"""Edge/IoT 디바이스 모니터링"""
from __future__ import annotations
import json, logging
from datetime import datetime
from typing import Optional
from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel
from sqlalchemy import select, desc
from sqlalchemy.ext.asyncio import AsyncSession
from core.auth import get_current_user
from database import get_db
from models import User, EdgeDevice, EdgeMetric, EdgeAlert

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api/edge", tags=["Edge/IoT"])

DEVICE_TYPES = ["SERVER_EDGE", "NETWORK_EDGE", "IOT_SENSOR", "CCTV", "KIOSK", "GATEWAY"]


class DeviceRegister(BaseModel):
    name: str; device_type: str; location: str = ""
    ip_hint: str = ""; protocol: str = "HTTP"  # HTTP|SNMP|MQTT
    metadata: dict = {}


class TelemetryIn(BaseModel):
    device_token: str; metrics: dict  # {"cpu":70,"memory":60,"temp":45}
    timestamp: Optional[int] = None  # epoch ms


class AlertCreate(BaseModel):
    device_id: int; alert_type: str; message: str; severity: str = "WARNING"


@router.get("/devices")
async def list_devices(db: AsyncSession = Depends(get_db), user: User = Depends(get_current_user)):
    rows = await db.execute(select(EdgeDevice).order_by(EdgeDevice.name))
    devices = rows.scalars().all()
    return [{"id":d.id,"name":d.name,"device_type":d.device_type,"location":d.location,
             "status":d.status,"last_seen":d.last_seen} for d in devices]


@router.post("/devices", status_code=201)
async def register_device(body: DeviceRegister, db: AsyncSession = Depends(get_db),
                          user: User = Depends(get_current_user)):
    import uuid
    d = EdgeDevice(
        name=body.name, device_type=body.device_type, location=body.location,
        protocol=body.protocol, device_token=str(uuid.uuid4()),
        meta_json=json.dumps(body.metadata), status="REGISTERED",
        registered_by=user.id, created_at=datetime.utcnow()
    )
    db.add(d); await db.commit(); await db.refresh(d)
    return {"id": d.id, "device_token": d.device_token}


@router.get("/devices/{device_id}")
async def get_device(device_id: int, db: AsyncSession = Depends(get_db),
                     user: User = Depends(get_current_user)):
    row = await db.execute(select(EdgeDevice).where(EdgeDevice.id == device_id))
    d = row.scalar_one_or_none()
    if not d: raise HTTPException(404)
    return {"id":d.id,"name":d.name,"device_type":d.device_type,"location":d.location,
            "protocol":d.protocol,"status":d.status,"last_seen":d.last_seen,
            "meta": json.loads(d.meta_json or "{}")}


@router.get("/devices/{device_id}/metrics")
async def get_metrics(device_id: int, limit: int = 100, db: AsyncSession = Depends(get_db),
                      user: User = Depends(get_current_user)):
    rows = await db.execute(
        select(EdgeMetric).where(EdgeMetric.device_id == device_id)
        .order_by(desc(EdgeMetric.recorded_at)).limit(limit)
    )
    metrics = rows.scalars().all()
    return [{"id":m.id,"metrics":json.loads(m.metrics_json or "{}"),
             "recorded_at":m.recorded_at} for m in metrics]


@router.get("/devices/{device_id}/alerts")
async def get_alerts(device_id: int, db: AsyncSession = Depends(get_db),
                     user: User = Depends(get_current_user)):
    rows = await db.execute(
        select(EdgeAlert).where(EdgeAlert.device_id == device_id)
        .order_by(desc(EdgeAlert.created_at)).limit(50)
    )
    return [{"id":a.id,"alert_type":a.alert_type,"message":a.message,
             "severity":a.severity,"created_at":a.created_at}
            for a in rows.scalars().all()]


@router.post("/telemetry", status_code=202)
async def ingest_telemetry(body: TelemetryIn, db: AsyncSession = Depends(get_db)):
    """디바이스 텔레메트리 수집 (Push 방식, 인증 불필요 — 내부망 전용)."""
    row = await db.execute(select(EdgeDevice).where(EdgeDevice.device_token == body.device_token))
    device = row.scalar_one_or_none()
    if not device:
        raise HTTPException(401, "등록되지 않은 디바이스")

    ts = datetime.utcfromtimestamp(body.timestamp / 1000) if body.timestamp else datetime.utcnow()
    db.add(EdgeMetric(device_id=device.id, metrics_json=json.dumps(body.metrics), recorded_at=ts))

    # 이상 감지 — 임계값 초과 시 알림
    cpu = body.metrics.get("cpu", 0)
    temp = body.metrics.get("temp", 0)
    if cpu > 90:
        db.add(EdgeAlert(device_id=device.id, alert_type="HIGH_CPU",
                         message=f"CPU {cpu}% 초과", severity="WARNING", created_at=datetime.utcnow()))
    if temp > 80:
        db.add(EdgeAlert(device_id=device.id, alert_type="HIGH_TEMP",
                         message=f"온도 {temp}°C 초과", severity="CRITICAL", created_at=datetime.utcnow()))

    device.last_seen = datetime.utcnow()
    device.status = "ONLINE"
    await db.commit()
    return {"ok": True}


@router.get("/topology")
async def get_topology(db: AsyncSession = Depends(get_db), user: User = Depends(get_current_user)):
    rows = await db.execute(select(EdgeDevice).order_by(EdgeDevice.device_type))
    devices = rows.scalars().all()
    nodes = [{"id": d.id, "name": d.name, "type": d.device_type,
              "location": d.location, "status": d.status} for d in devices]
    return {"nodes": nodes, "edge_count": len(nodes)}