package audio_test

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

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"git.d-ma.be/mathias/tapir/internal/adapters/audio"
	"git.d-ma.be/mathias/tapir/internal/uploads"
)

func TestParseProbe(t *testing.T) {
	tests := []struct {
		name string
		json string
		want uploads.Probe
	}{
		{
			name: "audio-only m4a",
			json: `{"streams":[{"codec_type":"audio","disposition":{"attached_pic":0}}],"format":{"duration":"2701.5"}}`,
			want: uploads.Probe{Duration: 2701*time.Second + 500*time.Millisecond, HasAudio: true},
		},
		{
			name: "mp4 with a real video stream",
			json: `{"streams":[{"codec_type":"video","disposition":{"attached_pic":0}},{"codec_type":"audio"}],"format":{"duration":"240.0"}}`,
			want: uploads.Probe{Duration: 240 * time.Second, HasAudio: true, HasVideo: true},
		},
		{
			name: "mp3 whose only video stream is attached cover art is NOT video",
			json: `{"streams":[{"codec_type":"audio"},{"codec_type":"video","disposition":{"attached_pic":1}}],"format":{"duration":"60"}}`,
			want: uploads.Probe{Duration: 60 * time.Second, HasAudio: true},
		},
		{
			name: "no streams at all",
			json: `{"streams":[],"format":{"duration":"10"}}`,
			want: uploads.Probe{Duration: 10 * time.Second},
		},
		{
			name: "duration absent means zero, which Validate rejects as unreadable",
			json: `{"streams":[{"codec_type":"audio"}],"format":{}}`,
			want: uploads.Probe{HasAudio: true},
		},
		{
			name: "duration reported as N/A means zero",
			json: `{"streams":[{"codec_type":"audio"}],"format":{"duration":"N/A"}}`,
			want: uploads.Probe{HasAudio: true},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := audio.ParseProbe([]byte(tt.json))

			require.NoError(t, err)
			assert.Equal(t, tt.want, got)
		})
	}
}

func TestParseProbe_GarbageIsAnError(t *testing.T) {
	_, err := audio.ParseProbe([]byte("not json"))
	assert.Error(t, err)
}

// stub writes an executable shell script standing in for ffprobe. This is a fake
// at the process boundary: the real binary is not on every host (it is not on
// koala), and what is under test is how Probe drives and interprets a process.
func stub(t *testing.T, body string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "ffprobe")
	require.NoError(t, os.WriteFile(p, []byte("#!/bin/sh\n"+body+"\n"), 0o755))
	return p
}

func TestFFprobeProbe_ParsesWhatTheProcessPrints(t *testing.T) {
	bin := stub(t, `echo '{"streams":[{"codec_type":"audio"}],"format":{"duration":"90"}}'`)

	got, err := (&audio.FFprobe{Bin: bin}).Probe(context.Background(), "/ignored")

	require.NoError(t, err)
	assert.Equal(t, uploads.Probe{Duration: 90 * time.Second, HasAudio: true}, got)
}

func TestFFprobeProbe_PassesTheFilePathAsTheLastArgument(t *testing.T) {
	out := filepath.Join(t.TempDir(), "args")
	bin := stub(t, `for a; do last="$a"; done; printf '%s' "$last" > `+out+`
echo '{"streams":[{"codec_type":"audio"}],"format":{"duration":"1"}}'`)

	_, err := (&audio.FFprobe{Bin: bin}).Probe(context.Background(), "/spool/upload-123")

	require.NoError(t, err)
	got, err := os.ReadFile(out)
	require.NoError(t, err)
	assert.Equal(t, "/spool/upload-123", string(got))
}

func TestFFprobeProbe_NonzeroExitMeansTheFileIsUnreadable(t *testing.T) {
	bin := stub(t, `echo "Invalid data found when processing input" >&2; exit 1`)

	_, err := (&audio.FFprobe{Bin: bin}).Probe(context.Background(), "/x")

	assert.ErrorIs(t, err, uploads.ErrUnreadable)
}

func TestFFprobeProbe_MissingBinaryIsOurFaultNotAnUnreadableFile(t *testing.T) {
	_, err := (&audio.FFprobe{Bin: filepath.Join(t.TempDir(), "no-such-ffprobe")}).Probe(context.Background(), "/x")

	require.Error(t, err)
	assert.False(t, errors.Is(err, uploads.ErrUnreadable),
		"a missing ffprobe must not be reported to the user as their file being bad")
}

func TestFFprobeProbe_StopsWhenTheContextIsCancelled(t *testing.T) {
	bin := stub(t, `sleep 30`)
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()

	start := time.Now()
	_, err := (&audio.FFprobe{Bin: bin}).Probe(ctx, "/x")

	require.Error(t, err)
	assert.Less(t, time.Since(start), 5*time.Second)
	assert.False(t, errors.Is(err, uploads.ErrUnreadable), "a timeout is not a verdict on the file")
}