import re
from typing import Any

import tornado
from tornado import httputil
from tornado.web import Application

from core.config import (
    BASE_URL,
    SERVER_OWNER_CALLSIGN,
    TELNET_SERVER_ADDRESS,
    TELNET_SERVER_ENABLED,
    TELNET_SERVER_PORT,
    WEB_UI_OPTIONS,
)
from core.constants import SOFTWARE_VERSION
from core.utils import infer_mode_type_from_mode, safe_json_dumps
from webserver.handlers.api.options import build_options


def dom_safe_name(name):
    """Strip characters from a name that are not allowed in HTML element IDs"""

    return re.sub(r"^[^A-Za-z0-9]+|\W+", "", name, flags=re.ASCII)


class PageTemplateHandler(tornado.web.RequestHandler):
    """Handler for all HTML pages generated from templates"""

    def __init__(
        self,
        application: "Application",
        request: httputil.HTTPServerRequest,
        **kwargs: Any,
    ):
        self._template_name = None
        super().__init__(application, request, **kwargs)

    def initialize(self, template_name):
        self._template_name = template_name

    def get_template_namespace(self):
        """Provide variables and helper functions to all page templates"""

        namespace = super().get_template_namespace()
        namespace.update(
            # Various options
            options=build_options(),
            web_ui_options=WEB_UI_OPTIONS,
            # Other single static parameters
            software_version=SOFTWARE_VERSION,
            server_owner_callsign=SERVER_OWNER_CALLSIGN,
            baseurl=BASE_URL,
            telnet_server_enabled=TELNET_SERVER_ENABLED,
            telnet_server_address=TELNET_SERVER_ADDRESS,
            telnet_server_port=TELNET_SERVER_PORT,
            # Function references that templates need
            dom_safe_name=dom_safe_name,
            safe_json_dumps=safe_json_dumps,
            infer_mode_type_from_mode=infer_mode_type_from_mode,
        )
        return namespace

    def get(self):
        self.render(f"{self._template_name}.html")