import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:p_tits_pas/models/relais_model.dart';
import 'package:p_tits_pas/models/user.dart';
import 'package:p_tits_pas/services/relais_service.dart';
import 'package:p_tits_pas/services/user_service.dart';

class AdminUserFormDialog extends StatefulWidget {
  final AppUser? initialUser;
  final bool withRelais;
  final bool adminMode;

  const AdminUserFormDialog({
    super.key,
    this.initialUser,
    this.withRelais = true,
    this.adminMode = false,
  });

  @override
  State<AdminUserFormDialog> createState() => _AdminUserFormDialogState();
}

class _AdminUserFormDialogState extends State<AdminUserFormDialog> {
  final _formKey = GlobalKey<FormState>();
  final _nomController = TextEditingController();
  final _prenomController = TextEditingController();
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();
  final _telephoneController = TextEditingController();
  final _passwordToggleFocusNode =
      FocusNode(skipTraversal: true, canRequestFocus: false);

  bool _isSubmitting = false;
  bool _obscurePassword = true;
  bool _isLoadingRelais = true;
  List<RelaisModel> _relais = [];
  String? _selectedRelaisId;
  bool get _isEditMode => widget.initialUser != null;

  @override
  void initState() {
    super.initState();
    final user = widget.initialUser;
    if (user != null) {
      _nomController.text = user.nom ?? '';
      _prenomController.text = user.prenom ?? '';
      _emailController.text = user.email;
      _telephoneController.text = _formatPhoneForDisplay(user.telephone ?? '');
      // En édition, on ne préremplit jamais le mot de passe.
      _passwordController.clear();
      final initialRelaisId = user.relaisId?.trim();
      _selectedRelaisId =
          (initialRelaisId == null || initialRelaisId.isEmpty)
              ? null
              : initialRelaisId;
    }
    if (widget.withRelais) {
      _loadRelais();
    } else {
      _isLoadingRelais = false;
    }
  }

  @override
  void dispose() {
    _nomController.dispose();
    _prenomController.dispose();
    _emailController.dispose();
    _passwordController.dispose();
    _telephoneController.dispose();
    _passwordToggleFocusNode.dispose();
    super.dispose();
  }

  Future<void> _loadRelais() async {
    try {
      final list = await RelaisService.getRelais();
      if (!mounted) return;
      final uniqueById = <String, RelaisModel>{};
      for (final relais in list) {
        uniqueById[relais.id] = relais;
      }

      final filtered = uniqueById.values.where((r) => r.actif).toList();
      if (_selectedRelaisId != null &&
          !filtered.any((r) => r.id == _selectedRelaisId)) {
        final selected = uniqueById[_selectedRelaisId!];
        if (selected != null) {
          filtered.add(selected);
        } else {
          _selectedRelaisId = null;
        }
      }

      setState(() {
        _relais = filtered;
        _isLoadingRelais = false;
      });
    } catch (_) {
      if (!mounted) return;
      setState(() {
        _selectedRelaisId = null;
        _relais = [];
        _isLoadingRelais = false;
      });
    }
  }

  String? _required(String? value, String field) {
    if (value == null || value.trim().isEmpty) {
      return '$field est requis';
    }
    return null;
  }

  String? _validateEmail(String? value) {
    final base = _required(value, 'Email');
    if (base != null) return base;
    final email = value!.trim();
    final ok = RegExp(r'^[^@]+@[^@]+\.[^@]+$').hasMatch(email);
    if (!ok) return 'Format email invalide';
    return null;
  }

  String? _validatePassword(String? value) {
    if (_isEditMode && (value == null || value.trim().isEmpty)) {
      return null;
    }
    final base = _required(value, 'Mot de passe');
    if (base != null) return base;
    if (value!.trim().length < 6) return 'Minimum 6 caractères';
    return null;
  }

  String? _validatePhone(String? value) {
    if (_isEditMode && (value == null || value.trim().isEmpty)) {
      return null;
    }
    final base = _required(value, 'Téléphone');
    if (base != null) return base;
    final digits = _normalizePhone(value!);
    if (digits.length != 10) {
      return 'Le téléphone doit contenir 10 chiffres';
    }
    if (!digits.startsWith('0')) {
      return 'Le téléphone doit commencer par 0';
    }
    return null;
  }

  String _normalizePhone(String raw) {
    return raw.replaceAll(RegExp(r'\D'), '');
  }

  String _formatPhoneForDisplay(String raw) {
    final normalized = _normalizePhone(raw);
    final digits =
        normalized.length > 10 ? normalized.substring(0, 10) : normalized;
    final buffer = StringBuffer();
    for (var i = 0; i < digits.length; i++) {
      if (i > 0 && i.isEven) buffer.write(' ');
      buffer.write(digits[i]);
    }
    return buffer.toString();
  }

  String _toTitleCase(String raw) {
    final trimmed = raw.trim();
    if (trimmed.isEmpty) return trimmed;
    final words = trimmed.split(RegExp(r'\s+'));
    final normalizedWords = words.map(_capitalizeComposedWord).toList();
    return normalizedWords.join(' ');
  }

  String _capitalizeComposedWord(String word) {
    if (word.isEmpty) return word;
    final lower = word.toLowerCase();
    final separators = <String>{"-", "'", "’"};
    final buffer = StringBuffer();
    var capitalizeNext = true;

    for (var i = 0; i < lower.length; i++) {
      final char = lower[i];
      if (capitalizeNext && RegExp(r'[a-zà-öø-ÿ]').hasMatch(char)) {
        buffer.write(char.toUpperCase());
        capitalizeNext = false;
      } else {
        buffer.write(char);
        capitalizeNext = separators.contains(char);
      }
    }
    return buffer.toString();
  }

  Future<void> _submit() async {
    if (_isSubmitting) return;
    if (!_formKey.currentState!.validate()) return;

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

    try {
      final normalizedNom = _toTitleCase(_nomController.text);
      final normalizedPrenom = _toTitleCase(_prenomController.text);
      final normalizedPhone = _normalizePhone(_telephoneController.text);
      final passwordProvided = _passwordController.text.trim().isNotEmpty;

      if (_isEditMode) {
        if (widget.adminMode) {
          await UserService.updateAdministrateur(
            adminId: widget.initialUser!.id,
            nom: normalizedNom,
            prenom: normalizedPrenom,
            email: _emailController.text.trim(),
            telephone: normalizedPhone.isEmpty
                ? _normalizePhone(widget.initialUser!.telephone ?? '')
                : normalizedPhone,
            password: passwordProvided ? _passwordController.text : null,
          );
        } else {
          final currentUser = widget.initialUser!;
          final initialNom = _toTitleCase(currentUser.nom ?? '');
          final initialPrenom = _toTitleCase(currentUser.prenom ?? '');
          final initialEmail = currentUser.email.trim();
          final initialPhone = _normalizePhone(currentUser.telephone ?? '');

          final onlyRelaisChanged =
              normalizedNom == initialNom &&
              normalizedPrenom == initialPrenom &&
              _emailController.text.trim() == initialEmail &&
              normalizedPhone == initialPhone &&
              !passwordProvided;

          if (onlyRelaisChanged) {
            await UserService.updateGestionnaireRelais(
              gestionnaireId: currentUser.id,
              relaisId: _selectedRelaisId,
            );
          } else {
            await UserService.updateGestionnaire(
              gestionnaireId: currentUser.id,
              nom: normalizedNom,
              prenom: normalizedPrenom,
              email: _emailController.text.trim(),
              telephone: normalizedPhone.isEmpty ? initialPhone : normalizedPhone,
              relaisId: _selectedRelaisId,
              password: passwordProvided ? _passwordController.text : null,
            );
          }
        }
      } else {
        if (widget.adminMode) {
          await UserService.createAdministrateur(
            nom: normalizedNom,
            prenom: normalizedPrenom,
            email: _emailController.text.trim(),
            password: _passwordController.text,
            telephone: _normalizePhone(_telephoneController.text),
          );
        } else {
          await UserService.createGestionnaire(
            nom: normalizedNom,
            prenom: normalizedPrenom,
            email: _emailController.text.trim(),
            password: _passwordController.text,
            telephone: _normalizePhone(_telephoneController.text),
            relaisId: _selectedRelaisId,
          );
        }
      }
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            _isEditMode
                ? (widget.adminMode
                    ? 'Administrateur modifié avec succès.'
                    : 'Gestionnaire modifié avec succès.')
                : (widget.adminMode
                    ? 'Administrateur créé avec succès.'
                    : 'Gestionnaire créé avec succès.'),
          ),
        ),
      );
      Navigator.of(context).pop(true);
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            e.toString().replaceFirst('Exception: ', ''),
          ),
          backgroundColor: Colors.red.shade700,
        ),
      );
    } finally {
      if (!mounted) return;
      setState(() {
        _isSubmitting = false;
      });
    }
  }

  Future<void> _delete() async {
    if (!_isEditMode || _isSubmitting) return;

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) {
        return AlertDialog(
          title: const Text('Confirmer la suppression'),
          content: Text(
            'Supprimer ${widget.initialUser!.fullName.isEmpty ? widget.initialUser!.email : widget.initialUser!.fullName} ?',
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(ctx).pop(false),
              child: const Text('Annuler'),
            ),
            FilledButton(
              onPressed: () => Navigator.of(ctx).pop(true),
              style: FilledButton.styleFrom(backgroundColor: Colors.red.shade700),
              child: const Text('Supprimer'),
            ),
          ],
        );
      },
    );

    if (confirmed != true) return;

    setState(() {
      _isSubmitting = true;
    });
    try {
      await UserService.deleteUser(widget.initialUser!.id);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Gestionnaire supprimé.')),
      );
      Navigator.of(context).pop(true);
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(e.toString().replaceFirst('Exception: ', '')),
          backgroundColor: Colors.red.shade700,
        ),
      );
      setState(() {
        _isSubmitting = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Row(
        children: [
          Expanded(
            child: Text(
              _isEditMode
                  ? (widget.adminMode
                      ? 'Modifier un administrateur'
                      : 'Modifier un gestionnaire')
                  : (widget.adminMode
                      ? 'Créer un administrateur'
                      : 'Créer un gestionnaire'),
            ),
          ),
          if (_isEditMode)
            IconButton(
              icon: const Icon(Icons.close),
              tooltip: 'Fermer',
              onPressed: _isSubmitting
                  ? null
                  : () => Navigator.of(context).pop(false),
            ),
        ],
      ),
      content: SizedBox(
        width: 620,
        child: Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Row(
                  children: [
                    Expanded(child: _buildPrenomField()),
                    const SizedBox(width: 12),
                    Expanded(child: _buildNomField()),
                  ],
                ),
                const SizedBox(height: 12),
                _buildEmailField(),
                const SizedBox(height: 12),
                Row(
                  children: [
                    Expanded(child: _buildPasswordField()),
                    const SizedBox(width: 12),
                    Expanded(child: _buildTelephoneField()),
                  ],
                ),
                if (widget.withRelais) ...[
                  const SizedBox(height: 12),
                  _buildRelaisField(),
                ],
              ],
            ),
          ),
        ),
      ),
      actions: [
        if (_isEditMode) ...[
          OutlinedButton(
            onPressed: _isSubmitting ? null : _delete,
            style: OutlinedButton.styleFrom(foregroundColor: Colors.red.shade700),
            child: const Text('Supprimer'),
          ),
          FilledButton.icon(
            onPressed: _isSubmitting ? null : _submit,
            icon: _isSubmitting
                ? const SizedBox(
                    width: 16,
                    height: 16,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.edit),
            label: Text(_isSubmitting ? 'Modification...' : 'Modifier'),
          ),
        ] else ...[
          OutlinedButton(
            onPressed:
                _isSubmitting ? null : () => Navigator.of(context).pop(false),
            child: const Text('Annuler'),
          ),
          FilledButton.icon(
            onPressed: _isSubmitting ? null : _submit,
            icon: _isSubmitting
                ? const SizedBox(
                    width: 16,
                    height: 16,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.person_add_alt_1),
            label: Text(_isSubmitting ? 'Création...' : 'Créer'),
          ),
        ],
      ],
    );
  }

  Widget _buildNomField() {
    return TextFormField(
      controller: _nomController,
      textCapitalization: TextCapitalization.words,
      decoration: const InputDecoration(
        labelText: 'Nom',
        border: OutlineInputBorder(),
      ),
      validator: (v) => _required(v, 'Nom'),
    );
  }

  Widget _buildPrenomField() {
    return TextFormField(
      controller: _prenomController,
      textCapitalization: TextCapitalization.words,
      decoration: const InputDecoration(
        labelText: 'Prénom',
        border: OutlineInputBorder(),
      ),
      validator: (v) => _required(v, 'Prénom'),
    );
  }

  Widget _buildEmailField() {
    return TextFormField(
      controller: _emailController,
      keyboardType: TextInputType.emailAddress,
      decoration: const InputDecoration(
        labelText: 'Email',
        border: OutlineInputBorder(),
      ),
      validator: _validateEmail,
    );
  }

  Widget _buildPasswordField() {
    return TextFormField(
      controller: _passwordController,
      obscureText: _obscurePassword,
      enableSuggestions: false,
      autocorrect: false,
      autofillHints: _isEditMode
          ? const <String>[]
          : const [AutofillHints.newPassword],
      decoration: InputDecoration(
        labelText: _isEditMode
            ? 'Nouveau mot de passe'
            : 'Mot de passe',
        border: const OutlineInputBorder(),
        suffixIcon: ExcludeFocus(
          child: IconButton(
            focusNode: _passwordToggleFocusNode,
            onPressed: () {
              setState(() {
                _obscurePassword = !_obscurePassword;
              });
            },
            icon: Icon(
              _obscurePassword ? Icons.visibility_off : Icons.visibility,
            ),
          ),
        ),
      ),
      validator: _validatePassword,
    );
  }

  Widget _buildTelephoneField() {
    return TextFormField(
      controller: _telephoneController,
      keyboardType: TextInputType.phone,
      inputFormatters: [
        FilteringTextInputFormatter.digitsOnly,
        LengthLimitingTextInputFormatter(10),
        _FrenchPhoneNumberFormatter(),
      ],
      decoration: const InputDecoration(
        labelText: 'Téléphone (ex: 06 12 34 56 78)',
        border: OutlineInputBorder(),
      ),
      validator: _validatePhone,
    );
  }

  Widget _buildRelaisField() {
    final selectedValue = _selectedRelaisId != null &&
            _relais.any((relais) => relais.id == _selectedRelaisId)
        ? _selectedRelaisId
        : null;

    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        DropdownButtonFormField<String?>(
          isExpanded: true,
          value: selectedValue,
          decoration: const InputDecoration(
            labelText: 'Relais principal',
            border: OutlineInputBorder(),
          ),
          items: [
            const DropdownMenuItem<String?>(
              value: null,
              child: Text('Aucun relais'),
            ),
            ..._relais.map(
              (relais) => DropdownMenuItem<String?>(
                value: relais.id,
                child: Text(relais.nom),
              ),
            ),
          ],
          onChanged: _isLoadingRelais
              ? null
              : (value) {
                  setState(() {
                    _selectedRelaisId = value;
                  });
                },
        ),
        if (_isLoadingRelais) ...[
          const SizedBox(height: 8),
          const LinearProgressIndicator(minHeight: 2),
        ],
      ],
    );
  }
}

class _FrenchPhoneNumberFormatter extends TextInputFormatter {
  const _FrenchPhoneNumberFormatter();

  @override
  TextEditingValue formatEditUpdate(
    TextEditingValue oldValue,
    TextEditingValue newValue,
  ) {
    final digits = newValue.text.replaceAll(RegExp(r'\D'), '');
    final normalized = digits.length > 10 ? digits.substring(0, 10) : digits;
    final buffer = StringBuffer();
    for (var i = 0; i < normalized.length; i++) {
      if (i > 0 && i.isEven) buffer.write(' ');
      buffer.write(normalized[i]);
    }
    final formatted = buffer.toString();

    return TextEditingValue(
      text: formatted,
      selection: TextSelection.collapsed(offset: formatted.length),
    );
  }
}