package service

import (
	"errors"
	"gorm.io/driver/mysql"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"videoplayer/dao"
	"videoplayer/proto"
)

func RunSQL(req *proto.RunSQLRequest) (map[string]interface{}, error) {

	dbmInfo, err := dao.FindDBManageByID(req.DB_ID)
	if err != nil {
		return nil, err
	}
	if dbmInfo.UserID != req.UserID {
		return nil, errors.New("unauthorized access to the database management system")
	}
	db_, err := GetGORMDBObject(&dbmInfo)
	if err != nil {
		return nil, err
	}
	res, err := dao.RunSQL(req.SQL, db_)
	if err != nil {
		return nil, err
	}
	// 记录执行历史
	history := &proto.SQLRunHistory{UserID: req.UserID, DB_ID: req.DB_ID, SQL: req.SQL, Status: 0}
	_, err = dao.CreateDBRunHistory(history)
	if err != nil {
		return nil, err
	}
	return res, nil
}

func GetGORMDBObject(dbmInfo *proto.DBManage) (db_ *gorm.DB, err error) {
	switch dbmInfo.DB_Type {
	case proto.DB_TYPE_MYSQL: // MySQL
		dsn := dbmInfo.DB_User + ":" + dbmInfo.DB_Password + "@tcp(" + dbmInfo.DB_IP + ":" + string(rune(dbmInfo.DB_Port)) + ")/" + dbmInfo.DB_NAME + "?charset=utf8mb4&parseTime=True&loc=Local"
		db_, err = gorm.Open(mysql.Open(dsn), &gorm.Config{})
		if err != nil {
			return nil, err
		}
	case proto.DB_TYPE_POSTGRES: // PostgreSQL
		dsn := "host=" + dbmInfo.DB_IP + " user=" + dbmInfo.DB_User + " password=" + dbmInfo.DB_Password + " dbname=" + dbmInfo.DB_NAME + " port=" + string(rune(dbmInfo.DB_Port)) + " sslmode=disable TimeZone=Asia/Shanghai"
		db_, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
		if err != nil {
			return nil, err
		}
	default:
		err = errors.New("unsupported database type")
	}

	return db_, err
}

func CreateDBManage(req *proto.CreateDBManageReq, userID uint) (proto.DBManage, error) {
	dbmInfo := proto.DBManage{
		UserID:      userID,
		DB_IP:       req.DB_IP,
		DB_Port:     req.DB_Port,
		DB_NAME:     req.DB_NAME,
		DB_User:     req.DB_User,
		DB_Password: req.DB_Password,
		DB_Type:     req.DB_Type,
		DB_Desc:     "",
		DB_STATUS:   0, // 初始状态为未连接
	}

	id, err := dao.CreateDBManage(dbmInfo)
	if err != nil {
		return proto.DBManage{}, err
	}
	dbmInfo.ID = id
	return dbmInfo, nil
}

func GetDBManageList(req *proto.GetDBManageReq, userID uint) ([]proto.DBManage, error) {
	var dbmList []proto.DBManage
	var err error

	if req.GET_TYPE == 0 { // 获取自己的数据库管理
		dbmList, err = dao.FindDBManageByAuthID(userID)
	} else if req.GET_TYPE == 1 { // 管理员获取所有数据库管理
		user := GetUserByIDFromUserCenter(int(userID))
		if user.Role != "admin" {
			return nil, errors.New("unauthorized access, only admin can get all database management")
		}
		dbmList, err = dao.FindAllDBManage()
	} else {
		return nil, errors.New("invalid get type")
	}
	if err != nil {
		return nil, err
	}
	return dbmList, nil
}

func GetSQLRunHistory(req *proto.GetSQLRunHistoryReq, userID int) ([]proto.SQLRunHistory, error) {
	var historyList []proto.SQLRunHistory
	var err error

	if req.GET_TYPE == 0 { // 获取自己的SQL执行历史
		historyList, err = dao.FindDBRunHistoryByAuthID(userID)
	} else if req.GET_TYPE == 1 { // 管理员获取所有SQL执行历史
		user := GetUserByIDFromUserCenter(userID)
		if user.Role != "admin" {
			return nil, errors.New("unauthorized access, only admin can get all SQL run history")
		}
		historyList, err = dao.FindAllSQLRunHistory()
	} else {
		return nil, errors.New("invalid get type")
	}
	if err != nil {
		return nil, err
	}
	return historyList, nil
}

func UpdateDBManage(req *proto.UpdateDBManageReq, userID int) (proto.DBManage, error) {
	dbmInfo, err := dao.FindDBManageByID(req.DB_ID)
	if err != nil {
		return proto.DBManage{}, err
	}
	if dbmInfo.UserID != uint(userID) && GetUserByIDFromUserCenter(userID).Role != "admin" {
		return proto.DBManage{}, errors.New("unauthorized access to the database management system")
	}
	dbmInfo.DB_IP = req.DB_IP
	dbmInfo.DB_Port = req.DB_Port
	dbmInfo.DB_NAME = req.DB_NAME
	dbmInfo.DB_User = req.DB_User
	dbmInfo.DB_Password = req.DB_Password
	dbmInfo.DB_Type = req.DB_Type

	err = dao.UpdateDBManage(dbmInfo.ID, &dbmInfo)
	if err != nil {
		return proto.DBManage{}, err
	}
	return dbmInfo, nil
}