import 'package:actors/actors.dart';
import 'package:flutter/material.dart';
import 'package:signals/signals_flutter.dart' show SignalBuilder;

import '../application/actors/fetch_actor.dart';
import '../application/controllers/browser_controller.dart';
import '../application/controllers/reader_settings_controller.dart';
import '../application/internal_pages.dart';
import '../database/database.dart';
import '../l10n/strings.dart';
import '../mews/document.dart';
import 'reader/palettes.dart';
import 'reader/reader_screen.dart';
/// Wires the app's dependencies together and provides them to the tree.
/// Everything is local-first: the database is created up front and the fetch
/// actor is the only path to the network.
class AppDependencies {
  AppDependencies({
    MewsDatabase? database,
    Actor<FetchCommand, FetchResult>? fetch,
    Strings? strings,
  })  : db = database ?? MewsDatabase(),
        fetch = fetch ?? Actor.create(FetchHandler.new),
        strings = strings ?? Strings() {
    settings = ReaderSettingsController(db);
    library = LibraryController(db);
    internalPages = InternalPages(
        db: db, library: library, settings: settings, strings: this.strings);
    browser = BrowserController(db: db, fetch: this.fetch, internalPages: internalPages);
  }

  /// Localized strings, also used to title the internal pages.
  final Strings strings;

  final MewsDatabase db;
  final Actor<FetchCommand, FetchResult> fetch;
  late final BrowserController browser;
  late final ReaderSettingsController settings;
  late final LibraryController library;
  late final InternalPages internalPages;

  Future<void> start() async {
    await settings.load();
    await library.load();
    await browser.restoreLastSession();
  }
}

class AppScope extends InheritedWidget {
  const AppScope({
    required this.deps,
    required this.strings,
    required super.child,
    super.key,
  });

  final AppDependencies deps;
  final Strings strings;

  static AppScope of(BuildContext context) =>
      context.getInheritedWidgetOfExactType<AppScope>()!;

  @override
  bool updateShouldNotify(AppScope oldWidget) => false;
}

class MewsApp extends StatelessWidget {
  const MewsApp({required this.deps, required this.strings, super.key});

  final AppDependencies deps;
  final Strings strings;

  @override
  Widget build(BuildContext context) {
    return AppScope(
      deps: deps,
      strings: strings,
      child: StringsScope(
        strings: strings,
        child: const _ThemedApp(),
      ),
    );
  }
}

/// The chrome (address bar, FOB, sheet, dialogs) follows the same palette
/// the reader selected for pages, so the whole app shares one color scheme.
class _ThemedApp extends StatelessWidget {
  const _ThemedApp();

  @override
  Widget build(BuildContext context) {
    final deps = AppScope.of(context).deps;
    return SignalBuilder(builder: (context) {
      final mode = switch (deps.settings.themeMode.value) {
        'light' => ThemeMode.light,
        'dark' => ThemeMode.dark,
        _ => ThemeMode.system,
      };
      final settings = deps.settings;
      final page = deps.browser.currentPage.value;
      final variant = settings.variant.value == 'site'
          ? (page?.variant ?? MewsVariant.plain)
          : pageVariantFromName(settings.variant.value);

      return MaterialApp(
        title: 'Mews',
        themeMode: mode,
        theme: _themeFor(paletteFor(pageVariant: variant, readerVariant: 'site', dark: false)),
        darkTheme: _themeFor(paletteFor(pageVariant: variant, readerVariant: 'site', dark: true)),
        home: const ReaderScreen(),
      );
    });
  }

  ThemeData _themeFor(MewsPalette palette) {
    final dark = palette.background.computeLuminance() < 0.5;
    final scheme = ColorScheme(
      brightness: dark ? Brightness.dark : Brightness.light,
      primary: palette.link,
      onPrimary: palette.background,
      primaryContainer: palette.link,
      onPrimaryContainer: palette.background,
      secondary: palette.border,
      onSecondary: palette.foreground,
      surface: palette.background,
      onSurface: palette.foreground,
      onSurfaceVariant: palette.foreground,
      surfaceContainerHighest: palette.preBackground,
      outline: palette.border,
      error: const Color(0xffba1a1a),
      onError: Colors.white,
    );
    return ThemeData(
      useMaterial3: true,
      colorScheme: scheme,
      scaffoldBackgroundColor: palette.background,
      // The FOB follows the palette, not the M3 container defaults.
      floatingActionButtonTheme: FloatingActionButtonThemeData(
        backgroundColor: palette.link,
        foregroundColor: palette.background,
      ),
      // Selection highlights and the caret follow the palette too.
      textSelectionTheme: TextSelectionThemeData(
        cursorColor: palette.link,
        selectionColor: palette.link.withValues(alpha: 0.3),
        selectionHandleColor: palette.link,
      ),
    );
  }
}