from typing import Any, List

from fastapi import APIRouter, Body, Depends, HTTPException
from fastapi.encoders import jsonable_encoder
from sqlalchemy.orm import Session

from backend.app.core import security
from backend.app.core.database import get_db
from backend.app.models import sql_models
from backend.app.schemas import schemas
from backend.app.api import deps

router = APIRouter()

@router.get("", response_model=List[schemas.User])
def read_users(
    db: Session = Depends(get_db),
    skip: int = 0,
    limit: int = 100,
    current_user: sql_models.User = Depends(deps.get_current_active_superuser),
) -> Any:
    """
    Retrieve users.
    """
    users = db.query(sql_models.User).offset(skip).limit(limit).all()
    return users

@router.post("", response_model=schemas.User)
def create_user(
    *,
    db: Session = Depends(get_db),
    user_in: schemas.UserCreate,
    current_user: sql_models.User = Depends(deps.get_current_active_superuser),
) -> Any:
    """
    Create new user.
    """
    user = db.query(sql_models.User).filter(sql_models.User.username == user_in.username).first()
    if user:
        raise HTTPException(
            status_code=400,
            detail="The user with this username already exists in the system.",
        )
    
    hashed_password = security.get_password_hash(user_in.password)
    db_user = sql_models.User(
        username=user_in.username,
        hashed_password=hashed_password,
        is_active=user_in.is_active,
        is_superuser=user_in.is_superuser,
    )
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    return db_user

@router.put("/{user_id}", response_model=schemas.User)
def update_user(
    *,
    db: Session = Depends(get_db),
    user_id: int,
    user_in: schemas.UserUpdate,
    current_user: sql_models.User = Depends(deps.get_current_active_superuser),
) -> Any:
    """
    Update a user.
    """
    user = db.query(sql_models.User).filter(sql_models.User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=404,
            detail="The user with this id does not exist in the system",
        )
    
    # Check if username collision if logic allowed changing username (but UserUpdate doesn't have username)
    # So we just update fields
    
    if user_in.password:
        user.hashed_password = security.get_password_hash(user_in.password)
    if user_in.is_active is not None:
        user.is_active = user_in.is_active
    if user_in.is_superuser is not None:
        user.is_superuser = user_in.is_superuser
        
    db.add(user)
    db.commit()
    db.refresh(user)
    return user

@router.delete("/{user_id}", response_model=schemas.User)
def delete_user(
    *,
    db: Session = Depends(get_db),
    user_id: int,
    current_user: sql_models.User = Depends(deps.get_current_active_superuser),
) -> Any:
    """
    Delete a user.
    """
    user = db.query(sql_models.User).filter(sql_models.User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=404,
            detail="The user with this id does not exist in the system",
        )
    if user.id == current_user.id:
        raise HTTPException(
            status_code=400,
            detail="Users cannot delete themselves",
        )
        
    db.delete(user)
    db.commit()
    return user