'use client';

import { useEffect, useRef, useState } from 'react';
import {
  CheckCircle2,
  Loader2,
  ShieldAlert,
  ShieldCheck,
  ShieldQuestion,
} from 'lucide-react';
import { getCapToken } from '@/lib/cap-solver';

type CapStatus = 'idle' | 'solving' | 'solved' | 'error';

interface CapWidgetProps {
  /** Called with the one-time token once the challenge is solved */
  onToken: (token: string) => void;
  /** Called when the challenge fails or encounters an error */
  onError?: (err: Error) => void;
  /** Whether to auto-start solving when the component mounts. Defaults to true. */
  autoStart?: boolean;
  /** PoW scope sent to the backend */
  scope?: string;
}

/**
 * Cap 人机验证小部件
 *
 * autoStart=true（默认）：挂载后立即在后台运行 PoW 求解，完成后回调 onToken。
 * autoStart=false：显示「点击开始验证」按钮，用户手动触发后才开始求解。
 */
export function CapWidget({
  onToken,
  onError,
  autoStart = true,
  scope = 'login',
}: CapWidgetProps) {
  const [status, setStatus] = useState<CapStatus>('idle');
  const [errorMsg, setErrorMsg] = useState('');
  const solving = useRef(false);

  const solve = async () => {
    if (solving.current) return;
    solving.current = true;
    setStatus('solving');
    setErrorMsg('');
    try {
      const token = await getCapToken(scope);
      setStatus('solved');
      onToken(token);
    } catch (err) {
      const error = err instanceof Error ? err : new Error(String(err));
      setStatus('error');
      setErrorMsg(error.message);
      onError?.(error);
    } finally {
      solving.current = false;
    }
  };

  // Auto-start on mount (only when autoStart is enabled)
  useEffect(() => {
    if (autoStart) {
      void solve();
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  return (
    <div className='flex items-center gap-2 rounded-lg border border-border/60 bg-muted/30 px-3 py-2 text-sm'>
      {/* idle + autoStart=false: 手动触发按钮 */}
      {status === 'idle' && !autoStart && (
        <button
          type='button'
          className='flex w-full items-center gap-2 text-left'
          onClick={() => void solve()}
        >
          <ShieldQuestion className='size-4 shrink-0 text-muted-foreground' />
          <span className='flex-1 text-muted-foreground'>点击开始人机验证</span>
        </button>
      )}

      {/* idle + autoStart=true: 等待自动开始（极短暂状态） */}
      {status === 'idle' && autoStart && (
        <>
          <ShieldAlert className='size-4 shrink-0 text-muted-foreground' />
          <span className='text-muted-foreground'>等待人机验证…</span>
        </>
      )}

      {status === 'solving' && (
        <>
          <Loader2 className='size-4 shrink-0 animate-spin text-primary' />
          <span className='text-muted-foreground'>正在完成人机验证…</span>
        </>
      )}

      {status === 'solved' && (
        <>
          <CheckCircle2 className='size-4 shrink-0 text-green-500' />
          <span className='text-green-600 dark:text-green-400'>
            人机验证通过
          </span>
          <ShieldCheck className='ml-auto size-4 shrink-0 text-green-500' />
        </>
      )}

      {status === 'error' && (
        <button
          type='button'
          className='flex w-full items-center gap-2 text-left'
          onClick={() => void solve()}
        >
          <ShieldAlert className='size-4 shrink-0 text-destructive' />
          <span className='flex-1 text-destructive'>
            {errorMsg || '人机验证失败'}
          </span>
          <span className='text-xs text-muted-foreground underline'>重试</span>
        </button>
      )}
    </div>
  );
}