server.py

from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import StreamingResponse, HTMLResponse
import subprocess
import httpx

app = FastAPI(title="Market-Data Observatory")

# Async HTTP client for proxying to ClickHouse's internal HTTP interface
ch_client = httpx.AsyncClient(base_url="http://127.0.0.1:8123", timeout=60.0)


# ── Refresh endpoint (git pull) ──
@app.post("/refresh")
def refresh():
    try:
        result = subprocess.check_output(
            "cd /app/data/ohlc_data && git pull",
            shell=True, stderr=subprocess.STDOUT
        )
        return {"status": "updated", "details": result.decode().strip()}
    except subprocess.CalledProcessError as e:
        msg = e.output.decode() if e.output else str(e)
        raise HTTPException(status_code=500, detail={"error": "Refresh failed", "message": msg})


# ── Health check ──
@app.get("/health")
async def health():
    try:
        r = await ch_client.get("/ping")
        return {"clickhouse": r.text.strip(), "status": "ok"}
    except Exception as e:
        raise HTTPException(status_code=503, detail={"status": "unhealthy", "error": str(e)})


# ── Catch-all reverse proxy to ClickHouse ──
# This gives you /play, /dashboard, native HTTP API, everything.
@app.api_route("/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "OPTIONS", "HEAD", "PATCH"])
async def proxy_to_clickhouse(request: Request, path: str):
    url = httpx.URL(path=f"/{path}", query=request.url.query.encode("utf-8"))

    # Forward headers, strip hop-by-hop
    headers = dict(request.headers)
    for h in ("host", "content-length", "transfer-encoding"):
        headers.pop(h, None)

    try:
        body = await request.body()
        req = ch_client.build_request(
            method=request.method,
            url=url,
            headers=headers,
            content=body,
        )
        r = await ch_client.send(req, stream=True)

        # Pass through ClickHouse response headers
        resp_headers = dict(r.headers)
        for h in ("content-length", "content-encoding", "transfer-encoding"):
            resp_headers.pop(h, None)

        return StreamingResponse(
            r.aiter_raw(),
            status_code=r.status_code,
            headers=resp_headers,
        )
    except httpx.RequestError as exc:
        raise HTTPException(status_code=502, detail=f"ClickHouse proxy error: {exc}")