<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think;

use think\App;
use think\Collection;
use think\db\Query;

/**
 * Class Db
 * @package think
 * @method Query table(string $table) static 指定数据表（含前缀）
 * @method Query name(string $name) static 指定数据表（不含前缀）
 * @method Query where(mixed $field, string $op = null, mixed $condition = null) static 查询条件
 * @method Query join(mixed $join, mixed $condition = null, string $type = 'INNER') static JOIN查询
 * @method Query union(mixed $union, boolean $all = false) static UNION查询
 * @method Query limit(mixed $offset, integer $length = null) static 查询LIMIT
 * @method Query order(mixed $field, string $order = null) static 查询ORDER
 * @method mixed value(string $field) static 获取某个字段的值
 * @method array column(string $field, string $key = '') static 获取某个列的值
 * @method mixed find(mixed $data = []) static 查询单个记录
 * @method mixed select(mixed $data = []) static 查询多个记录
 * @method integer insert(array $data, boolean $replace = false, boolean $getLastInsID = false, string $sequence = null) static 插入一条记录
 * @method integer insertAll(array $dataSet) static 插入多条记录
 * @method integer update(array $data) static 更新记录
 * @method integer delete(mixed $data = []) static 删除记录
 * @method boolean chunk(integer $count, callable $callback, string $column = null) static 分块获取数据
 * @method mixed query(string $sql, array $bind = [], boolean $fetch = false, boolean $master = false, mixed $class = false) static SQL查询
 * @method integer execute(string $sql, array $bind = [], boolean $fetch = false, boolean $getLastInsID = false, string $sequence = null) static SQL执行
 * @method PaginatorCollection paginate(integer $listRows = 15, boolean $simple = false, array $config = []) static 分页查询
 */
class Db
{
    //  数据库连接实例
    private static $instance = [];
    // 查询次数
    public static $queryTimes = 0;
    // 执行次数
    public static $executeTimes = 0;

    /**
     * 数据库初始化 并取得数据库类实例
     * @static
     * @access public
     * @param mixed         $config 连接配置
     * @param bool|string   $name 连接标识 true 强制重新连接
     * @return \think\db\Connection
     * @throws Exception
     */
    public static function connect($config = [], $name = false)
    {
        if (false === $name) {
            $name = md5(serialize($config));
        }
        if (true === $name || !isset(self::$instance[$name])) {
            // 解析连接参数 支持数组和字符串
            $options = self::parseConfig($config);
            if (empty($options['type'])) {
                throw new \InvalidArgumentException('Underfined db type');
            }
            $class = false !== strpos($options['type'], '\\') ? $options['type'] : '\\think\\db\\connector\\' . ucwords($options['type']);
            // 记录初始化信息
            App::$debug && Log::record('[ DB ] INIT ' . $options['type'] . ':' . var_export($options, true), 'info');
            if (true === $name) {
                return new $class($options);
            } else {
                self::$instance[$name] = new $class($options);
            }
        }
        return self::$instance[$name];
    }

    /**
     * 数据库连接参数解析
     * @static
     * @access private
     * @param mixed $config
     * @return array
     */
    private static function parseConfig($config)
    {
        if (empty($config)) {
            $config = Config::get('database');
        } elseif (is_string($config) && false === strpos($config, '/')) {
            // 支持读取配置参数
            $config = Config::get($config);
        }
        if (is_string($config)) {
            return self::parseDsn($config);
        } else {
            return $config;
        }
    }

    /**
     * DSN解析
     * 格式： mysql://username:passwd@localhost:3306/DbName?param1=val1&param2=val2#utf8
     * @static
     * @access private
     * @param string $dsnStr
     * @return array
     */
    private static function parseDsn($dsnStr)
    {
        $info = parse_url($dsnStr);
        if (!$info) {
            return [];
        }
        $dsn = [
            'type'     => $info['scheme'],
            'username' => isset($info['user']) ? $info['user'] : '',
            'password' => isset($info['pass']) ? $info['pass'] : '',
            'hostname' => isset($info['host']) ? $info['host'] : '',
            'hostport' => isset($info['port']) ? $info['port'] : '',
            'database' => !empty($info['path']) ? ltrim($info['path'], '/') : '',
            'charset'  => isset($info['fragment']) ? $info['fragment'] : 'utf8',
        ];

        if (isset($info['query'])) {
            parse_str($info['query'], $dsn['params']);
        } else {
            $dsn['params'] = [];
        }
        return $dsn;
    }

    // 调用驱动类的方法
    public static function __callStatic($method, $params)
    {
        // 自动初始化数据库
        return call_user_func_array([self::connect(), $method], $params);
    }
}
