<?php

declare(strict_types=1);
/**
 * This file is part of Hyperf.
 *
 * @link     https://www.hyperf.io
 * @document https://hyperf.wiki
 * @contact  group@hyperf.io
 * @license  https://github.com/hyperf/hyperf/blob/master/LICENSE
 */

namespace Hyperf\Database\Connectors;

use Exception;
use Hyperf\Database\DetectsLostConnections;
use PDO;
use Throwable;

class Connector
{
    use DetectsLostConnections;

    /**
     * The default PDO connection options.
     *
     * @var array
     */
    protected $options = [
        PDO::ATTR_CASE => PDO::CASE_NATURAL,
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_ORACLE_NULLS => PDO::NULL_NATURAL,
        PDO::ATTR_STRINGIFY_FETCHES => false,
        PDO::ATTR_EMULATE_PREPARES => false,
    ];

    /**
     * Create a new PDO connection.
     *
     * @param string $dsn
     * @return PDO
     * @throws Exception
     */
    public function createConnection($dsn, array $config, array $options)
    {
        [$username, $password] = [
            $config['username'] ?? null, $config['password'] ?? null,
        ];

        try {
            return $this->createPdoConnection(
                $dsn,
                $username,
                $password,
                $options
            );
        } catch (Exception $e) {
            return $this->tryAgainIfCausedByLostConnection(
                $e,
                $dsn,
                $username,
                $password,
                $options
            );
        }
    }

    /**
     * Get the PDO options based on the configuration.
     *
     * @return array
     */
    public function getOptions(array $config)
    {
        return array_replace($this->options, $config['options'] ?? []);
    }

    /**
     * Get the default PDO connection options.
     *
     * @return array
     */
    public function getDefaultOptions()
    {
        return $this->options;
    }

    /**
     * Set the default PDO connection options.
     */
    public function setDefaultOptions(array $options)
    {
        $this->options = $options;
    }

    /**
     * Create a new PDO connection instance.
     *
     * @param string $dsn
     * @param string $username
     * @param string $password
     * @param array $options
     * @return PDO
     */
    protected function createPdoConnection($dsn, $username, $password, $options)
    {
        return new PDO($dsn, $username, $password, $options);
    }

    /**
     * Determine if the connection is persistent.
     *
     * @param array $options
     * @return bool
     */
    protected function isPersistentConnection($options)
    {
        return isset($options[PDO::ATTR_PERSISTENT])
            && $options[PDO::ATTR_PERSISTENT];
    }

    /**
     * Handle an exception that occurred during connect execution.
     *
     * @param string $dsn
     * @param string $username
     * @param string $password
     * @param array $options
     * @return PDO
     * @throws Exception
     */
    protected function tryAgainIfCausedByLostConnection(Throwable $e, $dsn, $username, $password, $options)
    {
        if ($this->causedByLostConnection($e)) {
            return $this->createPdoConnection($dsn, $username, $password, $options);
        }

        throw $e;
    }
}