// app/manager/home/page.tsx (ou doctors/page.tsx, dependendo da sua rota)
"use client";

import React, { useEffect, useState, useCallback } from "react";
import ManagerLayout from "@/components/manager-layout";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { Button } from "@/components/ui/button";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Plus,
  Edit,
  Trash2,
  Eye,
  Calendar,
  Filter,
  MoreVertical,
  Loader2,
} from "lucide-react";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog";
import { doctorsService } from "services/doctorsApi.mjs";

interface Doctor {
  id: number;
  full_name: string;
  specialty: string;
  crm: string;
  phone_mobile: string | null;
  city: string | null;
  state: string | null;
}

interface DoctorDetails {
  nome: string;
  crm: string;
  especialidade: string;
  contato: { celular?: string; telefone1?: string };
  endereco: { cidade?: string; estado?: string };
  convenio?: string;
  vip?: boolean;
  status?: string;
  ultimo_atendimento?: string;
  proximo_atendimento?: string;
  error?: string;
}

export default function DoctorsPage() {
  const router = useRouter();

  const [doctors, setDoctors] = useState<Doctor[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [detailsDialogOpen, setDetailsDialogOpen] = useState(false);
  const [doctorDetails, setDoctorDetails] = useState<DoctorDetails | null>(
    null
  );
  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false);
  const [doctorToDeleteId, setDoctorToDeleteId] = useState<number | null>(null);

  // --- Lógica de Paginação ---
  const [itemsPerPage, setItemsPerPage] = useState(10);
  const [currentPage, setCurrentPage] = useState(1);

  // 1. Definição do total de páginas
  const totalPages = Math.ceil(doctors.length / itemsPerPage);

  // 2. Cálculo dos itens a serem exibidos na página atual
  const indexOfLastItem = currentPage * itemsPerPage;
  const indexOfFirstItem = indexOfLastItem - itemsPerPage;
  const currentItems = doctors.slice(indexOfFirstItem, indexOfLastItem);

  // 3. Função para mudar de página
  const paginate = (pageNumber: number) => setCurrentPage(pageNumber);

  // 4. Funções para Navegação ADICIONADAS
  const goToPrevPage = () => {
    setCurrentPage((prev) => Math.max(1, prev - 1));
  };

  const goToNextPage = () => {
    setCurrentPage((prev) => Math.min(totalPages, prev + 1));
  };

  // 5. Lógica para gerar os números das páginas visíveis (máximo de 5)
  const getVisiblePageNumbers = (totalPages: number, currentPage: number) => {
    const pages: number[] = [];
    const maxVisiblePages = 5;
    const halfRange = Math.floor(maxVisiblePages / 2);
    let startPage = Math.max(1, currentPage - halfRange);
    let endPage = Math.min(totalPages, currentPage + halfRange);

    if (endPage - startPage + 1 < maxVisiblePages) {
      if (endPage === totalPages) {
        startPage = Math.max(1, totalPages - maxVisiblePages + 1);
      }
      if (startPage === 1) {
        endPage = Math.min(totalPages, maxVisiblePages);
      }
    }
    
    for (let i = startPage; i <= endPage; i++) {
      pages.push(i);
    }
    return pages;
  };
  
  const visiblePageNumbers = getVisiblePageNumbers(totalPages, currentPage);
  // Fim da lógica de números de página visíveis

  // Lógica para mudar itens por página, resetando para a página 1
  const handleItemsPerPageChange = (value: string) => {
    setItemsPerPage(Number(value));
    setCurrentPage(1); // Resetar para a primeira página
  };
  // --- Fim da Lógica de Paginação ---

  const fetchDoctors = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const data: Doctor[] = await doctorsService.list();
      setDoctors(data || []);
      setCurrentPage(1); // Resetar para a primeira página ao carregar novos dados
    } catch (e: any) {
      console.error("Erro ao carregar lista de médicos:", e);
      setError(
        "Não foi possível carregar a lista de médicos. Verifique a conexão com a API."
      );
      setDoctors([]);
    } finally {
      setLoading(false);
    }
  }, []);

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

  const openDetailsDialog = async (doctor: Doctor) => {
    setDetailsDialogOpen(true);
    setDoctorDetails({
      nome: doctor.full_name,
      crm: doctor.crm,
      especialidade: doctor.specialty,
      contato: { celular: doctor.phone_mobile ?? undefined },
      endereco: {
        cidade: doctor.city ?? undefined,
        estado: doctor.state ?? undefined,
      },
      convenio: "Particular",
      vip: false,
      status: "Ativo",
      ultimo_atendimento: "N/A",
      proximo_atendimento: "N/A",
    });
  };

  const handleDelete = async () => {
    if (doctorToDeleteId === null) return;
    setLoading(true);
    try {
      await doctorsService.delete(doctorToDeleteId);
      setDeleteDialogOpen(false);
      setDoctorToDeleteId(null);
      await fetchDoctors();
    } catch (e) {
      console.error("Erro ao excluir:", e);
      alert("Erro ao excluir médico.");
    } finally {
      setLoading(false);
    }
  };

  const openDeleteDialog = (doctorId: number) => {
    setDoctorToDeleteId(doctorId);
    setDeleteDialogOpen(true);
  };

  const handleEdit = (doctorId: number) => {
    router.push(`/manager/home/${doctorId}/editar`);
  };

  return (
    <ManagerLayout>
      <div className="space-y-6 px-2 sm:px-4 md:px-6">
        {/* Cabeçalho */}
        <div className="flex flex-col sm:flex-row items-start sm:items-center justify-between gap-3">
          <div>
            <h1 className="text-2xl font-bold text-gray-900">
              Médicos Cadastrados
            </h1>
            <p className="text-sm text-gray-500">
              Gerencie todos os profissionais de saúde.
            </p>
          </div>
          <Link href="/manager/home/novo" className="w-full sm:w-auto">
            <Button className="w-full sm:w-auto bg-green-600 hover:bg-green-700">
              <Plus className="w-4 h-4 mr-2" />
              Adicionar Novo
            </Button>
          </Link>
        </div>

        {/* Filtros e Itens por Página */}
        <div className="flex flex-wrap items-center gap-3 bg-white p-3 sm:p-4 rounded-lg border border-gray-200">
          <Filter className="w-5 h-5 text-gray-400" />
          <Select>
            <SelectTrigger className="w-[160px] sm:w-[180px]">
              <SelectValue placeholder="Especialidade" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="cardiologia">Cardiologia</SelectItem>
              <SelectItem value="dermatologia">Dermatologia</SelectItem>
              <SelectItem value="pediatria">Pediatria</SelectItem>
            </SelectContent>
          </Select>
          <Select>
            <SelectTrigger className="w-[160px] sm:w-[180px]">
              <SelectValue placeholder="Status" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="ativo">Ativo</SelectItem>
              <SelectItem value="ferias">Férias</SelectItem>
              <SelectItem value="inativo">Inativo</SelectItem>
            </SelectContent>
          </Select>
          {/* Select de Itens por Página */}
          <Select
            onValueChange={handleItemsPerPageChange}
            defaultValue={String(itemsPerPage)}
          >
            <SelectTrigger className="w-[140px]">
              <SelectValue placeholder="Itens por pág." />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="5">5 por página</SelectItem>
              <SelectItem value="10">10 por página</SelectItem>
              <SelectItem value="20">20 por página</SelectItem>
            </SelectContent>
          </Select>
        </div>

        {/* Tabela */}
        <div className="bg-white rounded-lg border border-gray-200 shadow-md overflow-hidden">
          {loading ? (
            <div className="p-8 text-center text-gray-500">
              <Loader2 className="w-8 h-8 animate-spin mx-auto mb-3 text-green-600" />
              Carregando médicos...
            </div>
          ) : error ? (
            <div className="p-8 text-center text-red-600">{error}</div>
          ) : doctors.length === 0 ? (
            <div className="p-8 text-center text-gray-500">
              Nenhum médico cadastrado.{" "}
              <Link
                href="/manager/home/novo"
                className="text-green-600 hover:underline"
              >
                Adicione um novo
              </Link>
              .
            </div>
          ) : (
            <div className="overflow-x-auto">
              <table className="min-w-[700px] w-full divide-y divide-gray-200 text-sm sm:text-base">
                <thead className="bg-gray-50">
                  <tr>
                    <th className="px-4 py-3 text-left font-medium text-gray-500 uppercase tracking-wider">
                      Nome
                    </th>
                    <th className="px-4 py-3 text-left font-medium text-gray-500 uppercase tracking-wider hidden sm:table-cell">
                      CRM
                    </th>
                    <th className="px-4 py-3 text-left font-medium text-gray-500 uppercase tracking-wider hidden md:table-cell">
                      Especialidade
                    </th>
                    <th className="px-4 py-3 text-left font-medium text-gray-500 uppercase tracking-wider hidden lg:table-cell">
                      Celular
                    </th>
                    <th className="px-4 py-3 text-left font-medium text-gray-500 uppercase tracking-wider hidden xl:table-cell">
                      Cidade/Estado
                    </th>
                    <th className="px-4 py-3 text-right font-medium text-gray-500 uppercase tracking-wider">
                      Ações
                    </th>
                  </tr>
                </thead>
                <tbody className="bg-white divide-y divide-gray-200">
                  {/* Usando currentItems para a paginação */}
                  {currentItems.map((doctor) => (
                    <tr key={doctor.id} className="hover:bg-gray-50 transition">
                      <td className="px-4 py-3 font-medium text-gray-900">
                        {doctor.full_name}
                      </td>
                      <td className="px-4 py-3 text-gray-500 hidden sm:table-cell">
                        {doctor.crm}
                      </td>
                      <td className="px-4 py-3 text-gray-500 hidden md:table-cell">
                        {doctor.specialty}
                      </td>
                      <td className="px-4 py-3 text-gray-500 hidden lg:table-cell">
                        {doctor.phone_mobile || "N/A"}
                      </td>
                      <td className="px-4 py-3 text-gray-500 hidden xl:table-cell">
                        {doctor.city || doctor.state
                          ? `${doctor.city || ""}${
                              doctor.city && doctor.state ? "/" : ""
                            }${doctor.state || ""}`
                          : "N/A"}
                      </td>
                      <td className="px-4 py-3 text-right">
                        <div className="flex justify-end gap-2 flex-wrap sm:flex-nowrap">
                          <Button
                            variant="outline"
                            size="icon"
                            onClick={() => openDetailsDialog(doctor)}
                            title="Visualizar Detalhes"
                          >
                            <Eye className="h-4 w-4" />
                          </Button>
                          <Button
                            variant="outline"
                            size="icon"
                            onClick={() => handleEdit(doctor.id)}
                            title="Editar"
                          >
                            <Edit className="h-4 w-4 text-blue-600" />
                          </Button>
                          <Button
                            variant="outline"
                            size="icon"
                            onClick={() => openDeleteDialog(doctor.id)}
                            title="Excluir"
                          >
                            <Trash2 className="h-4 w-4 text-red-600" />
                          </Button>
                          <DropdownMenu>
                            <DropdownMenuTrigger asChild>
                              <Button
                                variant="ghost"
                                className="h-8 w-8 p-0"
                                title="Mais Ações"
                              >
                                <MoreVertical className="h-4 w-4" />
                              </Button>
                            </DropdownMenuTrigger>
                            <DropdownMenuContent align="end">
                              <DropdownMenuItem>
                                <Calendar className="mr-2 h-4 w-4" />
                                Agendar Consulta
                              </DropdownMenuItem>
                            </DropdownMenuContent>
                          </DropdownMenu>
                        </div>
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          )}
        </div>

        {/* Paginação ATUALIZADA */}
        {totalPages > 1 && (
          <div className="flex flex-wrap justify-center items-center gap-2 mt-4 p-4 bg-white rounded-lg border border-gray-200 shadow-md">
            
            {/* Botão Anterior */}
            <button
              onClick={goToPrevPage}
              disabled={currentPage === 1}
              className="flex items-center px-4 py-2 rounded-md font-medium transition-colors text-sm bg-gray-100 text-gray-700 hover:bg-gray-200 disabled:opacity-50 disabled:cursor-not-allowed border border-gray-300"
            >
              {"< Anterior"}
            </button>

            {/* Números das Páginas */}
            {visiblePageNumbers.map((number) => (
              <button
                key={number}
                onClick={() => paginate(number)}
                className={`px-4 py-2 rounded-md font-medium transition-colors text-sm border border-gray-300 ${
                  currentPage === number
                    ? "bg-green-600 text-white shadow-md border-green-600"
                    : "bg-gray-100 text-gray-700 hover:bg-gray-200"
                }`}
              >
                {number}
              </button>
            ))}
            
            {/* Botão Próximo */}
            <button
              onClick={goToNextPage}
              disabled={currentPage === totalPages}
              className="flex items-center px-4 py-2 rounded-md font-medium transition-colors text-sm bg-gray-100 text-gray-700 hover:bg-gray-200 disabled:opacity-50 disabled:cursor-not-allowed border border-gray-300"
            >
              {"Próximo >"}
            </button>
            
          </div>
        )}

        {/* Dialogs */}
        <AlertDialog open={deleteDialogOpen} onOpenChange={setDeleteDialogOpen}>
          <AlertDialogContent>
            <AlertDialogHeader>
              <AlertDialogTitle>Confirma a exclusão?</AlertDialogTitle>
              <AlertDialogDescription>
                Esta ação é irreversível e excluirá permanentemente o registro
                deste médico.
              </AlertDialogDescription>
            </AlertDialogHeader>
            <AlertDialogFooter>
              <AlertDialogCancel disabled={loading}>Cancelar</AlertDialogCancel>
              <AlertDialogAction
                onClick={handleDelete}
                className="bg-red-600 hover:bg-red-700"
                disabled={loading}
              >
                {loading && (
                  <Loader2 className="w-4 h-4 mr-2 animate-spin" />
                )}
                Excluir
              </AlertDialogAction>
            </AlertDialogFooter>
          </AlertDialogContent>
        </AlertDialog>

        <AlertDialog open={detailsDialogOpen} onOpenChange={setDetailsDialogOpen}>
          <AlertDialogContent className="max-w-[95%] sm:max-w-lg">
            <AlertDialogHeader>
              <AlertDialogTitle className="text-2xl">
                {doctorDetails?.nome}
              </AlertDialogTitle>
              <AlertDialogDescription className="text-left text-gray-700">
                {doctorDetails && (
                  <div className="space-y-3 text-left">
                    <h3 className="font-semibold mt-2">
                      Informações Principais
                    </h3>
                    <div className="grid grid-cols-1 sm:grid-cols-2 gap-y-2 gap-x-4 text-sm">
                      <div>
                        <strong>CRM:</strong> {doctorDetails.crm}
                      </div>
                      <div>
                        <strong>Especialidade:</strong>{" "}
                        {doctorDetails.especialidade}
                      </div>
                      <div>
                        <strong>Celular:</strong>{" "}
                        {doctorDetails.contato.celular || "N/A"}
                      </div>
                      <div>
                        <strong>Localização:</strong>{" "}
                        {`${doctorDetails.endereco.cidade || "N/A"}/${
                          doctorDetails.endereco.estado || "N/A"
                        }`}
                      </div>
                    </div>

                    <h3 className="font-semibold mt-4">
                      Atendimento e Convênio
                    </h3>
                    <div className="grid grid-cols-1 sm:grid-cols-2 gap-y-2 gap-x-4 text-sm">
                      <div>
                        <strong>Convênio:</strong>{" "}
                        {doctorDetails.convenio || "N/A"}
                      </div>
                      <div>
                        <strong>VIP:</strong>{" "}
                        {doctorDetails.vip ? "Sim" : "Não"}
                      </div>
                      <div>
                        <strong>Status:</strong>{" "}
                        {doctorDetails.status || "N/A"}
                      </div>
                      <div>
                        <strong>Último atendimento:</strong>{" "}
                        {doctorDetails.ultimo_atendimento || "N/A"}
                      </div>
                      <div>
                        <strong>Próximo atendimento:</strong>{" "}
                        {doctorDetails.proximo_atendimento || "N/A"}
                      </div>
                    </div>
                  </div>
                )}
              </AlertDialogDescription>
            </AlertDialogHeader>
            <AlertDialogFooter>
              <AlertDialogCancel>Fechar</AlertDialogCancel>
            </AlertDialogFooter>
          </AlertDialogContent>
        </AlertDialog>
      </div>
    </ManagerLayout>
  );
}