<?php namespace DBDiff\SQLGen\DiffToSQL;

use DBDiff\Exceptions\InvalidConstraintException;

use DBDiff\SQLGen\SQLGenInterface;

use DBDiff\SQLGen\Dialect\DialectRegistry;

use DBDiff\SQLGen\Dialect\SQLDialectInterface;

class AlterTableDropConstraintSQL implements SQLGenInterface {

protected $obj;

protected SQLDialectInterface $dialect;

public function __construct($obj, SQLDialectInterface $dialect = null) {

$this->obj = $obj;

$this->dialect = $dialect ?? DialectRegistry::get();

}

public function getUp(): string {

if (empty($this->obj->name)) {

throw new InvalidConstraintException(

"Cannot generate DROP CONSTRAINT for table `{$this->obj->table}`: constraint name is empty"

);

}

$schema = $this->obj->diff->getOldValue();

return $this->dialect->dropConstraint($this->obj->table, $this->obj->name, $schema);

}

public function getDown(): string {

$t = $this->dialect->quote($this->obj->table);

$schema = $this->obj->diff->getOldValue();

return "ALTER TABLE $t ADD $schema;";

}

}