package storage_test

import (
	"context"
	"errors"
	"io/fs"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"sneak.berlin/go/vaultik/internal/storage"
)

// newFileStorer builds a file:// backend rooted at a fresh temp directory.
//
//nolint:ireturn // conformance runs against the Storer interface by design
func newFileStorer(t *testing.T) storage.Storer {
	t.Helper()

	s, err := storage.NewFileStorer(t.TempDir())
	if err != nil {
		t.Fatalf("NewFileStorer: %v", err)
	}

	return s
}

// TestFileStorer runs the shared Storer contract against the file:// backend.
func TestFileStorer(t *testing.T) {
	t.Parallel()
	runStorerConformance(t, newFileStorer)
}

// TestFileStorerListMissingDestination checks that List and ListStream
// fail when the destination directory does not exist, instead of
// reporting an empty store.
func TestFileStorerListMissingDestination(t *testing.T) {
	t.Parallel()

	ctx := context.Background()

	s, err := storage.NewFileStorer(filepath.Join(t.TempDir(), "unmounted"))
	if err != nil {
		t.Fatalf("NewFileStorer: %v", err)
	}

	keys, err := s.List(ctx, "metadata/")
	if !errors.Is(err, fs.ErrNotExist) {
		t.Errorf("List = %v, %v; want a not-exist error", keys, err)
	}

	var streamErr error

	for object := range s.ListStream(ctx, "metadata/") {
		if object.Err != nil {
			streamErr = object.Err
		}
	}

	if !errors.Is(streamErr, fs.ErrNotExist) {
		t.Errorf("ListStream error = %v, want a not-exist error", streamErr)
	}
}

// TestFileStorerPutMissingDestination checks that a write fails when the
// destination directory has gone, even after earlier writes to it
// succeeded, and that it does not create the directory again.
func TestFileStorerPutMissingDestination(t *testing.T) {
	t.Parallel()

	ctx := context.Background()
	base := filepath.Join(t.TempDir(), "usbstick")

	err := os.Mkdir(base, 0o750)
	if err != nil {
		t.Fatalf("Mkdir: %v", err)
	}

	s, err := storage.NewFileStorer(base)
	if err != nil {
		t.Fatalf("NewFileStorer: %v", err)
	}

	err = s.Put(ctx, "blobs/aa/bb/first", strings.NewReader("first"))
	if err != nil {
		t.Fatalf("first Put: %v", err)
	}

	err = os.Rename(base, base+"-unplugged")
	if err != nil {
		t.Fatalf("Rename: %v", err)
	}

	err = s.Put(ctx, "blobs/aa/bb/second", strings.NewReader("second"))
	if !errors.Is(err, fs.ErrNotExist) {
		t.Errorf("Put = %v, want a not-exist error", err)
	}

	_, err = os.Stat(base)
	if !errors.Is(err, fs.ErrNotExist) {
		t.Errorf("Put created the destination directory again (Stat = %v)", err)
	}
}