/**
 * File Menu Component
 *
 * 文件自动补全菜单，支持键盘导航
 */

import { useEffect, useRef } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import { File, Folder } from 'lucide-react';
import { cn } from '../utils/cn.js';

export interface FileMenuItem {
  path: string;
  name: string;
  type: 'file' | 'directory';
  extension?: string;
}

interface FileMenuProps {
  /** 文件列表 */
  files: FileMenuItem[];
  /** 是否显示 */
  isOpen: boolean;
  /** 当前选中索引 */
  selectedIndex: number;
  /** 选择文件回调 */
  onSelect: (file: FileMenuItem) => void;
  /** 关闭菜单回调 */
  onClose: () => void;
  /** 选中索引变化回调 */
  onSelectedIndexChange: (index: number) => void;
  /** 是否正在加载 */
  isLoading?: boolean;
}

// 文件图标颜色
function getFileIconColor(extension?: string): string {
  const colors: Record<string, string> = {
    ts: 'text-blue-400',
    tsx: 'text-blue-400',
    js: 'text-yellow-400',
    jsx: 'text-yellow-400',
    json: 'text-yellow-500',
    md: 'text-fg-muted',
    css: 'text-pink-400',
    scss: 'text-pink-400',
    html: 'text-orange-400',
    py: 'text-green-400',
    go: 'text-cyan-400',
    rs: 'text-orange-500',
    vue: 'text-emerald-400',
    svelte: 'text-orange-500',
  };
  return colors[extension || ''] || 'text-fg-muted';
}

export function FileMenu({
  files,
  isOpen,
  selectedIndex,
  onSelect,
  onClose,
  onSelectedIndexChange,
  isLoading = false,
}: FileMenuProps) {
  const menuRef = useRef<HTMLDivElement>(null);
  const selectedRef = useRef<HTMLButtonElement>(null);

  // 滚动选中项到可见区域
  useEffect(() => {
    if (isOpen && selectedRef.current) {
      selectedRef.current.scrollIntoView({
        block: 'nearest',
        behavior: 'smooth',
      });
    }
  }, [selectedIndex, isOpen]);

  // 键盘导航
  useEffect(() => {
    if (!isOpen) return;

    const handleKeyDown = (e: KeyboardEvent) => {
      switch (e.key) {
        case 'ArrowDown':
          e.preventDefault();
          onSelectedIndexChange(selectedIndex < files.length - 1 ? selectedIndex + 1 : 0);
          break;
        case 'ArrowUp':
          e.preventDefault();
          onSelectedIndexChange(selectedIndex > 0 ? selectedIndex - 1 : files.length - 1);
          break;
        case 'Enter':
          e.preventDefault();
          if (files[selectedIndex]) {
            onSelect(files[selectedIndex]);
          }
          break;
        case 'Escape':
          e.preventDefault();
          onClose();
          break;
        case 'Tab':
          e.preventDefault();
          if (files[selectedIndex]) {
            onSelect(files[selectedIndex]);
          }
          break;
      }
    };

    document.addEventListener('keydown', handleKeyDown);
    return () => document.removeEventListener('keydown', handleKeyDown);
  }, [isOpen, files, selectedIndex, onSelect, onClose, onSelectedIndexChange]);

  return (
    <AnimatePresence>
      {isOpen && (
        <motion.div
          ref={menuRef}
          initial={{ opacity: 0, y: 8, scale: 0.96 }}
          animate={{ opacity: 1, y: 0, scale: 1 }}
          exit={{ opacity: 0, y: 8, scale: 0.96 }}
          transition={{ duration: 0.15 }}
          className="absolute bottom-full left-0 right-0 mb-2 mx-4 md:mx-0 z-50"
        >
          <div className="bg-surface-subtle border border-line rounded-lg shadow-xl overflow-hidden max-h-64 overflow-y-auto">
            {/* Header */}
            <div className="px-3 py-2 border-b border-line bg-surface-subtle/80 sticky top-0">
              <div className="flex items-center gap-2 text-xs text-fg-muted">
                <File size={12} />
                <span>Files</span>
                {files.length > 0 && <span className="text-fg-subtle">({files.length})</span>}
              </div>
            </div>

            {/* Loading */}
            {isLoading && files.length === 0 && (
              <div className="px-3 py-4 text-center text-fg-muted text-sm">Searching files...</div>
            )}

            {/* Empty state */}
            {!isLoading && files.length === 0 && (
              <div className="px-3 py-4 text-center text-fg-muted text-sm">No files found</div>
            )}

            {/* File list */}
            {files.length > 0 && (
              <div className="py-1">
                {files.map((file, index) => (
                  <button
                    key={file.path}
                    ref={index === selectedIndex ? selectedRef : null}
                    onClick={() => onSelect(file)}
                    onMouseEnter={() => onSelectedIndexChange(index)}
                    className={cn(
                      'w-full px-3 py-2 flex items-center gap-3 text-left transition-colors',
                      index === selectedIndex ? 'bg-primary-600/20' : 'hover:bg-surface-muted/50'
                    )}
                  >
                    {/* Icon */}
                    {file.type === 'directory' ? (
                      <Folder size={14} className="text-yellow-400 flex-shrink-0" />
                    ) : (
                      <File
                        size={14}
                        className={cn(getFileIconColor(file.extension), 'flex-shrink-0')}
                      />
                    )}

                    {/* Path */}
                    <span
                      className={cn(
                        'font-mono text-sm truncate',
                        index === selectedIndex ? 'text-primary-300' : 'text-fg-secondary'
                      )}
                    >
                      {file.path}
                    </span>

                    {/* Keyboard hint */}
                    {index === selectedIndex && (
                      <div className="ml-auto flex items-center gap-1 text-[10px] text-fg-subtle flex-shrink-0">
                        <kbd className="px-1 py-0.5 bg-surface-muted rounded">Enter</kbd>
                      </div>
                    )}
                  </button>
                ))}
              </div>
            )}

            {/* Footer hint */}
            <div className="px-3 py-1.5 border-t border-line bg-surface-subtle/80 sticky bottom-0">
              <div className="flex items-center gap-3 text-[10px] text-fg-subtle">
                <span>
                  <kbd className="px-1 py-0.5 bg-surface-muted rounded mr-1">↑</kbd>
                  <kbd className="px-1 py-0.5 bg-surface-muted rounded">↓</kbd> navigate
                </span>
                <span>
                  <kbd className="px-1 py-0.5 bg-surface-muted rounded">Tab</kbd> select
                </span>
                <span>
                  <kbd className="px-1 py-0.5 bg-surface-muted rounded">Esc</kbd> close
                </span>
              </div>
            </div>
          </div>
        </motion.div>
      )}
    </AnimatePresence>
  );
}