// Yukart display: the tablet app. Starts the link to the Orin and hands the screen to
// the shell (lib/shell.dart). Code layout: lib/README.md.

import 'package:flutter/material.dart';

import 'link/boundary.dart';
import 'link/net.dart';
import 'link/reading.dart';
import 'pages/link_test.dart';
import 'shell.dart';
import 'shell_scope.dart';
import 'theme/light.dart';
import 'theme/palette.dart';

/// Override for development, e.g. `--dart-define=YUKART_GW=ws://halogen.local:7700/`.
const defaultUrl = String.fromEnvironment(
  'YUKART_GW',
  defaultValue: 'ws://192.168.55.1:7700/',
);

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final themes = await Themes.load()
    ..followLight(lightLevels());
  final usb = UsbLink();
  await usb.bindFor(Uri.parse(defaultUrl));
  final boundary = Boundary(defaultUrl)..start();
  // The sun, for auto dark/bright: the car's position while GNSS has one.
  boundary.addListener(() {
    final lat = Reading.of(boundary, 'gnss_lat');
    final lon = Reading.of(boundary, 'gnss_lon');
    if (!lat.dim && !lon.dim && lat.number != null && lon.number != null) {
      themes.setPosition(lat.number!, lon.number!);
    }
  });
  final linkTest = LinkTest(usb);
  // Development hook: `am start ... --es linktest [dl:|bi:]<label>[@<host>]` runs the test
  // (`dl:` the download series, `bi:` burst latency against idle gaps), on the gateway's host unless one is given.
  Future<void> runLinkTest(String request) async {
    final mode = request.startsWith('dl:') || request.startsWith('bi:')
        ? request.substring(0, 2)
        : '';
    if (mode.isNotEmpty) request = request.substring(3);
    final at = request.indexOf('@');
    final label = at < 0 ? request : request.substring(0, at);
    final host = at < 0
        ? Uri.parse(boundary.url).host
        : request.substring(at + 1);
    shellView.value = ShellView.linkTest;
    await switch (mode) {
      'dl' => linkTest.runDownload(host, label),
      'bi' => linkTest.runBurstIdle(host, label),
      _ => linkTest.run(host, label),
    };
    await usb.bindFor(Uri.parse(boundary.url));
  }

  usb.onLinkTest = runLinkTest;
  runApp(
    YukartApp(boundary: boundary, usb: usb, linkTest: linkTest, themes: themes),
  );
  final pending = await usb.takeLinkTest();
  if (pending != null) {
    WidgetsBinding.instance.addPostFrameCallback((_) => runLinkTest(pending));
  }
}

class YukartApp extends StatelessWidget {
  const YukartApp({
    super.key,
    required this.boundary,
    required this.usb,
    required this.linkTest,
    required this.themes,
  });
  final Boundary boundary;
  final UsbLink usb;
  final LinkTest linkTest;
  final Themes themes;

  @override
  Widget build(BuildContext context) {
    // Every page takes its colours from the palette; switching dark/bright rebuilds them all.
    return ListenableBuilder(
      listenable: themes,
      builder: (context, _) => MaterialApp(
        title: 'Yukart',
        debugShowCheckedModeBanner: false,
        theme: themes.material(),
        builder: (context, child) =>
            AppTheme(palette: themes.current, child: child!),
        home: AppShell(
          boundary: boundary,
          usb: usb,
          linkTest: linkTest,
          themes: themes,
        ),
      ),
    );
  }
}