<?php

namespace Nest\Database\Migrations;

use Nest\Database\Database;
use Nest\Database\Migrations\Diff\Table;

/**
 * A database migration.
 */
abstract class Migration
{

	/**
	 * Construct a new database migration.
	 * @param Database $database The database of the migration.
	 * @param string $version Version identifier.
	 * @param string $name Database migration name.
	 */
	public function __construct(protected readonly Database $database, private readonly string $version, private readonly string $name)
	{
	}

	/**
	 * @return string The version identifier.
	 */
	public function getVersion(): string
	{
		return $this->version;
	}
	/**
	 * @return string The database migration name.
	 */
	public function getName(): string
	{
		return $this->name;
	}

	/**
	 * Describes operations of the current database migration.
	 * @return string Description of database migration.
	 */
	public abstract function getDescription(): string;

	/**
	 * Do the migration.
	 * @return void
	 */
	public abstract function up(): void;

	/**
	 * Undo the migration.
	 * @return void
	 */
	public abstract function down(): void;


	/**
	 * Create a new table diff manager.
	 * @param string $tableName Table name to alter.
	 * @return Table Table diff manager.
	 */
	protected function table(string $tableName): Table
	{
		return new Table($this->database, $tableName);
	}
}