<?php
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
namespace Magento\Framework\Setup;

use Magento\Framework\DB\Adapter\AdapterInterface;

/**
* @codeCoverageIgnore
*/
class ExternalFKSetup
{
/**
* @var SchemaSetupInterface
*/
protected $setup;

/**
* @var string
*/
protected $entityTable;

/**
* @var string
*/
protected $entityColumn;

/**
* @var string
*/
protected $externalTable;

/**
* @var string
*/
protected $externalColumn;

/**
* @var string
*/
protected $onDelete;

/**
* Install external foreign key
*
* @param SchemaSetupInterface $setup
* @param string $entityTable
* @param string $entityColumn
* @param string $externalTable
* @param string $externalColumn
* @param string $onDelete
* @return void
*/
public function install(
SchemaSetupInterface $setup,
$entityTable,
$entityColumn,
$externalTable,
$externalColumn,
$onDelete = AdapterInterface::FK_ACTION_CASCADE
) {
$this->setup = $setup;
$this->entityTable = $entityTable;
$this->entityColumn = $entityColumn;
$this->externalTable = $externalTable;
$this->externalColumn = $externalColumn;
$this->onDelete = $onDelete;

$this->execute();
}

/**
* Set external foreign key
*
* @return void
*/
protected function execute()
{
$entityTableInfo = $this->setup->getConnection()->describeTable(
$this->setup->getTable($this->entityTable)
);
if (!$entityTableInfo[$this->entityColumn]['PRIMARY']) {
$this->dropOldForeignKey();
$this->addForeignKeys();
} else {
$this->addDefaultForeignKey();
}
}

/**
* Get foreign keys for tables and columns
*
* @param string $refTable
* @param string $refColumn
* @param string $targetTable
* @param string $targetColumn
* @return array
* @SuppressWarnings(PHPMD.UnusedFormalParameter)
*/
protected function getForeignKeys(
$targetTable,
$targetColumn,
$refTable,
$refColumn
) {
$foreignKeys = $this->setup->getConnection()->getForeignKeys(
$this->setup->getTable($targetTable)
);
$foreignKeys = array_filter(
$foreignKeys,
function ($key) use ($targetColumn, $refTable, $refColumn) {
return $key['COLUMN_NAME'] == $targetColumn
&& $key['REF_TABLE_NAME'] == $refTable;
}
);
return $foreignKeys;
}

/**
* Remove foreign key if exists
*
* @param string $targetTable
* @param string $targetColumn
* @param string $refTable
* @param string $refColumn
* @return void
*/
protected function clearForeignKey(
$targetTable,
$targetColumn,
$refTable,
$refColumn
) {
$foreignKeys = $this->getForeignKeys($targetTable, $targetColumn, $refTable, $refColumn);
foreach ($foreignKeys as $foreignKey) {
$this->setup->getConnection()->dropForeignKey(
$foreignKey['TABLE_NAME'],
$foreignKey['FK_NAME']
);
}
}

/**
* Add default foreign key
*
* @return void
*/
protected function addDefaultForeignKey()
{
if (!count($this->getForeignKeys(
$this->externalTable,
$this->externalColumn,
$this->entityTable,
$this->entityColumn
))) {
$this->setup->getConnection()->addForeignKey(
$this->setup->getFkName(
$this->externalTable,
$this->externalColumn,
$this->entityTable,
$this->entityColumn
),
$this->setup->getTable($this->externalTable),
$this->externalColumn,
$this->setup->getTable($this->entityTable),
$this->entityColumn,
$this->onDelete
);
}
}

/**
* Add foreign keys to entity table
*
* @return void
*/
protected function addForeignKeys()
{
$foreignKeys = $this->setup->getConnection()->getForeignKeys(
$this->setup->getTable($this->entityTable)
);
$foreignKeys = array_filter(
$foreignKeys,
function ($key) {
return $key['COLUMN_NAME'] == $this->entityColumn;
}
);
foreach ($foreignKeys as $foreignKeyInfo) {
if (!count($this->getForeignKeys(
$this->externalTable,
$this->externalColumn,
$this->setup->getTablePlaceholder($foreignKeyInfo['REF_TABLE_NAME']),
$foreignKeyInfo['REF_COLUMN_NAME']
))) {
$this->setup->getConnection()->addForeignKey(
$this->setup->getFkName(
$this->externalTable,
$this->externalColumn,
$this->setup->getTablePlaceholder($foreignKeyInfo['REF_TABLE_NAME']),
$foreignKeyInfo['REF_COLUMN_NAME']
),
$this->setup->getTable($this->externalTable),
$this->externalColumn,
$foreignKeyInfo['REF_TABLE_NAME'],
$foreignKeyInfo['REF_COLUMN_NAME'],
$this->onDelete
);
}
}
}

/**
* Drop old foreign key
*
* @return void
*/
protected function dropOldForeignKey()
{
if (count($this->getForeignKeys(
$this->externalTable,
$this->externalColumn,
$this->entityTable,
$this->entityColumn
))) {
$this->clearForeignKey(
$this->externalTable,
$this->externalColumn,
$this->entityTable,
$this->entityColumn
);
}
}
}