from typing import List
from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from app.database.database import get_db
from app.schemas.todo import TodoCreate, TodoResponse, TodoUpdate

router = APIRouter()

@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
    """
    Create a new todo item
    """
    db_todo = Todo(title=todo.title)
    db.add(db_todo)
    db.commit()
    db.refresh(db_todo)
    return db_todo

@router.get("/", response_model=List[TodoResponse])
def list_todos(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    """
    List all todo items
    """
    todos = db.query(Todo).offset(skip).limit(limit).all()
    return todos

@router.get("/{todo_id}", response_model=TodoResponse)
def get_todo(todo_id: int, db: Session = Depends(get_db)):
    """
    Get a specific todo item by ID
    """
    todo = db.query(Todo).filter(Todo.id == todo_id).first()
    if todo is None:
        raise HTTPException(status_code=404, detail="Todo not found")
    return todo

@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_todo(todo_id: int, db: Session = Depends(get_db)):
    """
    Delete a todo item
    """
    todo = db.query(Todo).filter(Todo.id == todo_id).first()
    if todo is None:
        raise HTTPException(status_code=404, detail="Todo not found")
    db.delete(todo)
    db.commit()
    return None

@router.patch("/{todo_id}", response_model=TodoResponse)
def update_todo(todo_id: int, todo_update: TodoUpdate, db: Session = Depends(get_db)):
    """
    Update a todo item
    """
    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
    if db_todo is None:
        raise HTTPException(status_code=404, detail="Todo not found")
    
    # Update todo attributes if they are provided
    update_data = todo_update.dict(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_todo, key, value)
    
    db.commit()
    db.refresh(db_todo)
    return db_todo