// src/pages/Users/Users.jsx
// Page Utilisateurs : gestion réelle des utilisateurs via l'API admin
import { useState, useEffect, useCallback } from 'react';
import { Plus, Edit, Trash2, KeyRound } from 'lucide-react';
import DataTable from '../../components/common/DataTable';
import Button from '../../components/common/Button';
import LoadingSpinner from '../../components/common/LoadingSpinner';
import ErrorMessage from '../../components/common/ErrorMessage';
import {
  getUsers,
  createUser,
  updateUser,
  deleteUser,
  resetUserPassword,
} from '../../services/api';
import styles from './Users.module.css';

/* Rôles disponibles côté backend */
const ROLES = ['Admin', 'Superviseur', 'Consultant'];

export default function Users() {
  const [users, setUsers] = useState([]);
  const [loading, setLoading] = useState(true);
  const [erreur, setErreur] = useState('');

  /* Modale active : 'create' | 'edit' | 'reset' | null */
  const [modal, setModal] = useState(null);
  const [selected, setSelected] = useState(null);
  const [form, setForm] = useState({});
  const [formError, setFormError] = useState('');
  const [submitting, setSubmitting] = useState(false);

  const charger = useCallback(async () => {
    setLoading(true);
    setErreur('');
    try {
      const data = await getUsers();
      setUsers(Array.isArray(data) ? data : []);
    } catch (e) {
      setErreur(e.message || 'Erreur lors du chargement des utilisateurs.');
    } finally {
      setLoading(false);
    }
  }, []);

  /* Chargement initial. Le drapeau `annule` évite d'écrire dans un composant
     déjà démonté si l'utilisateur quitte la page pendant la requête. */
  useEffect(() => {
    let annule = false;

    async function chargerAuMontage() {
      try {
        const data = await getUsers();
        if (!annule) setUsers(Array.isArray(data) ? data : []);
      } catch (e) {
        if (!annule) setErreur(e.message || 'Erreur lors du chargement des utilisateurs.');
      } finally {
        if (!annule) setLoading(false);
      }
    }

    chargerAuMontage();
    return () => { annule = true; };
  }, []);

  /* Ouverture des modales */
  function ouvrirCreation() {
    setSelected(null);
    setForm({ username: '', email: '', password: '', role: 'Consultant' });
    setFormError('');
    setModal('create');
  }

  function ouvrirEdition(user) {
    setSelected(user);
    setForm({ email: user.email ?? '', role: user.role ?? 'Consultant', actif: !!user.actif });
    setFormError('');
    setModal('edit');
  }

  function ouvrirReset(user) {
    setSelected(user);
    setForm({ password: '' });
    setFormError('');
    setModal('reset');
  }

  function fermerModale() {
    setModal(null);
    setSelected(null);
    setForm({});
    setFormError('');
  }

  /* Suppression (soft delete) avec confirmation */
  async function handleDelete(user) {
    if (!window.confirm(`Désactiver l'utilisateur "${user.username}" ?`)) {
      return;
    }
    try {
      await deleteUser(user.id_user);
      await charger();
    } catch (e) {
      setErreur(e.message || 'Erreur lors de la suppression.');
    }
  }

  /* Soumission de la modale courante */
  async function handleSubmit(e) {
    e.preventDefault();
    setFormError('');
    setSubmitting(true);
    try {
      if (modal === 'create') {
        await createUser({
          username: form.username,
          email: form.email,
          password: form.password,
          role: form.role,
        });
      } else if (modal === 'edit') {
        await updateUser(selected.id_user, {
          email: form.email,
          role: form.role,
          actif: form.actif,
        });
      } else if (modal === 'reset') {
        await resetUserPassword(selected.id_user, form.password);
      }
      fermerModale();
      await charger();
    } catch (e) {
      setFormError(e.message || 'Une erreur est survenue.');
    } finally {
      setSubmitting(false);
    }
  }

  const columns = [
    { key: 'username', label: 'Identifiant' },
    { key: 'email', label: 'Email' },
    { key: 'role', label: 'Rôle' },
    {
      key: 'actif',
      label: 'Statut',
      render: (val) => (val ? 'Actif' : 'Inactif'),
    },
    {
      key: 'actions',
      label: 'Actions',
      render: (val, row) => (
        <div className={styles.actions}>
          <button className={styles.actionBtn} onClick={() => ouvrirEdition(row)}>
            <Edit size={14} />
            Modifier
          </button>
          <button className={styles.actionBtn} onClick={() => ouvrirReset(row)}>
            <KeyRound size={14} />
            Mot de passe
          </button>
          <button className={styles.actionBtn} onClick={() => handleDelete(row)}>
            <Trash2 size={14} />
            Désactiver
          </button>
        </div>
      ),
    },
  ];

  return (
    <div className={styles.page}>
      <div className={styles.header}>
        <h1 className={styles.title}>Utilisateurs</h1>
        <Button variant="primary" onClick={ouvrirCreation}>
          <Plus size={14} />
          Ajouter
        </Button>
      </div>

      {loading ? (
        <LoadingSpinner message="Chargement des utilisateurs..." />
      ) : erreur ? (
        <ErrorMessage message={erreur} onRetry={charger} />
      ) : (
        <DataTable
          columns={columns}
          data={users.map(u => ({ ...u, id: u.id_user }))}
          pageSize={50}
          emptyMessage="Aucun utilisateur trouvé."
        />
      )}

      {modal && (
        <div className={styles.overlay} role="dialog" aria-modal="true" onClick={fermerModale}>
          <div className={styles.modal} onClick={e => e.stopPropagation()}>
            <h2 className={styles.modalTitle}>
              {modal === 'create' && 'Nouvel utilisateur'}
              {modal === 'edit' && `Modifier ${selected?.username}`}
              {modal === 'reset' && `Réinitialiser le mot de passe de ${selected?.username}`}
            </h2>

            <form className={styles.form} onSubmit={handleSubmit}>
              {modal === 'create' && (
                <div className={styles.field}>
                  <label className={styles.label} htmlFor="username">Identifiant</label>
                  <input
                    id="username"
                    type="text"
                    className={styles.input}
                    value={form.username}
                    onChange={e => setForm(f => ({ ...f, username: e.target.value }))}
                    required
                  />
                </div>
              )}

              {(modal === 'create' || modal === 'edit') && (
                <div className={styles.field}>
                  <label className={styles.label} htmlFor="email">Email</label>
                  <input
                    id="email"
                    type="email"
                    className={styles.input}
                    value={form.email}
                    onChange={e => setForm(f => ({ ...f, email: e.target.value }))}
                    required
                  />
                </div>
              )}

              {(modal === 'create' || modal === 'reset') && (
                <div className={styles.field}>
                  <label className={styles.label} htmlFor="password">Mot de passe</label>
                  <input
                    id="password"
                    type="password"
                    className={styles.input}
                    value={form.password}
                    onChange={e => setForm(f => ({ ...f, password: e.target.value }))}
                    required
                  />
                </div>
              )}

              {(modal === 'create' || modal === 'edit') && (
                <div className={styles.field}>
                  <label className={styles.label} htmlFor="role">Rôle</label>
                  <select
                    id="role"
                    className={styles.input}
                    value={form.role}
                    onChange={e => setForm(f => ({ ...f, role: e.target.value }))}
                  >
                    {ROLES.map(r => (
                      <option key={r} value={r}>{r}</option>
                    ))}
                  </select>
                </div>
              )}

              {modal === 'edit' && (
                <div className={styles.checkboxField}>
                  <input
                    id="actif"
                    type="checkbox"
                    checked={form.actif}
                    onChange={e => setForm(f => ({ ...f, actif: e.target.checked }))}
                  />
                  <label htmlFor="actif">Compte actif</label>
                </div>
              )}

              {formError && <p className={styles.formError}>{formError}</p>}

              <div className={styles.modalActions}>
                <Button variant="neutral" type="button" onClick={fermerModale} disabled={submitting}>
                  Annuler
                </Button>
                <Button variant="primary" type="submit" disabled={submitting}>
                  {submitting ? 'Enregistrement...' : 'Enregistrer'}
                </Button>
              </div>
            </form>
          </div>
        </div>
      )}
    </div>
  );
}