#!/usr/bin/env python3
"""通过已登录抖音页的官方 IM SDK 读取私信、发送文本；不导航或点击用户主页。"""

import argparse
import json
import subprocess
import sys

from cdp_explicit import (  # pyright: ignore[reportMissingImports]
  add_cdp_args,
  configure,
  evaluate_script,
)
from follow_user import validate_uid

EXPRESSION = r"""
(async () => {
  const p = __PARAMS__;
  const fail = code => { throw new Error(code); };
  try {
    if (location.origin !== 'https://www.douyin.com') fail('WRONG_ORIGIN');
    const response = await fetch('/aweme/v1/web/user/profile/self/?device_platform=webapp&aid=6383',
      {credentials: 'include', signal: AbortSignal.timeout(15000)});
    if (!response.ok) fail('LOGIN_CHECK_FAILED');
    const profile = await response.json();
    if (profile.status_code !== 0 || !profile.user?.uid || profile.user.uid === '0')
      fail('LOGIN_REQUIRED');
    if (String(profile.user.uid) === p.uid) fail('SELF_TARGET');

    // 按模块特征发现当前版本，不固定 chunk 名称、模块数字 ID 或账号。
    let service;
    for (const key of Object.keys(window).filter(k => k.startsWith('@pc-im/im:'))) {
      const chunks = window[key];
      if (!Array.isArray(chunks)) continue;
      let req;
      chunks.push([['python_im_' + crypto.randomUUID()], {}, r => { req = r; }]);
      for (const [id, module] of Object.entries(req?.c || {})) {
        if (!String(req.m[id]).includes('getOrCreatePrivateConversationByUid')) continue;
        for (const exported of Object.values(module.exports || {})) {
          if (exported?.instance?.imSdkService) service = exported.instance.imSdkService;
        }
      }
    }
    if (!service) fail('IM_SDK_NOT_READY');
    const sdk = service.imSdkManager.getImSdkInstance();
    const sendManager = service.sendMessageManager;
    if (!sdk || !sendManager || typeof sendManager.createMessageBuilder !== 'function' ||
        typeof sendManager.sendMessage !== 'function') fail('IM_SDK_NOT_READY');
    const meta = c => ({id: String(c.id), short_id: String(c.shortId),
      uid: String(c.toParticipantUserId), type: c.type});
    const pack = m => ({server_id: String(m.serverId || ''), client_id: m.clientId || null,
      sender: String(m.sender), type: m.type, content: m.content,
      created_at: m.createdAt, server_status: m.serverStatus});
    let conversation = sdk.getConversationList().find(c =>
      c.type === 1 && String(c.toParticipantUserId) === p.uid);
    if (p.action === 'send' && !p.confirm) {
      return JSON.stringify({action: 'preview', sender_uid: String(profile.user.uid),
        uid: p.uid, text: p.text, conversation: conversation ? meta(conversation) : null,
        note: '未创建会话、未创建或发送消息；添加 --confirm 才会发送'});
    }
    if (!conversation && p.action === 'history') {
      conversation = await service.conversationManager.getConversationByUidOrShortIdIfOnline(
        {participantId: p.uid});
    }
    if (!conversation && p.action === 'send') {
      conversation = await service.conversationManager.getOrCreatePrivateConversationByUid(p.uid);
    }
    if (!conversation) fail('CONVERSATION_NOT_FOUND');
    if (conversation.type !== 1 || String(conversation.toParticipantUserId) !== p.uid)
      fail('TARGET_MISMATCH');
    if (p.action === 'history') {
      const result = await sdk.getMessagesByConversation({conversation,
        cursor: p.cursor, limit: p.limit});
      if (!Array.isArray(result?.messages)) fail('HISTORY_FAILED');
      return JSON.stringify({action: 'history', conversation: meta(conversation),
        messages: result.messages.map(pack), has_more: result.hasMore,
        next_cursor: result.cursor == null ? null : String(result.cursor)});
    }
    // 复用站内 sendMessageManager，不直接调用 sdk.sendMessage：站内流程会在发送前
    // 更新 identity security headers，并处理官方一次性风控验证/重试回调。
    const builder = sendManager.createMessageBuilder({
      conversation, messageType: 7, enterMethod: 'douyin_accounts_worker'});
    builder.toUid(p.uid).content(JSON.stringify({
      aweType: 700, type: 0, richTextInfos: [], text: p.text}));
    const result = await sendManager.sendMessage(builder);
    const message = builder.getMessage();
    if (!message) fail('MESSAGE_BUILD_FAILED');
    let checkInfo = {};
    if (typeof result?.checkMsg === 'string' && result.checkMsg) {
      try { checkInfo = JSON.parse(result.checkMsg); } catch (_) { /* fixed fields below */ }
    }
    // 仅明确的 SDK 成功结果算成功；超时或未知状态不能由本程序自动重发。
    // 不返回原始 checkMsg：它可能包含二次验证配置或其他敏感参数。
    return JSON.stringify({action: 'send', success: result?.success === true,
      status_code: result?.statusCode ?? null, check_code: String(result?.checkCode ?? ''),
      check_message_present: Boolean(result?.checkMsg),
      check_status_code: checkInfo?.status_code ?? null,
      verification_required: Boolean(checkInfo?.decision_conf),
      conversation: meta(conversation), message: pack(message)});
  } catch (error) {
    const known = ['WRONG_ORIGIN', 'LOGIN_CHECK_FAILED', 'LOGIN_REQUIRED', 'SELF_TARGET',
      'IM_SDK_NOT_READY', 'CONVERSATION_NOT_FOUND', 'TARGET_MISMATCH', 'HISTORY_FAILED',
      'MESSAGE_BUILD_FAILED'];
    return JSON.stringify({error: known.includes(error.message) ? error.message : 'SDK_REQUEST_FAILED'});
  }
})()
"""


def run_im(
  action: str,
  uid: str,
  *,
  text: str = "",
  confirm: bool = False,
  limit: int = 20,
  cursor: str = "9223372036854775807",
) -> dict:
  """单次请求；历史不会标记已读，发送默认只预览。"""
  validate_uid(uid)
  if action not in ("history", "send"):
    raise ValueError("action 必须为 history 或 send")
  if not isinstance(cursor, str) or not cursor.isascii() or not cursor.isdecimal():
    raise ValueError("cursor 必须是非负整数字符串")
  normalized = cursor.lstrip("0") or "0"
  if (
    len(normalized) > 19
    or (len(normalized) == 19 and normalized > "9223372036854775807")
    or not 1 <= limit <= 100
  ):
    raise ValueError("cursor 超出 int64 范围或 limit 不在 1..100")
  if action == "send" and (not isinstance(text, str) or not text.strip()):
    raise ValueError("消息不能为空")
  params = {
    "action": action,
    "uid": uid,
    "text": text,
    "confirm": confirm,
    "limit": limit,
    "cursor": normalized,
  }
  expression = EXPRESSION.replace("__PARAMS__", json.dumps(params, ensure_ascii=True))
  try:
    result = evaluate_script(expression)
    payload = json.loads(result.stdout.strip().splitlines()[-1])
  except (subprocess.SubprocessError, OSError, ValueError, IndexError) as exc:
    raise RuntimeError(
      "浏览器调用失败：检查 CDP、已登录首页和 SDK；发送结果可能未知，勿自动重发"
    ) from exc
  if not isinstance(payload, dict):
    raise RuntimeError("浏览器返回格式异常；勿自动重发")
  if payload.get("error"):
    raise RuntimeError(
      f"{payload['error']}：停止操作，请手动检查登录态/会话/SDK；勿自动重发"
    )
  return payload


def main() -> int:
  parser = argparse.ArgumentParser(description=__doc__, allow_abbrev=False)
  sub = parser.add_subparsers(dest="action", required=True)
  history = sub.add_parser("history", help="获取指定 UID 的一页历史消息")
  history.add_argument("uid")
  history.add_argument("--limit", type=int, default=20)
  history.add_argument("--cursor", default="9223372036854775807")
  send = sub.add_parser("send", help="发送文本，默认只预览")
  send.add_argument("uid")
  send.add_argument("--text", required=True)
  send.add_argument("--confirm", action="store_true", help="确认实际发送一次")
  add_cdp_args(history)
  add_cdp_args(send)
  args = parser.parse_args()
  configure(args)
  params = {
    k: v
    for k, v in vars(args).items()
    if k not in ("cdp_url", "expected_uid", "page_url")
  }
  try:
    result = run_im(**params)
    print(json.dumps(result, ensure_ascii=False, indent=2))
    return int(result.get("action") == "send" and not result.get("success"))
  except (ValueError, RuntimeError) as exc:
    print(f"失败：{exc}", file=sys.stderr)
    return 1


if __name__ == "__main__":
  raise SystemExit(main())