# -*- coding: utf-8 -*-
r"""
YouTube Studio 内容管理器「导出当前视图 → 逗号分隔值 (.csv)」下载脚本
（拦截响应 + 解码 zip + 自动保存到下载目录 + 重名去重）。

机制（已实证）：前端点击导出后向后端
    POST https://studio.youtube.com/youtubei/v1/yta_web/csv_export?alt=json
后端把打好的 zip 以 base64 内联在响应 `zippedData` 字段里（开头 `UEsDBBQ` 即 ZIP 文件头 `PK`）。
本脚本拦截该响应，base64 解码后按 `<维度标签> <起始日>_<结束日> <账号名>.zip` 写盘，
重名自动加 ` (n)` 后缀，n 从 1 起。

登录态：脚本不负责登录，必须复用已登录 YouTube Studio 的浏览器会话，二选一：
  - --user-data-dir + --channel chrome|msedge ：用已登录的用户数据目录启动（需先关闭该浏览器）
  - --connect http://localhost:9222            ：附加到已在调试端口运行的浏览器

用法：
  python youtube_export_download.py --selftest
  python youtube_export_download.py --url "<explore URL>" --channel chrome --user-data-dir "C:\Users\<you>\AppData\Local\Google\Chrome\User Data"
  python youtube_export_download.py --url "<explore URL>" --connect http://localhost:9222
"""

import argparse
import base64
import json
import os
import re
import sys

DOWNLOAD_DIR = r"D:\Downloads"  # 默认下载目录，可用 --download-dir 覆盖

# 维度类型 -> 文件名前缀标签（生产环境建议从页面「维度」按钮文本读取，这里兜底映射）。
DIMENSION_LABEL = {
    "VIDEO": "内容",
    "USER": "频道",
    "CONTENT_OWNER": "内容",
}

CSV_EXPORT_PATH = "/youtubei/v1/yta_web/csv_export"


def dedup_path(directory, filename):
    """返回不冲突的落盘路径；重名按 `名称 (n).后缀` 递增，n 从 1 起。"""
    directory = os.path.abspath(directory)
    base, ext = os.path.splitext(filename)
    candidate = os.path.join(directory, filename)
    n = 1
    while os.path.exists(candidate):
        candidate = os.path.join(directory, f"{base} ({n}){ext}")
        n += 1
    return candidate


def build_export_filename(export_query, account_name, dimension_label=None):
    """从 csv_export 请求体 `exportQuery` 反推文件名。"""
    def fmt_dateid(yyyymmdd):
        s = str(yyyymmdd)
        return f"{s[0:4]}-{s[4:6]}-{s[6:8]}"

    date_range = None
    dimension = None
    nodes = export_query.get("joinRequest", {}).get("nodes") or []
    for node in nodes:
        q = node.get("value", {}).get("query") or {}
        if not date_range:
            tr = q.get("timeRange", {}).get("dateIdRange")
            if tr and tr.get("inclusiveStart"):
                date_range = (tr["inclusiveStart"], tr.get("exclusiveEnd"))
        dims = q.get("dimensions") or []
        if dimension is None and dims:
            dimension = dims[0].get("type")

    if not date_range:
        raise ValueError("无法从 exportQuery 解析日期范围")

    if dimension_label is None:
        dimension_label = DIMENSION_LABEL.get(dimension or "", "")

    start, end = date_range
    return f"{dimension_label} {fmt_dateid(start)}_{fmt_dateid(end)} {account_name}.zip"


def decode_zipped_data(payload):
    """把 csv_export 响应 payload 里的 zippedData 解码为 zip 字节流。"""
    zipped = payload.get("zippedData")
    if not zipped:
        raise ValueError("响应中缺少 zippedData 字段")
    return base64.b64decode(zipped)


def intercept_and_save(page, account_name, download_dir):
    """给 page 绑定 response 拦截器：命中 csv_export 就把 zip 保存到下载目录。"""
    import pathlib

    saved = []

    def on_response(response):
        if CSV_EXPORT_PATH not in response.url:
            return
        try:
            payload = response.json()
            data = decode_zipped_data(payload)

            filename = None
            try:
                body = json.loads(response.request.post_data or "{}")
                filename = build_export_filename(body.get("exportQuery", {}), account_name)
            except Exception:
                filename = "export.zip"  # 反推失败兜底，避免丢内容

            filename = re.sub(r"[\\/:*?\"<>|]", "_", filename)  # Windows 非法字符
            path = dedup_path(download_dir, filename)
            pathlib.Path(path).write_bytes(data)
            saved.append((filename, len(data), path))
        except Exception as e:  # noqa: BLE001
            print(f"[interceptor] 处理 csv_export 响应失败: {e}", file=sys.stderr)

    page.on("response", on_response)
    return saved


def _default_user_data_dir(channel):
    """返回指定浏览器的默认用户数据目录（Windows），用于复用已登录会话。"""
    _local = os.environ.get("LOCALAPPDATA") or os.path.expanduser(r"~\AppData\Local")
    if channel == "msedge":
        return os.path.join(_local, "Microsoft", "Edge", "User Data")
    return os.path.join(_local, "Google", "Chrome", "User Data")


def run(url, user_data_dir=None, channel=None, cdp_url=None,
        download_dir=None, account_name=None):
    """启动/连接浏览器并触发导出。必须复用已登录会话，否则跳 Google 登录页。"""
    from playwright.sync_api import sync_playwright

    download_dir = download_dir or DOWNLOAD_DIR

    with sync_playwright() as p:
        browser = None
        context = None

        if cdp_url:
            browser = p.chromium.connect_over_cdp(cdp_url)
            context = browser.contexts[0] if browser.contexts else \
                browser.new_context(accept_downloads=True)
            page = context.new_page()
            page.goto(url, wait_until="domcontentloaded")
        elif user_data_dir:
            context = p.chromium.launch_persistent_context(
                user_data_dir=user_data_dir or _default_user_data_dir(channel),
                channel=channel,
                headless=False,
                accept_downloads=True,
                args=["--disable-blink-features=AutomationControlled"],
            )
            page = context.new_page()
            page.goto(url, wait_until="domcontentloaded")
        else:
            browser = p.chromium.launch(headless=False, channel=channel)
            context = browser.new_context(accept_downloads=True)
            page = context.new_page()
            page.goto(url, wait_until="domcontentloaded")

        if "accounts.google" in page.url:
            print("[!] 当前会话未登录，已跳转到 Google 登录页。", file=sys.stderr)
            print("    请用 --user-data-dir 或 --connect 复用已登录浏览器后重试。",
                  file=sys.stderr)

        if not account_name:
            account_name = "WL Media"
            try:
                account_name = page.locator(
                    "ytcp-account-item button, .account-switcher button"
                ).first.inner_text(timeout=5000).strip() or account_name
            except Exception:
                pass

        saved = intercept_and_save(page, account_name, download_dir)

        # 触发导出：点「导出当前视图」→「逗号分隔值 (.csv)」
        page.get_by_text("导出当前视图").click()
        page.get_by_text("逗号分隔值 (.csv)").click()
        page.wait_for_timeout(3000)

        if not saved:
            print("未捕获到 csv_export 响应，请确认已点击导出且登录态有效。")
        else:
            for name, size, path in saved:
                print(f"已保存: {path} ({size} bytes)")

        if browser is not None:
            browser.close()
        elif context is not None:
            context.close()


def selftest():
    import tempfile
    from pathlib import Path

    with tempfile.TemporaryDirectory() as td:
        p0 = Path(dedup_path(td, "需求文件.zip"))
        assert p0.name == "需求文件.zip", p0.name
        p0.write_bytes(b"a")

        p1 = Path(dedup_path(td, "需求文件.zip"))
        assert p1.name == "需求文件 (1).zip", p1.name
        p1.write_bytes(b"b")

        p2 = Path(dedup_path(td, "需求文件.zip"))
        assert p2.name == "需求文件 (2).zip", p2.name
        p2.write_bytes(b"c")

        assert Path(dedup_path(td, "需求文件.zip")).name == "需求文件 (3).zip"
        assert Path(dedup_path(td, "其他.zip")).name == "其他.zip"

        export_query = {
            "joinRequest": {"nodes": [{"value": {"query": {
                "dimensions": [{"type": "VIDEO"}],
                "timeRange": {"dateIdRange": {
                    "inclusiveStart": 20260723, "exclusiveEnd": 20260820}},
            }}}]},
        }
        name = build_export_filename(export_query, "WL Media")
        assert name == "内容 2026-07-23_2026-08-20 WL Media.zip", name

    print("selftest OK：去重与文件名反推逻辑全部通过")


if __name__ == "__main__":
    ap = argparse.ArgumentParser()
    ap.add_argument("--selftest", action="store_true", help="仅跑去重/命名自测")
    ap.add_argument("--url", help="explore URL")
    ap.add_argument("--user-data-dir", help="浏览器用户数据目录（复用登录态，需先关闭该浏览器）")
    ap.add_argument("--channel", choices=["chrome", "msedge"],
                    help="浏览器品牌，复用登录态时必填其一")
    ap.add_argument("--connect", help="通过 CDP 附加到已打开浏览器，如 http://localhost:9222")
    ap.add_argument("--download-dir", help=f"下载目录，默认 {DOWNLOAD_DIR}")
    ap.add_argument("--account-name", help="账号名（用于文件名），默认从页面读取")
    args = ap.parse_args()

    if args.selftest:
        selftest()
    elif args.url:
        run(args.url, user_data_dir=args.user_data_dir, channel=args.channel,
            cdp_url=args.connect, download_dir=args.download_dir,
            account_name=args.account_name)
    else:
        selftest()
        print("\n实际运行需先 pip install playwright，再复用登录态（二选一）：\n"
              "  方式 A: python youtube_export_download.py --url \"<explore URL>\" "
              "--channel chrome --user-data-dir <你的 Chrome User Data 目录>\n"
              "  方式 B: python youtube_export_download.py --url \"<explore URL>\" "
              "--connect http://localhost:9222")