text: # #!/usr/bin/env python3.9
  import asyncio
  import os
  
  import aiohttp
  import orjson
  from cmyui.logging import Ansi
  from cmyui.logging import log
  from fastapi import FastAPI
  from fastapi import status
  from fastapi.exceptions import RequestValidationError
  from fastapi.middleware.cors import CORSMiddleware
  from fastapi.requests import Request
  from fastapi.responses import Response
  from starlette.middleware.base import RequestResponseEndpoint
  
  import app.bg_loops
  import app.state
  import app.utils
  import settings
  from app.api import domains
  from app.api import middlewares
  from app.objects import collections
  
  
  def init_exception_handlers(asgi_app: FastAPI) -> None:
      @asgi_app.exception_handler(RequestValidationError)
      async def handle_validation_error(
          request: Request,
          exc: RequestValidationError,
      ) -> Response:
          print(f"Validation error on {request.url}", "\n", exc.errors())
  
          return Response(
              content=orjson.dumps(exc.errors()),
              status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
          )
  
  
  def init_middlewares(asgi_app: FastAPI) -> None:
      """Initialize our app's middleware stack."""
  
      @asgi_app.middleware("http")
      async def http_middleware(
          request: Request,
          call_next: RequestResponseEndpoint,
      ) -> Response:
          # if an osu! client is waiting on leaderboard data
          # and switches to another leaderboard, it will cancel
          # the previous request mid-way, resulting in a large
          # error in the console. this is to catch that :)
  
          try:
              return await call_next(request)
          except RuntimeError as exc:
              if exc.args[0] == "No response returned.":
                  # client disconnected from the server
                  # while we were sending the response.
                  return Response("Client is stupppod")
  
              # unrelated issue, raise normally
              raise exc
  
      # cors middleware
      asgi_app.add_middleware(
          CORSMiddleware,
          allow_origins=settings.CORS_ORIGINS,
          allow_credentials=True,
          allow_methods=["*"],
          allow_headers=["*"],
      )
  
      asgi_app.add_middleware(middlewares.MetricsMiddleware)
  
  
  def init_events(asgi_app: FastAPI) -> None:
      """Initialize our app's event handlers."""
  
      @asgi_app.on_event("startup")
      async def on_startup() -> None:
          app.state.loop = asyncio.get_running_loop()
  
          if os.geteuid() == 0:
              log(
                  "Running the server with root privileges is not recommended.",
                  Ansi.LRED,
              )
  
          app.state.services.http = aiohttp.ClientSession(
              json_serialize=lambda x: orjson.dumps(x).decode(),
          )
          await app.state.services.database.connect()
          await app.state.services.redis.initialize()
  
          if app.state.services.datadog is not None:
              app.state.services.datadog.start(
                  flush_in_thread=True,
                  flush_interval=15,
              )
              app.state.services.datadog.gauge("gulag.online_players", 0)
  
          await app.state.services.run_sql_migrations()
  
          async with app.state.services.database.connection() as db_conn:
              await collections.initialize_ram_caches(db_conn)
  
          await app.bg_loops.initialize_housekeeping_tasks()
  
      @asgi_app.on_event("shutdown")
      async def on_shutdown() -> None:
          # we want to attempt to gracefully finish any ongoing connections
          # and shut down any of the housekeeping tasks running in the background.
          await app.state.sessions.cancel_housekeeping_tasks()
  
          # shutdown services
  
          await app.state.services.http.close()
          await app.state.services.database.disconnect()
          await app.state.services.redis.close()
  
          if app.state.services.datadog is not None:
              app.state.services.datadog.stop()
              app.state.services.datadog.flush()
  
          if app.state.services.geoloc_db is not None:
              app.state.services.geoloc_db.close()
  
  
  def init_routes(asgi_app: FastAPI) -> None:
      """Initialize our app's route endpoints."""
      for domain in ("ppy.sh", settings.DOMAIN):
          asgi_app.host(f"a.{domain}", domains.ava.router)
  
          for subdomain in ("c", "ce", "c4", "c5", "c6"):
              asgi_app.host(f"{subdomain}.{domain}", domains.cho.router)
  
          asgi_app.host(f"osu.{domain}", domains.osu.router)
          asgi_app.host(f"b.{domain}", domains.map.router)
  
          # gulag's developer-facing api
          asgi_app.host(f"api.{domain}", domains.api.router)
  
  
  def init_api() -> FastAPI:
      """Create & initialize our app."""
      asgi_app = FastAPI()
  
      init_middlewares(asgi_app)
      init_exception_handlers(asgi_app)
      init_events(asgi_app)
      init_routes(asgi_app)
  
      return asgi_app
  
  
  asgi_app = init_api()
  