app_factory.py

# Copyright 2024 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Application factory for creating the FastAPI app and on_load handler."""

import logging
from typing import Callable, Generator

import mesop as me
from fastapi import FastAPI
from mesop.events import LoadEvent

from common.error_handling import UnknownHandlerIdFilter
from state.state import AppState

# Apply the filter to the root logger to suppress the benign error
root_logger = logging.getLogger()
root_logger.addFilter(UnknownHandlerIdFilter())



def create_app():
    """Create the FastAPI app instance."""
    app = FastAPI()
    return app


def create_on_load_handler(
    user_email: str, session_id: str
) -> Callable[[LoadEvent], Generator[None, None, None] | None]:
    """Create the on_load event handler."""

    def on_load(e: LoadEvent) -> Generator[None, None, None] | None:
        """On load event."""
        s = me.state(AppState)
        s.user_email = user_email
        s.session_id = session_id

        if s.theme_mode:
            if s.theme_mode == "light":
                me.set_theme_mode("light")
            elif s.theme_mode == "dark":
                me.set_theme_mode("dark")
        else:
            me.set_theme_mode("system")
            s.theme_mode = me.theme_brightness()
        yield

    return on_load


app = create_app()