from fastapi import APIRouter, Depends, Query
from sqlalchemy import text
from sqlalchemy.ext.asyncio import AsyncSession
from core.database import get_session

router = APIRouter()

VESDA_ZONES = {
    "sg-01": [
        {"zone_id": "vesda-hall-a", "room_id": "hall-a"},
        {"zone_id": "vesda-hall-b", "room_id": "hall-b"},
    ]
}

LEVEL_MAP = {0: "normal", 1: "alert", 2: "action", 3: "fire"}

VESDA_TYPES = ("vesda_level", "vesda_obscuration", "vesda_det1", "vesda_det2",
               "vesda_power", "vesda_flow")


@router.get("/status")
async def fire_status(
    site_id: str = Query(...),
    session: AsyncSession = Depends(get_session),
):
    """Latest VESDA readings per fire zone."""
    types_sql = ", ".join(f"'{t}'" for t in VESDA_TYPES)
    result = await session.execute(text(f"""
        SELECT DISTINCT ON (sensor_id)
            sensor_id, sensor_type, value
        FROM readings
        WHERE site_id     = :site_id
          AND sensor_type IN ({types_sql})
          AND recorded_at > NOW() - INTERVAL '2 minutes'
        ORDER BY sensor_id, recorded_at DESC
    """), {"site_id": site_id})

    zone_data: dict[str, dict] = {}
    for row in result.mappings().all():
        parts = row["sensor_id"].split("/")
        if len(parts) < 3:
            continue
        zone_id = parts[2]
        if zone_id not in zone_data:
            zone_data[zone_id] = {"zone_id": zone_id}
        v = float(row["value"])
        s_type = row["sensor_type"]
        if s_type == "vesda_level":
            zone_data[zone_id]["level"] = LEVEL_MAP.get(round(v), "normal")
        elif s_type == "vesda_obscuration":
            zone_data[zone_id]["obscuration_pct_m"] = round(v, 3)
        elif s_type == "vesda_det1":
            zone_data[zone_id]["detector_1_ok"] = v > 0.5
        elif s_type == "vesda_det2":
            zone_data[zone_id]["detector_2_ok"] = v > 0.5
        elif s_type == "vesda_power":
            zone_data[zone_id]["power_ok"] = v > 0.5
        elif s_type == "vesda_flow":
            zone_data[zone_id]["flow_ok"] = v > 0.5

    zone_room_map = {z["zone_id"]: z["room_id"] for z in VESDA_ZONES.get(site_id, [])}

    out = []
    for zone_cfg in VESDA_ZONES.get(site_id, []):
        zone_id = zone_cfg["zone_id"]
        d = zone_data.get(zone_id, {"zone_id": zone_id})
        d.setdefault("level", "normal")
        d.setdefault("obscuration_pct_m", None)
        d.setdefault("detector_1_ok", True)
        d.setdefault("detector_2_ok", True)
        d.setdefault("power_ok", True)
        d.setdefault("flow_ok", True)
        d["room_id"] = zone_room_map.get(zone_id)
        out.append(d)
    return out