import asyncio
import gzip
import json
from pathlib import Path
from typing import AsyncGenerator

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse, StreamingResponse

from .config import OUTPUT_DIR
from .runner import run_pipeline, scan_sorties

app = FastAPI(title="COSMA Pipeline Runner")
app.add_middleware(CORSMiddleware, allow_origins=["*"], allow_methods=["*"], allow_headers=["*"])

# Active pipeline jobs: sortie_id → asyncio.Queue
_jobs: dict[str, asyncio.Queue] = {}


@app.get("/sorties")
async def list_sorties():
    return await scan_sorties()


@app.post("/run/{sortie_id:path}")
async def run_sortie(sortie_id: str):
    if sortie_id in _jobs:
        return {"status": "already_running"}
    queue: asyncio.Queue = asyncio.Queue()
    _jobs[sortie_id] = queue
    asyncio.create_task(_run_and_cleanup(sortie_id, queue))
    return {"status": "started"}


async def _run_and_cleanup(sortie_id: str, queue: asyncio.Queue):
    try:
        await run_pipeline(sortie_id, queue)
    finally:
        await asyncio.sleep(30)
        _jobs.pop(sortie_id, None)


@app.get("/events/{sortie_id:path}")
async def sse_events(sortie_id: str):
    if sortie_id not in _jobs:
        raise HTTPException(404, "No active job for this sortie")

    async def generate() -> AsyncGenerator[str, None]:
        queue = _jobs[sortie_id]
        while True:
            try:
                event = await asyncio.wait_for(queue.get(), timeout=60)
                yield f"data: {json.dumps(event)}\n\n"
                if event.get("step") in ("error", "write") and event.get("pct") in (0, 100):
                    break
            except asyncio.TimeoutError:
                yield "data: {\"step\":\"ping\"}\n\n"

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


def _read_gz(path: Path) -> dict:
    with gzip.open(path) as f:
        return json.loads(f.read())


@app.get("/sorties/{sortie_id:path}/usv")
async def get_usv(sortie_id: str):
    p = OUTPUT_DIR / sortie_id / "processed" / "usv.json.gz"
    if not p.exists():
        raise HTTPException(404, "USV data not found — run pipeline first")
    return JSONResponse(_read_gz(p))


@app.get("/sorties/{sortie_id:path}/auvs")
async def list_auvs(sortie_id: str):
    proc = OUTPUT_DIR / sortie_id / "processed"
    auvs = [p.name.removesuffix(".json.gz").removeprefix("auv_")
            for p in proc.glob("auv_*.json.gz")]
    return sorted(auvs)


@app.get("/sorties/{sortie_id:path}/auv/{auv_id}")
async def get_auv(sortie_id: str, auv_id: str):
    p = OUTPUT_DIR / sortie_id / "processed" / f"auv_{auv_id}.json.gz"
    if not p.exists():
        raise HTTPException(404, f"AUV {auv_id} data not found")
    return JSONResponse(_read_gz(p))


@app.get("/sorties/{sortie_id:path}/tracks")
async def get_tracks(sortie_id: str):
    p = OUTPUT_DIR / sortie_id / "processed" / "tracks.geojson"
    if not p.exists():
        raise HTTPException(404, "tracks.geojson not found")
    with open(p) as f:
        return JSONResponse(json.load(f))