web_server.py

import http.server
from http import HTTPStatus
import json
import urllib.parse
from pathlib import Path, PurePath
from typing import Union
import html
import re


from translations import translate, check_lang


_root = Path(__file__).parent.joinpath("web", "web_root").resolve()
assert _root.is_dir()


def translate_json(m: re.Match[bytes]) -> bytes:
    try:
        loc_str = json.loads(m[0][1:-1])
    except json.JSONDecodeError:
        return m[0]
    return (">" + html.escape(translate(loc_str)) + "<").encode()


class FA_handler(http.server.BaseHTTPRequestHandler):
    resp = json.dumps({"test": "woot"}).encode("utf8")

    ext_map = {
        ".html": "text/html; charset=UTF-8",
        ".js": "text/javascript; charset=UTF-8",
        ".css": "text/css; charset=UTF-8",
        ".ico": "image/vnd.microsoft.icon",
        ".woff": "font/woff",
    }

    def send_file(self, path: Path):
        ext = path.suffix
        self.send_header("Content-Type", self.ext_map[ext])
        with path.open("br") as fp:
            buff = fp.read()
        if ext == ".html":
            buff = re.sub(rb">\[[^<>]*\]<", translate_json, buff)
        self.send_header("Content-Length", str(len(buff)))
        self.end_headers()
        if self.command == "GET":
            self.wfile.write(buff)

    def do(self):
        path = self.check_path()
        if not path:
            return
        if self.command == "OPTIONS":
            return self.finish_OPTIONS(path)
        if isinstance(path, urllib.parse.ParseResult):
            return self.api_call(path)
        if self.command not in ["GET", "HEAD"]:
            self.send_response(HTTPStatus.METHOD_NOT_ALLOWED)
            self.send_header("Content-Length", str(0))
            return
        self.send_response(HTTPStatus.OK)
        return self.send_file(path)

    def finish_OPTIONS(self, path):
        self.send_response(HTTPStatus.OK)
        allowed = ["OPTIONS", "HEAD", "GET"]
        if isinstance(path, urllib.parse.ParseResult):
            allowed += ["POST"]
        self.send_header("Allow", ", ".join(allowed))
        self.send_header("Content-Length", "0")
        self.end_headers()

    def api_call(self, path: urllib.parse.ParseResult):
        pass

    def do_OPTIONS(self):
        self.do()

    def do_HEAD(self) -> None:
        self.do()

    def do_GET(self) -> None:
        self.do()

    def do_POST(self) -> None:
        self.do()

    def check_path(self) -> Union[Path, urllib.parse.ParseResult, None]:
        path = urllib.parse.urlparse(self.path, "http", False)
        if path.path.startswith("/api/"):
            return path
        if path.path.endswith("/index.html"):
            self.send_response(HTTPStatus.MOVED_PERMANENTLY)
            self.send_header("Location", path.path.removesuffix("index.html"))
            self.end_headers()
            return None
        s_path = path.path
        if s_path.endswith("/"):
            s_path += "index.html"
        rel = PurePath("." + s_path)
        maybe_file = _root.joinpath(rel).resolve()
        if maybe_file.is_relative_to(_root) and maybe_file.is_file():
            return maybe_file
        self.send_response(HTTPStatus.NOT_FOUND)
        self.send_file(_root.joinpath("404.html"))
        return None

    def api_send_head(self):
        self.send_response(HTTPStatus.OK)
        self.send_header("Access-Control-Allow-Origin", "https://mods.factorio.com")
        self.send_header("Content-type", "application/json")
        self.send_header("Content-Length", str(len(self.resp)))
        self.end_headers()


check_lang()

server = http.server.HTTPServer(("127.0.0.1", 34197), FA_handler)
server.serve_forever()