from fastapi import APIRouter, Query
from app.config import CPS_LOG_PATH
import json

router = APIRouter()


@router.get("/timeline")
async def get_cps_timeline(hours: int = Query(default=24, ge=1, le=720)):
    """CPS data points for the last N hours."""
    if not CPS_LOG_PATH.exists():
        return {"data_points": [], "hours": hours}

    from datetime import datetime, timedelta

    cutoff = datetime.now() - timedelta(hours=hours)
    data_points = []

    try:
        with open(CPS_LOG_PATH) as f:
            for line in f:
                line = line.strip()
                if not line:
                    continue
                try:
                    entry = json.loads(line)
                    ts = datetime.fromisoformat(entry["ts"])
                    if ts >= cutoff:
                        data_points.append(entry)
                except (json.JSONDecodeError, KeyError, ValueError):
                    continue
    except OSError:
        return {"data_points": [], "hours": hours}

    return {
        "hours": hours,
        "data_points": data_points,
    }