"""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 sys

if sys.version_info >= (3, 9):
    from importlib.resources import files
else:
    from importlib_resources import files
import inspect
import mimetypes
import os
import posixpath
import secrets
import tempfile
import threading
import time
import traceback
from asyncio import TimeoutError as AsyncTimeOutError
from collections import defaultdict
from pathlib import Path
from typing import Any, Dict, List, Optional, Type

import fastapi
import httpx
import markupsafe
import orjson
from fastapi import Depends, FastAPI, File, HTTPException, UploadFile, WebSocket, status
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import (
    FileResponse,
    HTMLResponse,
    JSONResponse,
    PlainTextResponse,
)
from fastapi.security import OAuth2PasswordRequestForm
from fastapi.templating import Jinja2Templates
from gradio_client.documentation import document, set_documentation_group
from jinja2.exceptions import TemplateNotFound
from starlette.background import BackgroundTask
from starlette.responses import RedirectResponse, StreamingResponse
from starlette.websockets import WebSocketState

import gradio
import gradio.ranged_response as ranged_response
from gradio import route_utils, utils, wasm_utils
from gradio.context import Context
from gradio.data_classes import PredictBody, ResetBody
from gradio.deprecation import warn_deprecation
from gradio.exceptions import Error
from gradio.oauth import attach_oauth
from gradio.queueing import Estimation, Event
from gradio.route_utils import Request  # noqa: F401
from gradio.utils import (
    cancel_tasks,
    get_package_version,
    run_coro_in_background,
    set_task_name,
)

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()


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

    def __init__(self, **kwargs):
        self.tokens = {}
        self.auth = None
        self.blocks: gradio.Blocks | None = None
        self.state_holder = {}
        self.iterators = defaultdict(dict)
        self.iterators_to_reset = defaultdict(set)
        self.lock = utils.safe_get_lock()
        self.cookie_id = secrets.token_urlsafe(32)
        self.queue_token = secrets.token_urlsafe(32)
        self.startup_events_triggered = False
        self.uploaded_file_dir = os.environ.get("GRADIO_TEMP_DIR") or str(
            Path(tempfile.gettempdir()) / "gradio"
        )
        self.change_event: None | threading.Event = 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)
        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

    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
        # 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.root_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

    @staticmethod
    def create_app(
        blocks: gradio.Blocks, app_kwargs: Dict[str, Any] | None = None
    ) -> App:
        app_kwargs = app_kwargs or {}
        if not wasm_utils.IS_WASM:
            app_kwargs.setdefault("default_response_class", ORJSONResponse)
        app = App(**app_kwargs)
        app.configure_app(blocks)

        if not wasm_utils.IS_WASM:
            app.add_middleware(
                CORSMiddleware,
                allow_origins=["*"],
                allow_methods=["*"],
                allow_headers=["*"],
            )

        @app.get("/user")
        @app.get("/user/")
        def get_current_user(request: fastapi.Request) -> Optional[str]:
            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 or user is not None:
                return
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated"
            )

        async def ws_login_check(websocket: WebSocket) -> Optional[str]:
            token = websocket.cookies.get(
                f"access-token-{app.cookie_id}"
            ) or websocket.cookies.get(f"access-token-unsecure-{app.cookie_id}")
            return token  # token is returned to authenticate the websocket connection in the endpoint handler.

        @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:
            return {"app_id": app.get_blocks().app_id}

        async def send_ping_periodically(websocket: WebSocket):
            while True:
                await websocket.send_text("PING")
                await asyncio.sleep(1)

        async def listen_for_changes(websocket: WebSocket):
            assert app.change_event
            while True:
                if app.change_event.is_set():
                    await websocket.send_text("CHANGE")
                    app.change_event.clear()
                await asyncio.sleep(0.1)  # Short sleep to not make this a tight loop

        @app.websocket("/dev/reload")
        async def notify_changes(websocket: WebSocket):
            await websocket.accept()

            ping = asyncio.create_task(send_ping_periodically(websocket))
            notify = asyncio.create_task(listen_for_changes(websocket))
            tasks = {ping, notify}
            ping.add_done_callback(tasks.remove)
            notify.add_done_callback(tasks.remove)
            done, pending = await asyncio.wait(
                [ping, notify],
                return_when=asyncio.FIRST_COMPLETED,
            )

            for task in pending:
                task.cancel()

            if any(isinstance(task.exception(), Exception) for task in done):
                await websocket.close()

        @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 app.auth[username] == password
            ) 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".
        if app.blocks is not None and app.blocks.expects_oauth:
            attach_oauth(app)

        ###############
        # 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_path = request.scope.get("root_path", "")

            if app.auth is None or user is not None:
                config = app.get_blocks().config
                config["root"] = root_path
            else:
                config = {
                    "auth_required": True,
                    "auth_message": blocks.auth_message,
                    "space_id": app.get_blocks().space_id,
                    "root": root_path,
                }

            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(serialize: bool = True):
            config = app.get_blocks().config
            return gradio.blocks.get_api_info(config, serialize)  # type: ignore

        @app.get("/config/", dependencies=[Depends(login_check)])
        @app.get("/config", dependencies=[Depends(login_check)])
        def get_config(request: fastapi.Request):
            root_path = request.scope.get("root_path", "")
            config = app.get_blocks().config
            config["root"] = root_path
            return 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("/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 utils.validate_url(path_or_url):
                return RedirectResponse(
                    url=path_or_url, status_code=status.HTTP_302_FOUND
                )

            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_dotfile = any(part.startswith(".") for part in abs_path.parts)
            is_dir = abs_path.is_dir()

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

            in_app_dir = utils.is_in_or_equal(abs_path, app.cwd)
            created_by_app = str(abs_path) in set().union(*blocks.temp_file_sets)
            in_allowlist = any(
                utils.is_in_or_equal(abs_path, allowed_path)
                for allowed_path in blocks.allowed_paths
            )
            was_uploaded = utils.is_in_or_equal(abs_path, app.uploaded_file_dir)

            if not (in_app_dir or created_by_app or in_allowlist or was_uploaded):
                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
        ):
            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.session_hash not in app.iterators:
                return {"success": False}
            async with app.lock:
                app.iterators[body.session_hash][body.fn_index] = None
                app.iterators_to_reset[body.session_hash].add(body.fn_index)
            return {"success": True}

        # 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(
                    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,
            )

            try:
                output = await route_utils.call_process_api(
                    app=app,
                    body=body,
                    gr_request=gr_request,
                    fn_index_inferred=fn_index_inferred,
                )
            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.websocket("/queue/join")
        async def join_queue(
            websocket: WebSocket,
            token: Optional[str] = Depends(ws_login_check),
        ):
            blocks = app.get_blocks()
            if app.auth is not None and token is None:
                await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
                return
            if blocks._queue.server_app is None:
                blocks._queue.set_server_app(app)
            await websocket.accept()
            # In order to cancel jobs, we need the session_hash and fn_index
            # to create a unique id for each job
            try:
                await asyncio.wait_for(
                    websocket.send_json({"msg": "send_hash"}), timeout=5
                )
            except AsyncTimeOutError:
                return

            try:
                session_info = await asyncio.wait_for(
                    websocket.receive_json(), timeout=5
                )
            except AsyncTimeOutError:
                return

            event = Event(
                websocket, session_info["session_hash"], session_info["fn_index"]
            )
            # set the username into Event to allow using the same username for call_prediction
            event.username = app.tokens.get(token)
            event.session_hash = session_info["session_hash"]

            # Continuous events are not put in the queue  so that they do not
            # occupy the queue's resource as they are expected to run forever
            if blocks.dependencies[event.fn_index].get("every", 0):
                await cancel_tasks({f"{event.session_hash}_{event.fn_index}"})
                await blocks._queue.reset_iterators(event.session_hash, event.fn_index)
                blocks._queue.continuous_tasks.append(event)
                task = run_coro_in_background(
                    blocks._queue.process_events, [event], False
                )
                set_task_name(task, event.session_hash, event.fn_index, batch=False)
            else:
                rank = blocks._queue.push(event)

                if rank is None:
                    await blocks._queue.send_message(event, {"msg": "queue_full"})
                    await event.disconnect()
                    return
                estimation = blocks._queue.get_estimation()
                await blocks._queue.send_estimation(event, estimation, rank)
            while True:
                await asyncio.sleep(1)
                if websocket.application_state == WebSocketState.DISCONNECTED:
                    return

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

        @app.post("/upload", dependencies=[Depends(login_check)])
        async def upload_file(
            files: List[UploadFile] = File(...),
        ):
            output_files = []
            file_manager = gradio.File()
            for input_file in files:
                output_files.append(
                    await file_manager.save_uploaded_file(
                        input_file, app.uploaded_file_dir
                    )
                )
            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)

    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


set_documentation_group("routes")


@document()
def mount_gradio_app(
    app: fastapi.FastAPI,
    blocks: gradio.Blocks,
    path: str,
    gradio_api_url: str | None = None,
    app_kwargs: dict[str, Any] | 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.
        gradio_api_url: Deprecated and has no effect.
        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"}`
    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.config = blocks.get_config_file()
    blocks.validate_queue_settings()
    gradio_app = App.create_app(blocks, app_kwargs=app_kwargs)

    if gradio_api_url is not None:
        warn_deprecation("gradio_api_url is deprecated and has not effect.")

    @app.on_event("startup")
    async def start_queue():
        if gradio_app.get_blocks().enable_queue:
            gradio_app.get_blocks().startup_events()

    app.mount(path, gradio_app)
    return app