import { useMemo } from 'react';
import { Button } from '@/components/ui/button';
import { cn } from '@/lib/utils';
import { ChevronLeft, ChevronRight, MoreHorizontal } from 'lucide-react';

export interface PaginationProps {
  currentPage: number;
  totalPages: number;
  onPageChange: (page: number) => void;
  maxVisiblePages?: number;
  showFirstLast?: boolean;
  className?: string;
}

/**
 * Composant Pagination pour navigation entre pages de résultats.
 */
export function Pagination({
  currentPage,
  totalPages,
  onPageChange,
  maxVisiblePages = 5,
  showFirstLast = false,
  className,
}: PaginationProps) {
  const visiblePages = useMemo(() => {
    if (totalPages <= maxVisiblePages) {
      return Array.from({ length: totalPages }, (_, i) => i + 1);
    }

    const pages: (number | 'ellipsis-start' | 'ellipsis-end')[] = [];
    const half = Math.floor(maxVisiblePages / 2);

    let start = Math.max(1, currentPage - half);
    const end = Math.min(totalPages, start + maxVisiblePages - 1);

    // Ajuster si on est proche de la fin
    if (end === totalPages) {
      start = Math.max(1, totalPages - maxVisiblePages + 1);
    }

    // Première page
    if (showFirstLast && start > 1) {
      pages.push(1);
      if (start > 2) {
        pages.push('ellipsis-start');
      }
    } else if (start > 1) {
      pages.push(1);
      if (start > 2) {
        pages.push('ellipsis-start');
      }
    }

    // Pages visibles
    for (let i = start; i <= end; i++) {
      pages.push(i);
    }

    // Dernière page
    if (end < totalPages) {
      if (end < totalPages - 1) {
        pages.push('ellipsis-end');
      }
      pages.push(totalPages);
    }

    return pages;
  }, [currentPage, totalPages, maxVisiblePages, showFirstLast]);

  const handlePrevious = () => {
    if (currentPage > 1) {
      onPageChange(currentPage - 1);
    }
  };

  const handleNext = () => {
    if (currentPage < totalPages) {
      onPageChange(currentPage + 1);
    }
  };

  const handleFirst = () => {
    onPageChange(1);
  };

  const handleLast = () => {
    onPageChange(totalPages);
  };

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

  return (
    <nav
      aria-label="Pagination"
      className={cn('flex items-center justify-center gap-1', className)}
    >
      {showFirstLast && (
        <Button
          variant="outline"
          size="icon"
          onClick={handleFirst}
          disabled={currentPage === 1}
          aria-label="First page"
        >
          <ChevronLeft className="h-4 w-4" />
          <ChevronLeft className="h-4 w-4 -ml-2" />
        </Button>
      )}

      <Button
        variant="outline"
        size="icon"
        onClick={handlePrevious}
        disabled={currentPage === 1}
        aria-label="Previous page"
      >
        <ChevronLeft className="h-4 w-4" />
      </Button>

      {visiblePages.map((page, index) => {
        if (page === 'ellipsis-start' || page === 'ellipsis-end') {
          return (
            <div
              key={`ellipsis-${index}`}
              className="flex h-9 w-9 items-center justify-center"
            >
              <MoreHorizontal className="h-4 w-4 text-muted-foreground" />
            </div>
          );
        }

        return (
          <Button
            key={page}
            variant={currentPage === page ? 'default' : 'outline'}
            size="icon"
            onClick={() => onPageChange(page)}
            aria-label={`Go to page ${page}`}
            aria-current={currentPage === page ? 'page' : undefined}
            className={cn(
              'h-9 w-9',
              currentPage === page && 'bg-primary text-primary-foreground'
            )}
          >
            {page}
          </Button>
        );
      })}

      <Button
        variant="outline"
        size="icon"
        onClick={handleNext}
        disabled={currentPage === totalPages}
        aria-label="Next page"
      >
        <ChevronRight className="h-4 w-4" />
      </Button>

      {showFirstLast && (
        <Button
          variant="outline"
          size="icon"
          onClick={handleLast}
          disabled={currentPage === totalPages}
          aria-label="Last page"
        >
          <ChevronRight className="h-4 w-4" />
          <ChevronRight className="h-4 w-4 -ml-2" />
        </Button>
      )}
    </nav>
  );
}

