Set whether or not the ORM should automatically append fields.
     *
     * By default calling select() will disable auto-fields. You can re-enable
     * auto-fields with this method.
     *
     * @param bool|null $value The value to set or null to read the current value.
     * @return bool|$this Either the current value or the query object.
     */
    public function autoFields($value = null)
    {
        if ($value === null) {
            return $this->_autoFields;
        }
        $this->_autoFields = (bool)$value;
        return $this;
    }

    /**
     * Decorates the results iterator with MapReduce routines and formatters
     *
     * @param \Traversable $result Original results
     * @return \Cake\Datasource\ResultSetInterface
     */
    protected function _decorateResults($result)
    {
        $result = $this->_applyDecorators($result);

        if (!($result instanceof ResultSet) && $this->bufferResults()) {
            $class = $this->_decoratorClass();
            $result = new $class($result->buffered());
        }

        return $result;
    }
}
