package apistatus

import (
	"encoding/binary"

	"github.com/nspcc-dev/neofs-api-go/v2/status"
)

// ServerInternal describes failure statuses related to internal server errors.
// Instances provide Status and StatusV2 interfaces.
//
// The status is purely informative, the client should not go into details of the error except for debugging needs.
type ServerInternal struct {
	v2 status.Status
}

func (x ServerInternal) Error() string {
	return errMessageStatusV2(
		globalizeCodeV2(status.Internal, status.GlobalizeCommonFail),
		x.v2.Message(),
	)
}

// implements method of the FromStatusV2 local interface.
func (x *ServerInternal) fromStatusV2(st *status.Status) {
	x.v2 = *st
}

// ToStatusV2 implements StatusV2 interface method.
// If the value was returned by FromStatusV2, returns the source message.
// Otherwise, returns message with
//  * code: INTERNAL;
//  * string message: empty;
//  * details: empty.
func (x ServerInternal) ToStatusV2() *status.Status {
	x.v2.SetCode(globalizeCodeV2(status.Internal, status.GlobalizeCommonFail))
	return &x.v2
}

// SetMessage sets message describing internal error.
//
// Message should be used for debug purposes only.
func (x *ServerInternal) SetMessage(msg string) {
	x.v2.SetMessage(msg)
}

// Message returns message describing internal server error.
//
// Message should be used for debug purposes only. By default, it is empty.
func (x ServerInternal) Message() string {
	return x.v2.Message()
}

// WriteInternalServerErr writes err message to ServerInternal instance.
func WriteInternalServerErr(x *ServerInternal, err error) {
	x.SetMessage(err.Error())
}

// WrongMagicNumber describes failure status related to incorrect network magic.
// Instances provide Status and StatusV2 interfaces.
type WrongMagicNumber struct {
	v2 status.Status
}

func (x WrongMagicNumber) Error() string {
	return errMessageStatusV2(
		globalizeCodeV2(status.WrongMagicNumber, status.GlobalizeCommonFail),
		x.v2.Message(),
	)
}

// implements method of the FromStatusV2 local interface.
func (x *WrongMagicNumber) fromStatusV2(st *status.Status) {
	x.v2 = *st
}

// ToStatusV2 implements StatusV2 interface method.
// If the value was returned by FromStatusV2, returns the source message.
// Otherwise, returns message with
//  * code: WRONG_MAGIC_NUMBER;
//  * string message: empty;
//  * details: empty.
func (x WrongMagicNumber) ToStatusV2() *status.Status {
	x.v2.SetCode(globalizeCodeV2(status.WrongMagicNumber, status.GlobalizeCommonFail))
	return &x.v2
}

// WriteCorrectMagic writes correct network magic.
func (x *WrongMagicNumber) WriteCorrectMagic(magic uint64) {
	// serialize the number
	buf := make([]byte, 8)

	binary.BigEndian.PutUint64(buf, magic)

	// create corresponding detail
	var d status.Detail

	d.SetID(status.DetailIDCorrectMagic)
	d.SetValue(buf)

	// attach the detail
	x.v2.AppendDetails(&d)
}

// CorrectMagic returns network magic returned by the server.
// Second value indicates presence status:
//   * -1 if number is presented in incorrect format
//   * 0 if number is not presented
//   * +1 otherwise
func (x WrongMagicNumber) CorrectMagic() (magic uint64, ok int8) {
	x.v2.IterateDetails(func(d *status.Detail) bool {
		if d.ID() == status.DetailIDCorrectMagic {
			if val := d.Value(); len(val) == 8 {
				magic = binary.BigEndian.Uint64(val)
				ok = 1
			} else {
				ok = -1
			}
		}

		return ok != 0
	})

	return
}