package database

import (
	"errors"
	"fmt"
	"time"

	"github.com/spf13/cast"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

func New(config Config) (*gorm.DB, error) {
	db, err := config.Build(&gorm.Config{})
	if err != nil {
		return nil, err
	}

	sqldb, err := db.DB()
	if err != nil {
		return nil, err
	}

	if config.Has("max_open_conns") {
		sqldb.SetMaxOpenConns(config.GetInt("max_open_conns"))
	}

	if config.Has("max_idle_conns") {
		sqldb.SetMaxIdleConns(config.GetInt("max_idle_conns"))
	}

	if config.Has("conn_max_idle_time") {
		sqldb.SetConnMaxIdleTime(config.GetDuration("conn_max_idle_time") * time.Second)
	}

	if config.Has("conn_max_lifetime") {
		sqldb.SetConnMaxLifetime(config.GetDuration("conn_max_lifetime") * time.Second)
	}

	return db, nil
}

type Config map[string]interface{}

func (cfg Config) GetString(key string) string {
	return cast.ToString(cfg[key])
}

func (cfg Config) GetInt(key string) int {
	return cast.ToInt(cfg[key])
}

func (cfg Config) GetDuration(key string) time.Duration {
	return cast.ToDuration(cfg[key])
}

func (cfg Config) Has(key string) bool {
	_, ok := cfg[key]
	return ok
}

func (cfg Config) Build(opts ...gorm.Option) (*gorm.DB, error) {
	switch cfg.GetString("driver") {
	case "mysql":
		dsn := cfg.GetString("dsn")
		if dsn == "" {
			dsn = fmt.Sprintf(
				"%v:%v@tcp(%v:%v)/%v?charset=%v&parseTime=True&loc=Local",
				cfg.GetString("username"),
				cfg.GetString("password"),
				cfg.GetString("host"),
				cfg.GetInt("port"),
				cfg.GetString("database"),
				cfg.GetString("charset"),
			)
		}
		return gorm.Open(mysql.Open(dsn), opts...)
	default:
		return nil, errors.New("database driver not supported")
	}
}