import 'package:flutter/material.dart';
import 'package:openfoodfacts/openfoodfacts.dart';
import 'package:provider/provider.dart';
import 'package:smooth_app/background/background_task_manager.dart';
import 'package:smooth_app/background/background_task_progressing.dart';
import 'package:smooth_app/background/background_task_queue.dart';
import 'package:smooth_app/background/operation_type.dart';
import 'package:smooth_app/background/work_type.dart';
import 'package:smooth_app/database/dao_instant_string.dart';
import 'package:smooth_app/database/local_database.dart';
import 'package:smooth_app/generic_lib/dialogs/smooth_alert_dialog.dart';
import 'package:smooth_app/l10n/app_localizations.dart';
import 'package:smooth_app/widgets/smooth_app_bar.dart';
import 'package:smooth_app/widgets/smooth_scaffold.dart';

class OfflineTaskPage extends StatefulWidget {
  const OfflineTaskPage();

  @override
  State<OfflineTaskPage> createState() => _OfflineTaskState();
}

class _OfflineTaskState extends State<OfflineTaskPage> {
  @override
  Widget build(BuildContext context) {
    final AppLocalizations appLocalizations = AppLocalizations.of(context);
    final LocalDatabase localDatabase = context.watch<LocalDatabase>();
    final DaoInstantString daoInstantString = DaoInstantString(localDatabase);
    final Map<String, BackgroundTaskQueue> queues =
        <String, BackgroundTaskQueue>{};
    final List<String> taskIds = <String>[];
    for (final BackgroundTaskQueue queue in BackgroundTaskQueue.values) {
      final List<String> list = localDatabase.getAllTaskIds(queue.tagTaskQueue);
      taskIds.addAll(list);
      for (final String taskId in list) {
        queues[taskId] = queue;
      }
    }
    return SmoothScaffold(
      appBar: SmoothAppBar(
        title: Text(appLocalizations.background_task_title, maxLines: 2),
        actions: <Widget>[
          IconButton(
            onPressed: () => BackgroundTaskManager.runAgain(
              localDatabase,
              forceNowIfPossible: true,
            ),
            icon: const Icon(Icons.refresh),
          ),
        ],
      ),
      body: taskIds.isEmpty
          ? Center(child: Text(appLocalizations.background_task_list_empty))
          : ListView.builder(
              itemCount: taskIds.length,
              itemBuilder: (final BuildContext context, final int index) {
                final String taskId = taskIds[index];
                final String? status = daoInstantString.get(
                  BackgroundTaskManager.taskIdToErrorDaoInstantStringKey(
                    taskId,
                  ),
                );
                final String barcode = OperationType.getBarcode(taskId);
                final int? totalSize = OperationType.getTotalSize(taskId);
                final int? soFarSize = OperationType.getSoFarSize(taskId);
                final String? workText = _getWorkText(taskId);
                final String info;
                if (barcode != BackgroundTaskProgressing.noBarcode) {
                  info = '$barcode ';
                } else if (totalSize != null && soFarSize != null) {
                  info =
                      '${(100 * soFarSize) ~/ totalSize}% ${workText == null ? '' : '- $workText '}';
                } else {
                  info = '';
                }
                final BackgroundTaskQueue queue = queues[taskId]!;
                final String? productType = OperationType.getProductType(
                  taskId,
                );
                return ListTile(
                  leading: Icon(queue.iconData),
                  onTap: () async {
                    final bool? stopTask = await showDialog<bool>(
                      context: context,
                      builder: (final BuildContext context) =>
                          SmoothAlertDialog(
                            body: Text(
                              appLocalizations.background_task_question_stop,
                            ),
                            negativeAction: SmoothActionButton(
                              text: appLocalizations.no,
                              onPressed: () => Navigator.of(context).pop(false),
                            ),
                            positiveAction: SmoothActionButton(
                              text: appLocalizations.yes,
                              onPressed: () => Navigator.of(context).pop(true),
                            ),
                          ),
                    );
                    if (stopTask == true) {
                      await BackgroundTaskManager.getInstance(
                        localDatabase,
                        queue: queue,
                      ).removeTaskAsap(taskId);
                    }
                  },
                  title: Text(
                    '$info'
                    '(${OperationType.getOperationType(taskId)?.getLabel(appLocalizations) ?? appLocalizations.background_task_operation_unknown})'
                    '${productType == null ? '' : ' ($productType)'}',
                  ),
                  subtitle: Text(_getMessage(status, appLocalizations)),
                  trailing: const Icon(Icons.clear),
                );
              },
            ),
    );
  }

  String _getMessage(
    final String? status,
    final AppLocalizations appLocalizations,
  ) {
    switch (status) {
      case null:
        return appLocalizations.background_task_run_not_started;
      case BackgroundTaskManager.taskStatusStarted:
        return appLocalizations.background_task_run_started;
      case BackgroundTaskManager.taskStatusNoInternet:
        return appLocalizations.background_task_error_no_internet;
      case BackgroundTaskManager.taskStatusStopAsap:
        return appLocalizations.background_task_run_to_be_deleted;
    }
    // "startsWith" because there's some kind of "chr(13)" at the end.
    if (status.startsWith(
      'Exception: JSON expected, html found: <head><title>504 Gateway Time-out</title></head>',
    )) {
      return appLocalizations.background_task_error_server_time_out;
    }
    return status;
  }

  String? _getWorkText(final String taskId) {
    final String? work = OperationType.getWork(taskId);
    if (work == null || work.isEmpty) {
      return null;
    }
    final (WorkType workType, ProductType productType)? item = WorkType.extract(
      work,
    );
    if (item != null) {
      return '${item.$1.englishLabel} (${item.$2.offTag})';
    }
    return 'Unknown work ($work)!';
  }
}