import 'package:flutter/material.dart';
import 'package:p_tits_pas/models/relais_model.dart';
import 'package:p_tits_pas/models/user.dart';
import 'package:p_tits_pas/services/auth_service.dart';
import 'package:p_tits_pas/services/relais_service.dart';
import 'package:p_tits_pas/services/user_service.dart';
import 'package:p_tits_pas/utils/email_utils.dart';
import 'package:p_tits_pas/utils/name_format_utils.dart';
import 'package:p_tits_pas/utils/phone_utils.dart';
import 'package:p_tits_pas/utils/staff_deletion_rights.dart';
import 'package:p_tits_pas/widgets/dashboard/common/suppression_confirm_dialog.dart';
import 'package:p_tits_pas/widgets/dashboard/common/validation_detail_section.dart';
import 'package:p_tits_pas/widgets/dashboard/validation_modal_theme.dart';

/// Modale création / édition / consultation staff (gestionnaire / admin) — #164.
class StaffUserFormModal extends StatefulWidget {
  final AppUser? initialUser;
  final bool withRelais;
  final bool adminMode;
  final bool readOnly;

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

  @override
  State<StaffUserFormModal> createState() => _StaffUserFormModalState();
}

class _StaffUserFormModalState extends State<StaffUserFormModal> {
  static const double _modalWidth = 930;

  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;
  bool _dirty = false;
  List<RelaisModel> _relais = [];
  String? _selectedRelaisId;
  String? _currentUserId;
  String? _currentUserRole;

  String _baselineNom = '';
  String _baselinePrenom = '';
  String _baselineEmail = '';
  String _baselinePhone = '';
  String? _baselineRelaisId;

  bool get _isEditMode => widget.initialUser != null;
  bool get _isSuperAdminTarget =>
      (widget.initialUser?.role ?? '').toLowerCase() == 'super_admin';
  bool get _isSelfTarget =>
      _isEditMode &&
      _currentUserId != null &&
      widget.initialUser!.id == _currentUserId;
  bool get _canDeleteTarget {
    if (!_isEditMode || widget.readOnly) return false;
    if (_isSelfTarget || _isSuperAdminTarget) return false;
    return canDeleteGestionnaire(_currentUserRole);
  }

  bool get _isLockedAdminIdentity =>
      _isEditMode && widget.adminMode && _isSuperAdminTarget;

  bool get _fieldsEnabled => !widget.readOnly && !_isSubmitting;

  String get _targetRoleKey {
    if (widget.initialUser != null) {
      return (widget.initialUser!.role).toLowerCase();
    }
    return widget.adminMode ? 'administrateur' : 'gestionnaire';
  }

  String get _targetRoleLabel {
    switch (_targetRoleKey) {
      case 'super_admin':
        return 'Super administrateur';
      case 'administrateur':
        return 'Administrateur';
      case 'gestionnaire':
        return 'Gestionnaire';
      default:
        return 'Utilisateur';
    }
  }

  IconData get _targetRoleIcon {
    switch (_targetRoleKey) {
      case 'super_admin':
        return Icons.verified_user_outlined;
      case 'administrateur':
        return Icons.admin_panel_settings_outlined;
      case 'gestionnaire':
        return Icons.assignment_ind_outlined;
      default:
        return Icons.person_outline;
    }
  }

  @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 ?? '');
      _passwordController.clear();
      final initialRelaisId = user.relaisId?.trim();
      _selectedRelaisId =
          (initialRelaisId == null || initialRelaisId.isEmpty)
              ? null
              : initialRelaisId;
      _captureBaseline();
    }
    for (final c in [
      _nomController,
      _prenomController,
      _emailController,
      _passwordController,
      _telephoneController,
    ]) {
      c.addListener(_onFieldChanged);
    }
    if (widget.withRelais) {
      _loadRelais();
    } else {
      _isLoadingRelais = false;
    }
    _loadCurrentUserId();
  }

  void _captureBaseline() {
    _baselineNom = formatPersonNameCase(_nomController.text);
    _baselinePrenom = formatPersonNameCase(_prenomController.text);
    _baselineEmail = normalizeEmailText(_emailController.text);
    _baselinePhone = normalizePhone(_telephoneController.text);
    _baselineRelaisId = _selectedRelaisId;
  }

  void _onFieldChanged() {
    if (widget.readOnly || !_isEditMode) return;
    final dirty = _computeDirty();
    if (dirty != _dirty) setState(() => _dirty = dirty);
  }

  bool _computeDirty() {
    if (!_isEditMode) return true;
    final nom = formatPersonNameCase(_nomController.text);
    final prenom = formatPersonNameCase(_prenomController.text);
    final email = normalizeEmailText(_emailController.text);
    final phone = normalizePhone(_telephoneController.text);
    final passwordProvided = _passwordController.text.trim().isNotEmpty;
    return nom != _baselineNom ||
        prenom != _baselinePrenom ||
        email != _baselineEmail ||
        phone != _baselinePhone ||
        passwordProvided ||
        _selectedRelaisId != _baselineRelaisId;
  }

  Future<void> _loadCurrentUserId() async {
    final cached = await AuthService.getCurrentUser();
    if (!mounted) return;
    if (cached != null) {
      setState(() {
        _currentUserId = cached.id;
        _currentUserRole = cached.role;
      });
      return;
    }
    final refreshed = await AuthService.refreshCurrentUser();
    if (!mounted || refreshed == null) return;
    setState(() {
      _currentUserId = refreshed.id;
      _currentUserRole = refreshed.role;
    });
  }

  @override
  void dispose() {
    for (final c in [
      _nomController,
      _prenomController,
      _emailController,
      _passwordController,
      _telephoneController,
    ]) {
      c.removeListener(_onFieldChanged);
      c.dispose();
    }
    _passwordToggleFocusNode.dispose();
    super.dispose();
  }

  List<RelaisModel> _fallbackRelaisFromUser() {
    final id = _selectedRelaisId?.trim();
    if (id == null || id.isEmpty) return const [];
    final nom = (widget.initialUser?.relaisNom ?? '').trim();
    return [
      RelaisModel(
        id: id,
        nom: nom.isNotEmpty ? nom : 'Relais actuel',
        adresse: '',
        actif: true,
      ),
    ];
  }

  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 {
          filtered.addAll(_fallbackRelaisFromUser());
        }
      }

      setState(() {
        _relais = filtered;
        _isLoadingRelais = false;
      });
    } catch (_) {
      if (!mounted) return;
      setState(() {
        _relais = _fallbackRelaisFromUser();
        _isLoadingRelais = false;
      });
    }
  }

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

  Future<void> _submit() async {
    if (widget.readOnly) return;
    if (_isSubmitting) return;
    if (_isEditMode && !_dirty) return;
    if (!_formKey.currentState!.validate()) return;

    setState(() => _isSubmitting = true);

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

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

          final onlyRelaisChanged = normalizedNom == initialNom &&
              normalizedPrenom == initialPrenom &&
              normalizeEmailText(_emailController.text) == 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: normalizeEmailText(_emailController.text),
              telephone:
                  normalizedPhone.isEmpty ? initialPhone : normalizedPhone,
              relaisId: _selectedRelaisId,
              password: passwordProvided ? _passwordController.text : null,
            );
          }
        }
      } else {
        if (widget.adminMode) {
          await UserService.createAdministrateur(
            nom: normalizedNom,
            prenom: normalizedPrenom,
            email: normalizeEmailText(_emailController.text),
            password: _passwordController.text,
            telephone: normalizePhone(_telephoneController.text),
          );
        } else {
          await UserService.createGestionnaire(
            nom: normalizedNom,
            prenom: normalizedPrenom,
            email: normalizeEmailText(_emailController.text),
            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) {
        setState(() => _isSubmitting = false);
      }
    }
  }

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

    final name = widget.initialUser!.fullName.isEmpty
        ? widget.initialUser!.email
        : widget.initialUser!.fullName;
    final confirmed = await showSuppressionConfirmDialog(
      context,
      title: widget.adminMode
          ? 'Supprimer l\'administrateur'
          : 'Supprimer le gestionnaire',
      people: [
        widget.adminMode
            ? SuppressionPersonLine.administrateur(name)
            : SuppressionPersonLine.gestionnaire(name),
      ],
      footnotes: const [
        'Le compte sera définitivement supprimé.',
      ],
    );

    if (!confirmed) return;

    setState(() => _isSubmitting = true);
    try {
      await UserService.deleteUser(widget.initialUser!.id);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            widget.adminMode
                ? 'Administrateur supprimé.'
                : '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);
    }
  }

  String _headerTitle() {
    if (!_isEditMode) {
      return widget.adminMode
          ? 'Créer un administrateur'
          : 'Créer un gestionnaire';
    }
    final prenom = (_prenomController.text.trim().isNotEmpty
            ? _prenomController.text
            : (widget.initialUser?.prenom ?? ''))
        .trim();
    final nom = (_nomController.text.trim().isNotEmpty
            ? _nomController.text
            : (widget.initialUser?.nom ?? ''))
        .trim();
    final full = '$prenom $nom'.trim();
    if (full.isNotEmpty) return full;
    return widget.initialUser?.email ?? _targetRoleLabel;
  }

  Widget _buildFooter() {
    if (widget.readOnly) {
      return Row(
        children: [
          TextButton(
            onPressed:
                _isSubmitting ? null : () => Navigator.of(context).pop(false),
            child: const Text('Fermer'),
          ),
        ],
      );
    }

    if (!_isEditMode) {
      return Row(
        children: [
          TextButton(
            onPressed:
                _isSubmitting ? null : () => Navigator.of(context).pop(false),
            child: const Text('Annuler'),
          ),
          const Spacer(),
          ElevatedButton(
            style: ValidationModalTheme.primaryElevatedStyle,
            onPressed: _isSubmitting ? null : _submit,
            child: _isSubmitting
                ? const SizedBox(
                    width: 18,
                    height: 18,
                    child: CircularProgressIndicator(
                      strokeWidth: 2,
                      color: Colors.white,
                    ),
                  )
                : const Text('Créer'),
          ),
        ],
      );
    }

    return Row(
      children: [
        if (_canDeleteTarget)
          OutlinedButton(
            onPressed: _isSubmitting ? null : _delete,
            style: OutlinedButton.styleFrom(
              foregroundColor: Colors.red.shade700,
            ),
            child: const Text('Supprimer'),
          ),
        if (_canDeleteTarget) const SizedBox(width: 8),
        TextButton(
          onPressed:
              _isSubmitting ? null : () => Navigator.of(context).pop(false),
          child: const Text('Fermer'),
        ),
        const Spacer(),
        ElevatedButton(
          style: ValidationModalTheme.primaryElevatedStyle,
          onPressed: !_dirty || _isSubmitting ? null : _submit,
          child: _isSubmitting
              ? const SizedBox(
                  width: 18,
                  height: 18,
                  child: CircularProgressIndicator(
                    strokeWidth: 2,
                    color: Colors.white,
                  ),
                )
              : Text(_dirty ? 'Sauvegarder' : 'Aucune modification'),
        ),
      ],
    );
  }

  Widget _namedField({
    required String label,
    required TextEditingController controller,
    required String requiredLabel,
    bool enabled = true,
  }) {
    return ValidationLabeledField(
      label: label,
      field: SizedBox(
        height: ValidationFormMetrics.fieldHeight,
        child: TextFormField(
          controller: controller,
          enabled: enabled,
          textCapitalization: TextCapitalization.words,
          textAlignVertical: TextAlignVertical.center,
          inputFormatters: const [PersonNameInputFormatter()],
          style: ValidationFormMetrics.fieldTextStyle,
          decoration: ValidationFieldDecoration.input(),
          validator: (!enabled || widget.readOnly)
              ? null
              : (v) => _required(v, requiredLabel),
        ),
      ),
    );
  }

  Widget _passwordField() {
    return ValidationLabeledField(
      label: _isEditMode ? 'Nouveau mot de passe' : 'Mot de passe',
      field: SizedBox(
        height: ValidationFormMetrics.fieldHeight,
        child: TextFormField(
          controller: _passwordController,
          enabled: _fieldsEnabled,
          obscureText: _obscurePassword,
          enableSuggestions: false,
          autocorrect: false,
          autofillHints: _isEditMode
              ? const <String>[]
              : const [AutofillHints.newPassword],
          textAlignVertical: TextAlignVertical.center,
          style: ValidationFormMetrics.fieldTextStyle,
          decoration: ValidationFieldDecoration.input().copyWith(
            suffixIcon: widget.readOnly
                ? null
                : ExcludeFocus(
                    child: IconButton(
                      focusNode: _passwordToggleFocusNode,
                      onPressed: !_fieldsEnabled
                          ? null
                          : () {
                              setState(() {
                                _obscurePassword = !_obscurePassword;
                              });
                            },
                      icon: Icon(
                        _obscurePassword
                            ? Icons.visibility_off
                            : Icons.visibility,
                      ),
                    ),
                  ),
            errorStyle: TextStyle(color: Colors.red.shade700, fontSize: 11),
            errorMaxLines: 2,
          ),
          validator: widget.readOnly ? null : _validatePassword,
        ),
      ),
    );
  }

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

    return ValidationLabeledField(
      label: 'Relais principal',
      field: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          SizedBox(
            height: ValidationFormMetrics.fieldHeight,
            child: DropdownButtonFormField<String?>(
              isExpanded: true,
              value: selectedValue,
              decoration: ValidationFieldDecoration.input(),
              style: ValidationFormMetrics.fieldTextStyle,
              items: [
                const DropdownMenuItem<String?>(
                  value: null,
                  child: Text('Aucun relais'),
                ),
                ..._relais.map(
                  (relais) => DropdownMenuItem<String?>(
                    value: relais.id,
                    child: Text(relais.nom),
                  ),
                ),
              ],
              onChanged: (_isLoadingRelais || !_fieldsEnabled)
                  ? null
                  : (value) {
                      setState(() {
                        _selectedRelaisId = value;
                        if (_isEditMode) {
                          _dirty = _computeDirty();
                        }
                      });
                    },
            ),
          ),
          if (_isLoadingRelais) ...[
            const SizedBox(height: 8),
            const LinearProgressIndicator(minHeight: 2),
          ],
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final nameEnabled =
        _fieldsEnabled && !_isLockedAdminIdentity;

    return Dialog(
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: _modalWidth),
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Padding(
                padding: const EdgeInsets.fromLTRB(18, 16, 4, 10),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Padding(
                      padding: const EdgeInsets.only(top: 2, right: 10),
                      child: Icon(
                        _targetRoleIcon,
                        size: 22,
                        color: ValidationModalTheme.primaryActionBackground,
                      ),
                    ),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            _headerTitle(),
                            style: const TextStyle(
                              fontSize: 18,
                              fontWeight: FontWeight.w700,
                            ),
                          ),
                          if (_isEditMode) ...[
                            const SizedBox(height: 4),
                            Text(
                              _targetRoleLabel,
                              style: TextStyle(
                                fontSize: 13,
                                color: Colors.grey.shade700,
                              ),
                            ),
                          ],
                        ],
                      ),
                    ),
                    IconButton(
                      padding: EdgeInsets.zero,
                      constraints: const BoxConstraints(
                        minWidth: 40,
                        minHeight: 40,
                      ),
                      icon: const Icon(Icons.close),
                      onPressed: _isSubmitting
                          ? null
                          : () => Navigator.of(context).pop(false),
                      tooltip: 'Fermer',
                    ),
                  ],
                ),
              ),
              const Divider(height: 1),
              Padding(
                padding: const EdgeInsets.fromLTRB(20, 16, 20, 8),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Expanded(
                          child: _namedField(
                            label: 'Prénom',
                            controller: _prenomController,
                            requiredLabel: 'Prénom',
                            enabled: nameEnabled,
                          ),
                        ),
                        const SizedBox(width: 12),
                        Expanded(
                          child: _namedField(
                            label: 'Nom',
                            controller: _nomController,
                            requiredLabel: 'Nom',
                            enabled: nameEnabled,
                          ),
                        ),
                      ],
                    ),
                    SizedBox(height: ValidationFormMetrics.rowGapBelow),
                    ValidationLabeledField(
                      label: 'Email',
                      field: IgnorePointer(
                        ignoring: !_fieldsEnabled,
                        child: ValidationEmailField(
                          controller: _emailController,
                          hintText: 'ex. nom@domaine.fr',
                        ),
                      ),
                    ),
                    SizedBox(height: ValidationFormMetrics.rowGapBelow),
                    Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Expanded(child: _passwordField()),
                        const SizedBox(width: 12),
                        Expanded(
                          child: ValidationLabeledField(
                            label: 'Téléphone',
                            field: IgnorePointer(
                              ignoring: !_fieldsEnabled,
                              child: ValidationPhoneField(
                                controller: _telephoneController,
                                hintText: '06 12 34 56 78',
                                allowEmpty: _isEditMode,
                              ),
                            ),
                          ),
                        ),
                      ],
                    ),
                    if (widget.withRelais) ...[
                      SizedBox(height: ValidationFormMetrics.rowGapBelow),
                      _relaisField(),
                    ],
                  ],
                ),
              ),
              const Divider(height: 1),
              Padding(
                padding: const EdgeInsets.fromLTRB(12, 10, 16, 14),
                child: _buildFooter(),
              ),
            ],
          ),
        ),
      ),
    );
  }
}