package main

import (
	"database/sql"
	"errors"
	"fmt"
	"log"
	"sync"
	"time"

	_ "github.com/go-sql-driver/mysql"
	"github.com/redis/go-redis/v9"
)

type DBManager struct {
	MySQL *sql.DB
	Redis *redis.Client
}

// dbInstance holds the single instance of DBManager
var dbInstance *DBManager
var oncedb sync.Once

// GetDBManager provides a global access point to the DBManager instance
func GetDBManager() (*DBManager, error) {
	oncedb.Do(func() {
		config, _ := GetConfigManager()
		dbInstance = &DBManager{}
		initError = initDBManager(dbInstance, config)
	})
	return dbInstance, initError
}

// initDBManager initializes the DBManager instance with database connections
func initDBManager(dbManager *DBManager, config *ConfigManager) error {
	// 初始化 MySQL 连接
	//dsn := "username:password@tcp(localhost:3306)/aigrammar?parseTime=true"
	dsn := fmt.Sprintf("%s:%s@tcp(%s)/aigrammar?parseTime=true",
		config.GetDatabaseConfig().MysqlUser,
		config.GetDatabaseConfig().MysqlPass,
		config.GetDatabaseConfig().MysqlConn,
	)
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		log.Fatalf("Error opening MySQL database: %v", err)
		return errors.New("Error opening MySQL database:")
	}
	db.SetMaxOpenConns(25)
	db.SetMaxIdleConns(10)
	db.SetConnMaxLifetime(time.Minute * 5)
	dbManager.MySQL = db

	// 初始化 Redis 连接
	rdb := redis.NewClient(&redis.Options{
		Addr:     config.GetDatabaseConfig().RedisConn,
		Password: "", // no password set
		DB:       0,  // use default DB
		PoolSize: 10, // 连接池大小
	})

	dbManager.Redis = rdb

	return nil
}

func (db *DBManager) CloseDB() {
	db.MySQL.Close()
	db.Redis.Close()
}

/*
func NewDBManager(config *ConfigManager) (*DBManager, error) {
	dbManager := &DBManager{}

	// 初始化 MySQL 连接
	//dsn := "username:password@tcp(localhost:3306)/aigrammar?parseTime=true"
	dsn := fmt.Sprintf("%s:%s@tcp(%s)/aigrammar?parseTime=true",
		config.GetDatabaseConfig().MysqlUser,
		config.GetDatabaseConfig().MysqlPass,
		config.GetDatabaseConfig().MysqlConn,
	)
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		log.Fatalf("Error opening MySQL database: %v", err)
		return nil, errors.New("Error opening MySQL database: %v", err)
	}
	db.SetMaxOpenConns(25)
	db.SetMaxIdleConns(10)
	db.SetConnMaxLifetime(time.Minute * 5)
	dbManager.MySQL = db

	// 初始化 Redis 连接
	rdb := redis.NewClient(&redis.Options{
		Addr:     config.GetDatabaseConfig().RedisConn,
		Password: "", // no password set
		DB:       0,  // use default DB
		PoolSize: 10, // 连接池大小
	})

	dbManager.Redis = rdb

	return dbManager, nil
}

func (db *DBManager) CloseDB() {
	db.MySQL.Close()
	db.Redis.Close()
}

*/