import 'package:abawo_bt_app/controller/bluetooth.dart';
import 'package:abawo_bt_app/controller/shifter_device_telemetry.dart';
import 'package:abawo_bt_app/database/database.dart';
import 'package:abawo_bt_app/model/bluetooth_device_model.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

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

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final devicesAsync = ref.watch(nConnectedDevicesProvider);
    final connectionData = ref.watch(connectionStatusProvider).valueOrNull;

    return ListView(
      padding: const EdgeInsets.fromLTRB(20, 16, 20, 24),
      children: [
        Row(
          children: [
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'Devices',
                    style: Theme.of(context).textTheme.headlineMedium?.copyWith(
                          fontWeight: FontWeight.w700,
                        ),
                  ),
                  const SizedBox(height: 6),
                  Text(
                    'Manage connected hardware and jump back into setup.',
                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                          color: Theme.of(context)
                              .colorScheme
                              .onSurface
                              .withValues(alpha: 0.68),
                        ),
                  ),
                ],
              ),
            ),
            IconButton.filledTonal(
              tooltip: 'Connect a device',
              onPressed: () => context.push('/connect_device'),
              icon: const Icon(Icons.add),
            ),
          ],
        ),
        const SizedBox(height: 20),
        devicesAsync.when(
          loading: () => const _LoadingCard(),
          error: (error, _) => _MessageCard(
            title: 'Could not load devices',
            message: error.toString(),
          ),
          data: (devices) => _ActiveDeviceCard(
            devices: devices,
            connectionData: connectionData,
          ),
        ),
        const SizedBox(height: 20),
        Row(
          children: [
            Expanded(
              child: Text(
                'My Devices',
                style: Theme.of(context).textTheme.titleLarge?.copyWith(
                      fontWeight: FontWeight.w700,
                    ),
              ),
            ),
            TextButton.icon(
              onPressed: () => context.push('/connect_device'),
              icon: const Icon(Icons.add_circle_outline),
              label: const Text('Add Device'),
            ),
          ],
        ),
        const SizedBox(height: 10),
        const _SavedDevicesList(),
      ],
    );
  }
}

class _SavedDevicesList extends ConsumerStatefulWidget {
  const _SavedDevicesList();

  @override
  ConsumerState<_SavedDevicesList> createState() => _SavedDevicesListState();
}

class _SavedDevicesListState extends ConsumerState<_SavedDevicesList> {
  String? _connectingDeviceId;

  Future<void> _removeDevice(ConnectedDevice device) async {
    final shouldRemove = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('Remove device?'),
        content:
            Text('Do you want to remove ${device.deviceName} from the app?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(false),
            child: const Text('Cancel'),
          ),
          FilledButton(
            onPressed: () => Navigator.of(dialogContext).pop(true),
            child: const Text('Remove'),
          ),
        ],
      ),
    );

    if (shouldRemove != true || !mounted) {
      return;
    }

    final result = await ref
        .read(nConnectedDevicesProvider.notifier)
        .deleteConnectedDevice(device.id);

    if (!mounted) {
      return;
    }

    if (result.isErr()) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('Failed to remove device: ${result.unwrapErr()}'),
        ),
      );
      return;
    }

    if (_connectingDeviceId == device.deviceAddress) {
      setState(() {
        _connectingDeviceId = null;
      });
    }

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text('${device.deviceName} removed from the app.')),
    );
  }

  Future<void> _openDevice(ConnectedDevice device) async {
    if (_connectingDeviceId != null) {
      return;
    }

    setState(() {
      _connectingDeviceId = device.deviceAddress;
    });

    try {
      final controller = await ref.read(bluetoothProvider.future);
      final result = await controller.connectById(
        device.deviceAddress,
        timeout: const Duration(seconds: 10),
      );

      if (!mounted) {
        return;
      }

      if (result.isOk()) {
        await ref
            .read(nConnectedDevicesProvider.notifier)
            .updateConnectedDeviceLastConnected(device.id);

        if (!mounted) {
          return;
        }

        context.push('/device/${device.deviceAddress}');
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text(
              'Connection failed. Is the device turned on and in range?',
            ),
            duration: Duration(seconds: 3),
          ),
        );
      }
    } catch (error) {
      if (!mounted) {
        return;
      }

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error: $error')),
      );
    } finally {
      if (mounted) {
        setState(() {
          _connectingDeviceId = null;
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final devicesAsync = ref.watch(nConnectedDevicesProvider);
    final connectionData = ref.watch(connectionStatusProvider).valueOrNull;
    final connectedDeviceId = connectionData?.$2;
    final connectionState = connectionData?.$1;

    return devicesAsync.when(
      loading: () => const _LoadingCard(),
      error: (error, _) => _MessageCard(
        title: 'Could not load saved devices',
        message: error.toString(),
      ),
      data: (devices) {
        if (devices.isEmpty) {
          return _MessageCard(
            title: 'No devices yet',
            message: 'Add your first shifter to start configuring it.',
            actionLabel: 'Connect Device',
            onAction: () => context.push('/connect_device'),
          );
        }

        return Column(
          children: [
            for (final device in devices) ...[
              _SavedDeviceTile(
                device: device,
                isConnecting: device.deviceAddress == _connectingDeviceId,
                isConnected: connectedDeviceId == device.deviceAddress &&
                    connectionState == ConnectionStatus.connected,
                onTap: () => _openDevice(device),
                onRemove: () => _removeDevice(device),
              ),
              if (device != devices.last) const SizedBox(height: 12),
            ],
            const SizedBox(height: 12),
            OutlinedButton.icon(
              onPressed: () => context.push('/connect_device'),
              icon: const Icon(Icons.bluetooth_searching),
              label: const Text('Connect Device'),
            ),
          ],
        );
      },
    );
  }
}

class _ActiveDeviceCard extends ConsumerWidget {
  const _ActiveDeviceCard({
    required this.devices,
    required this.connectionData,
  });

  final List<ConnectedDevice> devices;
  final (ConnectionStatus, String?)? connectionData;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final shifterDevices = devices
        .where(
          (device) =>
              deviceTypeFromString(device.deviceType) ==
              DeviceType.universalShifters,
        )
        .toList()
      ..sort((a, b) {
        final aLastConnected = a.lastConnectedAt ?? a.createdAt;
        final bLastConnected = b.lastConnectedAt ?? b.createdAt;
        return bLastConnected.compareTo(aLastConnected);
      });

    if (shifterDevices.isEmpty) {
      return const SizedBox.shrink();
    }

    final connectedId = connectionData?.$2;
    final primaryDevice = connectedId == null
        ? shifterDevices.first
        : shifterDevices.firstWhere(
            (device) => device.deviceAddress == connectedId,
            orElse: () => shifterDevices.first,
          );
    final isConnected = connectedId == primaryDevice.deviceAddress &&
        connectionData?.$1 == ConnectionStatus.connected;

    final telemetry = ref.watch(
      shifterDeviceTelemetryCacheProvider.select(
        (cache) => cache[primaryDevice.deviceAddress],
      ),
    );
    final batteryLabel = telemetry?.batteryLabel ?? '--';
    const signalLabel = 'Ready';
    final firmwareLabel = telemetry?.firmwareLabel ?? '--';

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(18),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                ClipRRect(
                  borderRadius: BorderRadius.circular(18),
                  child: Image.asset(
                    'assets/images/shifter-wireframe.png',
                    width: 96,
                    height: 72,
                    fit: BoxFit.cover,
                  ),
                ),
                const SizedBox(width: 16),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        primaryDevice.deviceName,
                        style: Theme.of(context).textTheme.titleLarge?.copyWith(
                              fontWeight: FontWeight.w700,
                            ),
                      ),
                      const SizedBox(height: 8),
                      _StatusChip(
                        label: isConnected ? 'Connected' : 'Saved device',
                        color: isConnected
                            ? const Color(0xFF40C979)
                            : Theme.of(context).colorScheme.primary,
                      ),
                      const SizedBox(height: 10),
                      Text(
                        primaryDevice.deviceAddress,
                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
                              color: Theme.of(context)
                                  .colorScheme
                                  .onSurface
                                  .withValues(alpha: 0.62),
                            ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 18),
            Row(
              children: [
                Expanded(
                  child: _MetricTile(
                    label: 'Battery',
                    value: batteryLabel,
                    icon: Icons.battery_charging_full_rounded,
                  ),
                ),
                const SizedBox(width: 10),
                const Expanded(
                  child: _MetricTile(
                    label: 'Signal',
                    value: signalLabel,
                    icon: Icons.signal_cellular_alt,
                  ),
                ),
                const SizedBox(width: 10),
                Expanded(
                  child: _MetricTile(
                    label: 'Firmware',
                    value: firmwareLabel,
                    icon: Icons.memory_rounded,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

class _SavedDeviceTile extends StatelessWidget {
  const _SavedDeviceTile({
    required this.device,
    required this.isConnecting,
    required this.isConnected,
    required this.onTap,
    required this.onRemove,
  });

  final ConnectedDevice device;
  final bool isConnecting;
  final bool isConnected;
  final VoidCallback onTap;
  final VoidCallback onRemove;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Material(
      color: colorScheme.surface,
      borderRadius: BorderRadius.circular(22),
      child: InkWell(
        borderRadius: BorderRadius.circular(22),
        onTap: isConnecting ? null : onTap,
        child: Container(
          padding: const EdgeInsets.all(16),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(22),
            border: Border.all(
              color: isConnected
                  ? colorScheme.primary.withValues(alpha: 0.65)
                  : colorScheme.outlineVariant.withValues(alpha: 0.55),
            ),
          ),
          child: Row(
            children: [
              Container(
                width: 48,
                height: 48,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: isConnected
                      ? colorScheme.primary.withValues(alpha: 0.14)
                      : colorScheme.surfaceContainerHighest
                          .withValues(alpha: 0.7),
                ),
                child: Icon(
                  deviceTypeFromString(device.deviceType) ==
                          DeviceType.universalShifters
                      ? Icons.bluetooth_rounded
                      : Icons.memory_rounded,
                  color:
                      isConnected ? colorScheme.primary : colorScheme.onSurface,
                ),
              ),
              const SizedBox(width: 14),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      device.deviceName,
                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
                            fontWeight: FontWeight.w700,
                          ),
                    ),
                    const SizedBox(height: 4),
                    Text(
                      isConnected ? 'Connected' : 'Saved device',
                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                            color: isConnected
                                ? const Color(0xFF40C979)
                                : colorScheme.primary,
                            fontWeight: FontWeight.w600,
                          ),
                    ),
                    const SizedBox(height: 4),
                    Text(
                      device.deviceAddress,
                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
                            color:
                                colorScheme.onSurface.withValues(alpha: 0.62),
                          ),
                    ),
                  ],
                ),
              ),
              if (isConnecting)
                const SizedBox(
                  width: 20,
                  height: 20,
                  child: CircularProgressIndicator(strokeWidth: 2.4),
                )
              else
                Row(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    IconButton(
                      tooltip: 'Remove device',
                      onPressed: onRemove,
                      icon: const Icon(Icons.delete_outline),
                    ),
                    Icon(
                      Icons.chevron_right_rounded,
                      color: colorScheme.onSurface.withValues(alpha: 0.55),
                    ),
                  ],
                ),
            ],
          ),
        ),
      ),
    );
  }
}

class _MetricTile extends StatelessWidget {
  const _MetricTile({
    required this.label,
    required this.value,
    required this.icon,
  });

  final String label;
  final String value;
  final IconData icon;

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
      decoration: BoxDecoration(
        color: colorScheme.surfaceContainerHighest.withValues(alpha: 0.54),
        borderRadius: BorderRadius.circular(16),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(icon, size: 18, color: colorScheme.primary),
          const SizedBox(height: 10),
          Text(
            label,
            style: Theme.of(context).textTheme.bodySmall?.copyWith(
                  color: colorScheme.onSurface.withValues(alpha: 0.62),
                ),
          ),
          const SizedBox(height: 2),
          Text(
            value,
            style: Theme.of(context).textTheme.titleMedium?.copyWith(
                  fontWeight: FontWeight.w700,
                ),
          ),
        ],
      ),
    );
  }
}

class _MessageCard extends StatelessWidget {
  const _MessageCard({
    required this.title,
    required this.message,
    this.actionLabel,
    this.onAction,
  });

  final String title;
  final String message;
  final String? actionLabel;
  final VoidCallback? onAction;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(18),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              title,
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                    fontWeight: FontWeight.w700,
                  ),
            ),
            const SizedBox(height: 8),
            Text(
              message,
              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                    color: Theme.of(context)
                        .colorScheme
                        .onSurface
                        .withValues(alpha: 0.68),
                  ),
            ),
            if (actionLabel != null && onAction != null) ...[
              const SizedBox(height: 14),
              FilledButton.icon(
                onPressed: onAction,
                icon: const Icon(Icons.add_circle_outline),
                label: Text(actionLabel!),
              ),
            ],
          ],
        ),
      ),
    );
  }
}

class _LoadingCard extends StatelessWidget {
  const _LoadingCard();

  @override
  Widget build(BuildContext context) {
    return const Card(
      child: Padding(
        padding: EdgeInsets.all(28),
        child: Center(child: CircularProgressIndicator()),
      ),
    );
  }
}

class _StatusChip extends StatelessWidget {
  const _StatusChip({
    required this.label,
    required this.color,
  });

  final String label;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.12),
        borderRadius: BorderRadius.circular(999),
        border: Border.all(color: color.withValues(alpha: 0.24)),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(Icons.check_circle_outline, size: 14, color: color),
          const SizedBox(width: 6),
          Text(
            label,
            style: Theme.of(context).textTheme.bodySmall?.copyWith(
                  color: color,
                  fontWeight: FontWeight.w700,
                ),
          ),
        ],
      ),
    );
  }
}