// The software dash: smart-serow's HUD layout and widgets, fed from the boundary.
// A grid of boxes (lib/widgets/stat_box.dart): the instruments and the big numbers
// in the main row, smaller readouts and telltales below. Every value names its
// signal from contracts' signals.json and nothing else (app guideline 1).

import 'package:flutter/material.dart';

import '../link/boundary.dart';
import '../shell_scope.dart';
import '../link/reading.dart';
import '../theme/palette.dart';
import '../widgets/accel_graph.dart';
import '../widgets/gps_compass.dart';
import '../widgets/stat_box.dart';
import '../widgets/telltale.dart';
import '../widgets/whiskey_mark.dart';

class DashPage extends StatelessWidget {
  const DashPage({super.key, required this.boundary, required this.themes});
  final Boundary boundary;
  final Themes themes;

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: Listenable.merge([boundary, themes]),
      builder: (context, _) {
        final p = AppTheme.of(context);
        final b = boundary;
        Reading r(String n) => Reading.of(b, n);
        final rpm = r('engine_rpm');
        final speed = r('gnss_speed_kph');
        final pedal = r('accel_pedal_pct');
        final coolant = r('obd_coolant_temp_c');
        final lat = r('imu_accel_lat_g');
        final lon = r('imu_accel_lon_g');
        // The compass's states, from gnss_fix: none → acquiring, 2d/3d → fix, missing → none known.
        final fix = r('gnss_fix');
        final gpsState = fix.value == null
            ? null
            : fix.value == 'none'
            ? 'acquiring'
            : 'fix';

        return Scaffold(
          backgroundColor: p.background,
          body: SafeArea(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                _DashBar(boundary: b, themes: themes),
                Expanded(
                  child: Padding(
                    padding: const EdgeInsets.fromLTRB(16, 0, 16, 16),
                    child: Column(
                      children: [
                        // Main area: instruments and the big numbers.
                        Expanded(
                          flex: 7,
                          child: Row(
                            children: [
                              Expanded(
                                child: WhiskeyMark(
                                  roll: r('imu_roll_deg').number,
                                  pitch: r('imu_pitch_deg').number,
                                ),
                              ),
                              Expanded(
                                child: AccelGraph(
                                  ax: lat.number,
                                  ay: lon.number,
                                  maxG: 0.8,
                                  ghostTrackPeriod: const Duration(seconds: 4),
                                ),
                              ),
                              Expanded(
                                child: Column(
                                  children: [
                                    StatBoxMain(
                                      value: rpm.fixed(),
                                      label: 'RPM',
                                      dim: rpm.dim,
                                      isWarning: () => (rpm.number ?? 0) > 6000,
                                    ),
                                    StatBoxMain(
                                      value: speed.fixed(),
                                      unit: 'km/h',
                                      label: 'GNSS SPEED',
                                      dim: speed.dim,
                                    ),
                                  ],
                                ),
                              ),
                            ],
                          ),
                        ),
                        // Bottom row: smaller readouts and telltales.
                        Expanded(
                          flex: 2,
                          child: Row(
                            children: [
                              StatBox(
                                value: pedal.fixed(),
                                unit: '%',
                                label: 'PEDAL',
                                dim: pedal.dim,
                              ),
                              StatBox(
                                value: coolant.fixed(),
                                unit: '°C',
                                label: 'COOLANT',
                                dim: coolant.dim,
                                isWarning: () => (coolant.number ?? 0) > 105,
                              ),
                              Expanded(
                                child: GpsCompass(
                                  heading: r('gnss_heading_deg').number,
                                  gpsState: gpsState,
                                ),
                              ),
                              Telltale(
                                label: 'LEFT',
                                icon: Icons.arrow_left,
                                reading: r('indicator_left'),
                              ),
                              Telltale(
                                label: 'RIGHT',
                                icon: Icons.arrow_right,
                                reading: r('indicator_right'),
                              ),
                              Telltale(
                                label: 'BRAKE',
                                reading: r('brake_pedal'),
                              ),
                              Telltale(
                                label: 'PARK',
                                reading: r('handbrake'),
                                warn: true,
                              ),
                              Telltale(
                                label: 'LIGHTS',
                                reading: r('side_lights'),
                              ),
                              Telltale(
                                label: 'DOOR',
                                reading: r('door_open'),
                                warn: true,
                              ),
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
              ],
            ),
          ),
        );
      },
    );
  }
}

/// The dash's own thin top line: the menu, link state, and the dark/bright switch.
class _DashBar extends StatelessWidget {
  const _DashBar({required this.boundary, required this.themes});
  final Boundary boundary;
  final Themes themes;

  @override
  Widget build(BuildContext context) {
    final p = AppTheme.of(context);
    final (text, color) = switch (boundary.state) {
      LinkState.up => ('LINK', p.subdued),
      LinkState.connecting => ('CONNECTING', p.caution),
      LinkState.down => ('NO LINK', p.alarm),
    };
    return SizedBox(
      height: 40,
      child: Row(
        children: [
          MenuButton(color: p.subdued),
          Text(text, style: TextStyle(color: color, letterSpacing: 2)),
          const Spacer(),
          IconButton(
            tooltip: themes.isDark ? 'Bright' : 'Dark',
            onPressed: themes.toggle,
            icon: Icon(
              themes.isDark ? Icons.light_mode : Icons.dark_mode,
              color: p.subdued,
            ),
          ),
        ],
      ),
    );
  }
}