"""
Todo CRUD API endpoints
"""
from typing import List, Optional
from fastapi import APIRouter, Depends, HTTPException, Query, status
from sqlalchemy.orm import Session

# These imports will be updated once the database models and dependencies are created
# from app.db.session import get_db
# from app.models.todo import Todo
# from app.schemas.todo import TodoCreate, TodoUpdate, TodoResponse

router = APIRouter()


@router.get("/", response_model=List[dict])
async def list_todos(
    skip: int = Query(0, ge=0, description="Number of todos to skip"),
    limit: int = Query(100, ge=1, le=1000, description="Number of todos to return"),
    completed: Optional[bool] = Query(None, description="Filter by completion status"),
    priority: Optional[str] = Query(None, description="Filter by priority level"),
    # db: Session = Depends(get_db)
):
    """
    Retrieve a list of todos with optional filtering.
    
    - **skip**: Number of todos to skip (for pagination)
    - **limit**: Maximum number of todos to return
    - **completed**: Filter by completion status (true/false)
    - **priority**: Filter by priority level
    """
    # TODO: Implement once database models are available
    # query = db.query(Todo)
    # 
    # if completed is not None:
    #     query = query.filter(Todo.completed == completed)
    # if priority:
    #     query = query.filter(Todo.priority == priority)
    # 
    # todos = query.offset(skip).limit(limit).all()
    # return todos
    
    return {"message": "Waiting for database models to be implemented"}


@router.post("/", response_model=dict, status_code=status.HTTP_201_CREATED)
async def create_todo(
    # todo: TodoCreate,
    # db: Session = Depends(get_db)
):
    """
    Create a new todo item.
    
    - **title**: Todo title (required)
    - **description**: Todo description (optional)
    - **priority**: Priority level (optional)
    - **due_date**: Due date (optional)
    """
    # TODO: Implement once database models are available
    # db_todo = Todo(**todo.dict())
    # db.add(db_todo)
    # db.commit()
    # db.refresh(db_todo)
    # return db_todo
    
    return {"message": "Waiting for database models to be implemented"}


@router.get("/{todo_id}", response_model=dict)
async def get_todo(
    todo_id: int,
    # db: Session = Depends(get_db)
):
    """
    Retrieve a specific todo by ID.
    
    - **todo_id**: The ID of the todo to retrieve
    """
    # TODO: Implement once database models are available
    # todo = db.query(Todo).filter(Todo.id == todo_id).first()
    # if not todo:
    #     raise HTTPException(
    #         status_code=status.HTTP_404_NOT_FOUND,
    #         detail=f"Todo with id {todo_id} not found"
    #     )
    # return todo
    
    return {"message": f"Waiting for database models to be implemented for todo_id: {todo_id}"}


@router.put("/{todo_id}", response_model=dict)
async def update_todo(
    todo_id: int,
    # todo_update: TodoUpdate,
    # db: Session = Depends(get_db)
):
    """
    Update a specific todo by ID.
    
    - **todo_id**: The ID of the todo to update
    - **title**: Updated title (optional)
    - **description**: Updated description (optional)
    - **completed**: Updated completion status (optional)
    - **priority**: Updated priority level (optional)
    - **due_date**: Updated due date (optional)
    """
    # TODO: Implement once database models are available
    # todo = db.query(Todo).filter(Todo.id == todo_id).first()
    # if not todo:
    #     raise HTTPException(
    #         status_code=status.HTTP_404_NOT_FOUND,
    #         detail=f"Todo with id {todo_id} not found"
    #     )
    # 
    # update_data = todo_update.dict(exclude_unset=True)
    # for field, value in update_data.items():
    #     setattr(todo, field, value)
    # 
    # db.commit()
    # db.refresh(todo)
    # return todo
    
    return {"message": f"Waiting for database models to be implemented for todo_id: {todo_id}"}


@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_todo(
    todo_id: int,
    # db: Session = Depends(get_db)
):
    """
    Delete a specific todo by ID.
    
    - **todo_id**: The ID of the todo to delete
    """
    # TODO: Implement once database models are available
    # todo = db.query(Todo).filter(Todo.id == todo_id).first()
    # if not todo:
    #     raise HTTPException(
    #         status_code=status.HTTP_404_NOT_FOUND,
    #         detail=f"Todo with id {todo_id} not found"
    #     )
    # 
    # db.delete(todo)
    # db.commit()
    # return None
    
    raise HTTPException(
        status_code=status.HTTP_501_NOT_IMPLEMENTED,
        detail="Waiting for database models to be implemented"
    )