package photos

import (
	"bytes"
	"context"
	"image"
	"image/color"
	"image/png"
	"os"
	"path/filepath"
	"testing"

	"galo/internal/config"
	"galo/internal/models"
	"galo/internal/video"
)

// fakeStore implements the slice of Repository used by generateVideo.
type fakeStore struct {
	Repository
	orig      *Object
	siblings  []string
	objects   map[string]*Object
	bindings  map[string]string
	completed bool
	failmsgs  []string
	meta      [3]int64
}

func newFakeStore(orig *Object, siblings []string) *fakeStore {
	return &fakeStore{orig: orig, siblings: siblings, objects: map[string]*Object{}, bindings: map[string]string{}}
}

func (s *fakeStore) OriginalObject(context.Context, string) (*Object, error) { return s.orig, nil }
func (s *fakeStore) PhotosByOriginalObject(context.Context, string) ([]string, error) {
	return s.siblings, nil
}
func (s *fakeStore) CreateObject(_ context.Context, o *Object) error  { s.objects[o.ID] = o; return nil }
func (s *fakeStore) ActivateObject(context.Context, string) error     { return nil }
func (s *fakeStore) DeleteObjectRow(context.Context, string) error    { return nil }
func (s *fakeStore) MarkObjectDeleting(context.Context, string) error { return nil }
func (s *fakeStore) BindObject(_ context.Context, _, objectID, role string) error {
	s.bindings[role] = objectID
	return nil
}
func (s *fakeStore) CompleteVariantJob(context.Context, string) error { s.completed = true; return nil }
func (s *fakeStore) FailVariantJob(_ context.Context, _, msg string, _ int) error {
	s.failmsgs = append(s.failmsgs, msg)
	return nil
}
func (s *fakeStore) SetMediaMeta(_ context.Context, _, _ string, durationMS int64, width, height int) error {
	s.meta = [3]int64{durationMS, int64(width), int64(height)}
	return nil
}
func (s *fakeStore) GetByID(context.Context, string, string) (*models.Photo, error) {
	return nil, ErrNotFound
}

// writeFramePNG writes a small valid PNG the fake ffmpeg copies as its output.
func writeFramePNG(t *testing.T) string {
	t.Helper()
	img := image.NewRGBA(image.Rect(0, 0, 8, 8))
	for x := 0; x < 8; x++ {
		for y := 0; y < 8; y++ {
			img.Set(x, y, color.RGBA{R: uint8(x * 20), G: uint8(y * 20), B: 200, A: 255})
		}
	}
	var buf bytes.Buffer
	if err := png.Encode(&buf, img); err != nil {
		t.Fatalf("encode png: %v", err)
	}
	path := filepath.Join(t.TempDir(), "frame.png")
	if err := os.WriteFile(path, buf.Bytes(), 0o644); err != nil {
		t.Fatalf("write frame: %v", err)
	}
	return path
}

func writeScript(t *testing.T, name, body string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), name)
	if err := os.WriteFile(path, []byte(body), 0o755); err != nil {
		t.Fatalf("write %s: %v", name, err)
	}
	return path
}

func TestGenerateVideoHappyPath(t *testing.T) {
	frame := writeFramePNG(t)
	t.Setenv("FAKE_FRAME", frame)

	// A fake ffmpeg copies the frame to its output path (the last argument);
	// a fake ffprobe reports a web-compatible h264/aac source.
	ffmpeg := writeScript(t, "ffmpeg", "#!/bin/sh\nout=\"\"\nfor a in \"$@\"; do out=\"$a\"; done\ncp \"$FAKE_FRAME\" \"$out\"\n")
	ffprobe := writeScript(t, "ffprobe", "#!/bin/sh\ncat <<'JSON'\n{\"streams\":[{\"codec_type\":\"video\",\"codec_name\":\"h264\",\"profile\":\"High\",\"pix_fmt\":\"yuv420p\",\"width\":1280,\"height\":720},{\"codec_type\":\"audio\",\"codec_name\":\"aac\"}],\"format\":{\"format_name\":\"mov,mp4,m4a,3gp,3g2,mj2\",\"duration\":\"5.5\"}}\nJSON\n")

	tools := video.Detect(config.Video{FFmpegPath: ffmpeg, FFprobePath: ffprobe})
	if !tools.Available() {
		t.Fatalf("fake toolchain not detected: %+v", tools)
	}

	orig := &Object{ID: "obj1", StorageKey: "objects/obj1/original.mp4", State: ObjectReady}
	store := newFakeStore(orig, []string{"photo1"})
	svc := &Service{store: store, storage: fakeBackend{}}
	w := NewWorker(svc, 0, 0, 0, 1)
	w.SetVideo(tools, 1)

	w.generateVideo(context.Background(), "photo1")

	if len(store.failmsgs) != 0 {
		t.Fatalf("unexpected failures: %v", store.failmsgs)
	}
	if !store.completed {
		t.Fatalf("job not completed")
	}
	for _, role := range []string{RoleThumb, RoleMedium, RolePreview, RolePlayback} {
		if store.bindings[role] == "" {
			t.Fatalf("role %q not bound; bindings=%v", role, store.bindings)
		}
	}
	if store.objects[store.bindings[RolePlayback]].MimeType != "video/mp4" {
		t.Fatalf("playback mime = %q", store.objects[store.bindings[RolePlayback]].MimeType)
	}
	if store.meta != [3]int64{5500, 1280, 720} {
		t.Fatalf("media meta = %v, want duration/width/height", store.meta)
	}
}

func TestGenerateVideoProbeFailureFails(t *testing.T) {
	ffmpeg := writeScript(t, "ffmpeg", "#!/bin/sh\nexit 0\n")
	ffprobe := writeScript(t, "ffprobe", "#!/bin/sh\necho boom >&2\nexit 1\n")
	tools := video.Detect(config.Video{FFmpegPath: ffmpeg, FFprobePath: ffprobe})

	store := newFakeStore(&Object{ID: "obj1", StorageKey: "objects/obj1/original.mp4", State: ObjectReady}, []string{"photo1"})
	svc := &Service{store: store, storage: fakeBackend{}}
	w := NewWorker(svc, 0, 0, 0, 1)
	w.SetVideo(tools, 1)

	w.generateVideo(context.Background(), "photo1")
	if len(store.failmsgs) == 0 {
		t.Fatal("expected job failure on probe error")
	}
	if store.completed {
		t.Fatal("job must not complete after failure")
	}
}