package hopp

import "io"
import "bytes"
import "errors"
import "slices"
import "testing"

func TestEncodeMessageB(test *testing.T) {
	buffer := new(bytes.Buffer)
	payload := []byte { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 }
	err := encodeMessageB(buffer, 0x6B12, payload)
	correct := []byte {
		0x6B, 0x12,
		0x00, 0x06,
		0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
	}
	if err != nil {
		test.Fatal(err)
	}
	if got, correct := buffer.Bytes(), correct; !slices.Equal(got, correct) {
		test.Fatalf("not equal: %v %v", got, correct)
	}
}

func TestEncodeMessageBErr(test *testing.T) {
	buffer := new(bytes.Buffer)
	payload := make([]byte, 0x10000)
	err := encodeMessageB(buffer, 0x6B12, payload)
	if !errors.Is(err, ErrPayloadTooLarge) {
		test.Fatalf("wrong error: %v", err)
	}
}

func TestDecodeMessageB(test *testing.T) {
	method, payload, err := decodeMessageB(bytes.NewReader([]byte {
		0x6B, 0x12,
		0x00, 0x06,
		0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
	}))
	if err != nil {
		test.Fatal(err)
	}
	if got, correct := method, uint16(0x6B12); got != correct {
		test.Fatalf("not equal: %v %v", got, correct)
	}
	correctPayload := []byte { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 }
	if got, correct := payload, correctPayload; !slices.Equal(got, correct) {
		test.Fatalf("not equal: %v %v", got, correct)
	}
}

func TestDecodeMessageBErr(test *testing.T) {
	_, _, err := decodeMessageB(bytes.NewReader([]byte {
		0x6B, 0x12,
		0x01, 0x06,
		0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
	}))
	if !errors.Is(err, io.ErrUnexpectedEOF) {
		test.Fatalf("wrong error: %v", err)
	}
}