package transcode

import (
    "context"
    "os"
    "path/filepath"
    "testing"

    "github.com/go-audio/wav"
)

func samplePath(t *testing.T, name string) string {
    t.Helper()
    p := filepath.Join("..", "third_party", "whisper.cpp", "samples", name)
    if _, err := os.Stat(p); err != nil {
        t.Skip("sample not found:", p)
    }
    return p
}

func TestToWhisperWAV_mp3(t *testing.T) {
    src := samplePath(t, "jfk.mp3")
    dst := filepath.Join(t.TempDir(), "out.wav")
    if err := ToWhisperWAV(context.Background(), src, dst); err != nil {
        t.Fatal(err)
    }
    assertWhisperWAV(t, dst)
}

func TestToWhisperWAV_wav(t *testing.T) {
    src := samplePath(t, "jfk.wav")
    dst := filepath.Join(t.TempDir(), "out.wav")
    if err := ToWhisperWAV(context.Background(), src, dst); err != nil {
        t.Fatal(err)
    }
    assertWhisperWAV(t, dst)
}

func TestResolveFormat_noExtension_mp3(t *testing.T) {
    src := samplePath(t, "jfk.mp3")
    data, err := os.ReadFile(src)
    if err != nil {
        t.Fatal(err)
    }
    path := filepath.Join(t.TempDir(), "upload")
    if err := os.WriteFile(path, data, 0o644); err != nil {
        t.Fatal(err)
    }
    ext, err := resolveFormat(path)
    if err != nil || ext != ".mp3" {
        t.Fatalf("ext=%q err=%v", ext, err)
    }
}

func TestEngine_Available(t *testing.T) {
    if err := NewEngine("").Available(); err != nil {
        t.Fatal(err)
    }
}

func assertWhisperWAV(t *testing.T, path string) {
    t.Helper()
    f, err := os.Open(path)
    if err != nil {
        t.Fatal(err)
    }
    defer f.Close()
    dec := wav.NewDecoder(f)
    if !dec.IsValidFile() {
        t.Fatal("invalid wav")
    }
    buf, err := dec.FullPCMBuffer()
    if err != nil {
        t.Fatal(err)
    }
    if dec.SampleRate != 16000 {
        t.Fatalf("sample rate %d", dec.SampleRate)
    }
    if dec.NumChans != 1 {
        t.Fatalf("channels %d", dec.NumChans)
    }
    if len(buf.Data) == 0 {
        t.Fatal("empty audio")
    }
}