<?php

namespace RedBeanPHP;


/**
 * RedBeanPHP Finder.
 * Service class to find beans. For the most part this class
 * offers user friendly utility methods for interacting with the
 * OODB::find() method, which is rather complex. This class can be
 * used to find beans using plain old SQL queries.
 *
 * @file    RedBeanPHP/Finder.php
 * @author  Gabor de Mooij and the RedBeanPHP Community
 * @license BSD/GPLv2
 *
 * @copyright
 * copyright (c) G.J.G.T. (Gabor) de Mooij and the RedBeanPHP Community
 * This source file is subject to the BSD/GPLv2 License that is bundled
 * with this source code in the file license.txt.
 */
class Finder
{
	/**
	 * @var ToolBox
	 */
	protected $toolbox;

	/**
	 * @var OODB
	 */
	protected $redbean;

	/**
	 * Constructor.
	 * The Finder requires a toolbox.
	 *
	 * @param ToolBox $toolbox
	 */
	public function __construct( ToolBox $toolbox )
	{
		$this->toolbox = $toolbox;
		$this->redbean = $toolbox->getRedBean();
	}

	/**
	 * Finds a bean using a type and a where clause (SQL).
	 * As with most Query tools in RedBean you can provide values to
	 * be inserted in the SQL statement by populating the value
	 * array parameter; you can either use the question mark notation
	 * or the slot-notation (:keyname).
	 *
	 * @param string $type     type   the type of bean you are looking for
	 * @param string $sql      sql    SQL query to find the desired bean, starting right after WHERE clause
	 * @param array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return array
	 */
	public function find( $type, $sql = NULL, $bindings = array() )
	{
		if ( !is_array( $bindings ) ) {
			throw new RedException(
				'Expected array, ' . gettype( $bindings ) . ' given.'
			);
		}

		return $this->redbean->find( $type, array(), $sql, $bindings );
	}

	/**
	 * Like find() but also exports the beans as an array.
	 * This method will perform a find-operation. For every bean
	 * in the result collection this method will call the export() method.
	 * This method returns an array containing the array representations
	 * of every bean in the result set.
	 *
	 * @see Finder::find
	 *
	 * @param string $type     type   the type of bean you are looking for
	 * @param string $sql      sql    SQL query to find the desired bean, starting right after WHERE clause
	 * @param array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return array
	 */
	public function findAndExport( $type, $sql = NULL, $bindings = array() )
	{
		$arr = array();
		foreach ( $this->find( $type, $sql, $bindings ) as $key => $item ) {
			$arr[] = $item->export();
		}

		return $arr;
	}

	/**
	 * Like find() but returns just one bean instead of an array of beans.
	 * This method will return only the first bean of the array.
	 * If no beans are found, this method will return NULL.
	 *
	 * @see Finder::find
	 *
	 * @param string $type     type   the type of bean you are looking for
	 * @param string $sql      sql    SQL query to find the desired bean, starting right after WHERE clause
	 * @param array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return OODBBean
	 */
	public function findOne( $type, $sql = NULL, $bindings = array() )
	{
		$sql = $this->toolbox->getWriter()->glueLimitOne( $sql );

		$items = $this->find( $type, $sql, $bindings );

		if ( empty($items) ) {
			return NULL;
		}

		return reset( $items );
	}

	/**
	 * Like find() but returns the last bean of the result array.
	 * Opposite of Finder::findLast().
	 * If no beans are found, this method will return NULL.
	 *
	 * @see Finder::find
	 *
	 * @param string $type     the type of bean you are looking for
	 * @param string $sql      SQL query to find the desired bean, starting right after WHERE clause
	 * @param array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return OODBBean
	 */
	public function findLast( $type, $sql = NULL, $bindings = array() )
	{
		$items = $this->find( $type, $sql, $bindings );

		if ( empty($items) ) {
			return NULL;
		}

		return end( $items );
	}

	/**
	 * Tries to find beans of a certain type,
	 * if no beans are found, it dispenses a bean of that type.
	 *
	 * @see Finder::find
	 *
	 * @param  string $type     the type of bean you are looking for
	 * @param  string $sql      SQL query to find the desired bean, starting right after WHERE clause
	 * @param  array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return array
	 */
	public function findOrDispense( $type, $sql = NULL, $bindings = array() )
	{
		$foundBeans = $this->find( $type, $sql, $bindings );

		if ( empty( $foundBeans ) ) {
			return array( $this->redbean->dispense( $type ) );
		} else {
			return $foundBeans;
		}
	}

	/**
	 * Finds a BeanCollection using the repository.
	 * A bean collection can be used to retrieve one bean at a time using
	 * cursors - this is useful for processing large datasets. A bean collection
	 * will not load all beans into memory all at once, just one at a time.
	 *
	 * @param  string $type     the type of bean you are looking for
	 * @param  string $sql      SQL query to find the desired bean, starting right after WHERE clause
	 * @param  array  $bindings values array of values to be bound to parameters in query
	 *
	 * @return BeanCollection
	 */
	public function findCollection( $type, $sql, $bindings = array() )
	{
		return $this->redbean->findCollection( $type, $sql, $bindings );
	}

	/**
	 * Finds or creates a bean.
	 * Tries to find a bean with certain properties specified in the second
	 * parameter ($like). If the bean is found, it will be returned.
	 * If multiple beans are found, only the first will be returned.
	 * If no beans match the criteria, a new bean will be dispensed,
	 * the criteria will be imported as properties and this new bean
	 * will be stored and returned.
	 *
	 * Format of criteria set: property => value
	 * The criteria set also supports OR-conditions: property => array( value1, orValue2 )
	 *
	 * @param string $type type of bean to search for
	 * @param array  $like criteria set describing bean to search for
	 *
	 * @return OODBBean
	 */
	public function findOrCreate( $type, $like = array() )
	{
			$beans = $this->findLike( $type, $like );
			if ( count( $beans ) ) {
				$bean = reset( $beans );
				return $bean;
			}

			$bean = $this->redbean->dispense( $type );
			$bean->import( $like );
			$this->redbean->store( $bean );
			return $bean;
	}

	/**
	 * Finds beans by its type and a certain criteria set.
	 *
	 * Format of criteria set: property => value
	 * The criteria set also supports OR-conditions: property => array( value1, orValue2 )
	 *
	 * If the additional SQL is a condition, this condition will be glued to the rest
	 * of the query using an AND operator. Note that this is as far as this method
	 * can go, there is no way to glue additional SQL using an OR-condition.
	 * This method provides access to an underlying mechanism in the RedBeanPHP architecture
	 * to find beans using criteria sets. However, please do not use this method
	 * for complex queries, use plain SQL instead ( the regular find method ) as it is
	 * more suitable for the job. This method is
	 * meant for basic search-by-example operations.
	 *
	 * @param string $type       type of bean to search for
	 * @param array  $conditions criteria set describing the bean to search for
	 * @param string $sql        additional SQL (for sorting)
	 *
	 * @return array
	 */
	public function findLike( $type, $conditions = array(), $sql = '' )
	{
		if ( count( $conditions ) > 0 ) {
			foreach( $conditions as $key => $condition ) {
				if ( !count( $condition ) ) unset( $conditions[$key] );
			}
		}

		return $this->redbean->find( $type, $conditions, $sql );
	}

	/**
	 * Returns a hashmap with bean arrays keyed by type using an SQL
	 * query as its resource. Given an SQL query like 'SELECT movie.*, review.* FROM movie... JOIN review'
	 * this method will return movie and review beans.
	 *
	 * Example:
	 *
	 * <code>
	 * $stuff = $finder->findMulti('movie,review', '
	 *          SELECT movie.*, review.* FROM movie
	 *          LEFT JOIN review ON review.movie_id = movie.id');
	 * </code>
	 *
	 * After this operation, $stuff will contain an entry 'movie' containing all
	 * movies and an entry named 'review' containing all reviews (all beans).
	 * You can also pass bindings.
	 *
	 * If you want to re-map your beans, so you can use $movie->ownReviewList without
	 * having RedBeanPHP executing an SQL query you can use the fourth parameter to
	 * define a selection of remapping closures.
	 *
	 * The remapping argument (optional) should contain an array of arrays.
	 * Each array in the remapping array should contain the following entries:
	 *
	 * <code>
	 * array(
	 * 	'a'       => TYPE A
	 *    'b'       => TYPE B
	 *    'matcher' => MATCHING FUNCTION ACCEPTING A, B and ALL BEANS
	 *    'do'      => OPERATION FUNCTION ACCEPTING A, B, ALL BEANS, ALL REMAPPINGS
	 * )
	 * </code>
	 *
	 * Using this mechanism you can build your own 'preloader' with tiny function
	 * snippets (and those can be re-used and shared online of course).
	 *
	 * Example:
	 *
	 * <code>
	 * array(
	 * 	'a'       => 'movie'     //define A as movie
	 *    'b'       => 'review'    //define B as review
	 *    'matcher' => function( $a, $b ) {
	 *       return ( $b->movie_id == $a->id );  //Perform action if review.movie_id equals movie.id
	 *    }
	 *    'do'      => function( $a, $b ) {
	 *       $a->noLoad()->ownReviewList[] = $b; //Add the review to the movie
	 *       $a->clearHistory();                 //optional, act 'as if these beans have been loaded through ownReviewList'.
	 *    }
	 * )
	 * </code>
	 *
	 * The Query Template parameter is optional as well but can be used to
	 * set a different SQL template (sprintf-style) for processing the original query.
	 *
	 * @note the SQL query provided IS NOT THE ONE used internally by this function,
	 * this function will pre-process the query to get all the data required to find the beans.
	 *
	 * @note if you use the 'book.*' notation make SURE you're
	 * selector starts with a SPACE. ' book.*' NOT ',book.*'. This is because
	 * it's actually an SQL-like template SLOT, not real SQL.
	 *
	 * @note instead of an SQL query you can pass a result array as well.
	 *
	 * @param string|array $types         a list of types (either array or comma separated string)
	 * @param string|array $sqlOrArr      an SQL query or an array of prefetched records
	 * @param array        $bindings      optional, bindings for SQL query
	 * @param array        $remappings    optional, an array of remapping arrays
	 * @param string       $queryTemplate optional, query template
	 *
	 * @return array
	 */
	public function findMulti( $types, $sql, $bindings = array(), $remappings = array(), $queryTemplate = ' %s.%s AS %s__%s' )
	{
		if ( !is_array( $types ) ) $types = explode( ',', $types );
		if ( !is_array( $sql ) ) {
			$writer = $this->toolbox->getWriter();
			$adapter = $this->toolbox->getDatabaseAdapter();

			//Repair the query, replace book.* with book.id AS book_id etc..
			foreach( $types as $type ) {
				$pattern = " {$type}.*";
				if ( strpos( $sql, $pattern ) !== FALSE ) {
					$newSelectorArray = array();
					$columns = $writer->getColumns( $type );
					foreach( $columns as $column => $definition ) {
						$newSelectorArray[] = sprintf( $queryTemplate, $type, $column, $type, $column );
					}
					$newSelector = implode( ',', $newSelectorArray );
					$sql = str_replace( $pattern, $newSelector, $sql );
				}
			}

			$rows = $adapter->get( $sql, $bindings );
		} else {
			$rows = $sql;
		}

		//Gather the bean data from the query results using the prefix
		$wannaBeans = array();
		foreach( $types as $type ) {
			$wannaBeans[$type] = array();
			$prefix            = "{$type}__";
			foreach( $rows as $rowkey=>$row ) {
				$wannaBean = array();
				foreach( $row as $cell => $value ) {
					if ( strpos( $cell, $prefix ) === 0 ) {
						$property = substr( $cell, strlen( $prefix ) );
						unset( $rows[$rowkey][$cell] );
						$wannaBean[$property] = $value;
					}
				}
				if ( !isset( $wannaBean['id'] ) ) continue;
				if ( is_null( $wannaBean['id'] ) ) continue;
				$wannaBeans[$type][$wannaBean['id']] = $wannaBean;
			}
		}

		//Turn the rows into beans
		$beans = array();
		foreach( $wannaBeans as $type => $wannabees ) {
			$beans[$type] = $this->redbean->convertToBeans( $type, $wannabees );
		}

		//Apply additional re-mappings
		foreach($remappings as $remapping) {
			$a       = $remapping['a'];
			$b       = $remapping['b'];
			$matcher = $remapping['matcher'];
			$do      = $remapping['do'];
			foreach( $beans[$a] as $bean ) {
				foreach( $beans[$b] as $putBean ) {
					if ( $matcher( $bean, $putBean, $beans ) ) $do( $bean, $putBean, $beans, $remapping );
				}
			}
		}
		return $beans;
	}
}
