import 'dart:async';

import 'package:background_downloader/background_downloader.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:reelbox/media/download_service.dart';
import 'package:reelbox/media/downloads_page.dart';

import 'package:reelbox/state/app_state.dart';

import 'catalog_widget_test.dart' show CatalogApi, mountCatalog;

Future<AppState> mountRow(WidgetTester tester, Widget row) async {
  final state = await mountCatalog(tester, CatalogApi(), const Scaffold());
  await tester.pumpWidget(
    AppScope(
      state: state,
      child: MaterialApp(home: Scaffold(body: row)),
    ),
  );
  await tester.pump();
  return state;
}

void main() {
  testWidgets('secondary external downloaders live behind the quiet overflow', (
    tester,
  ) async {
    final selected = <String>[];
    final state = await mountRow(
      tester,
      ExternalDownloadMenu(onSelected: selected.add),
    );
    addTearDown(state.dispose);
    expect(find.byIcon(Icons.more_vert), findsOneWidget);
    expect(find.byIcon(Icons.download_for_offline_outlined), findsNothing);
    expect(find.text('ADM'), findsNothing);
    expect(selected, isEmpty);
    await tester.tap(find.byIcon(Icons.more_vert));
    await tester.pumpAndSettle();
    expect(find.text('External downloader: ADM'), findsOneWidget);
    expect(find.text('External downloader: IDM'), findsOneWidget);
    await tester.tap(find.text('External downloader: ADM'));
    await tester.pumpAndSettle();
    expect(selected, ['ADM']);
  });

  for (final status in [TaskStatus.paused, TaskStatus.failed]) {
    testWidgets(
      '${status.name} exposes its labeled recovery action and readable failures',
      (tester) async {
        var attempts = 0;
        final entry = DownloadEntry.fromTask(
          DownloadTask(url: 'https://media.example/movie.mp4'),
          taskStatus: status,
        );
        Future<void> recover() async {
          attempts++;
          throw StateError(
            'Cannot resume: this server does not support ranges.',
          );
        }

        final state = await mountRow(
          tester,
          DownloadControls(
            entry: entry,
            onPause: () async {},
            onResume: recover,
            onRetry: recover,
            onCancel: () async {},
          ),
        );
        addTearDown(state.dispose);
        final label = status == TaskStatus.paused ? 'Resume' : 'Retry';
        expect(find.widgetWithText(FilledButton, label), findsOneWidget);
        await tester.tap(find.text(label));
        await tester.pumpAndSettle();
        expect(attempts, 1);
        expect(
          find.text('Cannot resume: this server does not support ranges.'),
          findsOneWidget,
        );
        expect(tester.takeException(), isNull);
      },
    );
  }

  testWidgets(
    'failed unknown-length transfer stops animating and shows its actual cause',
    (tester) async {
      final entry = DownloadEntry.fromTask(
        DownloadTask(url: 'https://media.example/movie.mp4'),
        taskStatus: TaskStatus.failed,
        error: 'Connection refused by media server',
      );
      final state = await mountRow(
        tester,
        DownloadTransferDetails(entry: entry),
      );
      addTearDown(state.dispose);
      expect(
        tester
            .widget<LinearProgressIndicator>(
              find.byType(LinearProgressIndicator),
            )
            .value,
        0,
      );
      expect(find.textContaining('%'), findsNothing);
      expect(find.text('Connection refused by media server'), findsOneWidget);
      await tester.pumpAndSettle();
      expect(tester.takeException(), isNull);
    },
  );

  testWidgets(
    'download controls are labeled and dispatch once while an operation is pending',
    (tester) async {
      final pending = Completer<void>();
      var pauses = 0;
      var cancels = 0;
      final entry = DownloadEntry.fromTask(
        DownloadTask(url: 'https://media.example/movie.mp4'),
        taskStatus: TaskStatus.running,
      );
      final state = await mountRow(
        tester,
        DownloadControls(
          entry: entry,
          onPause: () {
            pauses++;
            return pending.future;
          },
          onResume: () async {},
          onRetry: () async {},
          onCancel: () async {
            cancels++;
          },
        ),
      );
      addTearDown(state.dispose);
      expect(find.widgetWithText(FilledButton, 'Pause'), findsOneWidget);
      expect(find.widgetWithText(OutlinedButton, 'Cancel'), findsOneWidget);
      await tester.tap(find.text('Pause'));
      await tester.tap(find.text('Pause'));
      await tester.pump();
      expect(pauses, 1);
      expect(
        tester
            .widget<OutlinedButton>(
              find.widgetWithText(OutlinedButton, 'Cancel'),
            )
            .onPressed,
        isNull,
      );
      pending.complete();
      await tester.pumpAndSettle();
      await tester.tap(find.text('Cancel'));
      await tester.pumpAndSettle();
      expect(cancels, 1);
      expect(tester.takeException(), isNull);
    },
  );

  for (final status in <TaskStatus, String>{
    TaskStatus.enqueued: 'Queued',
    TaskStatus.running: 'Downloading',
    TaskStatus.waitingToRetry: 'Waiting to retry',
    TaskStatus.paused: 'Paused',
    TaskStatus.complete: 'Downloaded',
    TaskStatus.failed: 'Failed',
    TaskStatus.canceled: 'Canceled',
    TaskStatus.notFound: 'Source not found',
  }.entries) {
    testWidgets(
      '${status.key.name} has a readable status and preserves measured progress',
      (tester) async {
        final entry = DownloadEntry.fromTask(
          DownloadTask(url: 'https://media.example/movie.mp4'),
          taskStatus: status.key,
          progress: .25,
          totalBytes: 4096,
          speed: 2048,
          error: status.key == TaskStatus.failed ? 'HTTP 403: expired URL' : '',
        );
        final state = await mountRow(
          tester,
          DownloadTransferDetails(entry: entry),
        );
        addTearDown(state.dispose);
        expect(find.text(status.value), findsOneWidget);
        expect(
          tester
              .widget<LinearProgressIndicator>(
                find.byType(LinearProgressIndicator),
              )
              .value,
          status.key == TaskStatus.complete ? 1 : .25,
        );
        expect(
          find.textContaining('/s'),
          status.key == TaskStatus.running ? findsOneWidget : findsNothing,
        );
        if (status.key == TaskStatus.failed) {
          expect(find.text('HTTP 403: expired URL'), findsOneWidget);
        }
        expect(tester.takeException(), isNull);
      },
    );
  }

  testWidgets(
    'queued Wi-Fi download shows its constraint without invented progress',
    (tester) async {
      final entry = DownloadEntry.fromTask(
        DownloadTask(
          url: 'https://media.example/movie.mp4',
          requiresWiFi: true,
        ),
      );
      final state = await mountRow(
        tester,
        DownloadTransferDetails(entry: entry),
      );
      addTearDown(state.dispose);
      expect(find.text('Queued · Wi-Fi required'), findsOneWidget);
      expect(find.textContaining('0%'), findsNothing);
      expect(find.textContaining('/s'), findsNothing);
      expect(
        tester
            .widget<LinearProgressIndicator>(
              find.byType(LinearProgressIndicator),
            )
            .value,
        isNull,
      );
      expect(tester.takeException(), isNull);
    },
  );
}