"""Host API endpoints."""

import logging
from typing import List, Optional
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from sqlalchemy import or_

from app.database import get_db
from app.models import Host, Service
from app.schemas import HostResponse, HostDetailResponse, ServiceResponse, NetworkStatistics
from app.services.topology_service import TopologyService

logger = logging.getLogger(__name__)

router = APIRouter()


@router.get("", response_model=List[HostResponse])
def list_hosts(
    status: Optional[str] = Query(None, description="Filter by status (online/offline)"),
    limit: int = Query(100, ge=1, le=1000),
    offset: int = Query(0, ge=0),
    search: Optional[str] = Query(None, description="Search by IP or hostname"),
    db: Session = Depends(get_db)
):
    """
    List discovered hosts.
    
    Args:
        status: Filter by host status
        limit: Maximum number of hosts to return
        offset: Number of hosts to skip
        search: Search query
        db: Database session
        
    Returns:
        List of hosts
    """
    query = db.query(Host)
    
    # Apply filters
    if status:
        query = query.filter(Host.status == status)
    
    if search:
        search_pattern = f"%{search}%"
        query = query.filter(
            or_(
                Host.ip_address.like(search_pattern),
                Host.hostname.like(search_pattern)
            )
        )
    
    # Order by last seen
    query = query.order_by(Host.last_seen.desc())
    
    # Apply pagination
    hosts = query.limit(limit).offset(offset).all()
    
    return hosts


@router.get("/statistics", response_model=NetworkStatistics)
def get_network_statistics(db: Session = Depends(get_db)):
    """
    Get network statistics.
    
    Args:
        db: Database session
        
    Returns:
        Network statistics
    """
    topology_service = TopologyService(db)
    stats = topology_service.get_network_statistics()
    
    # Get most common services
    from sqlalchemy import func
    service_counts = db.query(
        Service.service_name,
        func.count(Service.id).label('count')
    ).filter(
        Service.service_name.isnot(None)
    ).group_by(
        Service.service_name
    ).order_by(
        func.count(Service.id).desc()
    ).limit(10).all()
    
    # Get last scan time
    from app.models import Scan
    last_scan = db.query(Scan).order_by(Scan.started_at.desc()).first()
    
    return NetworkStatistics(
        total_hosts=stats['total_hosts'],
        online_hosts=stats['online_hosts'],
        offline_hosts=stats['offline_hosts'],
        total_services=stats['total_services'],
        total_scans=db.query(func.count(Scan.id)).scalar() or 0,
        last_scan=last_scan.started_at if last_scan else None,
        most_common_services=[
            {'service_name': s[0], 'count': s[1]}
            for s in service_counts
        ]
    )


@router.get("/by-service/{service_name}", response_model=List[HostResponse])
def get_hosts_by_service(
    service_name: str,
    limit: int = Query(100, ge=1, le=1000),
    offset: int = Query(0, ge=0),
    db: Session = Depends(get_db)
):
    """
    Get all hosts that provide a specific service.
    
    Args:
        service_name: Service name to filter by
        limit: Maximum number of hosts to return
        offset: Number of hosts to skip
        db: Database session
        
    Returns:
        List of hosts providing the service
    """
    hosts = db.query(Host).join(Service).filter(
        Service.service_name == service_name
    ).distinct().order_by(
        Host.last_seen.desc()
    ).limit(limit).offset(offset).all()
    
    return hosts


@router.get("/{host_id}", response_model=HostDetailResponse)
def get_host_detail(host_id: int, db: Session = Depends(get_db)):
    """
    Get detailed information about a specific host.
    
    Args:
        host_id: Host ID
        db: Database session
        
    Returns:
        Detailed host information
    """
    host = db.query(Host).filter(Host.id == host_id).first()
    
    if not host:
        raise HTTPException(status_code=404, detail=f"Host {host_id} not found")
    
    return host


@router.get("/{host_id}/services", response_model=List[ServiceResponse])
def get_host_services(host_id: int, db: Session = Depends(get_db)):
    """
    Get all services for a specific host.
    
    Args:
        host_id: Host ID
        db: Database session
        
    Returns:
        List of services
    """
    host = db.query(Host).filter(Host.id == host_id).first()
    
    if not host:
        raise HTTPException(status_code=404, detail=f"Host {host_id} not found")
    
    return host.services


@router.delete("/{host_id}")
def delete_host(host_id: int, db: Session = Depends(get_db)):
    """
    Delete a host from the database.
    
    Args:
        host_id: Host ID
        db: Database session
        
    Returns:
        Success message
    """
    host = db.query(Host).filter(Host.id == host_id).first()
    
    if not host:
        raise HTTPException(status_code=404, detail=f"Host {host_id} not found")
    
    db.delete(host)
    db.commit()
    
    logger.info(f"Deleted host {host_id} ({host.ip_address})")
    
    return {"message": f"Host {host_id} deleted successfully"}


@router.get("/ip/{ip_address}", response_model=HostResponse)
def get_host_by_ip(ip_address: str, db: Session = Depends(get_db)):
    """
    Get host information by IP address.
    
    Args:
        ip_address: IP address
        db: Database session
        
    Returns:
        Host information
    """
    host = db.query(Host).filter(Host.ip_address == ip_address).first()
    
    if not host:
        raise HTTPException(
            status_code=404,
            detail=f"Host with IP {ip_address} not found"
        )
    
    return host