from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy.orm import Session
from pydantic import BaseModel

from app.crud import todo
from app.db.session import get_db
from app.schemas.todo import TodoCreate, TodoResponse, TodoUpdate

router = APIRouter()


class BulkCompleteRequest(BaseModel):
    todo_ids: List[int]


@router.get("/", response_model=List[TodoResponse])
def read_todos(
    skip: int = 0,
    limit: int = 100,
    category: Optional[str] = Query(None, description="Filter by category"),
    completed: Optional[bool] = Query(None, description="Filter by completion status"),
    overdue_only: bool = Query(False, description="Show only overdue todos"),
    db: Session = Depends(get_db),
):
    """
    Retrieve todos with pagination and filtering.
    """
    todos = todo.get_multi(
        db,
        skip=skip,
        limit=limit,
        category=category,
        completed=completed,
        overdue_only=overdue_only,
    )
    return todos


@router.get("/categories/{category}", response_model=List[TodoResponse])
def read_todos_by_category(
    *,
    db: Session = Depends(get_db),
    category: str,
):
    """
    Get all todos by category.
    """
    return todo.get_by_category(db=db, category=category)


@router.get("/overdue", response_model=List[TodoResponse])
def read_overdue_todos(
    db: Session = Depends(get_db),
):
    """
    Get all overdue todos.
    """
    return todo.get_overdue(db=db)


@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
def create_todo(
    *,
    db: Session = Depends(get_db),
    todo_in: TodoCreate,
):
    """
    Create new todo.
    """
    return todo.create(db=db, obj_in=todo_in)


@router.get("/{todo_id}", response_model=TodoResponse)
def read_todo(
    *,
    db: Session = Depends(get_db),
    todo_id: int,
):
    """
    Get todo by ID.
    """
    todo_obj = todo.get(db=db, todo_id=todo_id)
    if not todo_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found"
        )
    return todo_obj


@router.put("/{todo_id}", response_model=TodoResponse)
def update_todo(
    *,
    db: Session = Depends(get_db),
    todo_id: int,
    todo_in: TodoUpdate,
):
    """
    Update a todo.
    """
    todo_obj = todo.get(db=db, todo_id=todo_id)
    if not todo_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found"
        )
    return todo.update(db=db, db_obj=todo_obj, obj_in=todo_in)


@router.delete("/{todo_id}", response_model=TodoResponse)
def delete_todo(
    *,
    db: Session = Depends(get_db),
    todo_id: int,
):
    """
    Delete a todo.
    """
    todo_obj = todo.remove(db=db, todo_id=todo_id)
    if not todo_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found"
        )
    return todo_obj


@router.post("/bulk-complete", response_model=List[TodoResponse])
def bulk_complete_todos(
    *,
    db: Session = Depends(get_db),
    request: BulkCompleteRequest,
):
    """
    Mark multiple todos as completed.
    """
    completed_todos = []
    not_found_ids = []
    
    for todo_id in request.todo_ids:
        todo_obj = todo.get(db=db, todo_id=todo_id)
        if todo_obj:
            updated_todo = todo.update(
                db=db, 
                db_obj=todo_obj, 
                obj_in={"completed": True}
            )
            completed_todos.append(updated_todo)
        else:
            not_found_ids.append(todo_id)
    
    if not_found_ids:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Todos not found: {not_found_ids}"
        )
    
    return completed_todos