// Package fault 定义不包含数据库或敏感参数的稳定业务错误。
package fault

import "errors"

type Error struct {
	Code    string `json:"code"`
	Message string `json:"message"`
}

func (e *Error) Error() string        { return e.Code + ": " + e.Message }
func New(code, message string) *Error { return &Error{Code: code, Message: message} }
func Code(err error) string {
	var e *Error
	if errors.As(err, &e) {
		return e.Code
	}
	return "UNAVAILABLE"
}

var (
	Unauthorized        = New("UNAUTHENTICATED", "valid credentials are required")
	Forbidden           = New("PERMISSION_DENIED", "operation is not allowed")
	NotFound            = New("NOT_FOUND", "resource not found")
	Conflict            = New("STATE_CONFLICT", "resource state does not allow this operation")
	IdempotencyConflict = New("IDEMPOTENCY_CONFLICT", "idempotency key was used with different content")
	Unavailable         = New("UNAVAILABLE", "service temporarily unavailable; retry using the original operation identity")
)

func Invalid(message string) error { return New("INVALID_ARGUMENT", message) }