package watcher

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

	"verstak/internal/core/activity"
	"verstak/internal/core/files"
	"verstak/internal/core/nodes"
	"verstak/internal/core/storage"
)

func setupWatcherTest(t *testing.T) (string, *storage.DB, *nodes.Repository, *files.Service, *activity.Service, func()) {
	t.Helper()

	vaultRoot, err := os.MkdirTemp("", "verstak-watcher-*")
	if err != nil {
		t.Fatal(err)
	}

	dbDir := filepath.Join(vaultRoot, ".verstak")
	if err := os.MkdirAll(dbDir, 0o750); err != nil {
		t.Fatal(err)
	}

	db, err := storage.Open(filepath.Join(dbDir, "index.db"))
	if err != nil {
		os.RemoveAll(vaultRoot)
		t.Fatalf("open db: %v", err)
	}

	nodeRepo := nodes.NewRepository(db)
	fileSvc := files.NewService(db, vaultRoot, nodeRepo)
	activitySvc := activity.NewService(db)

	cleanup := func() {
		db.Close()
		os.RemoveAll(vaultRoot)
	}

	return vaultRoot, db, nodeRepo, fileSvc, activitySvc, cleanup
}

// tempFileOutsideVault creates a temp file not inside the vault for import.
func tempFileOutsideVault(t *testing.T, content string) string {
	t.Helper()
	f, err := os.CreateTemp("", "verstak-import-*")
	if err != nil {
		t.Fatal(err)
	}
	if _, err := f.WriteString(content); err != nil {
		t.Fatal(err)
	}
	f.Close()
	return f.Name()
}

func TestScanner_NoChanges(t *testing.T) {
	vaultRoot, _, nodeRepo, fileSvc, activitySvc, cleanup := setupWatcherTest(t)
	defer cleanup()

	node, err := nodeRepo.Create(nil, nodes.TypeFolder, "test-folder", 0, "", "test-folder")
	if err != nil {
		t.Fatal(err)
	}

	dir := filepath.Join(vaultRoot, "test-folder")
	if err := os.MkdirAll(dir, 0o750); err != nil {
		t.Fatal(err)
	}

	// Import a file into vault (creates record + copies file).
	src := tempFileOutsideVault(t, "hello world")
	defer os.Remove(src)
	_, err = fileSvc.CopyIntoVault(node.ID, src, "test-folder")
	if err != nil {
		t.Fatal(err)
	}

	scanner := NewScanner(vaultRoot, nodeRepo, fileSvc, activitySvc)
	result, err := scanner.Run()
	if err != nil {
		t.Fatal(err)
	}

	if result.MissingFiles != 0 {
		t.Errorf("expected 0 missing, got %d", result.MissingFiles)
	}
	if result.RestoredFiles != 0 {
		t.Errorf("expected 0 restored, got %d", result.RestoredFiles)
	}
	if result.ModifiedFiles != 0 {
		t.Errorf("expected 0 modified, got %d", result.ModifiedFiles)
	}
	if result.NewFiles != 0 {
		t.Errorf("expected 0 new, got %d", result.NewFiles)
	}
	if result.NodesScanned != 1 {
		t.Errorf("expected 1 node scanned, got %d", result.NodesScanned)
	}
}

func TestScanner_MissingFile(t *testing.T) {
	vaultRoot, _, nodeRepo, fileSvc, activitySvc, cleanup := setupWatcherTest(t)
	defer cleanup()

	node, err := nodeRepo.Create(nil, nodes.TypeFolder, "test-folder", 0, "", "test-folder")
	if err != nil {
		t.Fatal(err)
	}
	dir := filepath.Join(vaultRoot, "test-folder")
	if err := os.MkdirAll(dir, 0o750); err != nil {
		t.Fatal(err)
	}

	// Import a file.
	src := tempFileOutsideVault(t, "bye")
	defer os.Remove(src)
	_, err = fileSvc.CopyIntoVault(node.ID, src, "test-folder")
	if err != nil {
		t.Fatal(err)
	}

	// Now remove the physical file from vault.
	vaultFiles, err := fileSvc.ListByNode(node.ID)
	if err != nil || len(vaultFiles) == 0 {
		t.Fatal("no vault files found")
	}
	rec := vaultFiles[0]
	absPath := filepath.Join(vaultRoot, rec.Path)
	if err := os.Remove(absPath); err != nil {
		t.Fatal(err)
	}

	scanner := NewScanner(vaultRoot, nodeRepo, fileSvc, activitySvc)
	result, err := scanner.Run()
	if err != nil {
		t.Fatal(err)
	}

	if result.MissingFiles != 1 {
		t.Errorf("expected 1 missing, got %d", result.MissingFiles)
	}

	// Verify the file record is now marked missing.
	trashed, err := fileSvc.ListTrashedByNode(node.ID)
	if err != nil {
		t.Fatal(err)
	}
	if len(trashed) != 1 {
		t.Errorf("expected 1 trashed record, got %d", len(trashed))
	}
	if !trashed[0].Missing {
		t.Error("expected record to be marked missing")
	}
}

func TestScanner_RestoredFile(t *testing.T) {
	vaultRoot, _, nodeRepo, fileSvc, activitySvc, cleanup := setupWatcherTest(t)
	defer cleanup()

	node, err := nodeRepo.Create(nil, nodes.TypeFolder, "test-folder", 0, "", "test-folder")
	if err != nil {
		t.Fatal(err)
	}
	dir := filepath.Join(vaultRoot, "test-folder")
	if err := os.MkdirAll(dir, 0o750); err != nil {
		t.Fatal(err)
	}

	// Import a file.
	src := tempFileOutsideVault(t, "back")
	defer os.Remove(src)
	rec, err := fileSvc.CopyIntoVault(node.ID, src, "test-folder")
	if err != nil {
		t.Fatal(err)
	}

	// Mark as missing and remove from disk.
	if err := fileSvc.MarkMissing(rec.ID, true); err != nil {
		t.Fatal(err)
	}
	absPath := filepath.Join(vaultRoot, rec.Path)
	if err := os.Remove(absPath); err != nil {
		t.Fatal(err)
	}

	// Re-create the file.
	if err := os.WriteFile(absPath, []byte("back again"), 0o640); err != nil {
		t.Fatal(err)
	}

	scanner := NewScanner(vaultRoot, nodeRepo, fileSvc, activitySvc)
	result, err := scanner.Run()
	if err != nil {
		t.Fatal(err)
	}

	if result.RestoredFiles != 1 {
		t.Errorf("expected 1 restored, got %d", result.RestoredFiles)
	}
}

func TestScanner_ModifiedFile(t *testing.T) {
	vaultRoot, _, nodeRepo, fileSvc, activitySvc, cleanup := setupWatcherTest(t)
	defer cleanup()

	node, err := nodeRepo.Create(nil, nodes.TypeFolder, "test-folder", 0, "", "test-folder")
	if err != nil {
		t.Fatal(err)
	}
	dir := filepath.Join(vaultRoot, "test-folder")
	if err := os.MkdirAll(dir, 0o750); err != nil {
		t.Fatal(err)
	}

	// Import a file.
	src := tempFileOutsideVault(t, "original")
	defer os.Remove(src)
	_, err = fileSvc.CopyIntoVault(node.ID, src, "test-folder")
	if err != nil {
		t.Fatal(err)
	}

	// Get the record to know the vault path.
	vaultFiles, err := fileSvc.ListByNode(node.ID)
	if err != nil || len(vaultFiles) == 0 {
		t.Fatal("no vault files found")
	}
	rec := vaultFiles[0]
	absPath := filepath.Join(vaultRoot, rec.Path)

	// Modify the file content.
	time.Sleep(10 * time.Millisecond)
	if err := os.WriteFile(absPath, []byte("modified"), 0o640); err != nil {
		t.Fatal(err)
	}

	scanner := NewScanner(vaultRoot, nodeRepo, fileSvc, activitySvc)
	result, err := scanner.Run()
	if err != nil {
		t.Fatal(err)
	}

	if result.ModifiedFiles != 1 {
		t.Errorf("expected 1 modified, got %d", result.ModifiedFiles)
	}
}

func TestIsHiddenOrMeta(t *testing.T) {
	tests := []struct {
		path     string
		expected bool
	}{
		{"/vault/.verstak/config.yml", true},
		{"/vault/.verstak/trash/file.txt", true},
		{"/vault/my-project/file.txt", false},
		{"/vault/.hidden/file.txt", true},
		{"/vault/project/.hidden/file.txt", true},
		{"/vault/project/file.txt", false},
	}
	for _, tc := range tests {
		got := isHiddenOrMeta(tc.path)
		if got != tc.expected {
			t.Errorf("isHiddenOrMeta(%q) = %v, want %v", tc.path, got, tc.expected)
		}
	}
}