package main

import (
	"encoding/binary"
	"math"
	"strings"
	"testing"
	"time"
)

func TestPCM16LEToFloat32(t *testing.T) {
	pcm := make([]byte, 6)
	binary.LittleEndian.PutUint16(pcm[0:], uint16(0))
	binary.LittleEndian.PutUint16(pcm[2:], uint16(32767))
	binary.LittleEndian.PutUint16(pcm[4:], uint16(32768))
	got := pcm16LEToFloat32(pcm)
	want := []float32{0, 32767.0 / 32768.0, -1}
	for i := range want {
		if math.Abs(float64(got[i]-want[i])) > 0.00001 {
			t.Fatalf("sample %d = %f, want %f", i, got[i], want[i])
		}
	}
}

func TestDurationSamples(t *testing.T) {
	if got := durationSamples(time.Second); got != sampleRate {
		t.Fatalf("one second = %d samples, want %d", got, sampleRate)
	}
	if got := durationSamples(1500 * time.Millisecond); got != 24000 {
		t.Fatalf("1.5 seconds = %d samples, want 24000", got)
	}
}

func TestRMSDBFS(t *testing.T) {
	if got := rmsDBFS([]float32{1, -1}); math.Abs(got) > 0.00001 {
		t.Fatalf("full-scale RMS = %f dBFS, want 0", got)
	}
	if got := rmsDBFS([]float32{0, 0}); !math.IsInf(got, -1) {
		t.Fatalf("silence = %f dBFS, want -Inf", got)
	}
}

func TestValidateSettings(t *testing.T) {
	if err := validateSettings(settings{mode: "fixed", chunkDuration: time.Second, threads: 1}); err != nil {
		t.Fatalf("valid settings failed: %v", err)
	}
	if err := validateSettings(settings{mode: "", chunkDuration: time.Second, threads: 1}); err == nil {
		t.Fatal("missing mode unexpectedly passed")
	}
}

func TestValidateModelsExplainsHowToInstallThem(t *testing.T) {
	_, err := validateModels(t.TempDir(), "vad")
	if err == nil {
		t.Fatal("missing models unexpectedly passed validation")
	}
	if !strings.Contains(err.Error(), "./scripts/download-models.sh") {
		t.Fatalf("missing-model error did not provide setup command: %v", err)
	}
}