import { useEffect, useRef, useState } from 'react';
import { FileText, ChevronDown, ChevronRight, Brain } from 'lucide-react';

interface OutlineStreamingViewProps {
  text: string;
  thinkingText?: string;
  /** 用户自带大纲时为 true：文案显示「整理你的大纲」而非「规划大纲」。 */
  organizing?: boolean;
}

export function OutlineStreamingView({ text, thinkingText, organizing }: OutlineStreamingViewProps) {
  const preRef = useRef<HTMLPreElement>(null);
  const thinkRef = useRef<HTMLPreElement>(null);
  const [thinkOpen, setThinkOpen] = useState(true);

  useEffect(() => {
    if (preRef.current) {
      preRef.current.scrollTop = preRef.current.scrollHeight;
    }
  }, [text]);

  useEffect(() => {
    if (thinkOpen && thinkRef.current) {
      thinkRef.current.scrollTop = thinkRef.current.scrollHeight;
    }
  }, [thinkingText, thinkOpen]);

  if (!text && !thinkingText) return null;

  return (
    <div className="px-4 pb-2 space-y-2">
      {/* 思考过程区（仅在有思考内容时展示） */}
      {thinkingText && (
        <div className="rounded-xl border border-amber-200 dark:border-amber-900 bg-amber-50/50 dark:bg-amber-950/20 overflow-hidden shadow-sm">
          <button
            type="button"
            onClick={() => setThinkOpen((v) => !v)}
            className="w-full flex items-center gap-2 px-3 py-2 border-b border-amber-200/60 dark:border-amber-900/60 bg-amber-100/40 dark:bg-amber-900/30 hover:bg-amber-100/70 dark:hover:bg-amber-900/50 transition-colors"
          >
            <Brain className="size-3.5 text-amber-500 shrink-0" />
            <span className="text-xs font-medium text-amber-600 dark:text-amber-400">
              思考过程
            </span>
            <span className="ml-auto text-amber-400">
              {thinkOpen
                ? <ChevronDown className="size-3.5" />
                : <ChevronRight className="size-3.5" />}
            </span>
          </button>
          {thinkOpen && (
            <pre
              ref={thinkRef}
              className="text-[11px] font-mono leading-relaxed p-3 text-amber-700/70 dark:text-amber-300/60 whitespace-pre-wrap max-h-40 overflow-y-auto italic"
            >
              {thinkingText}
              {/* 思考仍在进行时显示光标 */}
              {!text && (
                <span className="inline-block w-0.5 h-3.5 bg-amber-400 ml-0.5 align-text-bottom animate-[blink_1s_step-end_infinite]" />
              )}
            </pre>
          )}
        </div>
      )}

      {/* 正文流式区 */}
      {text && (
        <div className="rounded-xl border border-purple-200 dark:border-purple-900 bg-purple-50/50 dark:bg-purple-950/20 overflow-hidden shadow-sm">
          <div className="flex items-center gap-2 px-3 py-2 border-b border-purple-200/60 dark:border-purple-900/60 bg-purple-100/40 dark:bg-purple-900/30">
            <FileText className="size-3.5 text-purple-500 shrink-0" />
            <span className="text-xs font-medium text-purple-600 dark:text-purple-400">
              {organizing ? '作家正在整理你的大纲…' : '作家正在规划大纲…'}
            </span>
            <span className="ml-auto inline-flex gap-1">
              {[0, 1, 2].map((i) => (
                <span
                  key={i}
                  className="size-1 rounded-full bg-purple-400 animate-bounce"
                  style={{ animationDelay: `${i * 150}ms` }}
                />
              ))}
            </span>
          </div>
          <pre
            ref={preRef}
            className="text-[11px] font-mono leading-relaxed p-3 text-muted-foreground whitespace-pre-wrap max-h-52 overflow-y-auto"
          >
            {text}
            <span className="inline-block w-0.5 h-3.5 bg-purple-400 ml-0.5 align-text-bottom animate-[blink_1s_step-end_infinite]" />
          </pre>
        </div>
      )}

      <style>{`
        @keyframes blink {
          0%, 100% { opacity: 1; }
          50%       { opacity: 0; }
        }
      `}</style>
    </div>
  );
}