"use client";

import { useState, useMemo } from "react";
import {
  ChevronLeft,
  ChevronRight,
  ChevronsLeft,
  ChevronsRight,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { PaginationProps, PaginationConfig } from "@/lib/types";

const DEFAULT_CONFIG: PaginationConfig = {
  itemsPerPage: 20,
  maxVisiblePages: 5,
  showFirstLast: true,
  showPrevNext: true,
};

export function Pagination({
  currentPage,
  totalPages,
  totalItems,
  itemsPerPage,
  onPageChange,
  onItemsPerPageChange,
  config = {},
  className = "",
}: PaginationProps) {
  const [localItemsPerPage, setLocalItemsPerPage] = useState(itemsPerPage);
  const finalConfig = useMemo(
    () => ({ ...DEFAULT_CONFIG, ...config }),
    [config]
  );

  // Calcular índices dos itens
  const startIndex = (currentPage - 1) * itemsPerPage + 1;
  const endIndex = Math.min(currentPage * itemsPerPage, totalItems);

  // Gerar array de páginas visíveis com responsividade
  const visiblePages = useMemo(() => {
    const pages: (number | string)[] = [];
    // Reduzir maxVisiblePages em mobile (assumindo que usaremos classes Tailwind)
    const isMobile = typeof window !== "undefined" && window.innerWidth < 640;
    const maxVisible = isMobile ? 3 : finalConfig.maxVisiblePages;

    if (totalPages <= maxVisible) {
      // Se total de páginas é menor que o máximo, mostrar todas
      for (let i = 1; i <= totalPages; i++) {
        pages.push(i);
      }
    } else {
      // Lógica para mostrar páginas com ellipsis
      const halfVisible = Math.floor(maxVisible / 2);
      let startPage = Math.max(1, currentPage - halfVisible);
      const endPage = Math.min(totalPages, startPage + maxVisible - 1);

      // Ajustar se estivermos no final
      if (endPage - startPage + 1 < maxVisible) {
        startPage = Math.max(1, endPage - maxVisible + 1);
      }

      // Primeira página (ocultar em mobile)
      if (startPage > 1 && !isMobile) {
        pages.push(1);
        if (startPage > 2) {
          pages.push("...");
        }
      }

      // Páginas do meio
      for (let i = startPage; i <= endPage; i++) {
        pages.push(i);
      }

      // Última página (ocultar em mobile)
      if (endPage < totalPages && !isMobile) {
        if (endPage < totalPages - 1) {
          pages.push("...");
        }
        pages.push(totalPages);
      }
    }

    return pages;
  }, [currentPage, totalPages, finalConfig]);

  const handleItemsPerPageChange = (newItemsPerPage: string) => {
    const newValue = parseInt(newItemsPerPage);
    setLocalItemsPerPage(newValue);
    if (onItemsPerPageChange) {
      onItemsPerPageChange(newValue);
    }
  };

  const canGoPrevious = currentPage > 1;
  const canGoNext = currentPage < totalPages;

  if (totalPages <= 1) {
    return null;
  }

  return (
    <div className={`w-full ${className}`}>
      {/* Layout Mobile: Múltiplas linhas */}
      <div className="flex flex-col gap-3 sm:hidden">
        {/* Linha 1: Informação de resultados */}
        <div className="text-center text-sm text-gray-600 dark:text-gray-400">
          {startIndex}-{endIndex} de {totalItems} resultado
          {totalItems !== 1 ? "s" : ""}
        </div>

        {/* Linha 2: Controles de navegação */}
        <div className="flex justify-center">
          <div className="flex items-center gap-1 overflow-x-auto px-2 scrollbar-hide">
            {/* Página anterior */}
            <Button
              variant="outline"
              size="sm"
              onClick={() => onPageChange(currentPage - 1)}
              disabled={!canGoPrevious}
              className="h-9 w-9 p-0 flex-shrink-0"
            >
              <ChevronLeft className="h-4 w-4" />
            </Button>

            {/* Números das páginas */}
            {visiblePages.map((page, index) => (
              <div key={index} className="flex-shrink-0">
                {page === "..." ? (
                  <span className="px-2 py-1 text-sm text-gray-500">...</span>
                ) : (
                  <Button
                    variant={currentPage === page ? "default" : "outline"}
                    size="sm"
                    onClick={() => onPageChange(page as number)}
                    className="h-9 w-9 p-0"
                  >
                    {page}
                  </Button>
                )}
              </div>
            ))}

            {/* Próxima página */}
            <Button
              variant="outline"
              size="sm"
              onClick={() => onPageChange(currentPage + 1)}
              disabled={!canGoNext}
              className="h-9 w-9 p-0 flex-shrink-0"
            >
              <ChevronRight className="h-4 w-4" />
            </Button>
          </div>
        </div>

        {/* Linha 3: Seletor de itens por página (opcional) */}
        {onItemsPerPageChange && (
          <div className="flex justify-center">
            <div className="flex items-center gap-2">
              <span className="text-xs text-gray-600 dark:text-gray-400">
                Por página:
              </span>
              <Select
                value={localItemsPerPage.toString()}
                onValueChange={handleItemsPerPageChange}
              >
                <SelectTrigger className="w-16 h-8 text-xs">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="10">10</SelectItem>
                  <SelectItem value="20">20</SelectItem>
                  <SelectItem value="50">50</SelectItem>
                  <SelectItem value="100">100</SelectItem>
                </SelectContent>
              </Select>
            </div>
          </div>
        )}
      </div>

      {/* Layout Desktop: Linha única */}
      <div className="hidden sm:flex flex-row items-center justify-between gap-4">
        {/* Informações dos itens */}
        <div className="text-sm text-gray-600 dark:text-gray-400">
          Mostrando {startIndex} a {endIndex} de {totalItems} resultado
          {totalItems !== 1 ? "s" : ""}
        </div>

        {/* Controles de paginação */}
        <div className="flex items-center gap-2">
          {/* Seletor de itens por página */}
          {onItemsPerPageChange && (
            <div className="flex items-center gap-2 mr-4">
              <span className="text-sm text-gray-600 dark:text-gray-400">
                Por página:
              </span>
              <Select
                value={localItemsPerPage.toString()}
                onValueChange={handleItemsPerPageChange}
              >
                <SelectTrigger className="w-20 h-8">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="10">10</SelectItem>
                  <SelectItem value="20">20</SelectItem>
                  <SelectItem value="50">50</SelectItem>
                  <SelectItem value="100">100</SelectItem>
                </SelectContent>
              </Select>
            </div>
          )}

          {/* Botões de navegação */}
          <div className="flex items-center gap-1">
            {/* Primeira página */}
            {finalConfig.showFirstLast && (
              <Button
                variant="outline"
                size="sm"
                onClick={() => onPageChange(1)}
                disabled={!canGoPrevious}
                className="h-8 w-8 p-0"
              >
                <ChevronsLeft className="h-4 w-4" />
              </Button>
            )}

            {/* Página anterior */}
            {finalConfig.showPrevNext && (
              <Button
                variant="outline"
                size="sm"
                onClick={() => onPageChange(currentPage - 1)}
                disabled={!canGoPrevious}
                className="h-8 w-8 p-0"
              >
                <ChevronLeft className="h-4 w-4" />
              </Button>
            )}

            {/* Números das páginas */}
            {visiblePages.map((page, index) => (
              <div key={index}>
                {page === "..." ? (
                  <span className="px-3 py-1 text-sm text-gray-500">...</span>
                ) : (
                  <Button
                    variant={currentPage === page ? "default" : "outline"}
                    size="sm"
                    onClick={() => onPageChange(page as number)}
                    className="h-8 w-8 p-0"
                  >
                    {page}
                  </Button>
                )}
              </div>
            ))}

            {/* Próxima página */}
            {finalConfig.showPrevNext && (
              <Button
                variant="outline"
                size="sm"
                onClick={() => onPageChange(currentPage + 1)}
                disabled={!canGoNext}
                className="h-8 w-8 p-0"
              >
                <ChevronRight className="h-4 w-4" />
              </Button>
            )}

            {/* Última página */}
            {finalConfig.showFirstLast && (
              <Button
                variant="outline"
                size="sm"
                onClick={() => onPageChange(totalPages)}
                disabled={!canGoNext}
                className="h-8 w-8 p-0"
              >
                <ChevronsRight className="h-4 w-4" />
              </Button>
            )}
          </div>
        </div>
      </div>
    </div>
  );
}