package operations

import (
	"fmt"
	"github.com/pkg/errors"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

const (
	logLevelSilent = "silent"
	logLevelError  = "error"
	logLevelWarn   = "warn"
	logLevelInfo   = "info"
)

func newGormDB(dbConfig *Config) (*gorm.DB, error) {
	if dbConfig == nil {
		return nil, errors.New("没有传递数据库配置")
	}

	gormDB, err := newPostgresGormDB(dbConfig)
	if err != nil {
		return nil, err
	}

	return gormDB, nil
}

func newPostgresGormDB(dbConfig *Config) (*gorm.DB, error) {
	dsn := "host=%s port=%s user=%s password=%s dbname=%s sslmode=disable TimeZone=Asia/Shanghai"
	connStr := fmt.Sprintf(dsn, dbConfig.Address, dbConfig.Port, dbConfig.UserName, dbConfig.Password, dbConfig.Database)
	gormDB, err := gorm.Open(postgres.Open(connStr), &gorm.Config{
		Logger:      logger.Default.LogMode(chooseLogLevel(dbConfig.LogLevel)),
		PrepareStmt: true,
	})
	if err != nil {
		return nil, errors.New(err.Error())
	}

	return gormDB, nil
}

func destroyGormDB(gormDB *gorm.DB) error {
	if gormDB == nil {
		return nil
	}

	db, err := gormDB.DB()
	if err != nil {
		return errors.New(err.Error())
	}

	err = db.Close()
	if err != nil {
		return errors.New(err.Error())
	}

	db = nil

	return nil
}

func chooseLogLevel(logLevel string) logger.LogLevel {
	switch logLevel {
	case logLevelSilent:
		return logger.Silent
	case logLevelError:
		return logger.Error
	case logLevelWarn:
		return logger.Warn
	case logLevelInfo:
		return logger.Info
	default:
		return logger.Info
	}
}