package env

import (
	"flag"
	"fmt"
	"strings"
	"sync"
)

var (
	active  Environment
	dev     Environment = &environment{value: "dev"}
	fat     Environment = &environment{value: "fat"}
	uat     Environment = &environment{value: "uat"}
	pro     Environment = &environment{value: "pro"}
	envFlag *string
	once    sync.Once
)

var _ Environment = (*environment)(nil)

// Environment 环境配置
type Environment interface {
	Value() string
	IsDev() bool
	IsFat() bool
	IsUat() bool
	IsPro() bool
	t()
}

type environment struct {
	value string
}

func (e *environment) Value() string {
	return e.value
}

func (e *environment) IsDev() bool {
	return e.value == "dev"
}

func (e *environment) IsFat() bool {
	return e.value == "fat"
}

func (e *environment) IsUat() bool {
	return e.value == "uat"
}

func (e *environment) IsPro() bool {
	return e.value == "pro"
}

func (e *environment) t() {}

func init() {
	envFlag = flag.String("env", "", "请输入运行环境:\n dev:开发环境\n fat:测试环境\n uat:预上线环境\n pro:正式环境\n")
}

func setup() {
	val := ""
	if envFlag != nil && flag.Parsed() {
		val = *envFlag
	}

	switch strings.ToLower(strings.TrimSpace(val)) {
	case "dev":
		active = dev
	case "fat":
		active = fat
	case "uat":
		active = uat
	case "pro":
		active = pro
	default:
		active = fat
		if val != "" {
			fmt.Println("Warning: '-env' cannot be found, or it is illegal. The default 'fat' will be used.")
		}
	}
}

// Active 当前配置的env
func Active() Environment {
	once.Do(setup)
	return active
}