#!/usr/bin/env python3
"""直接传入数字 UID，通过接口关注；已关注则跳过，不打开目标主页。"""

import argparse
import json
import subprocess
import sys
from urllib.parse import urlencode

from cdp_explicit import add_cdp_args, configure, evaluate_script
from get_current_user import get_user_from_browser

PROFILE = "/aweme/v1/web/user/profile/other/"
FOLLOW = "/aweme/v1/web/commit/follow/user/"
PARAMS = {"device_platform": "webapp", "aid": 6383, "channel": "channel_pc_web"}


def validate_uid(uid: str) -> str:
    if (
        not isinstance(uid, str)
        or not uid.isascii()
        or not uid.isdecimal()
        or uid.startswith("0")
    ):
        raise ValueError("UID 必须为不带前导零的正整数数字字符串，不是主页链接或抖音号")
    return uid


def request(path: str, params: dict, body: dict | None = None) -> dict:
    url = path + "?" + urlencode({**PARAMS, **params})
    expression = """new Promise((resolve, reject) => {
      if (location.origin !== 'https://www.douyin.com')
        return reject(new Error('请先选择已登录的抖音标签页'));
      const xhr = new XMLHttpRequest();
      xhr.open(METHOD, URL);
      xhr.withCredentials = true;
      xhr.timeout = 20000;
      if (BODY !== null)
        xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
      xhr.onload = () => resolve(JSON.stringify({status: xhr.status, body: xhr.responseText}));
      xhr.onerror = () => reject(new Error('网络错误；如已发送关注，请先查询状态，勿自动重试'));
      xhr.ontimeout = () => reject(new Error('请求超时；如已发送关注，请先查询状态，勿自动重试'));
      xhr.send(BODY);
    })""".replace("METHOD", json.dumps("POST" if body is not None else "GET"))
    expression = expression.replace("URL", json.dumps(url)).replace(
        "BODY", json.dumps(urlencode(body) if body is not None else None)
    )
    result = evaluate_script(expression)
    try:
        response = json.loads(result.stdout.strip().splitlines()[-1])
        payload = json.loads(response["body"])
        if not isinstance(payload, dict):
            raise ValueError("响应不是对象")
    except (ValueError, KeyError, IndexError, TypeError) as exc:
        raise RuntimeError("无法解析接口响应，停止操作") from exc
    if response["status"] != 200 or payload.get("status_code") != 0:
        raise RuntimeError(
            f"接口失败：HTTP {response['status']}，status_code={payload.get('status_code')}；"
            "请检查登录态或风控提示，不会自动登录、重试或处理验证码"
        )
    return payload


def get_profile(uid: str) -> dict:
    user = request(PROFILE, {"user_id": validate_uid(uid)}).get("user")
    if not isinstance(user, dict) or user.get("uid") != uid:
        raise RuntimeError("返回用户 UID 与目标不匹配，停止操作")
    return user


def follow_user(uid: str, check_only: bool = False) -> dict:
    uid = validate_uid(uid)
    # 复用登录态检查；失败即退出，绝不尝试登录。
    try:
        current = get_user_from_browser()
    except RuntimeError as exc:
        raise RuntimeError("无法确认登录状态，请手动检查或登录后再运行") from exc
    if not current.get("uid") or str(current["uid"]) == "0":
        raise RuntimeError("登录状态已失效，请手动登录后再运行")
    if uid == str(current["uid"]):
        raise ValueError("不能关注自己")
    user = get_profile(uid)
    status = user.get("follow_status")
    if type(status) is not int or status not in (0, 1, 2):
        raise RuntimeError(f"未知关注状态 {status!r}，停止而不发送请求")
    action = "checked" if check_only else "already_following"
    if not check_only and status == 0:
        result = request(FOLLOW, {}, {"user_id": user["uid"], "type": 1})
        if type(result.get("follow_status")) is not int or result[
            "follow_status"
        ] not in (1, 2):
            raise RuntimeError("关注响应未确认成功；请使用 --check 查询，勿自动重试")
        verified = get_profile(uid)
        if verified["uid"] != user["uid"] or verified.get("follow_status") not in (
            1,
            2,
        ):
            raise RuntimeError(
                "关注请求已发出，但回查未确认；请使用 --check 查询，勿自动重试"
            )
        status = verified["follow_status"]
        action = "followed"
    return {
        "action": action,
        "uid": user["uid"],
        "sec_uid": user.get("sec_uid"),
        "nickname": user.get("nickname"),
        "follow_status": status,
    }


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__, allow_abbrev=False)
    parser.add_argument("uid", help="目标用户数字 UID（通知 users[].uid），不是抖音号")
    parser.add_argument("--check", action="store_true", help="只查询，不关注")
    add_cdp_args(parser)
    args = parser.parse_args()
    configure(args)
    try:
        uid = validate_uid(args.uid)
        print(json.dumps(follow_user(uid, args.check), ensure_ascii=False, indent=2))
    except (
        OSError,
        ValueError,
        RuntimeError,
        KeyError,
        TypeError,
        subprocess.SubprocessError,
    ) as exc:
        # 不回显浏览器 stderr：它可能包含带签名的请求 URL。
        message = (
            "浏览器连接或执行失败，请检查 CDP 与登录态"
            if isinstance(exc, subprocess.SubprocessError)
            else str(exc)
        )
        print(f"失败：{message}。不会自动登录或重试关注。", file=sys.stderr)
        return 1
    return 0


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