package mysql

import (
	"fmt"
	"os"
	"strings"

	"github.com/jmoiron/sqlx"
	"github.com/spf13/viper"
	"go.uber.org/zap"

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

var sqlFile = "dao/mysql/init.sql"

var db *sqlx.DB

func Init() (err error) {
	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/",
		viper.GetString("mysql.user"),
		viper.GetString("mysql.password"),
		viper.GetString("mysql.host"),
		viper.GetInt("mysql.port"),
	)
	db, err = sqlx.Connect("mysql", dsn)
	if err != nil {
		zap.L().Error("connect DB failed", zap.Error(err))
		return err
	}
	dbName := viper.GetString("mysql.dbname")
	err = createDatabaseIfNotExists(db, dbName)
	if err != nil {
		zap.L().Error("connect Database failed", zap.Error(err))
		return err
	}
	dsn = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s",
		viper.GetString("mysql.user"),
		viper.GetString("mysql.password"),
		viper.GetString("mysql.host"),
		viper.GetInt("mysql.port"),
		viper.GetString("mysql.dbname"),
	)
	db, err = sqlx.Connect("mysql", dsn)
	if err != nil {
		zap.L().Error("connect DB failed", zap.Error(err))
		return err
	}
	err = importTableIfNotExists()
	if err != nil {
		zap.L().Error("import Sql failed", zap.Error(err))
		return err
	}
	// 最大闲置连接
	db.SetMaxIdleConns(viper.GetInt("max_idle_conns"))
	// 最大连接
	db.SetMaxOpenConns(viper.GetInt("max_open_conns"))
	return
}

func createDatabaseIfNotExists(db *sqlx.DB, dbName string) error {
	_, err := db.Exec(fmt.Sprintf("CREATE DATABASE IF NOT EXISTS %s", dbName))
	return err
}

func importTableIfNotExists() error {
	return importSQL(db, sqlFile)
}

func importSQL(db *sqlx.DB, filePath string) error {
	sqlBytes, err := os.ReadFile(filePath)
	if err != nil {
		return err
	}

	sqlStatements := string(sqlBytes)
	statements := strings.Split(sqlStatements, ";")

	for _, statement := range statements {
		if strings.TrimSpace(statement) != "" {
			_, err = db.Exec(statement)
			if err != nil {
				return err
			}
		}
	}
	return err
}

func GetDb() *sqlx.DB {
	return db
}

func ChangeDb(anotherDb *sqlx.DB) {
	db = anotherDb
}

func Close() {
	_ = db.Close()
}