/*
NAME
  adpcm_test.go

DESCRIPTION
  adpcm_test.go contains tests for the adpcm package.

AUTHOR
  Trek Hopton <trek@ausocean.org>

LICENSE
  adpcm_test.go is Copyright (C) 2018 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 in gpl.txt.
  If not, see [GNU licenses](http://www.gnu.org/licenses).
*/

package adpcm

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

// TestEncodeBlock will read PCM data, encode it in blocks and generate ADPCM
// then compare the result with expected ADPCM.
func TestEncodeBlock(t *testing.T) {
	// Read input pcm.
	pcm, err := ioutil.ReadFile("../../../test/test-data/av/input/original_8kHz_adpcm_test.pcm")
	if err != nil {
		t.Errorf("Unable to read input PCM file: %v", err)
	}

	// Encode adpcm.
	numBlocks := len(pcm) / PcmBS
	comp := bytes.NewBuffer(make([]byte, 0, AdpcmBS*numBlocks))
	enc := NewEncoder(comp)
	_, err = enc.Write(pcm)
	if err != nil {
		t.Errorf("Unable to write to encoder: %v", err)
	}

	// Read expected adpcm file.
	exp, err := ioutil.ReadFile("../../../test/test-data/av/output/encoded_8kHz_adpcm_test.adpcm")
	if err != nil {
		t.Errorf("Unable to read expected ADPCM file: %v", err)
	}

	if !bytes.Equal(comp.Bytes(), exp) {
		t.Error("ADPCM generated does not match expected ADPCM")
	}
}

// TestDecodeBlock will read encoded ADPCM, decode it in blocks and then compare the
// resulting PCM with the expected decoded PCM.
func TestDecodeBlock(t *testing.T) {
	// Read adpcm.
	comp, err := ioutil.ReadFile("../../../test/test-data/av/input/encoded_8kHz_adpcm_test.adpcm")
	if err != nil {
		t.Errorf("Unable to read input ADPCM file: %v", err)
	}

	// Decode adpcm.
	numBlocks := len(comp) / AdpcmBS
	decoded := bytes.NewBuffer(make([]byte, 0, PcmBS*numBlocks))
	dec := NewDecoder(decoded)
	_, err = dec.Write(comp)
	if err != nil {
		t.Errorf("Unable to write to decoder: %v", err)
	}

	// Read expected pcm file.
	exp, err := ioutil.ReadFile("../../../test/test-data/av/output/decoded_8kHz_adpcm_test.pcm")
	if err != nil {
		t.Errorf("Unable to read expected PCM file: %v", err)
	}

	if !bytes.Equal(decoded.Bytes(), exp) {
		t.Error("PCM generated does not match expected PCM")
	}
}