"use client";

import { useState, useEffect } from "react";
import { ChevronRight, ChevronDown, Folder, FolderOpen, Tag } from "lucide-react";
import { cn } from "@/lib/utils";
import { LangCategory, getCategories } from "@/lib/api/multilang";

interface CategoryTreeProps {
  selectedCategoryId: number | null;
  onSelectCategory: (category: LangCategory | null) => void;
  onDoubleClickCategory?: (category: LangCategory) => void;
}

interface CategoryNodeProps {
  category: LangCategory;
  level: number;
  selectedCategoryId: number | null;
  onSelectCategory: (category: LangCategory) => void;
  onDoubleClickCategory?: (category: LangCategory) => void;
}

function CategoryNode({
  category,
  level,
  selectedCategoryId,
  onSelectCategory,
  onDoubleClickCategory,
}: CategoryNodeProps) {
  const [isExpanded, setIsExpanded] = useState(true);
  const hasChildren = category.children && category.children.length > 0;
  const isSelected = selectedCategoryId === category.categoryId;

  return (
    <div>
      <div
        className={cn(
          "flex cursor-pointer items-center gap-1 rounded-md px-2 py-1.5 text-sm transition-colors",
          isSelected
            ? "bg-primary text-primary-foreground"
            : "hover:bg-muted"
        )}
        style={{ paddingLeft: `${level * 16 + 8}px` }}
        onClick={() => onSelectCategory(category)}
        onDoubleClick={() => onDoubleClickCategory?.(category)}
      >
        {/* 확장/축소 아이콘 */}
        {hasChildren ? (
          <button
            className="shrink-0"
            onClick={(e) => {
              e.stopPropagation();
              setIsExpanded(!isExpanded);
            }}
          >
            {isExpanded ? (
              <ChevronDown className="h-4 w-4" />
            ) : (
              <ChevronRight className="h-4 w-4" />
            )}
          </button>
        ) : (
          <span className="w-4" />
        )}

        {/* 폴더/태그 아이콘 */}
        {hasChildren || level === 0 ? (
          isExpanded ? (
            <FolderOpen className="h-4 w-4 shrink-0 text-amber-500" />
          ) : (
            <Folder className="h-4 w-4 shrink-0 text-amber-500" />
          )
        ) : (
          <Tag className="h-4 w-4 shrink-0 text-blue-500" />
        )}

        {/* 카테고리 이름 */}
        <span className="truncate">{category.categoryName}</span>

        {/* prefix 표시 */}
        <span
          className={cn(
            "ml-auto text-xs",
            isSelected ? "text-primary-foreground/70" : "text-muted-foreground"
          )}
        >
          {category.keyPrefix}
        </span>
      </div>

      {/* 자식 카테고리 */}
      {hasChildren && isExpanded && (
        <div>
          {category.children!.map((child) => (
            <CategoryNode
              key={child.categoryId}
              category={child}
              level={level + 1}
              selectedCategoryId={selectedCategoryId}
              onSelectCategory={onSelectCategory}
              onDoubleClickCategory={onDoubleClickCategory}
            />
          ))}
        </div>
      )}
    </div>
  );
}

export function CategoryTree({
  selectedCategoryId,
  onSelectCategory,
  onDoubleClickCategory,
}: CategoryTreeProps) {
  const [categories, setCategories] = useState<LangCategory[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

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

  const loadCategories = async () => {
    try {
      setLoading(true);
      const response = await getCategories();
      if (response.success && response.data) {
        setCategories(response.data);
      } else {
        setError(response.error?.details || "카테고리 로드 실패");
      }
    } catch (err) {
      setError("카테고리 로드 중 오류 발생");
    } finally {
      setLoading(false);
    }
  };

  if (loading) {
    return (
      <div className="flex h-32 items-center justify-center">
        <div className="animate-pulse text-sm text-muted-foreground">
          카테고리 로딩 중...
        </div>
      </div>
    );
  }

  if (error) {
    return (
      <div className="flex h-32 items-center justify-center">
        <div className="text-sm text-destructive">{error}</div>
      </div>
    );
  }

  if (categories.length === 0) {
    return (
      <div className="flex h-32 items-center justify-center">
        <div className="text-sm text-muted-foreground">
          카테고리가 없습니다
        </div>
      </div>
    );
  }

  return (
    <div className="space-y-0.5">
      {/* 전체 선택 옵션 */}
      <div
        className={cn(
          "flex cursor-pointer items-center gap-2 rounded-md px-2 py-1.5 text-sm transition-colors",
          selectedCategoryId === null
            ? "bg-primary text-primary-foreground"
            : "hover:bg-muted"
        )}
        onClick={() => onSelectCategory(null)}
      >
        <Folder className="h-4 w-4 shrink-0" />
        <span>전체</span>
      </div>

      {/* 카테고리 트리 */}
      {categories.map((category) => (
        <CategoryNode
          key={category.categoryId}
          category={category}
          level={0}
          selectedCategoryId={selectedCategoryId}
          onSelectCategory={onSelectCategory}
          onDoubleClickCategory={onDoubleClickCategory}
        />
      ))}
    </div>
  );
}

export default CategoryTree;