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/raw-voice.pcm")
	if err != nil {
		t.Errorf("Unable to read input PCM file: %v", err)
	}
	//encode adpcm
	var comp []byte
	start := 0
	for i := 0; i < len(pcm); i++ {
		if i%1010 == 1009 {
			block := pcm[start : i+1]

			encBlock, err := EncodeBlock(block)
			if err != nil {
				//todo: use correct logging of error
				t.Errorf("Unable to encode block: %v", err)
			}
			comp = append(comp, encBlock...)
			start = i + 1
		}
	}
	//read expected adpcm file
	exp, err := ioutil.ReadFile("../../../test/test-data/av/output/encoded-voice.adpcm")
	if err != nil {
		t.Errorf("Unable to read expected ADPCM file: %v", err)
	}

	if !bytes.Equal(comp, 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-voice.adpcm")
	if err != nil {
		t.Errorf("Unable to read input ADPCM file: %v", err)
	}
	//decode adpcm
	var decoded []byte
	start := 0
	for i := 0; i < len(comp); i++ {
		if i%256 == 255 {
			block := comp[start : i+1]
			decBlock, err := DecodeBlock(block)
			if err != nil {
				t.Errorf("Unable to decode block: %v", err)
			}
			decoded = append(decoded, decBlock...)
			start = i + 1
		}
	}
	//read expected pcm file
	exp, err := ioutil.ReadFile("../../../test/test-data/av/output/decoded-voice.pcm")
	if err != nil {
		t.Errorf("Unable to read expected PCM file: %v", err)
	}

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