import 'package:enter_farma_plus_mobile/src/core/printing/bluetooth_print_service.dart';
import 'package:enter_farma_plus_mobile/src/core/storage/tenant_session_store.dart';
import 'package:enter_farma_plus_mobile/src/core/theme/app_tokens.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:print_bluetooth_thermal/print_bluetooth_thermal.dart';

/// Storage key for the saved printer MAC address.
const _printerMacKey = 'printer_mac';

/// Storage key for the saved printer display name.
const _printerNameKey = 'printer_name';

/// Shows the printer settings as a modal bottom sheet.
///
/// Usage:
/// ```dart
/// showPrinterSettings(context, ref);
/// ```
Future<void> showPrinterSettings(BuildContext context, WidgetRef ref) {
  return showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    builder: (_) => const _PrinterSettingsSheet(),
  );
}

// ---------------------------------------------------------------------------
// Sheet widget
// ---------------------------------------------------------------------------

class _PrinterSettingsSheet extends ConsumerStatefulWidget {
  const _PrinterSettingsSheet();

  @override
  ConsumerState<_PrinterSettingsSheet> createState() =>
      _PrinterSettingsSheetState();
}

class _PrinterSettingsSheetState extends ConsumerState<_PrinterSettingsSheet> {
  List<BluetoothInfo>? _devices;
  bool _scanning = false;
  bool _connecting = false;
  bool _printing = false;
  String? _connectedMac;
  String? _connectedName;
  String? _error;

  @override
  void initState() {
    super.initState();
    _loadSaved();
  }

  // ---------------------------------------------------------------------------
  // Persistence helpers
  // ---------------------------------------------------------------------------

  Future<void> _loadSaved() async {
    final storage = ref.read(secureStorageProvider);
    final mac = await storage.read(key: _printerMacKey);
    final name = await storage.read(key: _printerNameKey);

    if (mac != null && mac.isNotEmpty) {
      final printService = ref.read(bluetoothPrintServiceProvider);
      final live = await printService.refreshConnectionStatus();

      if (mounted) {
        setState(() {
          _connectedMac = mac;
          _connectedName = name;
          if (!live) {
            // Stored but not currently connected -- clear status indicator.
            _connectedMac = mac;
          }
        });
      }
    }
  }

  Future<void> _savePrinter(String mac, String name) async {
    final storage = ref.read(secureStorageProvider);
    await storage.write(key: _printerMacKey, value: mac);
    await storage.write(key: _printerNameKey, value: name);
  }

  Future<void> _clearPrinter() async {
    final storage = ref.read(secureStorageProvider);
    await storage.delete(key: _printerMacKey);
    await storage.delete(key: _printerNameKey);
  }

  // ---------------------------------------------------------------------------
  // Actions
  // ---------------------------------------------------------------------------

  Future<void> _scan() async {
    setState(() {
      _scanning = true;
      _error = null;
    });

    try {
      final printService = ref.read(bluetoothPrintServiceProvider);
      final devices = await printService.scanDevices();
      if (mounted) {
        setState(() {
          _devices = devices;
          _scanning = false;
          if (devices.isEmpty) {
            _error = 'No se encontraron dispositivos vinculados.\n'
                'Vincula la impresora desde los ajustes de Bluetooth del sistema.';
          }
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _scanning = false;
          _error = 'Error al buscar dispositivos: $e';
        });
      }
    }
  }

  Future<void> _connectTo(BluetoothInfo device) async {
    setState(() {
      _connecting = true;
      _error = null;
    });

    try {
      final printService = ref.read(bluetoothPrintServiceProvider);
      final ok = await printService.connect(device.macAdress);

      if (!mounted) return;

      if (ok) {
        await _savePrinter(device.macAdress, device.name);
        setState(() {
          _connectedMac = device.macAdress;
          _connectedName = device.name;
          _connecting = false;
        });
      } else {
        setState(() {
          _connecting = false;
          _error = 'No se pudo conectar a ${device.name}.';
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _connecting = false;
          _error = 'Error al conectar: $e';
        });
      }
    }
  }

  Future<void> _disconnect() async {
    final printService = ref.read(bluetoothPrintServiceProvider);
    await printService.disconnect();
    await _clearPrinter();

    if (mounted) {
      setState(() {
        _connectedMac = null;
        _connectedName = null;
      });
    }
  }

  Future<void> _testPrint() async {
    setState(() {
      _printing = true;
      _error = null;
    });

    try {
      final printService = ref.read(bluetoothPrintServiceProvider);
      await printService.printTest();

      if (mounted) {
        setState(() => _printing = false);
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Impresión de prueba enviada.')),
        );
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _printing = false;
          _error = 'Error al imprimir: $e';
        });
      }
    }
  }

  // ---------------------------------------------------------------------------
  // Build
  // ---------------------------------------------------------------------------

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final hasConnection = _connectedMac != null && _connectedMac!.isNotEmpty;

    return SafeArea(
      child: SingleChildScrollView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 24),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Drag handle
            Center(
              child: Container(
                width: 40,
                height: 4,
                margin: const EdgeInsets.only(bottom: 16),
                decoration: BoxDecoration(
                  color: AppTokens.border,
                  borderRadius: BorderRadius.circular(2),
                ),
              ),
            ),

            // Title row
            Row(
              children: [
                CircleAvatar(
                  backgroundColor: AppTokens.cta.withValues(alpha:0.12),
                  foregroundColor: AppTokens.cta,
                  child: const Icon(Icons.print_rounded),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'Impresora Bluetooth',
                        style: theme.textTheme.headlineSmall,
                      ),
                      const SizedBox(height: 4),
                      Text(
                        hasConnection
                            ? 'Conectada: ${_connectedName ?? _connectedMac}'
                            : 'Sin impresora conectada',
                        style: theme.textTheme.bodyMedium?.copyWith(
                          color: hasConnection
                              ? AppTokens.success
                              : AppTokens.secondary,
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 20),

            // Error banner
            if (_error != null) ...[
              Container(
                width: double.infinity,
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: AppTokens.danger.withValues(alpha:0.08),
                  borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
                  border: Border.all(color: AppTokens.danger.withValues(alpha:0.3)),
                ),
                child: Text(
                  _error!,
                  style: theme.textTheme.bodyMedium?.copyWith(
                    color: AppTokens.danger,
                  ),
                ),
              ),
              const SizedBox(height: 16),
            ],

            // Connected printer card
            if (hasConnection) ...[
              Card(
                margin: EdgeInsets.zero,
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Row(
                    children: [
                      const Icon(
                        Icons.bluetooth_connected_rounded,
                        color: AppTokens.success,
                      ),
                      const SizedBox(width: 12),
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              _connectedName ?? 'Impresora',
                              style: theme.textTheme.titleMedium,
                            ),
                            const SizedBox(height: 2),
                            Text(
                              _connectedMac!,
                              style: theme.textTheme.bodySmall?.copyWith(
                                color: AppTokens.secondary,
                              ),
                            ),
                          ],
                        ),
                      ),
                      IconButton(
                        onPressed: _disconnect,
                        icon: const Icon(Icons.link_off_rounded),
                        tooltip: 'Desconectar',
                        color: AppTokens.danger,
                      ),
                    ],
                  ),
                ),
              ),
              const SizedBox(height: 12),
              SizedBox(
                width: double.infinity,
                child: OutlinedButton.icon(
                  onPressed: _printing ? null : _testPrint,
                  icon: _printing
                      ? const SizedBox(
                          width: 16,
                          height: 16,
                          child: CircularProgressIndicator(strokeWidth: 2),
                        )
                      : const Icon(Icons.receipt_long_rounded),
                  label: Text(_printing ? 'Imprimiendo...' : 'Imprimir prueba'),
                ),
              ),
              const SizedBox(height: 16),
              const Divider(),
              const SizedBox(height: 12),
            ],

            // Scan button
            SizedBox(
              width: double.infinity,
              child: FilledButton.icon(
                onPressed: _scanning ? null : _scan,
                icon: _scanning
                    ? const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: Colors.white,
                        ),
                      )
                    : const Icon(Icons.bluetooth_searching_rounded),
                label: Text(
                  _scanning ? 'Buscando...' : 'Buscar dispositivos',
                ),
              ),
            ),
            const SizedBox(height: 16),

            // Device list
            if (_devices != null && _devices!.isNotEmpty) ...[
              Text(
                'Dispositivos vinculados',
                style: theme.textTheme.titleMedium,
              ),
              const SizedBox(height: 8),
              ...List.generate(_devices!.length, (i) {
                final device = _devices![i];
                final isCurrentlyConnected =
                    device.macAdress == _connectedMac;

                return Card(
                  margin: const EdgeInsets.only(bottom: 8),
                  child: ListTile(
                    leading: Icon(
                      isCurrentlyConnected
                          ? Icons.bluetooth_connected_rounded
                          : Icons.bluetooth_rounded,
                      color: isCurrentlyConnected
                          ? AppTokens.success
                          : AppTokens.secondary,
                    ),
                    title: Text(device.name),
                    subtitle: Text(
                      device.macAdress,
                      style: theme.textTheme.bodySmall?.copyWith(
                        color: AppTokens.secondary,
                      ),
                    ),
                    trailing: isCurrentlyConnected
                        ? Chip(
                            label: const Text('Conectada'),
                            backgroundColor:
                                AppTokens.success.withValues(alpha:0.12),
                            labelStyle: const TextStyle(
                              color: AppTokens.success,
                              fontSize: 12,
                            ),
                          )
                        : _connecting
                            ? const SizedBox(
                                width: 20,
                                height: 20,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                ),
                              )
                            : const Icon(
                                Icons.arrow_forward_ios_rounded,
                                size: 16,
                                color: AppTokens.secondary,
                              ),
                    onTap: (isCurrentlyConnected || _connecting)
                        ? null
                        : () => _connectTo(device),
                  ),
                );
              }),
            ],
          ],
        ),
      ),
    );
  }
}