'use client';

import { useState, useEffect, useCallback, useMemo } from 'react';
import { useRouter } from 'next/navigation';
import { adminService } from '@/services/admin.service';
import { User, CreateEmployeeData, UpdateUserData, PaginatedResponse } from '@/types';
import { Pagination } from '@/components/ui';
import { Search, UserPlus, X, Filter, RefreshCw, Users, Shield, Briefcase, UserCheck } from 'lucide-react';

export default function UserManagement() {
  const router = useRouter();
  const [users, setUsers] = useState<User[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [page, setPage] = useState(1);
  const [totalPages, setTotalPages] = useState(1);
  const [filterRole, setFilterRole] = useState<string>('');
  const [filterStatus, setFilterStatus] = useState<string>('');
  const [searchQuery, setSearchQuery] = useState<string>('');

  // Filtrage côté client par nom/email
  const filteredUsers = useMemo(() => {
    if (!searchQuery.trim()) return users;
    const query = searchQuery.toLowerCase().trim();
    return users.filter(user =>
      user.firstName?.toLowerCase().includes(query) ||
      user.lastName?.toLowerCase().includes(query) ||
      user.email?.toLowerCase().includes(query) ||
      `${user.firstName} ${user.lastName}`.toLowerCase().includes(query)
    );
  }, [users, searchQuery]);

  // Modals
  const [isCreateEmployeeModalOpen, setIsCreateEmployeeModalOpen] = useState(false);
  const [isEditUserModalOpen, setIsEditUserModalOpen] = useState(false);
  const [editingUser, setEditingUser] = useState<User | null>(null);

  // Form data
  const [employeeFormData, setEmployeeFormData] = useState<CreateEmployeeData>({
    email: '',
    password: '',
    firstName: '',
    lastName: '',
  });

  const [userFormData, setUserFormData] = useState<UpdateUserData>({});

  const loadUsers = useCallback(async () => {
    try {
      setLoading(true);
      setError(null);
      const filters: any = {};
      if (filterRole) filters.role = filterRole;
      if (filterStatus) filters.isActive = filterStatus === 'active';

      const response: PaginatedResponse<User> = await adminService.getAllUsers(
        page,
        100, // Charger plus pour le filtrage côté client
        Object.keys(filters).length > 0 ? filters : undefined
      );
      setUsers(response.data || []);
      setTotalPages(response.totalPages || 1);
    } catch (err: any) {
      setError(err.message || 'Erreur lors du chargement des utilisateurs');
      setUsers([]);
    } finally {
      setLoading(false);
    }
  }, [page, filterRole, filterStatus]);

  useEffect(() => {
    loadUsers();
  }, [loadUsers]);

  const handleCreateEmployee = async (e: React.FormEvent) => {
    e.preventDefault();
    try {
      await adminService.createEmployee(employeeFormData);
      setIsCreateEmployeeModalOpen(false);
      setEmployeeFormData({ email: '', password: '', firstName: '', lastName: '' });
      loadUsers();
    } catch (err: any) {
      alert(err.message || 'Erreur lors de la création de l\'employé');
    }
  };

  const handleEditUser = (user: User) => {
    setEditingUser(user);
    setUserFormData({
      role: user.role,
      firstName: user.firstName,
      lastName: user.lastName,
    });
    setIsEditUserModalOpen(true);
  };

  const handleUpdateUser = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!editingUser) return;

    try {
      await adminService.updateUser(editingUser.id, userFormData);
      setIsEditUserModalOpen(false);
      setEditingUser(null);
      loadUsers();
    } catch (err: any) {
      alert(err.message || 'Erreur lors de la modification de l\'utilisateur');
    }
  };

  const handleToggleUserStatus = async (user: User) => {
    const action = user.isActive ? 'désactiver' : 'réactiver';
    if (!confirm(`Êtes-vous sûr de vouloir ${action} cet utilisateur ?`)) return;

    try {
      await adminService.updateUser(user.id, { isActive: !user.isActive });
      loadUsers();
    } catch (err: any) {
      alert(err.message || `Erreur lors de la ${action}ation`);
    }
  };

  const getRoleBadgeColor = (role: string) => {
    switch (role) {
      case 'ADMIN':
        return 'bg-red-100 text-red-800';
      case 'EMPLOYEE':
        return 'bg-blue-100 text-blue-800';
      case 'CLIENT':
        return 'bg-green-100 text-green-800';
      default:
        return 'bg-gray-100 text-gray-800';
    }
  };

  // Fonction pour obtenir les initiales
  const getInitials = (firstName?: string, lastName?: string) => {
    const f = firstName?.charAt(0) || '';
    const l = lastName?.charAt(0) || '';
    return (f + l).toUpperCase() || '?';
  };

  // Fonction pour obtenir la couleur de l'avatar selon le rôle
  const getAvatarColor = (role: string) => {
    switch (role) {
      case 'ADMIN':
        return 'bg-gradient-to-br from-red-500 to-red-600';
      case 'EMPLOYEE':
        return 'bg-gradient-to-br from-blue-500 to-blue-600';
      case 'CLIENT':
        return 'bg-gradient-to-br from-green-500 to-green-600';
      default:
        return 'bg-gradient-to-br from-gray-500 to-gray-600';
    }
  };

  // Compter les utilisateurs par rôle
  const roleStats = useMemo(() => {
    const stats = { ADMIN: 0, EMPLOYEE: 0, CLIENT: 0 };
    filteredUsers.forEach(user => {
      if (user.role in stats) {
        stats[user.role as keyof typeof stats]++;
      }
    });
    return stats;
  }, [filteredUsers]);

  if (loading && users.length === 0) {
    return (
      <div className="flex items-center justify-center py-16">
        <div className="text-center">
          <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-blue-600 mx-auto mb-4"></div>
          <p className="text-gray-600">Chargement des utilisateurs...</p>
        </div>
      </div>
    );
  }

  return (
    <div className="p-6">
      {/* Section recherche */}
      <div className="bg-[#faf8f5] rounded-2xl p-6 mb-6 border border-gray-200">
        <div className="flex flex-col md:flex-row gap-4 items-center justify-between">
          <div className="flex-1 w-full">
            <div className="relative">
              <Search className="absolute left-4 top-1/2 transform -translate-y-1/2 w-5 h-5 text-gray-400" />
              <input
                type="text"
                placeholder="Rechercher par nom ou email..."
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                className="w-full pl-12 pr-4 py-3 rounded-xl bg-white text-gray-900 placeholder-gray-400 border border-gray-200 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
              />
            </div>
          </div>
          <div className="flex gap-3">
            <select
              value={filterRole}
              onChange={(e) => {
                setFilterRole(e.target.value);
                setPage(1);
              }}
              className="px-4 py-3 rounded-xl bg-white text-gray-700 border border-gray-200 focus:outline-none focus:ring-2 focus:ring-blue-500"
            >
              <option value="">Tous les rôles</option>
              <option value="CLIENT">Clients</option>
              <option value="EMPLOYEE">Employés</option>
              <option value="ADMIN">Administrateurs</option>
            </select>
            <select
              value={filterStatus}
              onChange={(e) => {
                setFilterStatus(e.target.value);
                setPage(1);
              }}
              className="px-4 py-3 rounded-xl bg-white text-gray-700 border border-gray-200 focus:outline-none focus:ring-2 focus:ring-blue-500"
            >
              <option value="">Tous les statuts</option>
              <option value="active">Actifs</option>
              <option value="inactive">Inactifs</option>
            </select>
            <button
              onClick={() => setIsCreateEmployeeModalOpen(true)}
              className="flex items-center gap-2 px-5 py-3 bg-white text-[#1e3a5f] rounded-xl font-semibold hover:bg-gray-100 transition-colors shadow-sm border border-gray-200"
            >
              <UserPlus className="w-5 h-5" />
              <span className="hidden sm:inline">Nouvel employé</span>
            </button>
          </div>
        </div>
      </div>

      {error && (
        <div className="bg-red-50 border border-red-200 text-red-700 px-4 py-3 rounded-xl mb-6 flex items-center gap-3">
          <div className="w-10 h-10 bg-red-100 rounded-full flex items-center justify-center">
            <X className="w-5 h-5 text-red-600" />
          </div>
          <span>{error}</span>
        </div>
      )}

      {/* Stats rapides */}
      <div className="grid grid-cols-2 md:grid-cols-4 gap-4 mb-6">
        <div className="bg-gradient-to-br from-gray-50 to-gray-100 rounded-xl p-4 border border-gray-200">
          <div className="flex items-center gap-3">
            <div className="w-10 h-10 bg-gray-200 rounded-lg flex items-center justify-center">
              <Users className="w-5 h-5 text-gray-600" />
            </div>
            <div>
              <p className="text-2xl font-bold text-gray-900">{filteredUsers.length}</p>
              <p className="text-xs text-gray-500">Total</p>
            </div>
          </div>
        </div>
        <div className="bg-gradient-to-br from-green-50 to-green-100 rounded-xl p-4 border border-green-200">
          <div className="flex items-center gap-3">
            <div className="w-10 h-10 bg-green-200 rounded-lg flex items-center justify-center">
              <UserCheck className="w-5 h-5 text-green-600" />
            </div>
            <div>
              <p className="text-2xl font-bold text-green-700">{roleStats.CLIENT}</p>
              <p className="text-xs text-green-600">Clients</p>
            </div>
          </div>
        </div>
        <div className="bg-gradient-to-br from-blue-50 to-blue-100 rounded-xl p-4 border border-blue-200">
          <div className="flex items-center gap-3">
            <div className="w-10 h-10 bg-blue-200 rounded-lg flex items-center justify-center">
              <Briefcase className="w-5 h-5 text-blue-600" />
            </div>
            <div>
              <p className="text-2xl font-bold text-blue-700">{roleStats.EMPLOYEE}</p>
              <p className="text-xs text-blue-600">Employés</p>
            </div>
          </div>
        </div>
        <div className="bg-gradient-to-br from-red-50 to-red-100 rounded-xl p-4 border border-red-200">
          <div className="flex items-center gap-3">
            <div className="w-10 h-10 bg-red-200 rounded-lg flex items-center justify-center">
              <Shield className="w-5 h-5 text-red-600" />
            </div>
            <div>
              <p className="text-2xl font-bold text-red-700">{roleStats.ADMIN}</p>
              <p className="text-xs text-red-600">Admins</p>
            </div>
          </div>
        </div>
      </div>

      {/* Table des utilisateurs */}
      <div className="bg-white rounded-2xl shadow-sm border border-gray-100 overflow-hidden">
        <table className="min-w-full">
          <thead className="bg-gradient-to-r from-gray-50 to-gray-100">
            <tr>
              <th className="px-6 py-4 text-left text-xs font-semibold text-gray-600 uppercase tracking-wider">
                Utilisateur
              </th>
              <th className="px-6 py-4 text-left text-xs font-semibold text-gray-600 uppercase tracking-wider">
                Rôle
              </th>
              <th className="px-6 py-4 text-left text-xs font-semibold text-gray-600 uppercase tracking-wider">
                Statut
              </th>
              <th className="px-6 py-4 text-left text-xs font-semibold text-gray-600 uppercase tracking-wider">
                Date création
              </th>
              <th className="px-6 py-4 text-left text-xs font-semibold text-gray-600 uppercase tracking-wider">
                Actions
              </th>
            </tr>
          </thead>
          <tbody className="divide-y divide-gray-100">
            {filteredUsers.length === 0 ? (
              <tr>
                <td colSpan={5} className="px-6 py-12 text-center">
                  <div className="flex flex-col items-center justify-center">
                    <div className="w-16 h-16 bg-gray-100 rounded-full flex items-center justify-center mb-4">
                      <Users className="w-8 h-8 text-gray-400" />
                    </div>
                    <p className="text-gray-500 font-medium">
                      {searchQuery ? 'Aucun résultat pour cette recherche' : 'Aucun utilisateur trouvé'}
                    </p>
                  </div>
                </td>
              </tr>
            ) : (
              filteredUsers.map((user) => (
                <tr key={user.id} className="hover:bg-gray-50 transition-colors">
                  <td className="px-6 py-4 whitespace-nowrap">
                    <div className="flex items-center gap-3">
                      <div className={`w-10 h-10 rounded-full flex items-center justify-center text-white font-bold text-sm ${getAvatarColor(user.role)}`}>
                        {getInitials(user.firstName, user.lastName)}
                      </div>
                      <div>
                        <div className="text-sm font-semibold text-gray-900">
                          {user.firstName} {user.lastName}
                        </div>
                        <div className="text-xs text-gray-500">{user.email}</div>
                      </div>
                    </div>
                  </td>
                  <td className="px-6 py-4 whitespace-nowrap">
                    <span className={`px-3 py-1 inline-flex text-xs leading-5 font-semibold rounded-full ${getRoleBadgeColor(user.role)}`}>
                      {user.role === 'ADMIN' ? 'Admin' : user.role === 'EMPLOYEE' ? 'Employé' : 'Client'}
                    </span>
                  </td>
                  <td className="px-6 py-4 whitespace-nowrap">
                    <div className="flex items-center gap-2">
                      <div className={`w-2 h-2 rounded-full ${user.isActive !== false ? 'bg-green-500' : 'bg-red-500'}`}></div>
                      <span className={`text-sm font-medium ${user.isActive !== false ? 'text-green-700' : 'text-red-700'}`}>
                        {user.isActive !== false ? 'Actif' : 'Inactif'}
                      </span>
                    </div>
                  </td>
                  <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-500">
                    {new Date(user.createdAt).toLocaleDateString('fr-FR')}
                  </td>
                  <td className="px-6 py-4 whitespace-nowrap">
                    <button
                      onClick={() => router.push(`/admin/utilisateurs/${user.id}`)}
                      className="px-4 py-2 text-sm font-medium text-blue-600 hover:text-blue-800 hover:bg-blue-50 rounded-lg transition-colors"
                    >
                      Détails
                    </button>
                  </td>
                </tr>
              ))
            )}
          </tbody>
        </table>
      </div>

      {/* Pagination */}
      <Pagination
        currentPage={page}
        totalPages={totalPages}
        onPageChange={setPage}
        showPageNumbers={false}
      />

      {/* Modal créer employé */}
      {isCreateEmployeeModalOpen && (
        <div className="fixed inset-0 bg-black/60 backdrop-blur-sm flex items-center justify-center z-50">
          <div className="bg-white rounded-2xl shadow-2xl max-w-md w-full mx-4 overflow-hidden">
            <div className="bg-gradient-to-r from-blue-600 to-indigo-600 px-6 py-4">
              <div className="flex items-center justify-between">
                <h2 className="text-xl font-bold text-white">Créer un employé</h2>
                <button
                  onClick={() => setIsCreateEmployeeModalOpen(false)}
                  className="w-8 h-8 bg-white/20 rounded-full flex items-center justify-center text-white hover:bg-white/30 transition-colors"
                >
                  <X className="w-5 h-5" />
                </button>
              </div>
            </div>
            <form onSubmit={handleCreateEmployee} className="p-6 space-y-4">
              <div>
                <label className="block text-sm font-semibold text-gray-700 mb-2">Email</label>
                <input
                  type="email"
                  value={employeeFormData.email}
                  onChange={(e) => setEmployeeFormData({ ...employeeFormData, email: e.target.value })}
                  className="w-full border border-gray-200 rounded-xl px-4 py-3 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                  placeholder="email@exemple.com"
                  required
                />
              </div>
              <div>
                <label className="block text-sm font-semibold text-gray-700 mb-2">Mot de passe</label>
                <input
                  type="password"
                  value={employeeFormData.password}
                  onChange={(e) => setEmployeeFormData({ ...employeeFormData, password: e.target.value })}
                  className="w-full border border-gray-200 rounded-xl px-4 py-3 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                  placeholder="••••••••"
                  required
                />
              </div>
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <label className="block text-sm font-semibold text-gray-700 mb-2">Prénom</label>
                  <input
                    type="text"
                    value={employeeFormData.firstName}
                    onChange={(e) => setEmployeeFormData({ ...employeeFormData, firstName: e.target.value })}
                    className="w-full border border-gray-200 rounded-xl px-4 py-3 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                    placeholder="Jean"
                    required
                  />
                </div>
                <div>
                  <label className="block text-sm font-semibold text-gray-700 mb-2">Nom</label>
                  <input
                    type="text"
                    value={employeeFormData.lastName}
                    onChange={(e) => setEmployeeFormData({ ...employeeFormData, lastName: e.target.value })}
                    className="w-full border border-gray-200 rounded-xl px-4 py-3 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                    placeholder="Dupont"
                    required
                  />
                </div>
              </div>
              <div className="flex gap-3 pt-4">
                <button
                  type="button"
                  onClick={() => setIsCreateEmployeeModalOpen(false)}
                  className="flex-1 px-4 py-3 bg-gray-100 text-gray-700 rounded-xl font-semibold hover:bg-gray-200 transition-colors"
                >
                  Annuler
                </button>
                <button
                  type="submit"
                  className="flex-1 px-4 py-3 bg-gradient-to-r from-blue-600 to-indigo-600 text-white rounded-xl font-semibold hover:from-blue-700 hover:to-indigo-700 transition-colors shadow-lg"
                >
                  Créer l'employé
                </button>
              </div>
            </form>
          </div>
        </div>
      )}

      {/* Modal modifier utilisateur */}
      {isEditUserModalOpen && editingUser && (
        <div className="fixed inset-0 bg-black/60 backdrop-blur-sm flex items-center justify-center z-50">
          <div className="bg-white rounded-2xl shadow-2xl max-w-md w-full mx-4 overflow-hidden">
            <div className="bg-gradient-to-r from-indigo-600 to-purple-600 px-6 py-4">
              <div className="flex items-center justify-between">
                <h2 className="text-xl font-bold text-white">Modifier l'utilisateur</h2>
                <button
                  onClick={() => setIsEditUserModalOpen(false)}
                  className="w-8 h-8 bg-white/20 rounded-full flex items-center justify-center text-white hover:bg-white/30 transition-colors"
                >
                  <X className="w-5 h-5" />
                </button>
              </div>
            </div>
            <form onSubmit={handleUpdateUser} className="p-6 space-y-4">
              <div className="flex items-center gap-4 p-4 bg-gray-50 rounded-xl">
                <div className={`w-12 h-12 rounded-full flex items-center justify-center text-white font-bold ${getAvatarColor(editingUser.role)}`}>
                  {getInitials(editingUser.firstName, editingUser.lastName)}
                </div>
                <div>
                  <p className="font-semibold text-gray-900">{editingUser.firstName} {editingUser.lastName}</p>
                  <p className="text-sm text-gray-500">{editingUser.email}</p>
                </div>
              </div>
              <div>
                <label className="block text-sm font-semibold text-gray-700 mb-2">Rôle</label>
                <select
                  value={userFormData.role}
                  onChange={(e) => setUserFormData({ ...userFormData, role: e.target.value as 'CLIENT' | 'EMPLOYEE' | 'ADMIN' })}
                  className="w-full border border-gray-200 rounded-xl px-4 py-3 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-transparent"
                >
                  <option value="CLIENT">Client</option>
                  <option value="EMPLOYEE">Employé</option>
                  <option value="ADMIN">Administrateur</option>
                </select>
              </div>
              <div className="flex gap-3 pt-4">
                <button
                  type="button"
                  onClick={() => setIsEditUserModalOpen(false)}
                  className="flex-1 px-4 py-3 bg-gray-100 text-gray-700 rounded-xl font-semibold hover:bg-gray-200 transition-colors"
                >
                  Annuler
                </button>
                <button
                  type="submit"
                  className="flex-1 px-4 py-3 bg-gradient-to-r from-indigo-600 to-purple-600 text-white rounded-xl font-semibold hover:from-indigo-700 hover:to-purple-700 transition-colors shadow-lg"
                >
                  Mettre à jour
                </button>
              </div>
            </form>
          </div>
        </div>
      )}
    </div>
  );
}