<?php

/**
 * This file is part of the CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace CodeIgniter\Database;

use CodeIgniter\Config\BaseConfig;
use InvalidArgumentException;

/**
 * Class Config
 */
class Config extends BaseConfig
{
	/**
	 * Cache for instance of any connections that
	 * have been requested as a "shared" instance.
	 *
	 * @var array
	 */
	static protected $instances = [];

	/**
	 * The main instance used to manage all of
	 * our open database connections.
	 *
	 * @var Database|null
	 */
	static protected $factory;

	//--------------------------------------------------------------------

	/**
	 * Creates the default
	 *
	 * @param string|array $group     The name of the connection group to use,
	 *                                or an array of configuration settings.
	 * @param boolean      $getShared Whether to return a shared instance of the connection.
	 *
	 * @return BaseConnection
	 */
	public static function connect($group = null, bool $getShared = true)
	{
		// If a DB connection is passed in, just pass it back
		if ($group instanceof BaseConnection)
		{
			return $group;
		}

		if (is_array($group))
		{
			$config = $group;
			$group  = 'custom-' . md5(json_encode($config));
		}

		$config = $config ?? config('Database');

		if (empty($group))
		{
			$group = ENVIRONMENT === 'testing' ? 'tests' : $config->defaultGroup;
		}

		if (is_string($group) && ! isset($config->$group) && strpos($group, 'custom-') !== 0)
		{
			throw new InvalidArgumentException($group . ' is not a valid database connection group.');
		}

		if ($getShared && isset(static::$instances[$group]))
		{
			return static::$instances[$group];
		}

		static::ensureFactory();

		if (isset($config->$group))
		{
			$config = $config->$group;
		}

		$connection = static::$factory->load($config, $group);

		static::$instances[$group] = &$connection;

		return $connection;
	}

	//--------------------------------------------------------------------

	/**
	 * Returns an array of all db connections currently made.
	 *
	 * @return array
	 */
	public static function getConnections(): array
	{
		return static::$instances;
	}

	/**
	 * Loads and returns an instance of the Forge for the specified
	 * database group, and loads the group if it hasn't been loaded yet.
	 *
	 * @param ConnectionInterface|string|array|null $group
	 *
	 * @return Forge
	 */
	public static function forge($group = null)
	{
		$db = static::connect($group);

		return static::$factory->loadForge($db);
	}

	//--------------------------------------------------------------------

	/**
	 * Returns a new instance of the Database Utilities class.
	 *
	 * @param string|array|null $group
	 *
	 * @return BaseUtils
	 */
	public static function utils($group = null)
	{
		$db = static::connect($group);

		return static::$factory->loadUtils($db);
	}

	//--------------------------------------------------------------------

	/**
	 * Returns a new instance of the Database Seeder.
	 *
	 * @param string|null $group
	 *
	 * @return Seeder
	 */
	public static function seeder(string $group = null)
	{
		$config = config('Database');

		return new Seeder($config, static::connect($group));
	}

	//--------------------------------------------------------------------

	/**
	 * Ensures the database Connection Manager/Factory is loaded and ready to use.
	 */
	protected static function ensureFactory()
	{
		if (static::$factory instanceof Database)
		{
			return;
		}

		static::$factory = new Database();
	}

	//--------------------------------------------------------------------
}