"""使用 pyppeteer 下载 URL（支持 JS 渲染）"""

import os
import asyncio
import tempfile
from typing import Optional, Tuple

from .common import (
    USER_AGENT,
    CHROME_ARGS,
    HIDE_AUTOMATION_SCRIPT_PUPPETEER
)


def download(url: str) -> Tuple[Optional[str], Optional[str]]:
    """
    使用 pyppeteer 下载 URL（支持 JS 渲染）

    Args:
        url: 目标 URL

    Returns:
        (content, error): content 成功时为 HTML 内容，失败时为 None
                         error 成功时为 None，失败时为错误信息
    """
    try:
        from pyppeteer import launch
    except ImportError:
        return None, "pyppeteer 库未安装"

    async def _download():
        pyppeteer_temp_dir = os.path.join(tempfile.gettempdir(), "pyppeteer_home")
        chromium_path = os.environ.get("LYXY_CHROMIUM_BINARY")
        if not chromium_path:
            os.environ["PYPPETEER_HOME"] = pyppeteer_temp_dir
        executable_path = chromium_path if (chromium_path and os.path.exists(chromium_path)) else None

        browser = None
        try:
            browser = await launch(
                headless=True,
                executablePath=executable_path,
                args=CHROME_ARGS
            )
            page = await browser.newPage()

            await page.evaluateOnNewDocument(HIDE_AUTOMATION_SCRIPT_PUPPETEER)

            await page.setJavaScriptEnabled(True)
            await page.goto(url, {"waitUntil": "networkidle2", "timeout": 30000})
            return await page.content()
        finally:
            if browser is not None:
                try:
                    await browser.close()
                except Exception:
                    pass

    try:
        content = asyncio.run(_download())
        if not content or not content.strip():
            return None, "下载内容为空"
        return content, None
    except Exception as e:
        return None, f"pyppeteer 下载失败: {str(e)}"