import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';

import 'avatar_crop_page.dart';
import 'file_pick.dart';

/// Result of the user's choice inside [showAvatarActionsSheet]. The sheet
/// only collects intent + the (cropped) image bytes — the actual upload /
/// delete and any loading state are the caller's responsibility, so failures
/// surface in the screen that owns the avatar, not in a transient sheet.
sealed class AvatarSheetResult {
  const AvatarSheetResult();
}

class AvatarUploadResult extends AvatarSheetResult {
  final Uint8List bytes;
  const AvatarUploadResult(this.bytes);
}

class AvatarRemoveResult extends AvatarSheetResult {
  const AvatarRemoveResult();
}

/// Bottom sheet with "from gallery", "take photo" and optional "remove"
/// actions. The picker + 1:1 cropper run with the sheet still mounted, so a
/// cancelled pick simply returns the user to the sheet. The sheet only pops
/// once a concrete result exists (or never, if everything was cancelled).
Future<AvatarSheetResult?> showAvatarActionsSheet(
  BuildContext context, {
  required bool allowRemove,
}) async {
  AvatarSheetResult? result;
  await showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    showDragHandle: true,
    useSafeArea: true,
    builder: (sheetContext) => SafeArea(
      child: SingleChildScrollView(
        padding: EdgeInsets.only(
          bottom: 16 + MediaQuery.viewInsetsOf(sheetContext).bottom,
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            ListTile(
              leading: const Icon(Icons.photo_library_outlined),
              title: const Text('Aus Galerie wählen'),
              onTap: () async {
                final bytes = await _pickAndCrop(
                  sheetContext,
                  FilePick.singleGalleryPick,
                );
                if (bytes == null || !sheetContext.mounted) return;
                result = AvatarUploadResult(bytes);
                Navigator.of(sheetContext).pop();
              },
            ),
            ListTile(
              leading: const Icon(Icons.photo_camera_outlined),
              title: const Text('Foto aufnehmen'),
              onTap: () async {
                final bytes = await _pickAndCrop(
                  sheetContext,
                  FilePick.cameraPick,
                );
                if (bytes == null || !sheetContext.mounted) return;
                result = AvatarUploadResult(bytes);
                Navigator.of(sheetContext).pop();
              },
            ),
            if (allowRemove) ...[
              const Divider(),
              ListTile(
                leading: Icon(
                  Icons.delete_outline,
                  color: Theme.of(sheetContext).colorScheme.error,
                ),
                title: Text(
                  'Profilbild entfernen',
                  style: TextStyle(
                    color: Theme.of(sheetContext).colorScheme.error,
                  ),
                ),
                onTap: () {
                  result = const AvatarRemoveResult();
                  Navigator.of(sheetContext).pop();
                },
              ),
            ],
          ],
        ),
      ),
    ),
  );
  return result;
}

Future<Uint8List?> _pickAndCrop(
  BuildContext context,
  Future<XFile?> Function() pick,
) async {
  final picked = await pick();
  if (picked == null) return null;
  final bytes = await picked.readAsBytes();
  if (!context.mounted) return null;
  return Navigator.of(context).push<Uint8List>(
    MaterialPageRoute(
      fullscreenDialog: true,
      builder: (_) => AvatarCropPage(imageBytes: bytes),
    ),
  );
}