"""The heavy container: the runner behind an internal API.

Separate from the FastAPI server on purpose. The API image stays light, a
VisionSuite upgrade does not restart production traffic, and an execution that
crashes does not take the other tablets' requests down with it.
"""
from __future__ import annotations

import json

import numpy as np
from fastapi import FastAPI, File, Form, HTTPException, UploadFile, status
from PIL import Image

from src.vision.runner import engine_version, run_graph

app = FastAPI(title="TieMeasureFlow Vision Worker", version="0.1.0")


@app.get("/health")
async def health() -> dict:
    return {"status": "ok", "engine_version": engine_version()}


@app.post("/run")
async def run(
    image: UploadFile = File(...),
    graph: str = Form(...),
) -> dict:
    try:
        parsed_graph = json.loads(graph)
    except json.JSONDecodeError as exc:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
            detail=f"graph is not valid JSON: {exc}",
        ) from exc

    frame = np.array(Image.open(image.file).convert("L"))

    try:
        outcome = run_graph(frame, parsed_graph)
    except ValueError as exc:
        # from_dict refuses a schema version it does not handle; that is a bad
        # request, not a server fault.
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
            detail=str(exc),
        ) from exc

    return {
        "outputs": outcome.outputs,
        "failures": [
            {"tool_id": f.tool_id, "tool_name": f.tool_name, "error": f.error}
            for f in outcome.failures
        ],
        "engine_version": outcome.engine_version,
        "duration_ms": outcome.duration_ms,
    }