browser_main.py

import os
import asyncio
from ..backend_base import BackendBase
from ...constants import JS_DIR, HTML_DIR
from .server import server_context, find_free_port
from playwright.async_api import async_playwright
from pathlib import Path
import shutil


THIS_DIR = os.path.dirname(os.path.realpath(__file__))


class BrowserMainBackend(BackendBase):
    def __init__(
        self, host_work_dir, work_dir, script, async_main, port, headless, slow_mo
    ):
        super().__init__(
            host_work_dir=host_work_dir,
            work_dir=work_dir,
            script=script,
            async_main=async_main,
        )
        if port is None:
            port = find_free_port()
        self.port = port
        self.headless = headless
        self.slow_mo = slow_mo

    def run(self):
        browser_main_html = "browser_main.html"
        main = HTML_DIR / browser_main_html
        shutil.copyfile(main, self.host_work_dir / browser_main_html)

        with server_context(work_dir=self.host_work_dir, port=self.port) as (
            server,
            url,
        ):
            page_url = f"{url}/{browser_main_html}"
            ret = asyncio.run(self.playwright_run_in_main_thread(page_url=page_url))
            if ret != 0:
                raise RuntimeError("return_code != 0")

    async def playwright_run_in_main_thread(self, page_url):
        async with async_playwright() as p:
            if self.slow_mo is None:
                browser = await p.chromium.launch(headless=self.headless)
            else:
                browser = await p.chromium.launch(
                    headless=self.headless, slow_mo=self.slow_mo
                )
            page = await browser.new_page()
            await page.goto(page_url)
            # n min = n_min * 60 * 1000 ms
            n_min = 4
            page.set_default_timeout(n_min * 60 * 1000)

            async def handle_console(msg):
                txt = str(msg)
                print(txt)

            page.on("console", handle_console)

            # await page.goto(page_url)
            status = await page.evaluate(
                f"""async () => {{

                    {self.js_utils()}


                    var collected_prints = ""
                    const print = (text) => {{
                        console.log(text)
                        collected_prints += text;
                        collected_prints += "\\n";
                    }}

                    var pyjs = await make_pyjs(print,print, true);

                    var r = globalThis.eval_main_script(pyjs, "{self.work_dir}","{self.script}");
                    if({int(self.async_main)}){{
                        r = r || await run_async_python_main(pyjs);
                    }}
                    return r;

                }}"""
            )
            return_code = int(status)
        return return_code