'use client';

import * as React from 'react';
import { Check, ChevronsUpDown } from 'lucide-react';
import { Button } from './button';
import {
  Command,
  CommandEmpty,
  CommandGroup,
  CommandInput,
  CommandItem,
  CommandList,
} from './command';
import { Popover, PopoverContent, PopoverTrigger } from './popover';
import { cn } from './utils';

export interface MultiSelectOption {
  value: string;
  label: string;
  depth?: number; // 트리 구조 들여쓰기용
}

interface MultiSelectComboboxProps {
  options: MultiSelectOption[];
  value: string[];
  onChange: (value: string[]) => void;
  placeholder?: string;
  searchPlaceholder?: string;
  emptyText?: string;
  disabled?: boolean;
  className?: string;
}

export function MultiSelectCombobox({
  options,
  value,
  onChange,
  placeholder = '선택하세요',
  searchPlaceholder = '검색...',
  emptyText = '결과가 없습니다.',
  disabled = false,
  className,
}: MultiSelectComboboxProps) {
  const [open, setOpen] = React.useState(false);

  const handleSelect = (selectedValue: string) => {
    if (value.includes(selectedValue)) {
      onChange(value.filter((v) => v !== selectedValue));
    } else {
      onChange([...value, selectedValue]);
    }
  };

  const handleSelectAll = () => {
    if (value.length === options.length) {
      onChange([]);
    } else {
      onChange(options.map((opt) => opt.value));
    }
  };

  const getDisplayText = () => {
    if (value.length === 0) return placeholder;
    if (value.length === options.length) return '전체';
    const firstItem = options.find((opt) => opt.value === value[0]);
    if (value.length === 1) return firstItem?.label || '';
    return `${firstItem?.label} 외 ${value.length - 1}`;
  };

  return (
    <Popover open={open} onOpenChange={setOpen}>
      <PopoverTrigger asChild>
        <Button
          variant="outline"
          role="combobox"
          aria-expanded={open}
          disabled={disabled}
          className={cn(
            'justify-between font-normal',
            !value.length && 'text-muted-foreground',
            className
          )}
        >
          <span className="truncate">{getDisplayText()}</span>
          <ChevronsUpDown className="ml-2 h-4 w-4 shrink-0 opacity-50" />
        </Button>
      </PopoverTrigger>
      <PopoverContent
        className="w-[200px] p-0"
        align="start"
        onPointerDownOutside={(e) => {
          e.preventDefault();
          setOpen(false);
        }}
        onInteractOutside={(e) => {
          e.preventDefault();
          setOpen(false);
        }}
      >
        <Command>
          <CommandInput placeholder={searchPlaceholder} />
          <CommandList>
            <CommandEmpty>{emptyText}</CommandEmpty>
            <CommandGroup>
              {/* 전체 선택 */}
              <CommandItem onSelect={handleSelectAll} className="cursor-pointer">
                <Check
                  className={cn(
                    'mr-2 h-4 w-4',
                    value.length === options.length ? 'opacity-100' : 'opacity-0'
                  )}
                />
                전체
              </CommandItem>
              {/* 개별 옵션 */}
              {options.map((option) => (
                <CommandItem
                  key={option.value}
                  value={option.label}
                  onSelect={() => handleSelect(option.value)}
                  className="cursor-pointer"
                  style={{ paddingLeft: option.depth ? `${(option.depth * 16) + 8}px` : undefined }}
                >
                  <Check
                    className={cn(
                      'mr-2 h-4 w-4 shrink-0',
                      value.includes(option.value) ? 'opacity-100' : 'opacity-0'
                    )}
                  />
                  <span className="truncate">{option.label}</span>
                </CommandItem>
              ))}
            </CommandGroup>
          </CommandList>
        </Command>
      </PopoverContent>
    </Popover>
  );
}