NeroReflex/Gishiki

<?php
/**************************************************************************
Copyright 2017 Benato Denis

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
 *****************************************************************************/

namespace Gishiki\Database\Runtime;

/**
 * This class is used to represent a selection criteria for database rows.
 *
 * @author Benato Denis <benato.denis96@gmail.com>
 */
final class SelectionCriteria
{
    const AND_HISTORIC_MARKER = 0b10000000;

    /**
     * @var array keeps track of the order clauses were inserted
     */
    protected $historic = [];

    /**
     * @var array both 'or' and 'and' are two arrays of sub-arrays
     */
    protected $criteria = [
        'and' => [],
        'or' => [],
    ];

    public static function select(array $selection = [])
    {
        //create an empty selection criteria
        $selectionCriteria = new self();

        foreach ($selection as $fieldName => $fieldValue) {
            (!is_array($fieldValue)) ?
                $selectionCriteria->andWhere($fieldName, FieldRelation::EQUAL, $fieldValue)
                    : $selectionCriteria->andWhere($fieldName, FieldRelation::IN_RANGE, $fieldValue);
        }

        return $selectionCriteria;
    }

    /**
     * Create a sub-clause and append it to the where clause using an and as conjunction.
     *
     * @param string $clause   can either be 'and' or 'or'
     * @param string $field    the name of the field/column to be related with the data
     * @param int    $relation the Relation between the field and the data
     * @param mixed  $data     the data to be related with the field
     *
     * @return SelectionCriteria the updated selection criteria
     *
     * @throws \InvalidArgumentException one parameter has a wrong type
     */
    protected function where($clause, $field, $relation, $data)
    {
        if (!is_string($field) || (strlen($field) <= 0)) {
            throw new \InvalidArgumentException('the field name must be a string');
        }
        if (($relation != FieldRelation::EQUAL) &&
            ($relation != FieldRelation::NOT_EQUAL) &&
            ($relation != FieldRelation::LESS_THAN) &&
            ($relation != FieldRelation::LESS_OR_EQUAL_THAN) &&
            ($relation != FieldRelation::GREATER_THAN) &&
            ($relation != FieldRelation::GREATER_OR_EQUAL_THAN) &&
            ($relation != FieldRelation::IN_RANGE) &&
            ($relation != FieldRelation::NOT_IN_RANGE) &&
            ($relation != FieldRelation::LIKE) &&
            ($relation != FieldRelation::NOT_LIKE)) {
            throw new \InvalidArgumentException('the Relation between a column and its value must be expressed by one of FieldRelation constants');
        }
        if ((is_object($data)) || (is_resource($data))) {
            throw new \InvalidArgumentException('the field data cannot be a php object or an extension native resource');
        }

        $this->criteria[$clause][] = [
            0 => $field,
            1 => $relation,
            2 => $data,
        ];
    }

    /**
     * Create a sub-clause and append it to the where clause using an and as conjunction.
     *
     * @param string $field    the name of the field/column to be related with the data
     * @param int    $relation the Relation between the field and the data
     * @param mixed  $data     the data to be related with the field
     *
     * @return SelectionCriteria the updated selection criteria
     *
     * @throws \InvalidArgumentException one parameter has a wrong type
     */
    public function andWhere($field, $relation, $data)
    {
        $this->where('and', $field, $relation, $data);

        $this->historic[] = self::AND_HISTORIC_MARKER | (count($this->criteria['and']) - 1);

        //return the modified filter
        return $this;
        //this is really important as it
        //allows the developer to chain
        //filter modifier functions
    }

    /**
     * Create a sub-clause and append it to the where clause using an or as conjunction.
     *
     * @param string $field    the name of the field/column to be related with the data
     * @param int    $relation the Relation between the field and the data
     * @param mixed  $data     the data to be related with the field
     *
     * @return SelectionCriteria the updated selection criteria
     *
     * @throws \InvalidArgumentException one parameter has a wrong type
     */
    public function orWhere($field, $relation, $data)
    {
        $this->where('or', $field, $relation, $data);

        $this->historic[] = count($this->criteria['or']) - 1;

        //return the modified filter
        return $this;
        //this is really important as it
        //allows the developer to chain
        //filter modifier functions
    }

    private function export()
    {
        $export = [
            'historic' => $this->historic,
            'criteria' => $this->criteria,
        ];

        return $export;
    }
}