import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../services/compass_service.dart';
import '../rides/ride_state_machine.dart';
import '../../models/telemetry_sample.dart';
import '../../services/telemetry_service.dart';
import '../../services/telemetry_service.dart';
import 'dashboard_config.dart';
import 'widgets/g_force_visualizer.dart';
import 'widgets/lean_visualizer.dart';

class DashboardScreen extends ConsumerWidget {
  const DashboardScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final telemetryAsync = ref.watch(telemetryStreamProvider);
    final rideSession = ref.watch(rideStateMachineProvider);
    final layoutMode = ref.watch(dashboardConfigProvider);

    TelemetrySample? telemetry = telemetryAsync.value;
    double currentSpeedMph = telemetry?.speed ?? 0.0;
    double heading = telemetry?.heading ?? 0.0;
    double leanAngle = telemetry?.leanAngle ?? 0.0;
    double accelG = telemetry?.longitudinalG ?? 0.0;
    double lateralG = telemetry?.lateralG ?? 0.0;

    return Theme(
      data: ThemeData.dark().copyWith(
        scaffoldBackgroundColor: Colors.black,
        colorScheme: const ColorScheme.dark(
          primary: Colors.cyanAccent,
          secondary: Colors.amberAccent,
          surface: Color(0xFF111111),
        ),
      ),
      child: Scaffold(
        body: SafeArea(
          child: LayoutBuilder(
            builder: (context, constraints) {
              final isLandscape = constraints.maxWidth > constraints.maxHeight;
              
              if (layoutMode == DashboardLayout.minimal) {
                return _buildMinimalLayout(context, currentSpeedMph, session: rideSession, ref: ref);
              }
              if (layoutMode == DashboardLayout.touring) {
                return _buildTouringLayout(context, currentSpeedMph, heading, rideSession, ref);
              }
              
              if (isLandscape) {
                return _buildLandscapeLayout(context, currentSpeedMph, heading, leanAngle, accelG, lateralG, rideSession, ref);
              }
              return _buildPortraitLayout(context, currentSpeedMph, heading, leanAngle, accelG, lateralG, rideSession, ref);
            },
          ),
        ),
      ),
    );
  }

  Widget _buildPortraitLayout(BuildContext context, double speed, double heading, double lean, double accelG, double lateralG, RideSession session, WidgetRef ref) {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _buildTopBar(context, heading, session, ref),
          const Spacer(flex: 1),
          _buildCenterSpeedometer(context, speed),
          const Spacer(flex: 1),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Expanded(child: GForceVisualizer(accelG: accelG, lateralG: lateralG, session: session)),
              Expanded(child: LeanVisualizer(lean: lean, session: session)),
            ],
          ),
          const SizedBox(height: 24),
          _buildTripStatsStrip(context, session),
          const SizedBox(height: 24),
          _buildActionButtons(context, session),
        ],
      ),
    );
  }

  Widget _buildLandscapeLayout(BuildContext context, double speed, double heading, double lean, double accelG, double lateralG, RideSession session, WidgetRef ref) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 24.0, vertical: 12.0),
      child: Row(
        children: [
          // Left Wing
          Expanded(
            flex: 2,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                GForceVisualizer(accelG: accelG, lateralG: lateralG, session: session),
                const SizedBox(height: 16),
                _buildTripStatsStrip(context, session, isVertical: true),
              ],
            ),
          ),
          // Center
          Expanded(
            flex: 3,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                _buildTopBar(context, heading, session, ref),
                _buildCenterSpeedometer(context, speed),
                _buildActionButtons(context, session),
              ],
            ),
          ),
          // Right Wing
          Expanded(
            flex: 2,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                LeanVisualizer(lean: lean, session: session),
                const SizedBox(height: 16),
                _buildDataBox(context, 'STATUS', session.state.name.toUpperCase()),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildTopBar(BuildContext context, double heading, RideSession session, WidgetRef ref) {
    final headingStr = CompassService.getHeadingString(heading);
    
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Row(
          children: [
            _buildLayoutSwitcher(ref),
            const SizedBox(width: 8),
            Text(
              headingStr, 
              style: const TextStyle(fontSize: 28, fontWeight: FontWeight.w900, color: Colors.cyanAccent),
            ),
            const SizedBox(width: 8),
            Text(
              '${heading.toStringAsFixed(0)}°', 
              style: const TextStyle(fontSize: 18, color: Colors.white70),
            ),
          ],
        ),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
          decoration: BoxDecoration(
            color: session.state == RideState.riding ? Colors.red.withValues(alpha: 0.2) : Colors.white10,
            borderRadius: BorderRadius.circular(16),
            border: Border.all(
              color: session.state == RideState.riding ? Colors.redAccent : Colors.white30,
            ),
          ),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              if (session.state == RideState.riding)
                const Padding(
                  padding: EdgeInsets.only(right: 6.0),
                  child: Icon(Icons.circle, color: Colors.redAccent, size: 12),
                ),
              Text(
                session.state == RideState.riding ? 'REC' : session.state.name.toUpperCase(),
                style: TextStyle(
                  fontWeight: FontWeight.bold,
                  letterSpacing: 1.2,
                  color: session.state == RideState.riding ? Colors.redAccent : Colors.white,
                ),
              ),
            ],
          ),
        ),
      ],
    );
  }

  Widget _buildCenterSpeedometer(BuildContext context, double speed) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Text(
          speed.toStringAsFixed(0),
          style: const TextStyle(
            fontSize: 140,
            height: 1.0,
            fontWeight: FontWeight.w900,
            fontFamily: 'Roboto', // Ideally a monospaced/numeric font
            color: Colors.white,
          ),
        ),
        const Text(
          'MPH',
          style: TextStyle(
            fontSize: 24,
            fontWeight: FontWeight.w700,
            letterSpacing: 4.0,
            color: Colors.cyanAccent,
          ),
        ),
      ],
    );
  }

  Widget _buildTripStatsStrip(BuildContext context, RideSession session, {bool isVertical = false}) {
    final children = [
      _buildDataBox(context, 'TRIP', '${session.tripDistanceMiles.toStringAsFixed(2)} MI'),
      _buildDataBox(context, 'TOP SPEED', '${session.topSpeedMph.toStringAsFixed(0)} MPH'),
      _buildDataBox(context, 'AVG SPEED', '${session.averageSpeedMph.toStringAsFixed(1)} MPH'),
    ];

    if (isVertical) {
      return Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: children.map((c) => Padding(padding: const EdgeInsets.only(bottom: 12), child: c)).toList(),
      );
    }

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: children,
    );
  }

  Widget _buildDataBox(BuildContext context, String label, String value) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(label, style: const TextStyle(color: Colors.white54, fontSize: 11, letterSpacing: 1.5)),
        const SizedBox(height: 2),
        Text(value, style: const TextStyle(color: Colors.white, fontSize: 20, fontWeight: FontWeight.w600)),
      ],
    );
  }
  
  Widget _buildActionButtons(BuildContext context, RideSession session) {
    return Consumer(
      builder: (context, ref, child) {
        final notifier = ref.read(rideStateMachineProvider.notifier);
        
        if (session.state == RideState.idle || session.state == RideState.finished) {
          return SizedBox(
            width: double.infinity,
            height: 60,
            child: ElevatedButton(
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.cyanAccent.withValues(alpha: 0.1),
                foregroundColor: Colors.cyanAccent,
                side: const BorderSide(color: Colors.cyanAccent, width: 2),
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
              ),
              onPressed: () => notifier.startRide(),
              child: const Text('START SESSION', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, letterSpacing: 2)),
            ),
          );
        } else if (session.state == RideState.riding) {
           return SizedBox(
            width: double.infinity,
            height: 60,
            child: ElevatedButton(
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.redAccent.withValues(alpha: 0.1),
                foregroundColor: Colors.redAccent,
                side: const BorderSide(color: Colors.redAccent, width: 2),
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
              ),
              onPressed: () => notifier.finishRide(),
              child: const Text('END SESSION', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, letterSpacing: 2)),
            ),
          );
        }
        return const SizedBox(height: 60);
      },
    );
  }

  Widget _buildLayoutSwitcher(WidgetRef ref) {
    return PopupMenuButton<DashboardLayout>(
      icon: const Icon(Icons.dashboard_customize, color: Colors.cyanAccent),
      onSelected: (layout) {
        ref.read(dashboardConfigProvider.notifier).setLayout(layout);
      },
      itemBuilder: (context) => [
        const PopupMenuItem(value: DashboardLayout.sport, child: Text('Sport Layout')),
        const PopupMenuItem(value: DashboardLayout.touring, child: Text('Touring Layout')),
        const PopupMenuItem(value: DashboardLayout.minimal, child: Text('Minimal Layout')),
      ],
    );
  }

  Widget _buildMinimalLayout(BuildContext context, double speed, {required RideSession session, required WidgetRef ref}) {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: Column(
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
               _buildLayoutSwitcher(ref),
               _buildDataBox(context, 'STATUS', session.state.name.toUpperCase()),
            ],
          ),
          const Spacer(),
          Text(
            speed.toStringAsFixed(0),
            style: const TextStyle(fontSize: 200, fontWeight: FontWeight.w900, height: 1.0, color: Colors.white),
          ),
          const Text('MPH', style: TextStyle(fontSize: 40, fontWeight: FontWeight.w700, color: Colors.cyanAccent)),
          const Spacer(),
          _buildActionButtons(context, session),
        ],
      ),
    );
  }

  Widget _buildTouringLayout(BuildContext context, double speed, double heading, RideSession session, WidgetRef ref) {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: Column(
        children: [
          _buildTopBar(context, heading, session, ref),
          const Spacer(),
          _buildCenterSpeedometer(context, speed),
          const Spacer(),
          Container(
            padding: const EdgeInsets.all(16),
            decoration: BoxDecoration(color: Colors.white10, borderRadius: BorderRadius.circular(16)),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                _buildDataBox(context, 'TRIP (MI)', session.tripDistanceMiles.toStringAsFixed(1)),
                _buildDataBox(context, 'AVG (MPH)', session.averageSpeedMph.toStringAsFixed(1)),
                _buildDataBox(context, 'ELEV (M)', session.elevationGain.toStringAsFixed(0)),
                _buildDataBox(context, 'MOVING', '${(session.movingTimeSeconds / 60).floor()}m'),
              ],
            ),
          ),
          const SizedBox(height: 24),
          _buildActionButtons(context, session),
        ],
      ),
    );
  }
}