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

from app.db.session import get_db
from app.models.todo import Todo
from app.schemas.todo import TodoCreate, TodoUpdate, Todo as TodoSchema

router = APIRouter()


@router.post("/todos", response_model=TodoSchema, status_code=status.HTTP_201_CREATED)
def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
    db_todo = Todo(
        title=todo.title,
        description=todo.description,
        completed=todo.completed
    )
    db.add(db_todo)
    db.commit()
    db.refresh(db_todo)
    return db_todo


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


@router.get("/todos/{todo_id}", response_model=TodoSchema)
def read_todo(todo_id: int, db: Session = Depends(get_db)):
    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")
    return db_todo


@router.put("/todos/{todo_id}", response_model=TodoSchema)
def update_todo(todo_id: int, todo: TodoUpdate, db: Session = Depends(get_db)):
    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_data = todo.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_todo, key, value)
    
    db.commit()
    db.refresh(db_todo)
    return db_todo


@router.delete("/todos/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
def delete_todo(todo_id: int, db: Session = Depends(get_db)):
    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")
    
    db.delete(db_todo)
    db.commit()
    return None