package db

import (
	"database/sql"
	"fmt"
	"strings"
	"time"
)

func driverKey(d string) string {
	return strings.ToLower(strings.TrimSpace(d))
}

func isMySQLFamily(d string) bool {
	switch driverKey(d) {
	case "mysql", "mariadb", "tidb", "oceanbase", "polardb", "tdsql":
		return true
	default:
		return false
	}
}

func isPostgresFamily(d string) bool {
	switch driverKey(d) {
	case "postgresql", "postgres", "gaussdb", "opengauss", "kingbase":
		return true
	default:
		return false
	}
}

// Open 按驱动打开 *sql.DB
func Open(c ConnReq) (*sql.DB, error) {
	var (
		db  *sql.DB
		err error
	)
	switch {
	case isMySQLFamily(c.Driver):
		db, err = openMySQL(c)
	case isPostgresFamily(c.Driver):
		db, err = openPostgres(c)
	case driverKey(c.Driver) == "sqlserver" || driverKey(c.Driver) == "mssql":
		db, err = openMSSQL(c)
	case driverKey(c.Driver) == "oracle":
		db, err = openOracle(c)
	case driverKey(c.Driver) == "sqlite":
		db, err = openSQLite(c)
	default:
		return nil, fmt.Errorf("驱动「%s」尚未实现（当前支持: mysql/mariadb/tidb、postgresql、sqlserver、oracle、sqlite、redis）", c.Driver)
	}
	if err != nil {
		return nil, err
	}
	db.SetConnMaxLifetime(2 * time.Minute)
	db.SetMaxOpenConns(5)
	db.SetMaxIdleConns(2)
	return db, nil
}

func TestConnection(c ConnReq) error {
	dial, tun, err := ApplySSHTunnel(c)
	if err != nil {
		return err
	}
	if tun != nil {
		defer tun.Close()
	}
	if err := testDial(dial); err != nil {
		return fmt.Errorf("数据库: %w", err)
	}
	return nil
}

func testDial(c ConnReq) error {
	if isRedis(c.Driver) {
		return testRedis(c)
	}
	db, err := Open(c)
	if err != nil {
		return err
	}
	defer db.Close()
	return db.Ping()
}