package service

import (
	"encoding/json"
	"os"
	"path/filepath"
	"testing"
)

func TestApplyMetadataPreservesEngagementAndPermissions(t *testing.T) {
	e := newExecEnv(t)
	existing := writeItem(t, e.cfg.LibraryDir, "existing", `name = "Old"
video_id = "old"
`, map[string]string{
		"video.mp4": "dummy",
		"info.json": `{"id":"old","title":"Old","comments":[{"id":"c1","text":"archived"}],"heatmap":[{"start_time":0,"end_time":1,"value":1}],"filesize":123}`,
	})
	source := filepath.Join(e.scratch, "refreshed.info.json")
	if err := os.WriteFile(source, []byte(`{"id":"new","title":"New","description":"updated","comments":[]}`), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := e.svc.applyMetadata(existing, infoJSON{ID: "new", Title: "New", Description: "updated"}, source); err != nil {
		t.Fatalf("applyMetadata: %v", err)
	}

	data, err := os.ReadFile(filepath.Join(existing, "info.json"))
	if err != nil {
		t.Fatal(err)
	}
	var got map[string]json.RawMessage
	if err := json.Unmarshal(data, &got); err != nil {
		t.Fatalf("parse installed info JSON: %v", err)
	}
	if _, ok := got["comments"]; !ok {
		t.Fatal("refreshed sidecar lost archived comments")
	}
	if _, ok := got["heatmap"]; !ok {
		t.Fatal("refreshed sidecar lost archived heatmap")
	}
	if string(got["title"]) != `"New"` {
		t.Errorf("title = %s, want New", got["title"])
	}
	if mode := fileMode(t, filepath.Join(existing, "info.json")); mode != 0o644 {
		t.Errorf("info.json mode = %o, want 0644", mode)
	}
}

func TestApplyMetadataRollsBackMarkerWhenSidecarInstallFails(t *testing.T) {
	e := newExecEnv(t)
	existing := writeItem(t, e.cfg.LibraryDir, "rollback", `name = "Old"
video_id = "old"
`, map[string]string{"video.mp4": "dummy"})
	markerPath := filepath.Join(existing, itemMarkerName)
	before, err := os.ReadFile(markerPath)
	if err != nil {
		t.Fatal(err)
	}
	// A directory at the destination makes the final rename fail after the
	// marker has been written, exercising the rollback path.
	infoPath := filepath.Join(existing, "info.json")
	if err := os.Mkdir(infoPath, 0o755); err != nil {
		t.Fatal(err)
	}
	source := filepath.Join(e.scratch, "rollback.info.json")
	if err := os.WriteFile(source, []byte(`{"id":"new","title":"New"}`), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := e.svc.applyMetadata(existing, infoJSON{ID: "new", Title: "New"}, source); err == nil {
		t.Fatal("expected sidecar installation to fail")
	}
	after, err := os.ReadFile(markerPath)
	if err != nil {
		t.Fatal(err)
	}
	if string(after) != string(before) {
		t.Errorf("marker changed after failed sidecar install:\nbefore: %s\nafter: %s", before, after)
	}
}

func fileMode(t *testing.T, path string) os.FileMode {
	t.Helper()
	info, err := os.Stat(path)
	if err != nil {
		t.Fatal(err)
	}
	return info.Mode().Perm()
}