"""Alert management endpoints"""

from fastapi import APIRouter, HTTPException, Query, Path, Body
from typing import List, Dict, Optional
from datetime import datetime
import uuid

router = APIRouter()

# In-memory storage
alerts_db = {}
alerts_list = []

@router.get("/", response_model=List[Dict])
async def get_alerts(
    active_only: bool = Query(True, description="Return only active alerts"),
    zone: Optional[str] = Query(None, description="Filter by zone"),
    level: Optional[str] = Query(None, description="Filter by alert level")
):
    """Get alerts"""
    alerts = [a for a in alerts_list if not active_only or a.get('active', True)]
    
    if zone:
        alerts = [a for a in alerts if a.get('zone') == zone]
    
    if level:
        alerts = [a for a in alerts if a.get('level') == level]
    
    return alerts

@router.get("/active", response_model=List[Dict])
async def get_active_alerts():
    """Get currently active alerts"""
    return [a for a in alerts_list if a.get('active', False)]

@router.get("/{alert_id}", response_model=Dict)
async def get_alert(
    alert_id: str = Path(..., description="Alert ID")
):
    """Get alert by ID"""
    if alert_id not in alerts_db:
        raise HTTPException(status_code=404, detail="Alert not found")
    return alerts_db[alert_id]

@router.post("/", response_model=Dict, status_code=201)
async def create_alert(
    alert_data: Dict = Body(...)
):
    """Create new alert"""
    alert_id = str(uuid.uuid4())
    alert = {
        "id": alert_id,
        "created_at": datetime.utcnow().isoformat(),
        "updated_at": datetime.utcnow().isoformat(),
        "active": True,
        "acknowledged": False,
        **alert_data
    }
    alerts_db[alert_id] = alert
    alerts_list.append(alert)
    return alert

@router.put("/{alert_id}/acknowledge", response_model=Dict)
async def acknowledge_alert(
    alert_id: str = Path(...),
    user: str = Query(..., description="User acknowledging the alert")
):
    """Acknowledge an alert"""
    if alert_id not in alerts_db:
        raise HTTPException(status_code=404, detail="Alert not found")
    
    alerts_db[alert_id]["acknowledged"] = True
    alerts_db[alert_id]["acknowledged_by"] = user
    alerts_db[alert_id]["acknowledged_at"] = datetime.utcnow().isoformat()
    alerts_db[alert_id]["updated_at"] = datetime.utcnow().isoformat()
    
    return alerts_db[alert_id]

@router.put("/{alert_id}/resolve", response_model=Dict)
async def resolve_alert(
    alert_id: str = Path(...)
):
    """Resolve/cancel an alert"""
    if alert_id not in alerts_db:
        raise HTTPException(status_code=404, detail="Alert not found")
    
    alerts_db[alert_id]["active"] = False
    alerts_db[alert_id]["resolved_at"] = datetime.utcnow().isoformat()
    alerts_db[alert_id]["updated_at"] = datetime.utcnow().isoformat()
    
    return alerts_db[alert_id]

@router.get("/stats/summary", response_model=Dict)
async def get_alert_statistics():
    """Get alert statistics"""
    active = len([a for a in alerts_list if a.get('active', False)])
    acknowledged = len([a for a in alerts_list if a.get('acknowledged', False)])
    
    return {
        "total_alerts": len(alerts_list),
        "active_alerts": active,
        "acknowledged_alerts": acknowledged,
        "by_level": {
            "LOW": len([a for a in alerts_list if a.get('level') == 'LOW']),
            "MODERATE": len([a for a in alerts_list if a.get('level') == 'MODERATE']),
            "HIGH": len([a for a in alerts_list if a.get('level') == 'HIGH']),
            "SEVERE": len([a for a in alerts_list if a.get('level') == 'SEVERE']),
            "CATASTROPHIC": len([a for a in alerts_list if a.get('level') == 'CATASTROPHIC'])
        }
    }

@router.post("/thresholds", response_model=Dict)
async def check_thresholds(
    zone: str = Query(..., description="Coastal zone"),
    chi: float = Query(..., description="CHI value")
):
    """Check if thresholds are crossed and create alert if needed"""
    
    # Determine alert level based on CHI
    if chi < 0.30:
        level = "LOW"
        message = f"Monitoring mode for {zone}"
    elif chi < 0.60:
        level = "MODERATE"
        message = f"Tsunami advisory for {zone}"
    elif chi < 0.80:
        level = "HIGH"
        message = f"Tsunami WARNING for {zone} - prepare evacuation"
    elif chi < 1.00:
        level = "SEVERE"
        message = f"SEVERE TSUNAMI THREAT for {zone} - EVACUATE IMMEDIATELY"
    else:
        level = "CATASTROPHIC"
        message = f"CATASTROPHIC TSUNAMI for {zone} - maximum impact expected"
    
    # Create alert if level is >= MODERATE
    if chi >= 0.30:
        alert = await create_alert({
            "zone": zone,
            "chi": chi,
            "level": level,
            "message": message
        })
        return {
            "alert_created": True,
            "threshold_crossed": True,
            "alert": alert
        }
    
    return {
        "alert_created": False,
        "threshold_crossed": False,
        "level": level,
        "message": message
    }