import 'package:flutter/material.dart';
import 'package:notas/data/local_vault_service.dart';
import 'package:notas/widgets/search_app_bar.dart';
import 'package:notas/data/api_client.dart';

class SettingsScreen extends StatefulWidget {
  const SettingsScreen({
    super.key,
    required this.onDeleteAllData,
    required this.onBackToHome,
    required this.onForceSync,
  });

  final Future<void> Function() onDeleteAllData;
  final VoidCallback onBackToHome;
  final Future<void> Function() onForceSync;

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  bool _isBusy = false;
  bool _isSyncing = false;
  final TextEditingController _endpointController = TextEditingController();
  final TextEditingController _encryptionKeyController = TextEditingController();
  bool _endpointLoading = true;
  bool _encryptionKeyLoading = false;
  bool _encryptionKeyVisible = false;

  Future<void> _confirmAndDeleteAll() async {
    final bool? confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Borrar todos los datos'),
        content: const Text('¿Estás seguro? Esta acción eliminará la base de datos local y la clave de cifrado. Asegúrate de tener una copia de seguridad si es necesario o cuenta sincronizada.'),
        actions: [
          TextButton(onPressed: () => Navigator.of(context).pop(false), child: const Text('Cancelar')),
          TextButton(onPressed: () => Navigator.of(context).pop(true), child: const Text('Borrar', style: TextStyle(color: Colors.red))),
        ],
      ),
    );

    if (confirmed != true) return;

    setState(() {
      _isBusy = true;
    });

    try {
      await widget.onDeleteAllData();

      if (!mounted) return;

      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Todos los datos locales han sido eliminados.')),
      );
    } catch (error) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error al borrar los datos: $error')),
      );
    } finally {
      if (!mounted) return;
      setState(() {
        _isBusy = false;
      });
    }
  }

  Future<void> _forceSync() async {
    if (_isBusy || _isSyncing) {
      return;
    }

    setState(() {
      _isSyncing = true;
    });

    try {
      await widget.onForceSync();

      if (!mounted) return;

      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Sincronización forzada completada.')),
      );
    } catch (error) {
      if (!mounted) return;

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error al forzar la sincronización: $error')),
      );
    } finally {
      if (!mounted) return;

      setState(() {
        _isSyncing = false;
      });
    }
  }

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

  Future<void> _loadEndpoint() async {
    final String endpoint = await ApiConfig.getEndpoint();
    if (!mounted) return;
    _endpointController.text = endpoint;
    setState(() {
      _endpointLoading = false;
    });
  }

  Future<void> _loadEncryptionKey() async {
    setState(() {
      _encryptionKeyLoading = true;
    });

    try {
      final String? encryptionKey = await LocalVaultService.instance.readEncryptionKey();

      if (!mounted) return;

      if (encryptionKey == null || encryptionKey.isEmpty) {
        _encryptionKeyController.text = '';
        _encryptionKeyVisible = false;
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('No se pudo leer la clave de cifrado.')),
        );
        return;
      }

      _encryptionKeyController.text = encryptionKey;
      _encryptionKeyVisible = true;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Clave de cifrado mostrada.')),
      );
    } catch (error) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error al leer la clave de cifrado: $error')),
      );
    } finally {
      if (mounted) {
        setState(() {
          _encryptionKeyLoading = false;
        });
      }
    }
  }

  void _hideEncryptionKey() {
    setState(() {
      _encryptionKeyVisible = false;
      _encryptionKeyController.clear();
    });
  }

  @override
  void dispose() {
    _endpointController.dispose();
    _encryptionKeyController.dispose();
    super.dispose();
  }

  Future<void> _saveEndpoint() async {
    final String value = _endpointController.text.trim();
    try {
      await ApiConfig.setEndpoint(value);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Endpoint guardado')));
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error guardando endpoint: $e')));
    }
  }

  Future<void> _resetEndpoint() async {
    await ApiConfig.clearEndpoint();
    final String endpoint = await ApiConfig.getEndpoint();
    if (!mounted) return;
    _endpointController.text = endpoint;
    ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Endpoint restaurado al valor por defecto')));
  }

  Widget _buildResponsiveInputActionsRow({
    required Widget input,
    required List<Widget> actions,
  }) {
    return LayoutBuilder(
      builder: (context, constraints) {
        final bool isCompact = constraints.maxWidth < 600;

        if (isCompact) {
          return Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              SizedBox(width: double.infinity, child: input),
              const SizedBox(height: 8),
              Align(
                alignment: Alignment.centerRight,
                child: Wrap(
                  alignment: WrapAlignment.end,
                  spacing: 8,
                  runSpacing: 8,
                  children: actions,
                ),
              ),
            ],
          );
        }

        return Row(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Expanded(child: input),
            const SizedBox(width: 8),
            Center(
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  for (int index = 0; index < actions.length; index++) ...[
                    if (index > 0) const SizedBox(width: 8),
                    actions[index],
                  ],
                ],
              ),
            ),
          ],
        );
      },
    );
  }

  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            colors: [
              Color(0xFF191A1D),
              Color(0xFF222326),
              Color(0xFF101114),
            ],
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
          ),
        ),
        child: SafeArea(
          child: Column(
            children: [
              SearchAppBar(
                onLeadingPressed: widget.onBackToHome,
                leadingIcon: Icons.arrow_back,
                leadingTooltip: 'Atrás',
                showSearch: false,
                titleText: 'Configuración',
              ),
              Expanded(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        children: [
                          const Expanded(
                            child: Text('Borrar datos locales:'),
                          ),
                          ElevatedButton.icon(
                            style: ElevatedButton.styleFrom(
                              backgroundColor: Colors.redAccent,
                              foregroundColor: Colors.white,
                              textStyle: const TextStyle(fontWeight: FontWeight.w600),
                            ),
                            onPressed: _isBusy ? null : _confirmAndDeleteAll,
                            icon: _isBusy
                                ? const SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(strokeWidth: 2),
                                  )
                                : const Icon(Icons.delete_forever),
                            label: const Text('Borrar'),
                          ),
                        ],
                      ),
                      const SizedBox(height: 16),
                      Row(
                        children: [
                          const Expanded(
                            child: Text('Forzar sincronizacion total:'),
                          ),
                          ElevatedButton.icon(
                            style: ElevatedButton.styleFrom(
                              backgroundColor: Colors.amber,
                              foregroundColor: Colors.black,
                              textStyle: const TextStyle(fontWeight: FontWeight.w700),
                            ),
                            onPressed: (_isBusy || _isSyncing) ? null : _forceSync,
                            icon: _isSyncing
                                ? const SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(strokeWidth: 2),
                                  )
                                : const Icon(Icons.sync),
                            label: const Text('Sincronizar'),
                          ),
                        ],
                      ),
                      const SizedBox(height: 24),
                      const Text('API endpoint (ej: http://localhost:3000/api)'),
                      const SizedBox(height: 8),
                      _buildResponsiveInputActionsRow(
                        input: _endpointLoading
                            ? const SizedBox(height: 48, child: Center(child: CircularProgressIndicator()))
                            : TextField(
                                controller: _endpointController,
                                style: const TextStyle(color: Colors.white),
                                keyboardType: TextInputType.url,
                                decoration: InputDecoration(
                                  labelText: 'API endpoint',
                                  labelStyle: TextStyle(color: Colors.white.withValues(alpha: 0.7)),
                                  filled: true,
                                  fillColor: Colors.white.withValues(alpha: 0.05),
                                  border: OutlineInputBorder(
                                    borderRadius: BorderRadius.circular(14),
                                    borderSide: BorderSide(color: Colors.white.withValues(alpha: 0.12)),
                                  ),
                                  enabledBorder: OutlineInputBorder(
                                    borderRadius: BorderRadius.circular(14),
                                    borderSide: BorderSide(color: Colors.white.withValues(alpha: 0.12)),
                                  ),
                                  focusedBorder: OutlineInputBorder(
                                    borderRadius: BorderRadius.circular(14),
                                    borderSide: const BorderSide(color: Colors.amber, width: 1.2),
                                  ),
                                ),
                              ),
                        actions: [
                          ElevatedButton(
                            onPressed: _endpointLoading ? null : _saveEndpoint,
                            child: const Text('Guardar'),
                          ),
                          OutlinedButton(
                            onPressed: _endpointLoading ? null : _resetEndpoint,
                            child: const Text('Restaurar'),
                          ),
                        ],
                      ),
                      const SizedBox(height: 24),
                      const Text('Clave de cifrado local'),
                      const SizedBox(height: 8),
                      _buildResponsiveInputActionsRow(
                        input: TextField(
                          controller: _encryptionKeyController,
                          readOnly: true,
                          obscureText: !_encryptionKeyVisible,
                          enableSuggestions: false,
                          autocorrect: false,
                          style: const TextStyle(color: Colors.white),
                          decoration: InputDecoration(
                            labelText: _encryptionKeyVisible ? 'Clave de cifrado' : 'Oculta hasta pulsar mostrar',
                            labelStyle: TextStyle(color: Colors.white.withValues(alpha: 0.7)),
                            filled: true,
                            fillColor: Colors.white.withValues(alpha: 0.05),
                            border: OutlineInputBorder(
                              borderRadius: BorderRadius.circular(14),
                              borderSide: BorderSide(color: Colors.white.withValues(alpha: 0.12)),
                            ),
                            enabledBorder: OutlineInputBorder(
                              borderRadius: BorderRadius.circular(14),
                              borderSide: BorderSide(color: Colors.white.withValues(alpha: 0.12)),
                            ),
                            focusedBorder: OutlineInputBorder(
                              borderRadius: BorderRadius.circular(14),
                              borderSide: const BorderSide(color: Colors.amber, width: 1.2),
                            ),
                          ),
                        ),
                        actions: [
                          ElevatedButton(
                            onPressed: _encryptionKeyLoading ? null : _loadEncryptionKey,
                            child: _encryptionKeyLoading
                                ? const SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(strokeWidth: 2),
                                  )
                                : const Text('Mostrar'),
                          ),
                          OutlinedButton(
                            onPressed: _encryptionKeyVisible ? _hideEncryptionKey : null,
                            child: const Text('Ocultar'),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}