<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

namespace ExpressionEngine\Service\Model\Relation;

use ExpressionEngine\Service\Model\Model;
use ExpressionEngine\Service\Model\Association\ToMany;

/**
 * HasAndBelongsToMany Relation
 */
class HasAndBelongsToMany extends Relation
{
    protected $pivot = array();

    /**
     *
     */
    public function canSaveAcross()
    {
        return false;
    }

    /**
     * Get pivot data
     */
    public function getPivot()
    {
        return $this->pivot;
    }

    public function getInverseOptions()
    {
        $options = parent::getInverseOptions();
        $options['pivot'] = [
            'table' => $this->pivot['table'],
            'left' => $this->pivot['right'],
            'right' => $this->pivot['left'],
        ];

        return $options;
    }

    /**
     *
     */
    public function createAssociation()
    {
        return new ToMany($this);
    }

    /**
     *
     */
    public function modifyEagerQuery($query, $from_alias, $to_alias)
    {
        list($from, $to) = $this->getKeys();

        $pivot_table = $this->pivot['table'];
        $pivot_as = "{$from_alias}_{$to_alias}_{$pivot_table}";

        // from -> pivot
        $query->join(
            "{$pivot_table} as {$pivot_as}",
            "{$pivot_as}.{$this->pivot['left']} = {$from_alias}_{$this->from_table}.{$from}",
            'LEFT'
        );

        // pivot -> to
        $query->join(
            "{$this->to_table} as {$to_alias}_{$this->to_table}",
            "{$to_alias}_{$this->to_table}.{$to} = {$pivot_as}.{$this->pivot['right']}",
            'LEFT'
        );
    }

    /**
     *
     */
    public function modifyLazyQuery($query, $source, $to_alias)
    {
        list($from, $to) = $this->getKeys();

        $from_alias = str_replace(':', '_m_', $source->getName());
        $pivot_table = $this->pivot['table'];
        $pivot_as = "{$from_alias}_{$to_alias}_{$pivot_table}";

        // pivot -> to_alias
        $query->join(
            "{$pivot_table} as {$pivot_as}",
            "{$pivot_as}.{$this->pivot['right']} = {$to_alias}_{$this->to_table}.{$to}",
            'LEFT'
        );

        $query->where("{$pivot_as}.{$this->pivot['left']}", $source->$from);
    }

    /**
     *
     */
    public function insert(Model $source, $targets)
    {
        if (empty($targets)) {
            return;
        }

        foreach ($targets as $target) {
            $this->datastore->rawQuery()
                ->set($this->pivot['left'], $source->{$this->from_key})
                ->set($this->pivot['right'], $target->{$this->to_key})
                ->insert($this->pivot['table']);
        }
    }

    /**
     *
     */
    public function drop(Model $source, $targets = null)
    {
        $query = $this->datastore
            ->rawQuery()
            ->where($this->pivot['left'], $source->{$this->from_key});

        if (! empty($targets)) {
            $ids = array();

            foreach ($targets as $target) {
                $ids[] = $target->{$this->to_key};
            }

            if (empty($ids)) {
                return;
            }

            $query->where_in($this->pivot['right'], $ids);
        }

        $query->delete($this->pivot['table']);
    }

    public function set(Model $source, $targets)
    {
        $this->drop($source, null);
        $this->insert($source, $targets);
    }

    /**
    *
    */
    public function fillLinkIds(Model $source, Model $target)
    {
        return; // nada
    }

    /**
     *
     */
    public function linkIds(Model $source, Model $target)
    {
        return; // nada
    }

    /**
     *
     */
    public function unlinkIds(Model $source, Model $target)
    {
        return; // nada
    }

    /**
    *
    */
    public function markLinkAsClean(Model $source, Model $target)
    {
        return; // nada
    }

    /**
     *
     */
    protected function deriveKeys()
    {
        $from = $this->from_key ?: $this->from_primary_key;
        $to = $this->to_key ?: $this->to_primary_key;

        return array($from, $to);
    }

    /**
     * Process pivot information
     *
     * In a model the pivot key can either be an array or a table name.
     * If it is a table name, then the lhs and rhs keys must equal the pk's
     * of the two models
     */
    protected function processOptions($options)
    {
        parent::processOptions($options);

        $pivot = $options['pivot'];

        if (! is_array($pivot)) {
            $pivot = array('table' => $pivot);
        }

        $defaults = array(
            'left' => $this->from_primary_key,
            'right' => $this->to_primary_key
        );

        $this->is_weak = true;
        $this->pivot = array_merge($defaults, $pivot);
    }
}

// EOF
