app.py

import httpx
from fastapi import FastAPI, Request
from fastapi.responses import StreamingResponse, JSONResponse
from fastapi.middleware.cors import CORSMiddleware
import uvicorn
import subprocess
import signal
import time
import os

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


PYTHON_PORT = 7860
NODE_PORT = 4321
NODE_SCRIPT_PATH = "build"

node_process = subprocess.Popen(["node", NODE_SCRIPT_PATH])


def handle_sigterm(signum, frame):
    print("Stopping Node.js server...")
    node_process.terminate()
    node_process.wait()
    exit(0)


signal.signal(signal.SIGTERM, handle_sigterm)

client = httpx.AsyncClient()

@app.on_event("shutdown")
def shutdown_event():
    print("Stopping Node.js server...")
    node_process.terminate()
    node_process.wait()


@app.get("/config")
async def route_with_config():
    return JSONResponse(content={"one": "hello", "two": "from", "three": "Python"})


# async def proxy_to_node(request: Request):
    

#     # Preserve the full path including query parameters
#     full_path = request.url.path
#     if request.url.query:
#         full_path += f"?{request.url.query}"

#     url = f"http://localhost:{NODE_PORT}{full_path}"

#     headers = {
#         k: v
#         for k, v in request.headers.items()
#         if k.lower() not in ["host", "content-length"]
#     }

#     print(headers)
#     # body = await request.body()

#     # async with client:
#     #     response = await client.request(
#     #         method=request.method, url=url, headers=headers, content=body
#     #     )

#     # return StreamingResponse(
#     #     response.iter_bytes(),
#     #     status_code=response.status_code,
#     #     headers=response.headers,
#     # )

#     req = client.build_request("GET", httpx.URL(url), headers=headers)
#     r = await client.send(req, stream=True)

#     return StreamingResponse(
#         r.aiter_raw(), headers=r.headers
#     )

async def proxy_to_node(
        request: Request,
        server_name: str,
        node_port: int,
        python_port: int,
        scheme: str = "http",
        mounted_path: str = "",
):
    start_time = time.time()

    full_path = request.url.path
    if mounted_path:
        full_path = full_path.replace(mounted_path, "")
    if request.url.query:
        full_path += f"?{request.url.query}"

    url = f"{scheme}://{server_name}:{node_port}{full_path}"

    headers = dict(request.headers)


    print(
        headers,
    )

    server_url = f"{scheme}://{server_name}"
    if python_port:
        server_url += f":{python_port}"
    if mounted_path:
        server_url += mounted_path

    headers["x-gradio-server"] = server_url
    headers["x-gradio-port"] = str(python_port)

    print(
        f"Proxying request from {request.url.path} to {url} with server url {server_url}"
    )

    if os.getenv("GRADIO_LOCAL_DEV_MODE"):
        headers["x-gradio-local-dev-mode"] = "1"

    print(f"Time to prepare request: {time.time() - start_time:.4f} seconds")

    print(
        f"Total setup time before streaming: {time.time() - start_time:.4f} seconds"
    )

    req = client.build_request("GET", httpx.URL(url), headers=headers)
    r = await client.send(req, stream=True)
    print(f"Time to prepare request: {time.time() - start_time:.4f} seconds")

    print(f"\nHeaders: {r.headers}\n")

    return StreamingResponse(r.aiter_raw(), headers=r.headers)


@app.api_route(
    "/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"]
)
async def catch_all(request: Request, path: str):
    return await proxy_to_node(
        request,
        "0.0.0.0",
        4321,
        request.url.port,
        request.url.scheme,
        "",
    )


if __name__ == "__main__":
    print(
        f"Starting dual server. Python handles specific routes, Node handles the rest."
    )
    uvicorn.run(app, host="0.0.0.0", port=PYTHON_PORT)