import { useState } from 'react';
import { Link } from 'react-router-dom';
import { Shield, Plus, Search, Edit, Trash2, Lock } from 'lucide-react';
import {
  useRoles,
  useDeleteRole,
  usePermissions,
  getPermissionCategoryLabel,
} from '@/hooks/useRbac';

export default function RolesPage() {
  const [searchTerm, setSearchTerm] = useState('');
  const [selectedRole, setSelectedRole] = useState<string | null>(null);

  const { data: roles, isLoading } = useRoles();
  const { data: permissions } = usePermissions();
  const deleteMutation = useDeleteRole();

  const handleDelete = async (id: string, isSystem: boolean) => {
    if (isSystem) {
      alert('System roles cannot be deleted.');
      return;
    }
    if (window.confirm('Are you sure you want to delete this role?')) {
      await deleteMutation.mutateAsync(id);
    }
  };

  const filteredRoles = roles?.filter((role: any) =>
    role.name.toLowerCase().includes(searchTerm.toLowerCase())
  );

  const selectedRoleData = roles?.find((r: any) => r.id === selectedRole);

  // Group permissions by category
  const permissionsByCategory = permissions?.reduce((acc: any, perm: any) => {
    if (!acc[perm.category]) {
      acc[perm.category] = [];
    }
    acc[perm.category].push(perm);
    return acc;
  }, {});

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900 dark:text-white">Roles & Permissions</h1>
          <p className="text-gray-500 dark:text-gray-400">
            Manage user roles and their permissions
          </p>
        </div>
        <Link
          to="/dashboard/rbac/roles/new"
          className="inline-flex items-center gap-2 rounded-lg bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700"
        >
          <Plus className="h-4 w-4" />
          New Role
        </Link>
      </div>

      <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
        {/* Roles List */}
        <div className="lg:col-span-1">
          <div className="rounded-lg border border-gray-200 bg-white dark:border-gray-700 dark:bg-gray-800">
            <div className="border-b border-gray-200 p-4 dark:border-gray-700">
              <div className="relative">
                <Search className="absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-gray-400" />
                <input
                  type="text"
                  placeholder="Search roles..."
                  value={searchTerm}
                  onChange={(e) => setSearchTerm(e.target.value)}
                  className="w-full rounded-lg border border-gray-300 bg-white py-2 pl-10 pr-4 text-sm focus:border-blue-500 focus:outline-none focus:ring-1 focus:ring-blue-500 dark:border-gray-600 dark:bg-gray-700 dark:text-white"
                />
              </div>
            </div>
            <div className="max-h-[600px] overflow-y-auto p-4">
              {isLoading ? (
                <div className="flex items-center justify-center py-8">
                  <div className="h-8 w-8 animate-spin rounded-full border-4 border-blue-600 border-t-transparent" />
                </div>
              ) : filteredRoles?.length ? (
                <div className="space-y-2">
                  {filteredRoles.map((role: any) => (
                    <button
                      key={role.id}
                      onClick={() => setSelectedRole(role.id)}
                      className={`w-full rounded-lg p-3 text-left transition-colors ${
                        selectedRole === role.id
                          ? 'bg-blue-50 ring-2 ring-blue-500 dark:bg-blue-900/20'
                          : 'hover:bg-gray-50 dark:hover:bg-gray-700'
                      }`}
                    >
                      <div className="flex items-center justify-between">
                        <div className="flex items-center gap-3">
                          <div className={`rounded-lg p-2 ${
                            role.is_system
                              ? 'bg-purple-100 dark:bg-purple-900/20'
                              : 'bg-gray-100 dark:bg-gray-700'
                          }`}>
                            <Shield className={`h-5 w-5 ${
                              role.is_system
                                ? 'text-purple-600 dark:text-purple-400'
                                : 'text-gray-600 dark:text-gray-400'
                            }`} />
                          </div>
                          <div>
                            <p className="font-medium text-gray-900 dark:text-white">{role.name}</p>
                            <p className="text-xs text-gray-500 dark:text-gray-400">
                              {role.permissions?.length || 0} permissions
                            </p>
                          </div>
                        </div>
                        {role.is_system && (
                          <Lock className="h-4 w-4 text-gray-400" />
                        )}
                      </div>
                    </button>
                  ))}
                </div>
              ) : (
                <p className="py-8 text-center text-gray-500 dark:text-gray-400">
                  No roles found.
                </p>
              )}
            </div>
          </div>
        </div>

        {/* Role Details */}
        <div className="lg:col-span-2">
          {selectedRoleData ? (
            <div className="rounded-lg border border-gray-200 bg-white dark:border-gray-700 dark:bg-gray-800">
              <div className="flex items-center justify-between border-b border-gray-200 p-4 dark:border-gray-700">
                <div>
                  <h2 className="text-lg font-semibold text-gray-900 dark:text-white">
                    {selectedRoleData.name}
                  </h2>
                  <p className="text-sm text-gray-500 dark:text-gray-400">
                    {selectedRoleData.description || 'No description'}
                  </p>
                </div>
                <div className="flex gap-2">
                  {!selectedRoleData.is_system && (
                    <>
                      <Link
                        to={`/dashboard/rbac/roles/${selectedRoleData.id}/edit`}
                        className="inline-flex items-center gap-2 rounded-lg border border-gray-300 bg-white px-3 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50 dark:border-gray-600 dark:bg-gray-800 dark:text-gray-300 dark:hover:bg-gray-700"
                      >
                        <Edit className="h-4 w-4" />
                        Edit
                      </Link>
                      <button
                        onClick={() => handleDelete(selectedRoleData.id, selectedRoleData.is_system)}
                        className="inline-flex items-center gap-2 rounded-lg border border-red-300 bg-white px-3 py-2 text-sm font-medium text-red-700 hover:bg-red-50 dark:border-red-600 dark:bg-gray-800 dark:text-red-400 dark:hover:bg-red-900/20"
                      >
                        <Trash2 className="h-4 w-4" />
                        Delete
                      </button>
                    </>
                  )}
                </div>
              </div>

              {/* Role Info */}
              <div className="border-b border-gray-200 p-4 dark:border-gray-700">
                <div className="grid grid-cols-3 gap-4">
                  <div>
                    <p className="text-sm text-gray-500 dark:text-gray-400">Type</p>
                    <p className="font-medium text-gray-900 dark:text-white">
                      {selectedRoleData.is_system ? 'System' : 'Custom'}
                    </p>
                  </div>
                  <div>
                    <p className="text-sm text-gray-500 dark:text-gray-400">Default</p>
                    <p className="font-medium text-gray-900 dark:text-white">
                      {selectedRoleData.is_default ? 'Yes' : 'No'}
                    </p>
                  </div>
                  <div>
                    <p className="text-sm text-gray-500 dark:text-gray-400">Slug</p>
                    <p className="font-mono text-sm text-gray-900 dark:text-white">
                      {selectedRoleData.slug}
                    </p>
                  </div>
                </div>
              </div>

              {/* Permissions */}
              <div className="p-4">
                <h3 className="mb-4 font-medium text-gray-900 dark:text-white">Permissions</h3>
                {permissionsByCategory && Object.keys(permissionsByCategory).length > 0 ? (
                  <div className="space-y-4">
                    {Object.entries(permissionsByCategory).map(([category, perms]: [string, any]) => {
                      const rolePermSlugs = selectedRoleData.permissions?.map((p: any) => p.slug) || [];
                      const categoryPerms = perms.filter((p: any) => rolePermSlugs.includes(p.slug));
                      if (categoryPerms.length === 0) return null;

                      return (
                        <div key={category}>
                          <h4 className="mb-2 text-sm font-medium text-gray-700 dark:text-gray-300">
                            {getPermissionCategoryLabel(category)}
                          </h4>
                          <div className="flex flex-wrap gap-2">
                            {categoryPerms.map((perm: any) => (
                              <span
                                key={perm.id}
                                className="inline-flex items-center rounded-full bg-blue-100 px-3 py-1 text-xs font-medium text-blue-800 dark:bg-blue-900/20 dark:text-blue-400"
                              >
                                {perm.name}
                              </span>
                            ))}
                          </div>
                        </div>
                      );
                    })}
                  </div>
                ) : (
                  <p className="text-sm text-gray-500 dark:text-gray-400">
                    No permissions assigned to this role.
                  </p>
                )}
              </div>
            </div>
          ) : (
            <div className="flex h-full items-center justify-center rounded-lg border border-gray-200 bg-white p-12 dark:border-gray-700 dark:bg-gray-800">
              <div className="text-center">
                <Shield className="mx-auto h-12 w-12 text-gray-300 dark:text-gray-600" />
                <p className="mt-4 text-gray-500 dark:text-gray-400">
                  Select a role to view its details and permissions
                </p>
              </div>
            </div>
          )}
        </div>
      </div>
    </div>
  );
}