package errcode

import (
	"fmt"
	"net/http"
)

// Error 业务错误
type Error struct {
	code    int
	msg     string
	details []string
}

// codes 用于注册时去重检查
var codes = map[int]string{}

// NewError 注册并创建一个错误码
func NewError(code int, msg string) *Error {
	if _, exists := codes[code]; exists {
		panic(fmt.Sprintf("error code %d already exists, please change", code))
	}
	codes[code] = msg
	return &Error{code: code, msg: msg}
}

func (e *Error) Error() string {
	return fmt.Sprintf("error code: %d, msg: %s", e.code, e.msg)
}

func (e *Error) Code() int         { return e.code }
func (e *Error) Msg() string       { return e.msg }
func (e *Error) Details() []string { return e.details }

func (e *Error) Msgf(args ...interface{}) string {
	return fmt.Sprintf(e.msg, args...)
}

// WithDetails 附加详细信息（返回副本）
func (e *Error) WithDetails(details ...string) *Error {
	newError := *e
	newError.details = append(newError.details, details...)
	return &newError
}

// StatusCode 业务码 → HTTP 状态码
// 仅对少数特殊错误返回非 200，其余统一 200，由前端按业务 code 处理
func (e *Error) StatusCode() int {
	switch e.code {
	case Success.Code():
		return http.StatusOK

	// 鉴权类返回 401，便于前端拦截器统一处理跳转登录
	case Unauthorized.Code(),
		UnauthorizedTokenError.Code(),
		UnauthorizedTokenTimeout.Code(),
		UnauthorizedTokenMissing.Code():
		return http.StatusUnauthorized

	// 越权/无权限返回 403，便于网关与审计识别越权事件
	case Forbidden.Code():
		return http.StatusForbidden

	// 限流返回 429，便于网关识别限流事件
	case TooManyRequests.Code():
		return http.StatusTooManyRequests

	// 系统错误返回 500，便于运维监控告警
	case ServerError.Code(),
		DatabaseError.Code(),
		CacheError.Code(),
		RPCError.Code(),
		UnknownError.Code(),
		MattingFailed.Code(),
		ClassifyFailed.Code():
		return http.StatusInternalServerError
	}
	return http.StatusOK
}