"use client";

import { useEffect, useState } from "react";
import dynamic from "next/dynamic";
import { Check } from "lucide-react";
import type { OrbState } from "thinking-orbs";

import { prefetchOnIdle } from "@/components/chat-chunk-prefetch";
import { activityCompletedSteps, activityElapsedLabel } from "@/lib/chat-message-view";

const labels = {
  working: "正在处理任务…",
  searching: "正在搜索相关信息…",
  solving: "正在分析问题…",
  listening: "正在聆听…",
  composing: "正在组织回答…",
  shaping: "正在生成结果…",
} as const satisfies Record<OrbState, string>;

const importThinkingOrb = () => import("thinking-orbs");

const ThinkingOrb = dynamic(async () => (await importThinkingOrb()).ThinkingOrb, {
  loading: () => (
    <span aria-hidden="true" style={{ display: "block", flex: "0 0 auto", height: 20, width: 20 }} />
  ),
  ssr: false,
});

prefetchOnIdle(importThinkingOrb);

export type AgentActivityState = OrbState;

function ActivityElapsed({ startedAt }: Readonly<{ startedAt: number }>) {
  const [now, setNow] = useState(() => Date.now());
  useEffect(() => {
    const timer = window.setInterval(() => setNow(Date.now()), 1000);
    return () => window.clearInterval(timer);
  }, []);
  const label = activityElapsedLabel(startedAt, now);
  if (!label) return null;
  return <span className="agent-activity-status__elapsed" aria-hidden="true">{label}</span>;
}

function MessageThinkingTrace({
  text,
  hasAnswer,
}: Readonly<{
  text: string;
  hasAnswer: boolean;
}>) {
  const [userOpen, setUserOpen] = useState<boolean | null>(null);
  const open = userOpen ?? !hasAnswer;
  if (!text.trim()) return null;
  return (
    <details
      className="message-thinking"
      open={open}
      onToggle={(event) => {
        setUserOpen((event.currentTarget as HTMLDetailsElement).open);
      }}
    >
      <summary>思考过程</summary>
      <div className="message-thinking-body">{text}</div>
    </details>
  );
}

export function AgentActivityStatus({
  state,
  label = labels[state],
  startedAt,
  completedTrail,
  thinkingText,
  hasAnswer = false,
  showLive = true,
}: Readonly<{
  state: AgentActivityState;
  label?: string;
  startedAt?: number;
  completedTrail?: string;
  thinkingText?: string;
  hasAnswer?: boolean;
  showLive?: boolean;
}>) {
  const completedSteps = activityCompletedSteps(completedTrail);
  const live = showLive && !hasAnswer;
  if (!live && completedSteps.length === 0 && !thinkingText?.trim()) return null;

  return (
    <div className="agent-thinking-panel agent-activity-status">
      {(live || completedSteps.length > 0) && (
        <ol className="agent-thinking-timeline">
          {completedSteps.map((step) => (
            <li className="agent-thinking-step is-done" key={step}>
              <span className="agent-thinking-marker" aria-hidden="true">
                <Check />
              </span>
              <span>{step}</span>
            </li>
          ))}
          {live ? (
            <li className="agent-thinking-step is-live">
              <span className="agent-thinking-marker is-live-marker">
                <ThinkingOrb aria-hidden="true" state={state} size={20} />
              </span>
              <span className="agent-activity-status__live" role="status">
                <span key={label} className="agent-activity-status__text">{label}</span>
                {startedAt ? <ActivityElapsed key={startedAt} startedAt={startedAt} /> : null}
              </span>
            </li>
          ) : null}
        </ol>
      )}
      {thinkingText ? <MessageThinkingTrace text={thinkingText} hasAnswer={hasAnswer} /> : null}
    </div>
  );
}