/*
NAME
	flac_test.go

DESCRIPTION
  flac_test.go provides utilities to test FLAC audio decoding

AUTHOR
  Saxon Nelson-Milton <saxon@ausocean.org>

LICENSE
  flac_test.go is Copyright (C) 2017-2019 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 flac

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

const (
	testFile = "/home/saxon/Desktop/robot.flac"
	outFile  = "testOut.wav"
)

// TestWriteSeekerWrite checks that basic writing to the ws works as expected.
func TestWriteSeekerWrite(t *testing.T) {
	ws := &writeSeeker{}

	const tstStr1 = "hello"
	ws.Write([]byte(tstStr1))
	got := string(ws.buf)
	if got != tstStr1 {
		t.Errorf("Write failed, got: %v, want: %v", got, tstStr1)
	}

	const tstStr2 = " world"
	const want = "hello world"
	ws.Write([]byte(tstStr2))
	got = string(ws.buf)
	if got != want {
		t.Errorf("Second write failed, got: %v, want: %v", got, want)
	}
}

// TestWriteSeekerSeek checks that writing and seeking works as expected, i.e. we
// can write, then seek to a knew place in the buf, and write again, either replacing
// bytes, or appending bytes.
func TestWriteSeekerSeek(t *testing.T) {
	ws := &writeSeeker{}

	const tstStr1 = "hello"
	want1 := tstStr1
	ws.Write([]byte(tstStr1))
	got := string(ws.buf)
	if got != tstStr1 {
		t.Errorf("Unexpected output, got: %v, want: %v", got, want1)
	}

	const tstStr2 = " world"
	const want2 = tstStr1 + tstStr2
	ws.Write([]byte(tstStr2))
	got = string(ws.buf)
	if got != want2 {
		t.Errorf("Unexpected output, got: %v, want: %v", got, want2)
	}

	const tstStr3 = "k!"
	const want3 = "hello work!"
	ws.Seek(-2, io.SeekEnd)
	ws.Write([]byte(tstStr3))
	got = string(ws.buf)
	if got != want3 {
		t.Errorf("Unexpected output, got: %v, want: %v", got, want3)
	}

	const tstStr4 = "gopher"
	const want4 = "hello gopher"
	ws.Seek(6, io.SeekStart)
	ws.Write([]byte(tstStr4))
	got = string(ws.buf)
	if got != want4 {
		t.Errorf("Unexpected output, got: %v, want: %v", got, want4)
	}
}

// TestDecodeFlac checks that we can load a flac file and decode to wav, writing
// to a wav file.
func TestDecodeFlac(t *testing.T) {
	b, err := ioutil.ReadFile(testFile)
	if err != nil {
		t.Fatalf("Could not read test file, failed with err: %v", err.Error())
	}
	out, err := Decode(b)
	if err != nil {
		t.Errorf("Could not decode, failed with err: %v", err.Error())
	}
	f, err := os.Create(outFile)
	if err != nil {
		t.Fatalf("Could not create output file, failed with err: %v", err.Error())
	}
	_, err = f.Write(out)
	if err != nil {
		t.Fatalf("Could not write to output file, failed with err: %v", err.Error())
	}
}