<?php
// +------------------------------------------------+
// |http://www.cjango.com                           |
// +------------------------------------------------+
// | 修复BUG不是一朝一夕的事情，等我喝醉了再说吧！  |
// +------------------------------------------------+
// | Author: 小陈叔叔 <Jason.Chen>                  |
// +------------------------------------------------+
namespace app\common\service;

use think\Config;
use think\Loader;
use think\Session;
use tools\Format;

class Database extends _Init
{

    /**
     * 获取表信息
     * @return array
     */
    public static function getTables()
    {
        $list = array_map('array_change_key_case', Loader::db()->query('SHOW TABLE STATUS'));
        foreach ($list as $key => $value) {
            $list[$key]['data_length']  = Format::byte($value['data_length']);
            $list[$key]['index_length'] = Format::byte($value['index_length']);
        }

        return $list;
    }

    /**
     * 备份数据库
     * @param  [type] $tables [description]
     * @param  [type] $id     [description]
     * @param  [type] $start  [description]
     * @return [type]         [description]
     */
    public static function backup($tables = null, $id = null, $start = null)
    {
        if (IS_POST && !empty($tables) && is_array($tables)) {
            //初始化
            $config = Config::get('backdata');
            // 检查是否有正在执行的任务
            if (!is_writeable($config['path'])) {
                return '备份目录不存在或不可写，请检查后重试！';
            }
            $lock = "{$config['path']}backup.lock";
            if (is_file($lock)) {
                return '检测到一个任务正在执行，请稍后再试！';
            } else {
                file_put_contents($lock, time()); //创建锁文件
            }

            Session::set('backup_config', $config);
            //生成备份文件信息
            $file = array(
                'name' => date('Ymd-His', time()),
                'part' => 1,
            );
            Session::set('backup_file', $file);
            //缓存要备份的表
            Session::set('backup_tables', $tables);
            //创建备份文件
            $Database = new \tools\Database($file, $config);
            if (false !== $Database->create()) {
                Logs::write('备份数据库', ['table' => $tables]);
                return [
                    'msg'  => '初始化成功！',
                    'data' => ['id' => 0, 'start' => 0],
                ];
            } else {
                return '初始化失败，备份文件创建失败！';
            }
        } elseif (IS_GET && is_numeric($id) && is_numeric($start)) {
            //备份数据
            $tables = Session::get('backup_tables');
            //备份指定表
            $Database = new \tools\Database(Session::get('backup_file'), Session::get('backup_config'));
            $start    = $Database->backup($tables[$id], $start);
            if (false === $start) {
                return '备份出错！';
            } elseif (0 === $start) {
                //下一表
                if (isset($tables[++$id])) {
                    return [
                        'msg'  => '备份完成！',
                        'data' => ['id' => $id, 'start' => 0],
                    ];
                } else {
                    //备份完成，清空缓存
                    unlink(Session::get('backup_config.path') . 'backup.lock');
                    Session::delete('backup_tables');
                    Session::delete('backup_file');
                    Session::delete('backup_config');
                    return [
                        'msg'  => '备份完成！',
                        'data' => '',
                    ];
                }
            } else {
                $rate = floor(100 * ($start[0] / $start[1]));
                return [
                    'msg'  => '"正在备份..({$rate}%)"',
                    'data' => ['id' => $id, 'start' => $start[0]],
                ];
            }
        }
    }

    /**
     * [del description]
     * @param  [type] $time [description]
     * @return [type]       [description]
     */
    public static function del($time)
    {
        $path = [];
        if (is_array($time)) {
            foreach ($time as $value) {
                $name = date('Ymd-His', $value) . '-*.sql*';
                $file = Config::get('backdata.path') . $name;
                $path = array_merge($path, glob($file));
            }
        } else {
            $name = date('Ymd-His', $time) . '-*.sql*';
            $file = Config::get('backdata.path') . $name;
            $path = glob($file);
        }
        try {
            array_map("unlink", $path);
            Logs::write('删除备份文件', ['files' => $path]);
            return true;
        } catch (\Exception $e) {
            return '备份文件删除失败，请检查权限！';
        }
    }

    /**
     * 备份文件卷列表
     * @return array
     */
    public static function backupList()
    {
        $path = Config::get('backdata.path');

        $list = [];
        if (is_dir($path)) {
            $flag = \FilesystemIterator::KEY_AS_FILENAME;
            $glob = new \FilesystemIterator($path, $flag);
            $list = [];
            foreach ($glob as $name => $file) {
                if (preg_match('/^\d{8,8}-\d{6,6}-\d+\.sql(?:\.gz)?$/', $name)) {
                    $name = sscanf($name, '%4s%2s%2s-%2s%2s%2s-%d');
                    $date = "{$name[0]}-{$name[1]}-{$name[2]}";
                    $time = "{$name[3]}:{$name[4]}:{$name[5]}";
                    $part = $name[6];
                    if (isset($list["{$date} {$time}"])) {
                        $info         = $list["{$date} {$time}"];
                        $info['part'] = max($info['part'], $part);
                        $info['size'] += $file->getSize();
                    } else {
                        $info['part'] = $part;
                        $info['size'] = $file->getSize();
                    }
                    $extension               = strtoupper(pathinfo($file->getFilename(), PATHINFO_EXTENSION));
                    $info['compress']        = ($extension === 'SQL') ? '-' : $extension;
                    $info['time']            = strtotime("{$date} {$time}");
                    $list["{$date} {$time}"] = $info;
                }
                krsort($list);
            }
        }
        array_walk($list, function ($val, $key) use (&$list) {
            $list[$key]['size'] = Format::byte($val['size']);
        });

        return $list;
    }
}