/*
DESCRIPTION
  extract_test.go provides testing for extract.go.

AUTHOR
  Scott Barnard <scott@ausocean.org>

LICENSE
  Copyright (C) 2020 the Australian Ocean Lab (AusOcean)

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License
  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
*/

package jpeg

import (
	"bytes"
	"io"
	"io/ioutil"
	"testing"
)

type testReader struct {
	i int
}

func (r *testReader) Read(b []byte) (int, error) {
	if r.i >= len(testPackets) {
		return 0, io.EOF
	}
	copy(b, testPackets[r.i])
	r.i++
	return len(testPackets[r.i-1]), nil
}

func TestExtract(t *testing.T) {
	got := &bytes.Buffer{}
	err := NewExtractor().Extract(got, &testReader{}, 0)
	if err != nil {
		t.Fatalf("could not extract: %v", err)
	}

	want, err := ioutil.ReadFile("testdata/expect.mjpeg")
	if err != nil {
		t.Fatalf("could not read file for wanted JPEG data: %v", err)
	}

	if !bytes.Equal(got.Bytes(), want) {
		t.Error("did not get expected result")
	}
}