package stomp

import (
	"github.com/go-stomp/stomp/v3/frame"
)

// Error values
var (
	ErrInvalidCommand           = newErrorMessage("invalid command")
	ErrInvalidFrameFormat       = newErrorMessage("invalid frame format")
	ErrUnsupportedVersion       = newErrorMessage("unsupported version")
	ErrCompletedTransaction     = newErrorMessage("transaction is completed")
	ErrNackNotSupported         = newErrorMessage("NACK not supported in STOMP 1.0")
	ErrNotReceivedMessage       = newErrorMessage("cannot ack/nack a message, not from server")
	ErrCannotNackAutoSub        = newErrorMessage("cannot send NACK for a subscription with ack:auto")
	ErrCompletedSubscription    = newErrorMessage("subscription is unsubscribed")
	ErrClosedUnexpectedly       = newErrorMessage("connection closed unexpectedly")
	ErrAlreadyClosed            = newErrorMessage("connection already closed")
	ErrMsgSendTimeout           = newErrorMessage("msg send timeout")
	ErrMsgReceiptTimeout        = newErrorMessage("msg receipt timeout")
	ErrDisconnectReceiptTimeout = newErrorMessage("disconnect receipt timeout")
	ErrNilOption                = newErrorMessage("nil option")
)

// StompError implements the Error interface, and provides
// additional information about a STOMP error.
type Error struct {
	Message string
	Frame   *frame.Frame
}

func (e Error) Error() string {
	return e.Message
}

func missingHeader(name string) Error {
	return newErrorMessage("missing header: " + name)
}

func newErrorMessage(msg string) Error {
	return Error{Message: msg}
}

func newError(f *frame.Frame) Error {
	e := Error{Frame: f}

	if f.Command == frame.ERROR {
		if message := f.Header.Get(frame.Message); message != "" {
			e.Message = message
		} else {
			e.Message = "ERROR frame, missing message header"
		}
	} else {
		e.Message = "Unexpected frame: " + f.Command
	}
	return e
}