from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel
import json
import time
from pathlib import Path
from engine import BrowserFrameAnalyzer

app = FastAPI()
BASE_DIR = Path(__file__).resolve().parent
app.mount("/static", StaticFiles(directory=str(BASE_DIR)), name="static")

browser_analyzers: dict = {}
SESSION_TTL_SECONDS = 30 * 60


class BrowserFrameInput(BaseModel):
    session_id: str
    image: str
    label: str = "Browser Camera"


@app.get("/")
def home():
    return FileResponse(BASE_DIR / "templates" / "browser_camera.html")


@app.get("/browser-camera")
def browser_camera_page():
    return FileResponse(BASE_DIR / "templates" / "browser_camera.html")


@app.get("/alerts")
def alerts():
    data = []
    try:
        with open("alerts.jsonl") as f:
            for line in f:
                data.append(json.loads(line))
    except Exception:
        pass
    return data


@app.post("/predict-frame")
def predict_frame(payload: BrowserFrameInput):
    session_id = payload.session_id.strip()
    if not session_id:
        raise HTTPException(status_code=400, detail="session_id is required")

    now = time.time()
    expired = [
        key for key, item in browser_analyzers.items()
        if now - item["last_seen"] > SESSION_TTL_SECONDS
    ]
    for key in expired:
        browser_analyzers.pop(key, None)

    item = browser_analyzers.get(session_id)
    if item is None:
        item = {
            "analyzer": BrowserFrameAnalyzer(payload.label.strip() or "Browser Camera"),
            "last_seen": now,
        }
        browser_analyzers[session_id] = item
    item["last_seen"] = now

    try:
        result = item["analyzer"].analyze_data_url(payload.image)
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc

    return result