routes.py

"""Implements a FastAPI server to run the gradio interface. Note that some types in this
module use the Optional/Union notation so that they work correctly with pydantic."""

from __future__ import annotations

import asyncio
import contextlib
import math
import sys

if sys.version_info >= (3, 9):
    from importlib.resources import files
else:
    from importlib_resources import files
import hashlib
import inspect
import json
import mimetypes
import os
import posixpath
import secrets
import time
import traceback
from pathlib import Path
from queue import Empty as EmptyQueue
from typing import (
    TYPE_CHECKING,
    Any,
    AsyncIterator,
    Callable,
    Dict,
    List,
    Literal,
    Optional,
    Type,
    Union,
)

import fastapi
import httpx
import markupsafe
import orjson
from fastapi import (
    BackgroundTasks,
    Depends,
    FastAPI,
    HTTPException,
    status,
)
from fastapi.responses import (
    FileResponse,
    HTMLResponse,
    JSONResponse,
    PlainTextResponse,
)
from fastapi.security import OAuth2PasswordRequestForm
from fastapi.templating import Jinja2Templates
from gradio_client import utils as client_utils
from gradio_client.documentation import document
from gradio_client.utils import ServerMessage
from jinja2.exceptions import TemplateNotFound
from multipart.multipart import parse_options_header
from starlette.background import BackgroundTask
from starlette.datastructures import UploadFile as StarletteUploadFile
from starlette.responses import RedirectResponse, StreamingResponse

import gradio
from gradio import ranged_response, route_utils, utils, wasm_utils
from gradio.context import Context
from gradio.data_classes import (
    CancelBody,
    ComponentServerBlobBody,
    ComponentServerJSONBody,
    DataWithFiles,
    PredictBody,
    ResetBody,
    SimplePredictBody,
)
from gradio.exceptions import Error
from gradio.oauth import attach_oauth
from gradio.route_utils import (  # noqa: F401
    CustomCORSMiddleware,
    FileUploadProgress,
    FileUploadProgressNotQueuedError,
    FileUploadProgressNotTrackedError,
    GradioMultiPartParser,
    GradioUploadFile,
    MultiPartException,
    Request,
    compare_passwords_securely,
    create_lifespan_handler,
    move_uploaded_files_to_cache,
)
from gradio.server_messages import (
    CloseStreamMessage,
    EstimationMessage,
    EventMessage,
    HeartbeatMessage,
    ProcessCompletedMessage,
    ProcessGeneratingMessage,
    UnexpectedErrorMessage,
)
from gradio.state_holder import StateHolder
from gradio.utils import cancel_tasks, get_package_version, get_upload_folder

if TYPE_CHECKING:
    from gradio.blocks import Block


mimetypes.init()

STATIC_TEMPLATE_LIB = files("gradio").joinpath("templates").as_posix()  # type: ignore
STATIC_PATH_LIB = files("gradio").joinpath("templates", "frontend", "static").as_posix()  # type: ignore
BUILD_PATH_LIB = files("gradio").joinpath("templates", "frontend", "assets").as_posix()  # type: ignore
VERSION = get_package_version()


class ORJSONResponse(JSONResponse):
    media_type = "application/json"

    @staticmethod
    def _render(content: Any) -> bytes:
        return orjson.dumps(
            content,
            option=orjson.OPT_SERIALIZE_NUMPY | orjson.OPT_PASSTHROUGH_DATETIME,
            default=str,
        )

    def render(self, content: Any) -> bytes:
        return ORJSONResponse._render(content)

    @staticmethod
    def _render_str(content: Any) -> str:
        return ORJSONResponse._render(content).decode("utf-8")


def toorjson(value):
    return markupsafe.Markup(
        ORJSONResponse._render_str(value)
        .replace("<", "\\u003c")
        .replace(">", "\\u003e")
        .replace("&", "\\u0026")
        .replace("'", "\\u0027")
    )


templates = Jinja2Templates(directory=STATIC_TEMPLATE_LIB)
templates.env.filters["toorjson"] = toorjson

client = httpx.AsyncClient()

file_upload_statuses = FileUploadProgress()


class App(FastAPI):
    """
    FastAPI App Wrapper
    """

    def __init__(
        self,
        auth_dependency: Callable[[fastapi.Request], str | None] | None = None,
        **kwargs,
    ):
        self.tokens = {}
        self.auth = None
        self.blocks: gradio.Blocks | None = None
        self.state_holder = StateHolder()
        self.iterators: dict[str, AsyncIterator] = {}
        self.iterators_to_reset: set[str] = set()
        self.lock = utils.safe_get_lock()
        self.stop_event = utils.safe_get_stop_event()
        self.cookie_id = secrets.token_urlsafe(32)
        self.queue_token = secrets.token_urlsafe(32)
        self.startup_events_triggered = False
        self.uploaded_file_dir = get_upload_folder()
        self.change_count: int = 0
        self.change_type: Literal["reload", "error"] | None = None
        self.reload_error_message: str | None = None
        self._asyncio_tasks: list[asyncio.Task] = []
        self.auth_dependency = auth_dependency
        self.api_info = None
        self.all_app_info = None
        # Allow user to manually set `docs_url` and `redoc_url`
        # when instantiating an App; when they're not set, disable docs and redoc.
        kwargs.setdefault("docs_url", None)
        kwargs.setdefault("redoc_url", None)
        self.custom_component_hashes: dict[str, str] = {}
        super().__init__(**kwargs)

    def configure_app(self, blocks: gradio.Blocks) -> None:
        auth = blocks.auth
        if auth is not None:
            if not callable(auth):
                self.auth = {account[0]: account[1] for account in auth}
            else:
                self.auth = auth
        else:
            self.auth = None

        self.blocks = blocks
        self.cwd = os.getcwd()
        self.favicon_path = blocks.favicon_path
        self.tokens = {}
        self.root_path = blocks.root_path
        self.state_holder.set_blocks(blocks)

    def get_blocks(self) -> gradio.Blocks:
        if self.blocks is None:
            raise ValueError("No Blocks has been configured for this app.")
        return self.blocks

    def build_proxy_request(self, url_path):
        url = httpx.URL(url_path)
        assert self.blocks  # noqa: S101
        # Don't proxy a URL unless it's a URL specifically loaded by the user using
        # gr.load() to prevent SSRF or harvesting of HF tokens by malicious Spaces.
        is_safe_url = any(
            url.host == httpx.URL(root).host for root in self.blocks.proxy_urls
        )
        if not is_safe_url:
            raise PermissionError("This URL cannot be proxied.")
        is_hf_url = url.host.endswith(".hf.space")
        headers = {}
        if Context.hf_token is not None and is_hf_url:
            headers["Authorization"] = f"Bearer {Context.hf_token}"
        rp_req = client.build_request("GET", url, headers=headers)
        return rp_req

    def _cancel_asyncio_tasks(self):
        for task in self._asyncio_tasks:
            task.cancel()
        self._asyncio_tasks = []

    @staticmethod
    def create_app(
        blocks: gradio.Blocks,
        app_kwargs: Dict[str, Any] | None = None,
        auth_dependency: Callable[[fastapi.Request], str | None] | None = None,
    ) -> App:
        app_kwargs = app_kwargs or {}
        app_kwargs.setdefault("default_response_class", ORJSONResponse)
        delete_cache = blocks.delete_cache or (None, None)
        app_kwargs["lifespan"] = create_lifespan_handler(
            app_kwargs.get("lifespan", None), *delete_cache
        )
        app = App(auth_dependency=auth_dependency, **app_kwargs)
        app.configure_app(blocks)

        if not wasm_utils.IS_WASM:
            app.add_middleware(CustomCORSMiddleware)

        @app.get("/user")
        @app.get("/user/")
        def get_current_user(request: fastapi.Request) -> Optional[str]:
            if app.auth_dependency is not None:
                return app.auth_dependency(request)
            token = request.cookies.get(
                f"access-token-{app.cookie_id}"
            ) or request.cookies.get(f"access-token-unsecure-{app.cookie_id}")
            return app.tokens.get(token)

        @app.get("/login_check")
        @app.get("/login_check/")
        def login_check(user: str = Depends(get_current_user)):
            if (app.auth is None and app.auth_dependency is None) or user is not None:
                return
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated"
            )

        @app.get("/token")
        @app.get("/token/")
        def get_token(request: fastapi.Request) -> dict:
            token = request.cookies.get(f"access-token-{app.cookie_id}")
            return {"token": token, "user": app.tokens.get(token)}

        @app.get("/app_id")
        @app.get("/app_id/")
        def app_id(request: fastapi.Request) -> dict:  # noqa: ARG001
            return {"app_id": app.get_blocks().app_id}

        @app.get("/dev/reload", dependencies=[Depends(login_check)])
        async def notify_changes(
            request: fastapi.Request,
        ):
            async def reload_checker(request: fastapi.Request):
                heartbeat_rate = 15
                check_rate = 0.05
                last_heartbeat = time.perf_counter()
                current_count = app.change_count

                while True:
                    if await request.is_disconnected():
                        return

                    if app.change_count != current_count:
                        current_count = app.change_count
                        msg = (
                            json.dumps(f"{app.reload_error_message}")
                            if app.change_type == "error"
                            else "{}"
                        )
                        yield f"""event: {app.change_type}\ndata: {msg}\n\n"""

                    await asyncio.sleep(check_rate)
                    if time.perf_counter() - last_heartbeat > heartbeat_rate:
                        yield """event: heartbeat\ndata: {}\n\n"""
                        last_heartbeat = time.time()

            return StreamingResponse(
                reload_checker(request),
                media_type="text/event-stream",
            )

        @app.post("/login")
        @app.post("/login/")
        def login(form_data: OAuth2PasswordRequestForm = Depends()):
            username, password = form_data.username.strip(), form_data.password
            if app.auth is None:
                return RedirectResponse(url="/", status_code=status.HTTP_302_FOUND)
            if (
                not callable(app.auth)
                and username in app.auth
                and compare_passwords_securely(password, app.auth[username])  # type: ignore
            ) or (callable(app.auth) and app.auth.__call__(username, password)):
                token = secrets.token_urlsafe(16)
                app.tokens[token] = username
                response = JSONResponse(content={"success": True})
                response.set_cookie(
                    key=f"access-token-{app.cookie_id}",
                    value=token,
                    httponly=True,
                    samesite="none",
                    secure=True,
                )
                response.set_cookie(
                    key=f"access-token-unsecure-{app.cookie_id}",
                    value=token,
                    httponly=True,
                )
                return response
            else:
                raise HTTPException(status_code=400, detail="Incorrect credentials.")

        ###############
        # OAuth Routes
        ###############

        # Define OAuth routes if the app expects it (i.e. a LoginButton is defined).
        # It allows users to "Sign in with HuggingFace". Otherwise, add the default
        # logout route.
        if app.blocks is not None and app.blocks.expects_oauth:
            attach_oauth(app)
        else:

            @app.get("/logout")
            def logout(user: str = Depends(get_current_user)):
                response = RedirectResponse(url="/", status_code=status.HTTP_302_FOUND)
                response.delete_cookie(key=f"access-token-{app.cookie_id}", path="/")
                response.delete_cookie(
                    key=f"access-token-unsecure-{app.cookie_id}", path="/"
                )
                # A user may have multiple tokens, so we need to delete all of them.
                for token in list(app.tokens.keys()):
                    if app.tokens[token] == user:
                        del app.tokens[token]
                return response

        ###############
        # Main Routes
        ###############

        @app.head("/", response_class=HTMLResponse)
        @app.get("/", response_class=HTMLResponse)
        def main(request: fastapi.Request, user: str = Depends(get_current_user)):
            mimetypes.add_type("application/javascript", ".js")
            blocks = app.get_blocks()
            root = route_utils.get_root_url(
                request=request, route_path="/", root_path=app.root_path
            )
            if (app.auth is None and app.auth_dependency is None) or user is not None:
                config = app.get_blocks().config
                config = route_utils.update_root_in_config(config, root)
            elif app.auth_dependency:
                raise HTTPException(
                    status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated"
                )
            else:
                config = {
                    "auth_required": True,
                    "auth_message": blocks.auth_message,
                    "space_id": app.get_blocks().space_id,
                    "root": root,
                }

            try:
                template = (
                    "frontend/share.html" if blocks.share else "frontend/index.html"
                )
                return templates.TemplateResponse(
                    template,
                    {"request": request, "config": config},
                )
            except TemplateNotFound as err:
                if blocks.share:
                    raise ValueError(
                        "Did you install Gradio from source files? Share mode only "
                        "works when Gradio is installed through the pip package."
                    ) from err
                else:
                    raise ValueError(
                        "Did you install Gradio from source files? You need to build "
                        "the frontend by running /scripts/build_frontend.sh"
                    ) from err

        @app.get("/info/", dependencies=[Depends(login_check)])
        @app.get("/info", dependencies=[Depends(login_check)])
        def api_info(all_endpoints: bool = False):
            if all_endpoints:
                if not app.all_app_info:
                    app.all_app_info = app.get_blocks().get_api_info(all_endpoints=True)
                return app.all_app_info
            if not app.api_info:
                app.api_info = app.get_blocks().get_api_info()
            return app.api_info

        @app.get("/config/", dependencies=[Depends(login_check)])
        @app.get("/config", dependencies=[Depends(login_check)])
        def get_config(request: fastapi.Request):
            config = app.get_blocks().config
            root = route_utils.get_root_url(
                request=request, route_path="/config", root_path=app.root_path
            )
            config = route_utils.update_root_in_config(config, root)
            return ORJSONResponse(content=config)

        @app.get("/static/{path:path}")
        def static_resource(path: str):
            static_file = safe_join(STATIC_PATH_LIB, path)
            return FileResponse(static_file)

        @app.get("/custom_component/{id}/{type}/{file_name}")
        def custom_component_path(
            id: str, type: str, file_name: str, req: fastapi.Request
        ):
            config = app.get_blocks().config
            components = config["components"]
            location = next(
                (item for item in components if item["component_class_id"] == id), None
            )

            if location is None:
                raise HTTPException(status_code=404, detail="Component not found.")

            component_instance = app.get_blocks().get_component(location["id"])

            module_name = component_instance.__class__.__module__
            module_path = sys.modules[module_name].__file__

            if module_path is None or component_instance is None:
                raise HTTPException(status_code=404, detail="Component not found.")

            path = safe_join(
                str(Path(module_path).parent),
                f"{component_instance.__class__.TEMPLATE_DIR}/{type}/{file_name}",
            )

            key = f"{id}-{type}-{file_name}"

            if key not in app.custom_component_hashes:
                app.custom_component_hashes[key] = hashlib.md5(
                    Path(path).read_text().encode()
                ).hexdigest()

            version = app.custom_component_hashes.get(key)
            headers = {"Cache-Control": "max-age=0, must-revalidate"}
            if version:
                headers["ETag"] = version

            if version and req.headers.get("if-none-match") == version:
                return PlainTextResponse(status_code=304, headers=headers)

            return FileResponse(path, headers=headers)

        @app.get("/assets/{path:path}")
        def build_resource(path: str):
            build_file = safe_join(BUILD_PATH_LIB, path)
            return FileResponse(build_file)

        @app.get("/favicon.ico")
        async def favicon():
            blocks = app.get_blocks()
            if blocks.favicon_path is None:
                return static_resource("img/logo.svg")
            else:
                return FileResponse(blocks.favicon_path)

        @app.head("/proxy={url_path:path}", dependencies=[Depends(login_check)])
        @app.get("/proxy={url_path:path}", dependencies=[Depends(login_check)])
        async def reverse_proxy(url_path: str):
            # Adapted from: https://github.com/tiangolo/fastapi/issues/1788
            try:
                rp_req = app.build_proxy_request(url_path)
            except PermissionError as err:
                raise HTTPException(status_code=400, detail=str(err)) from err
            rp_resp = await client.send(rp_req, stream=True)
            return StreamingResponse(
                rp_resp.aiter_raw(),
                status_code=rp_resp.status_code,
                headers=rp_resp.headers,  # type: ignore
                background=BackgroundTask(rp_resp.aclose),
            )

        @app.head("/file={path_or_url:path}", dependencies=[Depends(login_check)])
        @app.get("/file={path_or_url:path}", dependencies=[Depends(login_check)])
        async def file(path_or_url: str, request: fastapi.Request):
            blocks = app.get_blocks()
            if client_utils.is_http_url_like(path_or_url):
                return RedirectResponse(
                    url=path_or_url, status_code=status.HTTP_302_FOUND
                )

            if route_utils.starts_with_protocol(path_or_url):
                raise HTTPException(403, f"File not allowed: {path_or_url}.")

            abs_path = utils.abspath(path_or_url)

            in_blocklist = any(
                utils.is_in_or_equal(abs_path, blocked_path)
                for blocked_path in blocks.blocked_paths
            )

            is_dir = abs_path.is_dir()

            if in_blocklist or is_dir:
                raise HTTPException(403, f"File not allowed: {path_or_url}.")

            created_by_app = False
            for temp_file_set in blocks.temp_file_sets:
                if abs_path in temp_file_set:
                    created_by_app = True
                    break
            in_allowlist = any(
                utils.is_in_or_equal(abs_path, allowed_path)
                for allowed_path in blocks.allowed_paths
            )
            is_static_file = utils.is_static_file(abs_path)
            was_uploaded = utils.is_in_or_equal(abs_path, app.uploaded_file_dir)
            is_cached_example = utils.is_in_or_equal(
                abs_path, utils.abspath(utils.get_cache_folder())
            )

            if not (
                created_by_app
                or in_allowlist
                or was_uploaded
                or is_cached_example
                or is_static_file
            ):
                raise HTTPException(403, f"File not allowed: {path_or_url}.")

            if not abs_path.exists():
                raise HTTPException(404, f"File not found: {path_or_url}.")

            range_val = request.headers.get("Range", "").strip()
            if range_val.startswith("bytes=") and "-" in range_val:
                range_val = range_val[6:]
                start, end = range_val.split("-")
                if start.isnumeric() and end.isnumeric():
                    start = int(start)
                    end = int(end)
                    response = ranged_response.RangedFileResponse(
                        abs_path,
                        ranged_response.OpenRange(start, end),
                        dict(request.headers),
                        stat_result=os.stat(abs_path),
                    )
                    return response

            return FileResponse(abs_path, headers={"Accept-Ranges": "bytes"})

        @app.get(
            "/stream/{session_hash}/{run}/{component_id}",
            dependencies=[Depends(login_check)],
        )
        async def stream(
            session_hash: str,
            run: int,
            component_id: int,
            request: fastapi.Request,  # noqa: ARG001
        ):
            stream: list = (
                app.get_blocks()
                .pending_streams[session_hash]
                .get(run, {})
                .get(component_id, None)
            )
            if stream is None:
                raise HTTPException(404, "Stream not found.")

            def stream_wrapper():
                check_stream_rate = 0.01
                max_wait_time = 120  # maximum wait between yields - assume generator thread has crashed otherwise.
                wait_time = 0
                while True:
                    if len(stream) == 0:
                        if wait_time > max_wait_time:
                            return
                        wait_time += check_stream_rate
                        time.sleep(check_stream_rate)
                        continue
                    wait_time = 0
                    next_stream = stream.pop(0)
                    if next_stream is None:
                        return
                    yield next_stream

            return StreamingResponse(stream_wrapper())

        @app.get("/file/{path:path}", dependencies=[Depends(login_check)])
        async def file_deprecated(path: str, request: fastapi.Request):
            return await file(path, request)

        @app.post("/reset/")
        @app.post("/reset")
        async def reset_iterator(body: ResetBody):
            if body.event_id not in app.iterators:
                return {"success": False}
            async with app.lock:
                del app.iterators[body.event_id]
                app.iterators_to_reset.add(body.event_id)
                await app.get_blocks()._queue.clean_events(event_id=body.event_id)
            return {"success": True}

        @app.get("/heartbeat/{session_hash}")
        def heartbeat(
            session_hash: str,
            request: fastapi.Request,
            background_tasks: BackgroundTasks,
            username: str = Depends(get_current_user),
        ):
            """Clients make a persistent connection to this endpoint to keep the session alive.
            When the client disconnects, the session state is deleted.
            """
            heartbeat_rate = 0.25 if os.getenv("GRADIO_IS_E2E_TEST", None) else 15

            async def wait():
                await asyncio.sleep(heartbeat_rate)
                return "wait"

            async def stop_stream():
                await app.stop_event.wait()
                return "stop"

            async def iterator():
                while True:
                    try:
                        yield "data: ALIVE\n\n"
                        # We need to close the heartbeat connections as soon as the server stops
                        # otherwise the server can take forever to close
                        wait_task = asyncio.create_task(wait())
                        stop_stream_task = asyncio.create_task(stop_stream())
                        done, _ = await asyncio.wait(
                            [wait_task, stop_stream_task],
                            return_when=asyncio.FIRST_COMPLETED,
                        )
                        done = [d.result() for d in done]
                        if "stop" in done:
                            raise asyncio.CancelledError()
                    except asyncio.CancelledError:
                        req = Request(request, username, session_hash=session_hash)
                        root_path = route_utils.get_root_url(
                            request=request,
                            route_path=f"/hearbeat/{session_hash}",
                            root_path=app.root_path,
                        )
                        body = PredictBody(
                            session_hash=session_hash, data=[], request=request
                        )
                        unload_fn_indices = [
                            i
                            for i, dep in enumerate(app.get_blocks().fns)
                            if any(t for t in dep.targets if t[1] == "unload")
                        ]
                        for fn_index in unload_fn_indices:
                            # The task runnning this loop has been cancelled
                            # so we add tasks in the background
                            background_tasks.add_task(
                                route_utils.call_process_api,
                                app=app,
                                body=body,
                                gr_request=req,
                                fn_index_inferred=fn_index,
                                root_path=root_path,
                            )
                        # This will mark the state to be deleted in an hour
                        if session_hash in app.state_holder.session_data:
                            app.state_holder.session_data[session_hash].is_closed = True
                        return

            return StreamingResponse(iterator(), media_type="text/event-stream")

        # had to use '/run' endpoint for Colab compatibility, '/api' supported for backwards compatibility
        @app.post("/run/{api_name}", dependencies=[Depends(login_check)])
        @app.post("/run/{api_name}/", dependencies=[Depends(login_check)])
        @app.post("/api/{api_name}", dependencies=[Depends(login_check)])
        @app.post("/api/{api_name}/", dependencies=[Depends(login_check)])
        async def predict(
            api_name: str,
            body: PredictBody,
            request: fastapi.Request,
            username: str = Depends(get_current_user),
        ):
            fn_index_inferred = route_utils.infer_fn_index(
                app=app, api_name=api_name, body=body
            )

            if not app.get_blocks().api_open and app.get_blocks().queue_enabled_for_fn(
                fn_index_inferred
            ):
                raise HTTPException(
                    detail="This API endpoint does not accept direct HTTP POST requests. Please join the queue to use this API.",
                    status_code=status.HTTP_404_NOT_FOUND,
                )

            gr_request = route_utils.compile_gr_request(
                app,
                body,
                fn_index_inferred=fn_index_inferred,
                username=username,
                request=request,
            )
            root_path = route_utils.get_root_url(
                request=request, route_path=f"/api/{api_name}", root_path=app.root_path
            )
            try:
                output = await route_utils.call_process_api(
                    app=app,
                    body=body,
                    gr_request=gr_request,
                    fn_index_inferred=fn_index_inferred,
                    root_path=root_path,
                )
                if (  # noqa: SIM102
                    (blocks := app.get_blocks())
                    .fns[fn_index_inferred]
                    .is_cancel_function
                ):
                    # Need to complete the job so that the client disconnects
                    if body.session_hash in blocks._queue.pending_messages_per_session:
                        for event_id in output["data"]:
                            message = ProcessCompletedMessage(
                                output={}, success=True, event_id=event_id
                            )
                            blocks._queue.pending_messages_per_session[  # type: ignore
                                body.session_hash
                            ].put_nowait(message)

            except BaseException as error:
                show_error = app.get_blocks().show_error or isinstance(error, Error)
                traceback.print_exc()
                return JSONResponse(
                    content={"error": str(error) if show_error else None},
                    status_code=500,
                )
            return output

        @app.post("/call/{api_name}", dependencies=[Depends(login_check)])
        @app.post("/call/{api_name}/", dependencies=[Depends(login_check)])
        async def simple_predict_post(
            api_name: str,
            body: SimplePredictBody,
            request: fastapi.Request,
            username: str = Depends(get_current_user),
        ):
            full_body = PredictBody(**body.model_dump(), simple_format=True)
            inferred_fn_index = route_utils.infer_fn_index(
                app=app, api_name=api_name, body=full_body
            )
            full_body.fn_index = inferred_fn_index
            return await queue_join_helper(full_body, request, username)

        @app.post("/queue/join", dependencies=[Depends(login_check)])
        async def queue_join(
            body: PredictBody,
            request: fastapi.Request,
            username: str = Depends(get_current_user),
        ):
            if body.session_hash is None:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail="Session hash not found.",
                )
            return await queue_join_helper(body, request, username)

        async def queue_join_helper(
            body: PredictBody,
            request: fastapi.Request,
            username: str,
        ):
            blocks = app.get_blocks()

            if blocks._queue.server_app is None:
                blocks._queue.set_server_app(app)

            if blocks._queue.stopped:
                raise HTTPException(
                    status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
                    detail="Queue is stopped.",
                )

            success, event_id = await blocks._queue.push(
                body=body, request=request, username=username
            )
            if not success:
                status_code = (
                    status.HTTP_503_SERVICE_UNAVAILABLE
                    if "Queue is full." in event_id
                    else status.HTTP_400_BAD_REQUEST
                )
                raise HTTPException(status_code=status_code, detail=event_id)
            return {"event_id": event_id}

        @app.post("/cancel")
        async def cancel_event(body: CancelBody):
            await cancel_tasks({f"{body.session_hash}_{body.fn_index}"})
            blocks = app.get_blocks()
            # Need to complete the job so that the client disconnects
            if body.session_hash in blocks._queue.pending_messages_per_session:
                message = ProcessCompletedMessage(
                    output={}, success=True, event_id=body.event_id
                )
                blocks._queue.pending_messages_per_session[
                    body.session_hash
                ].put_nowait(message)
            return {"success": True}

        @app.get("/call/{api_name}/{event_id}", dependencies=[Depends(login_check)])
        async def simple_predict_get(
            request: fastapi.Request,
            event_id: str,
        ):
            def process_msg(message: EventMessage) -> str | None:
                if isinstance(message, ProcessCompletedMessage):
                    event = "complete" if message.success else "error"
                    data = message.output.get("data")
                elif isinstance(message, ProcessGeneratingMessage):
                    event = "generating" if message.success else "error"
                    data = message.output.get("data")
                elif isinstance(message, HeartbeatMessage):
                    event = "heartbeat"
                    data = None
                elif isinstance(message, UnexpectedErrorMessage):
                    event = "error"
                    data = message.message
                else:
                    return None
                return f"event: {event}\ndata: {json.dumps(data)}\n\n"

            return await queue_data_helper(request, event_id, process_msg)

        @app.get("/queue/data", dependencies=[Depends(login_check)])
        async def queue_data(
            request: fastapi.Request,
            session_hash: str,
        ):
            def process_msg(message: EventMessage) -> str:
                return f"data: {orjson.dumps(message.model_dump()).decode('utf-8')}\n\n"

            return await queue_data_helper(request, session_hash, process_msg)

        async def queue_data_helper(
            request: fastapi.Request,
            session_hash: str,
            process_msg: Callable[[EventMessage], str | None],
        ):
            blocks = app.get_blocks()

            async def sse_stream(request: fastapi.Request):
                try:
                    last_heartbeat = time.perf_counter()
                    while True:
                        if await request.is_disconnected():
                            await blocks._queue.clean_events(session_hash=session_hash)
                            return

                        if (
                            session_hash
                            not in blocks._queue.pending_messages_per_session
                        ):
                            raise HTTPException(
                                status_code=status.HTTP_404_NOT_FOUND,
                                detail="Session not found.",
                            )

                        heartbeat_rate = 15
                        check_rate = 0.05
                        message = None
                        try:
                            messages = blocks._queue.pending_messages_per_session[
                                session_hash
                            ]
                            message = messages.get_nowait()
                        except EmptyQueue:
                            await asyncio.sleep(check_rate)
                            if time.perf_counter() - last_heartbeat > heartbeat_rate:
                                # Fix this
                                message = HeartbeatMessage()
                                # Need to reset last_heartbeat with perf_counter
                                # otherwise only a single hearbeat msg will be sent
                                # and then the stream will retry leading to infinite queue 😬
                                last_heartbeat = time.perf_counter()

                        if blocks._queue.stopped:
                            message = UnexpectedErrorMessage(
                                message="Server stopped unexpectedly.",
                                success=False,
                            )
                        if message:
                            response = process_msg(message)
                            if response is not None:
                                yield response
                            if (
                                isinstance(message, ProcessCompletedMessage)
                                and message.event_id
                            ):
                                blocks._queue.pending_event_ids_session[
                                    session_hash
                                ].remove(message.event_id)
                                if message.msg == ServerMessage.server_stopped or (
                                    message.msg == ServerMessage.process_completed
                                    and (
                                        len(
                                            blocks._queue.pending_event_ids_session[
                                                session_hash
                                            ]
                                        )
                                        == 0
                                    )
                                ):
                                    message = CloseStreamMessage()
                                    response = process_msg(message)
                                    if response is not None:
                                        yield response
                                    return
                except BaseException as e:
                    message = UnexpectedErrorMessage(
                        message=str(e),
                    )
                    response = process_msg(message)
                    if isinstance(e, asyncio.CancelledError):
                        del blocks._queue.pending_messages_per_session[session_hash]
                        await blocks._queue.clean_events(session_hash=session_hash)
                    if response is not None:
                        yield response
                    raise e

            return StreamingResponse(
                sse_stream(request),
                media_type="text/event-stream",
            )

        async def get_item_or_file(
            request: fastapi.Request,
        ) -> Union[ComponentServerJSONBody, ComponentServerBlobBody]:
            content_type = request.headers.get("Content-Type")

            if isinstance(content_type, str) and content_type.startswith(
                "multipart/form-data"
            ):
                files = []
                data = {}
                async with request.form() as form:
                    for key, value in form.items():
                        if (
                            isinstance(value, list)
                            and len(value) > 1
                            and isinstance(value[0], StarletteUploadFile)
                        ):
                            for i, v in enumerate(value):
                                if isinstance(v, StarletteUploadFile):
                                    filename = v.filename
                                    contents = await v.read()
                                    files.append((filename, contents))
                                else:
                                    data[f"{key}-{i}"] = v
                        elif isinstance(value, StarletteUploadFile):
                            filename = value.filename
                            contents = await value.read()
                            files.append((filename, contents))
                        else:
                            data[key] = value

                return ComponentServerBlobBody(
                    data=DataWithFiles(data=data, files=files),
                    component_id=data["component_id"],
                    session_hash=data["session_hash"],
                    fn_name=data["fn_name"],
                )
            else:
                try:
                    data = await request.json()
                    return ComponentServerJSONBody(
                        data=data["data"],
                        component_id=data["component_id"],
                        session_hash=data["session_hash"],
                        fn_name=data["fn_name"],
                    )

                except Exception:
                    raise HTTPException(
                        status_code=status.HTTP_400_BAD_REQUEST,
                        detail="Invalid JSON body.",
                    ) from None

        @app.post(
            "/component_server",
            dependencies=[Depends(login_check)],
        )
        @app.post(
            "/component_server/",
            dependencies=[Depends(login_check)],
        )
        async def component_server(
            request: fastapi.Request,
        ):
            body = await get_item_or_file(request)
            state = app.state_holder[body.session_hash]
            component_id = body.component_id
            block: Block
            if component_id in state:
                block = state[component_id]
            else:
                block = app.get_blocks().blocks[component_id]
            fn = getattr(block, body.fn_name, None)
            if fn is None or not getattr(fn, "_is_server_fn", False):
                raise HTTPException(
                    status_code=status.HTTP_404_NOT_FOUND,
                    detail="Function not found.",
                )
            return fn(body.data)

        @app.get(
            "/queue/status",
            dependencies=[Depends(login_check)],
            response_model=EstimationMessage,
        )
        async def get_queue_status():
            return app.get_blocks()._queue.get_status()

        @app.get("/upload_progress")
        def get_upload_progress(upload_id: str, request: fastapi.Request):
            async def sse_stream(request: fastapi.Request):
                last_heartbeat = time.perf_counter()
                is_done = False
                while True:
                    if await request.is_disconnected():
                        file_upload_statuses.stop_tracking(upload_id)
                        return
                    if is_done:
                        file_upload_statuses.stop_tracking(upload_id)
                        return

                    heartbeat_rate = 15
                    check_rate = 0.05
                    try:
                        if file_upload_statuses.is_done(upload_id):
                            message = {"msg": "done"}
                            is_done = True
                        else:
                            update = file_upload_statuses.pop(upload_id)
                            message = {
                                "msg": "update",
                                "orig_name": update.filename,
                                "chunk_size": update.chunk_size,
                            }
                        yield f"data: {json.dumps(message)}\n\n"
                    except FileUploadProgressNotTrackedError:
                        return
                    except FileUploadProgressNotQueuedError:
                        await asyncio.sleep(check_rate)
                        if time.perf_counter() - last_heartbeat > heartbeat_rate:
                            message = {"msg": "heartbeat"}
                            yield f"data: {json.dumps(message)}\n\n"
                            last_heartbeat = time.perf_counter()

            return StreamingResponse(
                sse_stream(request),
                media_type="text/event-stream",
            )

        @app.post("/upload", dependencies=[Depends(login_check)])
        async def upload_file(
            request: fastapi.Request,
            bg_tasks: BackgroundTasks,
            upload_id: Optional[str] = None,
        ):
            content_type_header = request.headers.get("Content-Type")
            content_type: bytes
            content_type, _ = parse_options_header(content_type_header or "")
            if content_type != b"multipart/form-data":
                raise HTTPException(status_code=400, detail="Invalid content type.")

            try:
                if upload_id:
                    file_upload_statuses.track(upload_id)
                max_file_size = app.get_blocks().max_file_size
                max_file_size = max_file_size if max_file_size is not None else math.inf
                multipart_parser = GradioMultiPartParser(
                    request.headers,
                    request.stream(),
                    max_files=1000,
                    max_fields=1000,
                    max_file_size=max_file_size,
                    upload_id=upload_id if upload_id else None,
                    upload_progress=file_upload_statuses if upload_id else None,
                )
                form = await multipart_parser.parse()
            except MultiPartException as exc:
                code = 413 if "maximum allowed size" in exc.message else 400
                return PlainTextResponse(exc.message, status_code=code)

            output_files = []
            files_to_copy = []
            locations: list[str] = []

            for temp_file in form.getlist("files"):
                if not isinstance(temp_file, GradioUploadFile):
                    raise TypeError("File is not an instance of GradioUploadFile")
                if temp_file.filename:
                    file_name = Path(temp_file.filename).name
                    name = client_utils.strip_invalid_filename_characters(file_name)
                else:
                    name = f"tmp{secrets.token_hex(5)}"
                directory = Path(app.uploaded_file_dir) / temp_file.sha.hexdigest()
                directory.mkdir(exist_ok=True, parents=True)
                dest = (directory / name).resolve()
                temp_file.file.close()
                # we need to move the temp file to the cache directory
                # but that's possibly blocking and we're in an async function
                # so we try to rename (this is what shutil.move tries first)
                # which should be super fast.
                # if that fails, we move in the background.
                try:
                    os.rename(temp_file.file.name, dest)
                except OSError:
                    files_to_copy.append(temp_file.file.name)
                    locations.append(str(dest))
                output_files.append(dest)
                blocks.upload_file_set.add(str(dest))
            if files_to_copy:
                bg_tasks.add_task(
                    move_uploaded_files_to_cache, files_to_copy, locations
                )
            return output_files

        @app.on_event("startup")
        @app.get("/startup-events")
        async def startup_events():
            if not app.startup_events_triggered:
                app.get_blocks().startup_events()
                app.startup_events_triggered = True
                return True
            return False

        @app.get("/theme.css", response_class=PlainTextResponse)
        def theme_css():
            return PlainTextResponse(app.get_blocks().theme_css, media_type="text/css")

        @app.get("/robots.txt", response_class=PlainTextResponse)
        def robots_txt():
            if app.get_blocks().share:
                return "User-agent: *\nDisallow: /"
            else:
                return "User-agent: *\nDisallow: "

        return app


########
# Helper functions
########


def safe_join(directory: str, path: str) -> str:
    """Safely path to a base directory to avoid escaping the base directory.
    Borrowed from: werkzeug.security.safe_join"""
    _os_alt_seps: List[str] = [
        sep for sep in [os.path.sep, os.path.altsep] if sep is not None and sep != "/"
    ]

    if path == "":
        raise HTTPException(400)
    if route_utils.starts_with_protocol(path):
        raise HTTPException(403)
    filename = posixpath.normpath(path)
    fullpath = os.path.join(directory, filename)
    if (
        any(sep in filename for sep in _os_alt_seps)
        or os.path.isabs(filename)
        or filename == ".."
        or filename.startswith("../")
        or os.path.isdir(fullpath)
    ):
        raise HTTPException(403)

    if not os.path.exists(fullpath):
        raise HTTPException(404, "File not found")

    return fullpath


def get_types(cls_set: List[Type]):
    docset = []
    types = []
    for cls in cls_set:
        doc = inspect.getdoc(cls) or ""
        doc_lines = doc.split("\n")
        for line in doc_lines:
            if "value (" in line:
                types.append(line.split("value (")[1].split(")")[0])
        docset.append(doc_lines[1].split(":")[-1])
    return docset, types


@document()
def mount_gradio_app(
    app: fastapi.FastAPI,
    blocks: gradio.Blocks,
    path: str,
    app_kwargs: dict[str, Any] | None = None,
    *,
    auth: Callable | tuple[str, str] | list[tuple[str, str]] | None = None,
    auth_message: str | None = None,
    auth_dependency: Callable[[fastapi.Request], str | None] | None = None,
    root_path: str | None = None,
    allowed_paths: list[str] | None = None,
    blocked_paths: list[str] | None = None,
    favicon_path: str | None = None,
    show_error: bool = True,
    max_file_size: str | int | None = None,
) -> fastapi.FastAPI:
    """Mount a gradio.Blocks to an existing FastAPI application.

    Parameters:
        app: The parent FastAPI application.
        blocks: The blocks object we want to mount to the parent app.
        path: The path at which the gradio application will be mounted.
        app_kwargs: Additional keyword arguments to pass to the underlying FastAPI app as a dictionary of parameter keys and argument values. For example, `{"docs_url": "/docs"}`
        auth: If provided, username and password (or list of username-password tuples) required to access the gradio app. Can also provide function that takes username and password and returns True if valid login.
        auth_message: If provided, HTML message provided on login page for this gradio app.
        auth_dependency: A function that takes a FastAPI request and returns a string user ID or None. If the function returns None for a specific request, that user is not authorized to access the gradio app (they will see a 401 Unauthorized response). To be used with external authentication systems like OAuth. Cannot be used with `auth`.
        root_path: The subpath corresponding to the public deployment of this FastAPI application. For example, if the application is served at "https://example.com/myapp", the `root_path` should be set to "/myapp". A full URL beginning with http:// or https:// can be provided, which will be used in its entirety. Normally, this does not need to provided (even if you are using a custom `path`). However, if you are serving the FastAPI app behind a proxy, the proxy may not provide the full path to the Gradio app in the request headers. In which case, you can provide the root path here.
        allowed_paths: List of complete filepaths or parent directories that this gradio app is allowed to serve. Must be absolute paths. Warning: if you provide directories, any files in these directories or their subdirectories are accessible to all users of your app.
        blocked_paths: List of complete filepaths or parent directories that this gradio app is not allowed to serve (i.e. users of your app are not allowed to access). Must be absolute paths. Warning: takes precedence over `allowed_paths` and all other directories exposed by Gradio by default.
        favicon_path: If a path to a file (.png, .gif, or .ico) is provided, it will be used as the favicon for this gradio app's page.
        show_error: If True, any errors in the gradio app will be displayed in an alert modal and printed in the browser console log. Otherwise, errors will only be visible in the terminal session running the Gradio app.
        max_file_size: The maximum file size in bytes that can be uploaded. Can be a string of the form "<value><unit>", where value is any positive integer and unit is one of "b", "kb", "mb", "gb", "tb". If None, no limit is set.
    Example:
        from fastapi import FastAPI
        import gradio as gr
        app = FastAPI()
        @app.get("/")
        def read_main():
            return {"message": "This is your main app"}
        io = gr.Interface(lambda x: "Hello, " + x + "!", "textbox", "textbox")
        app = gr.mount_gradio_app(app, io, path="/gradio")
        # Then run `uvicorn run:app` from the terminal and navigate to http://localhost:8000/gradio.
    """
    blocks.dev_mode = False
    blocks.max_file_size = utils._parse_file_size(max_file_size)
    blocks.config = blocks.get_config_file()
    blocks.validate_queue_settings()
    if auth is not None and auth_dependency is not None:
        raise ValueError(
            "You cannot provide both `auth` and `auth_dependency` in mount_gradio_app(). Please choose one."
        )
    if (
        auth
        and not callable(auth)
        and not isinstance(auth[0], tuple)
        and not isinstance(auth[0], list)
    ):
        blocks.auth = [auth]
    else:
        blocks.auth = auth
    blocks.auth_message = auth_message
    blocks.favicon_path = favicon_path
    blocks.allowed_paths = allowed_paths or []
    blocks.blocked_paths = blocked_paths or []
    blocks.show_error = show_error

    if not isinstance(blocks.allowed_paths, list):
        raise ValueError("`allowed_paths` must be a list of directories.")
    if not isinstance(blocks.blocked_paths, list):
        raise ValueError("`blocked_paths` must be a list of directories.")

    if root_path is not None:
        blocks.root_path = root_path

    gradio_app = App.create_app(
        blocks, app_kwargs=app_kwargs, auth_dependency=auth_dependency
    )
    old_lifespan = app.router.lifespan_context

    @contextlib.asynccontextmanager
    async def new_lifespan(app: FastAPI):
        async with old_lifespan(
            app
        ):  # Instert the startup events inside the FastAPI context manager
            async with gradio_app.router.lifespan_context(gradio_app):
                gradio_app.get_blocks().startup_events()
                yield

    app.router.lifespan_context = new_lifespan

    app.mount(path, gradio_app)
    return app