/**
 * Userbot (selfbot) entry — runs the assistant on a single USER account token,
 * which is the only kind of account Discord lets Go Live (screen-share).
 *
 * Voice goes through @discordjs/voice (>=0.19 + @snazzah/davey for Discord's
 * DAVE E2EE) using the selfbot client's `voiceAdapterCreator`. The selfbot
 * library's OWN native voice connection does NOT complete the current
 * (DAVE/v8) handshake and times out, so we deliberately reuse the normal-bot
 * VoiceSession (receive -> Whisper -> reply -> TTS playback) instead, just with
 * a user-account channel.
 *
 * Stage 1 (this module): log in, join (auto from DISCORD_VOICE_CHANNEL_ID or via
 * "!자비스 join"), converse by voice. Go-Live broadcast + broadcast-coupled
 * search routing land in stage 2.
 *
 * ToS WARNING: automating a user account ("selfbot") violates Discord's ToS and
 * can get the account banned. Use a throwaway/burner account only.
 */
import type { VoiceBasedChannel } from "discord.js";
import { config } from "./config.ts";
import { joinChannel, leaveGuild } from "./voice.ts";
import { maybeCoupleBroadcast, stopBroadcast } from "./broadcast.ts";

type AnyClient = any;

async function loadSelfbot(): Promise<any> {
  try {
    return await import("discord.js-selfbot-v13");
  } catch (e) {
    throw new Error(
      "유저봇 의존성이 없습니다. 설치: bun add discord.js-selfbot-v13\n" +
        `원본 오류: ${(e as Error).message}`,
    );
  }
}

export interface TurnInfo {
  /** Discord user ID of the speaker, so the transcript shows whose audio
   *  produced each turn (and which user a dropped/VAD turn belongs to). */
  user?: string;
  /** Resolved display name (server nickname / global name); shown instead of
   *  the raw user ID when available. */
  userName?: string;
  transcript: string;
  reply: string;
  note?: string;
  /** Wall-clock epoch-ms markers for each pipeline stage. STT is the gap
   *  between listenEndMs and llmStartMs. */
  listenStartMs?: number;
  listenEndMs?: number;
  llmStartMs?: number;
  llmEndMs?: number;
  ttsStartMs?: number;
  ttsEndMs?: number;
}

/** Local wall-clock HH:MM:SS for an epoch-ms instant. */
function clock(ms?: number): string {
  if (ms == null) return "?";
  const d = new Date(ms);
  const p = (n: number) => String(n).padStart(2, "0");
  return `${p(d.getHours())}:${p(d.getMinutes())}:${p(d.getSeconds())}`;
}

/** Seconds between two epoch-ms instants, 1 decimal, or null if either side is
 *  missing or the span is negative (clock skew / out-of-order markers). */
function durSec(a?: number, b?: number): string | null {
  if (a == null || b == null) return null;
  const s = (b - a) / 1000;
  if (s < 0) return null;
  return s.toFixed(1);
}

/** Build the transcript-channel message: transcript + reply, plus a per-stage
 *  timing breakdown (listening / LLM / TTS) with start→end wall-clock times and
 *  durations, so it's obvious what took long. Pure + exported for testing. */
export function formatTurnMessage(info: TurnInfo): string {
  const who = info.userName || info.user ? `👤 ${info.userName || info.user}  ` : "";
  const head = info.transcript
    ? `${who}🎤 들음 → 🗣️ "${info.transcript}"\n🤖 답변: ${(info.reply || "").trim() || "(무응답)"}`
    : `${who}🎤 들음 → ❌ ${info.note || "무시됨"}`;

  const lines: string[] = [];
  const listen = durSec(info.listenStartMs, info.listenEndMs);
  if (listen != null) {
    lines.push(`   👂 듣기 ${listen}초  ${clock(info.listenStartMs)} → ${clock(info.listenEndMs)}`);
  }
  const llm = durSec(info.llmStartMs, info.llmEndMs);
  if (llm != null) {
    const stt = durSec(info.listenEndMs, info.llmStartMs);
    const gap = stt != null && Number(stt) >= 0.1 ? `  (STT/전송 ${stt}초)` : "";
    lines.push(`   🧠 LLM ${llm}초  ${clock(info.llmStartMs)} → ${clock(info.llmEndMs)}${gap}`);
  }
  const tts = durSec(info.ttsStartMs, info.ttsEndMs);
  if (tts != null) {
    lines.push(`   🔊 TTS ${tts}초  ${clock(info.ttsStartMs)} → ${clock(info.ttsEndMs)}`);
  }

  if (!lines.length) return head;
  const lastEnd = info.ttsEndMs ?? info.llmEndMs ?? info.listenEndMs;
  const total = durSec(info.listenStartMs, lastEnd);
  const totalNote = total != null ? ` (합계 ${total}초)` : "";
  return `${head}\n⏱️ 타이밍${totalNote}\n${lines.join("\n")}`;
}

/** Mirror EVERY heard utterance (and why it did/didn't answer) to a text
 *  channel, so misses and latency are diagnosable without hearing the bot. */
async function postTranscript(client: AnyClient, info: TurnInfo): Promise<void> {
  const chId = config.transcriptChannelId;
  if (!chId) return;
  const msg = formatTurnMessage(info);
  try {
    const ch: any = await client.channels.fetch(chId).catch(() => null);
    if (ch?.send) await ch.send(msg);
  } catch (e) {
    console.error("[userbot] transcript post failed:", e);
  }
}

async function joinAndListen(client: AnyClient, channelId: string): Promise<void> {
  const channel: any = await client.channels.fetch(channelId).catch(() => null);
  if (!channel || channel.isVoice?.() === false) {
    console.error(`[userbot] voice channel ${channelId} not found / not a voice channel`);
    return;
  }
  // The selfbot VoiceChannel is runtime-compatible with @discordjs/voice's
  // joinVoiceChannel (it exposes id, guild.id and guild.voiceAdapterCreator).
  const session = await joinChannel(channel as unknown as VoiceBasedChannel);
  session.onTurn = (info) => {
    console.log(`👤 ${info.userName || info.user || "?"} 🗣️  ${info.transcript || "(" + (info.note || "empty") + ")"}\n🤖 ${info.reply}`);
    // Mirror every heard utterance (and the reply / drop reason) to a text
    // channel so you can see what the bot understood even when it doesn't answer.
    void postTranscript(client, info);
  };
  // Screen-share mode (STREAM_BROWSER=true): auto-start the broadcast on join,
  // report its live state to the brain each turn, and let the brain toggle it by
  // voice. Userbot is the only mode that can actually Go Live, so without this
  // wiring the broadcast never starts. No-op when STREAM_BROWSER=false.
  await maybeCoupleBroadcast(session, { guildId: channel.guild.id, voiceChannelId: channel.id });
  console.log(`🎙️  유저봇이 '${channel.name}' 음성채널에 참여했습니다.`);
}

export async function runUserbot(): Promise<void> {
  if (!config.selfbotToken) {
    throw new Error("DISCORD_SELFBOT_TOKEN이 설정되지 않았습니다 (.env). 버너 계정 토큰을 넣어주세요.");
  }
  const selfbot = await loadSelfbot();
  const client = new selfbot.Client();

  client.on("ready", async () => {
    console.log(`✓ 유저봇 로그인: ${client.user?.tag}`);
    if (config.autoJoinChannelId) {
      await joinAndListen(client, config.autoJoinChannelId).catch((e) =>
        console.error("[userbot] auto-join failed:", e),
      );
    } else {
      console.log('[userbot] DISCORD_VOICE_CHANNEL_ID 미설정 — "!자비스 join" 명령을 기다립니다.');
    }
  });

  // Text-command control (userbots cannot use slash commands): join the
  // caller's current voice channel, or leave.
  client.on("messageCreate", async (msg: any) => {
    const content = (msg.content || "").trim();
    if (content === "!자비스 join" || content === "!jarvis join") {
      const ch = msg.member?.voice?.channel || msg.author?.voice?.channel;
      if (ch) await joinAndListen(client, ch.id).catch((e) => console.error("[userbot] join cmd:", e));
    } else if (content === "!자비스 leave" || content === "!jarvis leave") {
      // Leaving voice also ends the broadcast — don't leave a stream live with
      // no session driving it.
      await stopBroadcast(config.guildId);
      leaveGuild(config.guildId);
    }
  });

  await client.login(config.selfbotToken);
}