package database_test

import (
	"context"
	"database/sql"
	"errors"
	"os"
	"slices"
	"testing"
	"time"

	"sneak.berlin/go/vaultik/internal/database"
	"sneak.berlin/go/vaultik/internal/types"
)

// errTestRollback is the sentinel returned from transaction bodies to
// force a rollback in tests.
var errTestRollback = errors.New("test rollback")

func TestFileRepository(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repo := database.NewFileRepository(db)

	// Test Create
	file := &database.File{
		Path:       testFileTxt,
		MTime:      time.Now().Truncate(time.Second),
		Size:       1024,
		Mode:       0644,
		UID:        1000,
		GID:        1000,
		LinkTarget: "",
	}

	err := repo.Create(ctx, nil, file)
	if err != nil {
		t.Fatalf("failed to create file: %v", err)
	}

	// Test GetByPath
	retrieved, err := repo.GetByPath(ctx, file.Path.String())
	if err != nil {
		t.Fatalf("failed to get file: %v", err)
	}

	if retrieved == nil {
		t.Fatal("expected file, got nil")
	}

	if retrieved.Path != file.Path {
		t.Errorf("path mismatch: got %s, want %s", retrieved.Path, file.Path)
	}

	if !retrieved.MTime.Equal(file.MTime) {
		t.Errorf("mtime mismatch: got %v, want %v", retrieved.MTime, file.MTime)
	}

	if retrieved.Size != file.Size {
		t.Errorf("size mismatch: got %d, want %d", retrieved.Size, file.Size)
	}

	if retrieved.Mode != file.Mode {
		t.Errorf("mode mismatch: got %o, want %o", retrieved.Mode, file.Mode)
	}

	// Test Update (upsert)
	file.Size = 2048
	file.MTime = time.Now().Truncate(time.Second)

	err = repo.Create(ctx, nil, file)
	if err != nil {
		t.Fatalf("failed to update file: %v", err)
	}

	retrieved, err = repo.GetByPath(ctx, file.Path.String())
	if err != nil {
		t.Fatalf("failed to get updated file: %v", err)
	}

	if retrieved.Size != 2048 {
		t.Errorf("size not updated: got %d, want %d", retrieved.Size, 2048)
	}
}

func TestFileRepositoryListDelete(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repo := database.NewFileRepository(db)

	file := &database.File{
		Path:  testFileTxt,
		MTime: time.Now().Truncate(time.Second),
		Size:  1024,
		Mode:  0644,
		UID:   1000,
		GID:   1000,
	}

	err := repo.Create(ctx, nil, file)
	if err != nil {
		t.Fatalf("failed to create file: %v", err)
	}

	// Test ListModifiedSince
	files, err := repo.ListModifiedSince(ctx, time.Now().Add(-1*time.Hour))
	if err != nil {
		t.Fatalf("failed to list files: %v", err)
	}

	if len(files) != 1 {
		t.Errorf("expected 1 file, got %d", len(files))
	}

	// Test Delete
	err = repo.Delete(ctx, nil, file.Path.String())
	if err != nil {
		t.Fatalf("failed to delete file: %v", err)
	}

	retrieved, err := repo.GetByPath(ctx, file.Path.String())
	if err != nil {
		t.Fatalf("error getting deleted file: %v", err)
	}

	if retrieved != nil {
		t.Error("expected nil for deleted file")
	}
}

func TestFileRepositoryListUnderPath(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repo := database.NewFileRepository(db)

	const (
		docDir  = "/home/u/doc"
		docFile = "/home/u/doc/a.txt"
	)

	// In path order, so the root case can expect all of them as listed.
	paths := []string{
		"/home/u/50%/x.txt",
		"/home/u/50percent/y.txt",
		"/home/u/DOC/c.txt",
		"/home/u/a_b/x.txt",
		"/home/u/axb/y.txt",
		docDir,
		"/home/u/doc.txt.bak",
		docFile,
		"/home/u/doc/sub/b.txt",
		"/home/u/doc2/b.txt",
	}

	for _, path := range paths {
		err := repo.Create(ctx, nil, &database.File{
			Path:  types.FilePath(path),
			MTime: time.Now().Truncate(time.Second),
			Mode:  0644,
		})
		if err != nil {
			t.Fatalf("failed to create %s: %v", path, err)
		}
	}

	docTree := []string{docDir, docFile, "/home/u/doc/sub/b.txt"}

	tests := []struct {
		name string
		path string
		want []string
	}{
		{"directory", docDir, docTree},
		{"directory with trailing slash", docDir + "/", docTree},
		{"directory differing only in case", "/home/u/DOC",
			[]string{"/home/u/DOC/c.txt"}},
		{"file", docFile, []string{docFile}},
		{"underscore is literal", "/home/u/a_b",
			[]string{"/home/u/a_b/x.txt"}},
		{"percent is literal", "/home/u/50%",
			[]string{"/home/u/50%/x.txt"}},
		{"root", "/", paths},
	}

	for _, tt := range tests {
		files, err := repo.ListUnderPath(ctx, tt.path)
		if err != nil {
			t.Fatalf("%s: failed to list files: %v", tt.name, err)
		}

		got := make([]string, 0, len(files))
		for _, f := range files {
			got = append(got, f.Path.String())
		}

		if !slices.Equal(got, tt.want) {
			t.Errorf("%s: listing %q got %q, want %q",
				tt.name, tt.path, got, tt.want)
		}
	}
}

func TestFileRepositorySymlink(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repo := database.NewFileRepository(db)

	// Test symlink
	symlink := &database.File{
		Path:       "/test/link",
		MTime:      time.Now().Truncate(time.Second),
		Size:       0,
		Mode:       uint32(0777 | os.ModeSymlink),
		UID:        1000,
		GID:        1000,
		LinkTarget: "/test/target",
	}

	err := repo.Create(ctx, nil, symlink)
	if err != nil {
		t.Fatalf("failed to create symlink: %v", err)
	}

	retrieved, err := repo.GetByPath(ctx, symlink.Path.String())
	if err != nil {
		t.Fatalf("failed to get symlink: %v", err)
	}

	if !retrieved.IsSymlink() {
		t.Error("expected IsSymlink() to be true")
	}

	if retrieved.LinkTarget != symlink.LinkTarget {
		t.Errorf("link target mismatch: got %s, want %s",
			retrieved.LinkTarget, symlink.LinkTarget)
	}
}

// An mtime after 2262 or before 1678 does not fit in int64 nanoseconds
// since the epoch, and must still come back from the database unchanged.
func TestFileRepositoryMTimeOutsideInt64NanosecondRange(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repo := database.NewFileRepository(db)

	mtimes := []time.Time{
		time.Date(2300, time.January, 1, 0, 0, 0, 123456789, time.UTC),
		time.Date(1601, time.January, 1, 0, 0, 0, 987654321, time.UTC),
	}

	for _, mtime := range mtimes {
		created := &database.File{
			Path:  types.FilePath("/created-" + mtime.Format(time.RFC3339Nano)),
			MTime: mtime,
		}

		err := repo.Create(ctx, nil, created)
		if err != nil {
			t.Fatalf("failed to create file: %v", err)
		}

		batched := &database.File{
			ID:    types.NewFileID(),
			Path:  types.FilePath("/batched-" + mtime.Format(time.RFC3339Nano)),
			MTime: mtime,
		}

		err = repo.CreateBatch(ctx, nil, []*database.File{batched})
		if err != nil {
			t.Fatalf("failed to batch create file: %v", err)
		}

		for _, path := range []types.FilePath{created.Path, batched.Path} {
			retrieved, err := repo.GetByPath(ctx, path.String())
			if err != nil {
				t.Fatalf("failed to get file: %v", err)
			}

			if !retrieved.MTime.Equal(mtime) {
				t.Errorf("%s: mtime got %v, want %v",
					path, retrieved.MTime, mtime)
			}
		}
	}
}

func TestFileRepositoryTransaction(t *testing.T) {
	t.Parallel()

	db, cleanup := setupTestDB(t)
	defer cleanup()

	ctx := context.Background()
	repos := database.NewRepositories(db)

	// Test transaction rollback
	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
		file := &database.File{
			Path:  testTxFile,
			MTime: time.Now().Truncate(time.Second),
			Size:  1024,
			Mode:  0644,
			UID:   1000,
			GID:   1000,
		}

		err := repos.Files.Create(ctx, tx, file)
		if err != nil {
			return err
		}

		// Return error to trigger rollback
		return errTestRollback
	})
	if !errors.Is(err, errTestRollback) {
		t.Fatalf("expected rollback error, got: %v", err)
	}

	// Verify file was not created
	retrieved, err := repos.Files.GetByPath(ctx, testTxFile)
	if err != nil {
		t.Fatalf("error checking for file: %v", err)
	}

	if retrieved != nil {
		t.Error("file should not exist after rollback")
	}
}