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';

/// Bottom sheet with "from gallery" and "take photo" actions for choosing a
/// chat background. Returns the picked image bytes **as-is** — cropping is a
/// separate, explicit step (see [cropChatBackgroundImage]) so the user isn't
/// forced through a cropper after every pick. Returns `null` if the user
/// cancelled everything.
Future<Uint8List?> showChatBackgroundPickerSheet(BuildContext context) async {
  Uint8List? 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 _pickRaw(FilePick.singleGalleryPick);
                if (bytes == null || !sheetContext.mounted) return;
                result = bytes;
                Navigator.of(sheetContext).pop();
              },
            ),
            ListTile(
              leading: const Icon(Icons.photo_camera_outlined),
              title: const Text('Foto aufnehmen'),
              onTap: () async {
                final bytes = await _pickRaw(FilePick.cameraPick);
                if (bytes == null || !sheetContext.mounted) return;
                result = bytes;
                Navigator.of(sheetContext).pop();
              },
            ),
          ],
        ),
      ),
    ),
  );
  return result;
}

/// Opens the free-form cropper on [bytes] and returns the cropped result, or
/// `null` if the user cancelled. Free aspect ratio since the background fills
/// the whole screen.
Future<Uint8List?> cropChatBackgroundImage(
  BuildContext context,
  Uint8List bytes,
) => Navigator.of(context).push<Uint8List>(
  MaterialPageRoute(
    fullscreenDialog: true,
    builder: (_) => AvatarCropPage(imageBytes: bytes, aspectRatio: null),
  ),
);

Future<Uint8List?> _pickRaw(Future<XFile?> Function() pick) async {
  final picked = await pick();
  if (picked == null) return null;
  return picked.readAsBytes();
}