'use client';

import { useState, useEffect, useCallback } from 'react';
import { UsersRound, Edit, Users, Check, X, Plus } from 'lucide-react';
import { permissionGroupsAPI } from '@/lib/api/admin';
import type { PermissionGroup } from '@/lib/api/admin';
import Modal from '@/components/Modal';
import LoadingSpinner from '@/components/LoadingSpinner';

const MODULES = [
  { id: 'contacts', name: 'إدارة جهات الاتصال', nameEn: 'Contact Management' },
  { id: 'crm', name: 'إدارة علاقات العملاء', nameEn: 'CRM' },
  { id: 'inventory', name: 'المخزون والأصول', nameEn: 'Inventory & Assets' },
  { id: 'projects', name: 'المهام والمشاريع', nameEn: 'Tasks & Projects' },
  { id: 'hr', name: 'الموارد البشرية', nameEn: 'HR Management' },
  { id: 'marketing', name: 'التسويق', nameEn: 'Marketing' },
  { id: 'admin', name: 'لوحة الإدارة', nameEn: 'Admin' },
];

const ACTIONS = [
  { id: 'read', name: 'عرض' },
  { id: 'create', name: 'إنشاء' },
  { id: 'update', name: 'تعديل' },
  { id: 'delete', name: 'حذف' },
  { id: 'export', name: 'تصدير' },
  { id: 'approve', name: 'اعتماد' },
  { id: 'merge', name: 'دمج' },
];

function hasAction(perm: { actions?: unknown } | undefined, action: string): boolean {
  if (!perm?.actions) return false;
  const actions = Array.isArray(perm.actions) ? perm.actions : [];
  return actions.includes('*') || actions.includes('all') || actions.includes(action);
}

function buildPermissionsFromMatrix(matrix: Record<string, Record<string, boolean>>) {
  return MODULES.filter((m) => Object.values(matrix[m.id] || {}).some(Boolean)).map((m) => {
    const actions = ACTIONS.filter((a) => matrix[m.id]?.[a.id]).map((a) => a.id);
    return {
      module: m.id,
      resource: '*',
      actions: actions.length === ACTIONS.length ? ['*'] : actions,
    };
  });
}

function buildMatrixFromPermissions(permissions: { module: string; resource: string; actions: string[] }[]) {
  const matrix: Record<string, Record<string, boolean>> = {};
  for (const m of MODULES) {
    matrix[m.id] = {};
    const perm = permissions.find((p) => p.module === m.id && (p.resource === '*' || p.resource === m.id));
    const hasAll = perm && (Array.isArray(perm.actions)
      ? perm.actions.includes('*') || perm.actions.includes('all')
      : false);
    for (const a of ACTIONS) {
      matrix[m.id][a.id] = hasAll || hasAction(perm, a.id);
    }
  }
  return matrix;
}

export default function PermissionGroupsPage() {
  const [groups, setGroups] = useState<PermissionGroup[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [selectedId, setSelectedId] = useState<string | null>(null);
  const [showEditModal, setShowEditModal] = useState(false);
  const [showCreateModal, setShowCreateModal] = useState(false);
  const [createForm, setCreateForm] = useState({ name: '', nameAr: '', description: '' });
  type PermissionMatrix = Record<string, Record<string, boolean>>;
  const [permissionMatrix, setPermissionMatrix] = useState<PermissionMatrix>({});
  const [saving, setSaving] = useState(false);

  const fetchGroups = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const list = await permissionGroupsAPI.getAll();
      setGroups(list);
      if (selectedId && !list.find((g) => g.id === selectedId)) setSelectedId(null);
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : 'فشل تحميل المجموعات');
    } finally {
      setLoading(false);
    }
  }, [selectedId]);

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

  const currentGroup = groups.find((g) => g.id === selectedId);

  useEffect(() => {
    if (currentGroup) {
      setPermissionMatrix(buildMatrixFromPermissions(currentGroup.permissions || []));
    }
  }, [currentGroup?.id, currentGroup?.permissions]);

  const handleCreate = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!createForm.name.trim()) {
      alert('الاسم مطلوب');
      return;
    }
    setSaving(true);
    try {
      const group = await permissionGroupsAPI.create({
        name: createForm.name.trim(),
        nameAr: createForm.nameAr.trim() || undefined,
        description: createForm.description.trim() || undefined,
      });
      setShowCreateModal(false);
      setCreateForm({ name: '', nameAr: '', description: '' });
      await fetchGroups();
      setSelectedId(group.id);
      setShowEditModal(true);
    } catch (err: unknown) {
      alert(err instanceof Error ? err.message : 'فشل الإنشاء');
    } finally {
      setSaving(false);
    }
  };

  const handleSavePermissions = async () => {
    if (!selectedId) return;
    setSaving(true);
    try {
      const permissions = buildPermissionsFromMatrix(permissionMatrix);
      await permissionGroupsAPI.updatePermissions(selectedId, permissions);
      setShowEditModal(false);
      fetchGroups();
    } catch (err: unknown) {
      alert(err instanceof Error ? err.message : 'فشل الحفظ');
    } finally {
      setSaving(false);
    }
  };

  const handleTogglePermission = (moduleId: string, actionId: string) => {
    setPermissionMatrix((prev) => ({
      ...prev,
      [moduleId]: {
        ...(prev[moduleId] || {}),
        [actionId]: !prev[moduleId]?.[actionId],
      },
    }));
  };

  return (
    <div>
      <div className="mb-8 flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-bold text-gray-900 mb-2">مجموعات الصلاحيات</h1>
          <p className="text-gray-600">مجموعات اختيارية تضيف صلاحيات إضافية للمستخدمين بغض النظر عن وظائفهم</p>
        </div>
        <button
          onClick={() => setShowCreateModal(true)}
          className="flex items-center gap-2 px-6 py-3 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-all shadow-md"
        >
          <Plus className="h-5 w-5" />
          <span className="font-semibold">إضافة مجموعة</span>
        </button>
      </div>

      {loading ? (
        <div className="flex justify-center p-12">
          <LoadingSpinner />
        </div>
      ) : error ? (
        <div className="text-center text-red-600 p-12">{error}</div>
      ) : (
        <div className="grid grid-cols-1 lg:grid-cols-3 gap-8">
          <div className="lg:col-span-1 space-y-4">
            <h2 className="text-xl font-bold text-gray-900 mb-4">المجموعات ({groups.length})</h2>
            {groups.map((g) => (
              <div
                key={g.id}
                onClick={() => setSelectedId(g.id)}
                className={`p-4 rounded-xl border-2 cursor-pointer transition-all ${
                  selectedId === g.id ? 'border-blue-600 bg-blue-50' : 'border-gray-200 bg-white hover:border-blue-300'
                }`}
              >
                <div className="flex items-center gap-3 mb-2">
                  <div className={`p-2 rounded-lg ${selectedId === g.id ? 'bg-blue-600' : 'bg-blue-100'}`}>
                    <UsersRound className={`h-5 w-5 ${selectedId === g.id ? 'text-white' : 'text-blue-600'}`} />
                  </div>
                  <div>
                    <h3 className="font-bold text-gray-900">{g.nameAr || g.name}</h3>
                    <p className="text-xs text-gray-600">{g.name}</p>
                  </div>
                </div>
                <div className="flex items-center justify-between">
                  <span className="text-sm text-gray-600">
                    <Users className="h-4 w-4 inline mr-1" />
                    {g._count?.userRoles ?? 0} مستخدم
                  </span>
                  <button
                    onClick={(e) => {
                      e.stopPropagation();
                      setSelectedId(g.id);
                      setShowEditModal(true);
                    }}
                    className="p-1.5 text-blue-600 hover:bg-blue-50 rounded"
                  >
                    <Edit className="h-4 w-4" />
                  </button>
                </div>
              </div>
            ))}
          </div>

          <div className="lg:col-span-2">
            {currentGroup ? (
              <div className="bg-white rounded-xl shadow-lg border p-6">
                <div className="flex justify-between mb-6">
                  <div>
                    <h2 className="text-2xl font-bold text-gray-900">{currentGroup.nameAr || currentGroup.name}</h2>
                    <p className="text-gray-600">{currentGroup.name}</p>
                  </div>
                  <button
                    onClick={() => setShowEditModal(true)}
                    className="px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700"
                  >
                    تعديل الصلاحيات
                  </button>
                </div>
                <h3 className="text-lg font-bold mb-4">مصفوفة الصلاحيات</h3>
                <div className="overflow-x-auto">
                  <table className="w-full">
                    <thead>
                      <tr className="border-b-2 border-gray-200">
                        <th className="px-4 py-3 text-right text-sm font-bold min-w-[200px]">الوحدة</th>
                        {ACTIONS.map((a) => (
                          <th key={a.id} className="px-4 py-3 text-center text-sm font-bold">{a.name}</th>
                        ))}
                      </tr>
                    </thead>
                    <tbody className="divide-y divide-gray-200">
                      {MODULES.map((m) => (
                        <tr key={m.id} className="hover:bg-gray-50">
                          <td className="px-4 py-4">
                            <p className="font-semibold">{m.name}</p>
                            <p className="text-xs text-gray-600">{m.nameEn}</p>
                          </td>
                          {ACTIONS.map((a) => {
                            const has = permissionMatrix[m.id]?.[a.id];
                            return (
                              <td key={a.id} className="px-4 py-4 text-center">
                                <div
                                  className={`w-10 h-10 rounded-lg flex items-center justify-center mx-auto ${
                                    has ? 'bg-green-500 text-white' : 'bg-gray-200 text-gray-500'
                                  }`}
                                >
                                  {has ? <Check className="h-6 w-6" /> : <X className="h-6 w-6" />}
                                </div>
                              </td>
                            );
                          })}
                        </tr>
                      ))}
                    </tbody>
                  </table>
                </div>
              </div>
            ) : (
              <div className="bg-white rounded-xl shadow-lg border p-12 text-center">
                <UsersRound className="h-16 w-16 text-gray-300 mx-auto mb-4" />
                <h3 className="text-xl font-bold text-gray-900 mb-2">اختر مجموعة</h3>
                <p className="text-gray-600">أو أنشئ مجموعة جديدة لإضافة صلاحيات اختيارية للمستخدمين</p>
              </div>
            )}
          </div>
        </div>
      )}

      <Modal isOpen={showCreateModal} onClose={() => setShowCreateModal(false)} title="إضافة مجموعة صلاحيات" size="md">
        <form onSubmit={handleCreate} className="space-y-4">
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Name *</label>
            <input
              type="text"
              value={createForm.name}
              onChange={(e) => setCreateForm((p) => ({ ...p, name: e.target.value }))}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg"
              placeholder="e.g. Campaign Approver"
            />
          </div>
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Name (Arabic)</label>
            <input
              type="text"
              value={createForm.nameAr}
              onChange={(e) => setCreateForm((p) => ({ ...p, nameAr: e.target.value }))}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg"
            />
          </div>
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Description</label>
            <textarea
              value={createForm.description}
              onChange={(e) => setCreateForm((p) => ({ ...p, description: e.target.value }))}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg"
              rows={2}
            />
          </div>
          <div className="flex gap-3 justify-end pt-4">
            <button type="button" onClick={() => setShowCreateModal(false)} className="px-6 py-3 border rounded-lg">
              Cancel
            </button>
            <button type="submit" disabled={saving} className="px-6 py-3 bg-blue-600 text-white rounded-lg disabled:opacity-50">
              {saving ? 'Creating...' : 'Create'}
            </button>
          </div>
        </form>
      </Modal>

      <Modal
        isOpen={showEditModal}
        onClose={() => setShowEditModal(false)}
        title={`تعديل صلاحيات: ${currentGroup?.nameAr || currentGroup?.name || ''}`}
        size="2xl"
      >
        {currentGroup && (
          <div>
            <div className="overflow-x-auto mb-6">
              <table className="w-full">
                <thead>
                  <tr className="border-b-2 border-gray-200">
                    <th className="px-4 py-3 text-right text-sm font-bold">الوحدة</th>
                    {ACTIONS.map((a) => (
                      <th key={a.id} className="px-4 py-3 text-center text-sm font-bold">{a.name}</th>
                    ))}
                  </tr>
                </thead>
                <tbody className="divide-y divide-gray-200">
                  {MODULES.map((m) => (
                    <tr key={m.id}>
                      <td className="px-4 py-4 font-semibold">{m.name}</td>
                      {ACTIONS.map((a) => (
                        <td key={a.id} className="px-4 py-4 text-center">
                          <button
                            type="button"
                            onClick={() => handleTogglePermission(m.id, a.id)}
                            className={`w-10 h-10 rounded-lg flex items-center justify-center mx-auto ${
                              permissionMatrix[m.id]?.[a.id] ? 'bg-green-500 text-white' : 'bg-gray-200 text-gray-500'
                            }`}
                          >
                            {permissionMatrix[m.id]?.[a.id] ? <Check className="h-6 w-6" /> : <X className="h-6 w-6" />}
                          </button>
                        </td>
                      ))}
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
            <div className="flex gap-3 justify-end">
              <button onClick={() => setShowEditModal(false)} className="px-6 py-3 border rounded-lg">
                إلغاء
              </button>
              <button onClick={handleSavePermissions} disabled={saving} className="px-6 py-3 bg-blue-600 text-white rounded-lg disabled:opacity-50">
                {saving ? 'جاري الحفظ...' : 'حفظ'}
              </button>
            </div>
          </div>
        )}
      </Modal>
    </div>
  );
}
