import 'package:file_picker/file_picker.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import 'imports_api.dart';

/// Picking a report is the one part of the import screen that touches the platform, so it
/// sits behind this one-method interface: widget tests (and a future drag-and-drop variant)
/// override [reportPickerProvider] instead of mocking a plugin.
abstract class ReportPicker {
  Future<PickedReport?> pick();
}

/// The extensions the report parsers accept.
const reportExtensions = ['html', 'htm', 'xlsx', 'csv'];

class FilePickerReportPicker implements ReportPicker {
  const FilePickerReportPicker();

  @override
  Future<PickedReport?> pick() async {
    // file_picker 11 exposes `pickFiles` as a static on [FilePicker]; the old
    // `FilePicker.platform` singleton is gone.
    final result = await FilePicker.pickFiles(
      type: FileType.custom,
      allowedExtensions: reportExtensions,
      // On web there is no path at all, only bytes; asking for bytes everywhere would read
      // a 16 MB report into memory for nothing on desktop.
      withData: kIsWeb,
    );
    if (result == null || result.files.isEmpty) return null;
    final file = result.files.first;
    return PickedReport(name: file.name, bytes: file.bytes, path: file.path);
  }
}

final reportPickerProvider = Provider<ReportPicker>((ref) => const FilePickerReportPicker());