package database

import (
	domainUpdate "RenewCMS/internal/domain/update"
	"fmt"
	"net"
	"strings"
	"time"

	mysqldriver "github.com/go-sql-driver/mysql"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

const (
	DriverMySQL = "mysql"

	mysqlCharset         = "utf8mb4"
	mysqlLocation        = "UTC"
	mysqlCollation       = "utf8mb4_bin"
	mysqlConnectTimeout  = 5 * time.Second
	mysqlSessionSQLMode  = "'ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'"
	mysqlTableOptionsKey = "gorm:table_options"
	redactedPassword     = "***"
)

type mysqlDriver struct{}

type MySQLConfig struct {
	Host     string
	Port     string
	User     string
	Password string
	Name     string
	TLS      string
}

func MySQLDSN(config MySQLConfig) string {
	dsn := mysqldriver.NewConfig()
	dsn.User = config.User
	dsn.Passwd = config.Password
	dsn.Net = "tcp"
	dsn.Addr = net.JoinHostPort(config.Host, config.Port)
	dsn.DBName = config.Name
	dsn.TLSConfig = config.TLS
	dsn.ParseTime = true
	dsn.ClientFoundRows = true
	dsn.Collation = mysqlCollation
	dsn.Timeout = mysqlConnectTimeout
	dsn.Params = map[string]string{
		"charset":  mysqlCharset,
		"loc":      mysqlLocation,
		"sql_mode": mysqlSessionSQLMode,
	}
	return dsn.FormatDSN()
}

func (mysqlDriver) Open(source string) (*gorm.DB, error) {
	parsed, err := mysqldriver.ParseDSN(source)
	if err != nil {
		return nil, fmt.Errorf("the mysql connection settings are invalid")
	}
	db, err := gorm.Open(mysql.Open(source), &gorm.Config{})
	if err != nil {
		return nil, fmt.Errorf("cannot use the mysql server at %s: %s", parsed.Addr, redact(err.Error(), parsed.Passwd))
	}
	return db, nil
}

func (mysqlDriver) NewBackup(db *gorm.DB, directory string, now func() time.Time) domainUpdate.DatabaseBackup {
	return NewMySQLBackup(db, directory, now)
}

func redact(message string, secret string) string {
	if secret == "" {
		return message
	}
	return strings.ReplaceAll(message, secret, redactedPassword)
}

func tableOptionsFor(db *gorm.DB) *gorm.DB {
	if db.Dialector.Name() == DriverMySQL {
		return db.Set(mysqlTableOptionsKey, "DEFAULT CHARSET="+mysqlCharset+" COLLATE="+mysqlCollation)
	}
	return db
}