<?php

namespace Symlink\ORM;

use Symlink\ORM\Repositories\BaseRepository;

class QueryBuilder {

private $where;

private $order_by;

private $limit;

/**

* The prepared query run through $wpdb->prepare().

* @var

*/

private $query;

/**

* Reference to the repository.

* @var \Symlink\ORM\Repositories\BaseRepository

*/

private $repository;

/**

* QueryBuilder constructor.

*/

public function __construct( BaseRepository $repository ) {

// Set some default values.

$this->where = [];

$this->order_by;

$this->limit;

// And store the sent repository.

$this->repository = $repository;

}

/**

* Add a WHERE clause to the query.

*

* @param $property

* @param $value

* @param $operator

*

* @return $this

* @throws \Symlink\ORM\Exceptions\InvalidOperatorException

* @throws \Symlink\ORM\Exceptions\PropertyDoesNotExistException

*/

public function where( $property, $value, $operator ) {

// Check the property exists.

if ( ! in_array( $property, $this->repository->getObjectProperties() ) && $property != 'ID' ) {

throw new \Symlink\ORM\Exceptions\PropertyDoesNotExistException( sprintf( __( 'Property %s does not exist in model %s.' ), $property, $this->repository->getObjectClass() ) );

}

// Check the operator is valid.

if ( ! in_array( $operator, [

'<',

'<=',

'=',

'!=',

'<>',

'>',

'>=',

'IN',

'NOT IN',

'LIKE',

'NOT LIKE',

'REGEXP',

'NOT REGEXP',

] )

) {

throw new \Symlink\ORM\Exceptions\InvalidOperatorException( sprintf( __( 'Operator %s is not valid.' ), $operator ) );

}

// Add the entry.

$this->where[] = [

'property' => $property,

'operator' => $operator,

'value' => $value,

'placeholder' => $this->repository->getObjectPropertyPlaceholders()[ $property ]

];

return $this;

}

/**

* Set the ORDER BY clause.

*

* @param $property

* @param $operator

*

* @return $this

* @throws \Symlink\ORM\Exceptions\InvalidOperatorException

* @throws \Symlink\ORM\Exceptions\PropertyDoesNotExistException

*/

public function orderBy( $property, $operator ) {

// Check the property exists.

if ( ! in_array( $property, $this->repository->getObjectProperties() ) && $property != 'ID' ) {

throw new \Symlink\ORM\Exceptions\PropertyDoesNotExistException( sprintf( __( 'Property %s does not exist in model %s.' ), $property, $this->repository->getObjectClass() ) );

}

// Check the operator is valid.

if ( ! in_array( $operator, [

'ASC',

'DESC',

] )

) {

throw new \Symlink\ORM\Exceptions\InvalidOperatorException( sprintf( __( 'Operator %s is not valid.' ), $operator ) );

}

// Save it

$this->order_by = "ORDER BY " . $property . " " . $operator . "

";

return $this;

}

/**

* Set the limit clause.

*

* @param $count

* @param int $offset

*

* @return $this

*/

public function limit( $count, $offset = 0 ) {

// Ignore if not valid.

if ( is_numeric( $offset ) && is_numeric( $count ) && $offset >= 0 && $count > 0 ) {

$this->limit = "LIMIT " . $count . " OFFSET " . $offset . "

";

}

return $this;

}

/**

* Build the query and process through $wpdb->prepare().

* @return $this

*/

public function buildQuery() {

global $wpdb;

$values = [];

$sql = "SELECT * FROM " . $wpdb->prefix . $this->repository->getDBTable() . "

";

// Combine the WHERE clauses and add to the SQL statement.

if ( count( $this->where ) ) {

$sql .= "WHERE

";

$combined_where = [];

foreach ( $this->where as $where ) {

// Operators is not "IN" or "NOT IN"

if ( $where['operator'] != 'IN' && $where['operator'] != 'NOT IN' ) {

$combined_where[] = $where['property'] . " " . $where['operator'] . " " . $where['placeholder'] . "

";

$values[] = $where['value'];

} // Operator is "IN" or "NOT IN"

else {

// Fail silently.

if ( is_array( $where['value'] ) ) {

$combined_where[] = $where['property'] . " " . $where['operator'] . " (" . implode( ", ", array_pad( [], count( $where['value'] ), $where['placeholder'] ) ) . ")

";

$values = array_merge( $values, $where['value'] );

}

}

}

$sql .= implode( ' AND ', $combined_where ); // @todo - should allow more than AND in future.

}

// Add the ORDER BY clause.

if ( $this->order_by ) {

$sql .= $this->order_by;

}

// Add the LIMIT clause.

if ( $this->limit ) {

$sql .= $this->limit;

}

// Save it.

$this->query = count( $this->where ) ? $wpdb->prepare( $sql, $values ) : $sql;

return $this;

}

/**

* Run the query returning either a single object or an array of objects.

*

* @param bool $always_array

*

* @return array|mixed

* @throws \Symlink\ORM\Exceptions\NoQueryException

*/

public function getResults( $always_array = false ) {

global $wpdb;

if ( $this->query ) {

// Classname for this repository.

$object_classname = $this->repository->getObjectClass();

/**

* Get in cache if exists or retrieve in DB and save in cache for later use in the current request

*/

// Cache group (Where the cache contents are grouped)

$cache_group = 'wordpress_orm_getResults';

// Cache key

$cache_key = md5( $this->query );

$results = wp_cache_get( $cache_key, $cache_group );

if ( $results === false ) {

// Get items

$results = $wpdb->get_results( $this->query );

// Cache result

wp_cache_add( $cache_key, $results, $cache_group );

}

// Loop through the database results, building the objects.

$objects = array_map( function ( $result ) use ( &$object_classname ) {

// Create a new blank object.

$object = new $object_classname();

// Fill in all the properties.

array_walk( $result, function ( $value, $property ) use ( &$object ) {

$object->set( $property, $value );

} );

// Track the object.

$em = Manager::getManager();

$em->track( $object );

// Save it.

return $object;

}, $results );

// There were no results.

if ( ! count( $objects ) ) {

return null;

}

// Return just an object if there was only one result.

if ( count( $objects ) == 1 && ! $always_array ) {

return $objects[0];

}

// Otherwise, the return an array of objects.

return $objects;

} else {

throw new \Symlink\ORM\Exceptions\NoQueryException( __( 'No query was built. Run ->buildQuery() first.' ) );

}

}

}