from pathlib import Path

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session

from app.api.deps import get_current_user, get_db
from app.models.router import Router
from app.models.user import User
from app.schemas.router import RouterCreate, RouterResponse, RouterTestConnection, RouterUpdate
from app.services.router_service import router_service
from app.services.settings_service import settings_service

router = APIRouter()


def serialize_router(router: Router, global_ssh_key: str | None = None) -> RouterResponse:
    has_router_key = bool((router.ssh_key or '').strip())
    has_global_key = bool((global_ssh_key or '').strip())
    payload = RouterResponse.model_validate(router, from_attributes=True).model_dump()
    payload['uses_global_ssh_key'] = has_global_key and not has_router_key
    payload['has_effective_ssh_key'] = has_router_key or has_global_key
    return RouterResponse.model_validate(payload)


@router.get("", response_model=list[RouterResponse])
def list_routers(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    settings = settings_service.get_or_create(db)
    routers = db.query(Router).filter(Router.owner_id == current_user.id).order_by(Router.created_at.desc()).all()
    return [serialize_router(router, settings.global_ssh_key) for router in routers]


@router.post("", response_model=RouterResponse)
def create_router(payload: RouterCreate, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    router = Router(**payload.model_dump(), owner_id=current_user.id)
    db.add(router)
    db.commit()
    db.refresh(router)
    settings = settings_service.get_or_create(db)
    return serialize_router(router, settings.global_ssh_key)


@router.get("/{router_id}", response_model=RouterResponse)
def get_router(router_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    router = db.query(Router).filter(Router.id == router_id, Router.owner_id == current_user.id).first()
    if not router:
        raise HTTPException(status_code=404, detail="Router not found")
    settings = settings_service.get_or_create(db)
    return serialize_router(router, settings.global_ssh_key)


@router.put("/{router_id}", response_model=RouterResponse)
def update_router(router_id: int, payload: RouterUpdate, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    router = db.query(Router).filter(Router.id == router_id, Router.owner_id == current_user.id).first()
    if not router:
        raise HTTPException(status_code=404, detail="Router not found")
    for key, value in payload.model_dump(exclude_unset=True).items():
        setattr(router, key, value)
    db.add(router)
    db.commit()
    db.refresh(router)
    settings = settings_service.get_or_create(db)
    return serialize_router(router, settings.global_ssh_key)


@router.delete("/{router_id}")
def delete_router(router_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    router = db.query(Router).filter(Router.id == router_id, Router.owner_id == current_user.id).first()
    if not router:
        raise HTTPException(status_code=404, detail="Router not found")
    for backup in list(router.backups):
        path = Path(backup.file_path)
        if path.exists():
            path.unlink()
    db.delete(router)
    db.commit()
    return {"message": "Router deleted"}


@router.get("/{router_id}/test-connection", response_model=RouterTestConnection)
def test_connection(router_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    router = db.query(Router).filter(Router.id == router_id, Router.owner_id == current_user.id).first()
    if not router:
        raise HTTPException(status_code=404, detail="Router not found")
    settings = settings_service.get_or_create(db)
    return router_service.test_connection(db, router, settings.global_ssh_key)