from sqlalchemy.orm import Session
from app.models.task import Task, TaskStatus
from app.schemas.task import TaskCreate, TaskUpdate
from typing import List, Optional


def get_tasks_by_user(
    db: Session, user_id: int, skip: int = 0, limit: int = 100
) -> List[Task]:
    return (
        db.query(Task).filter(Task.owner_id == user_id).offset(skip).limit(limit).all()
    )


def get_task_by_id(db: Session, task_id: int, user_id: int) -> Optional[Task]:
    return db.query(Task).filter(Task.id == task_id, Task.owner_id == user_id).first()


def create_task(db: Session, task: TaskCreate, user_id: int) -> Task:
    db_task = Task(**task.dict(), owner_id=user_id)
    db.add(db_task)
    db.commit()
    db.refresh(db_task)
    return db_task


def update_task(
    db: Session, task_id: int, task_update: TaskUpdate, user_id: int
) -> Optional[Task]:
    db_task = get_task_by_id(db, task_id, user_id)
    if not db_task:
        return None

    update_data = task_update.dict(exclude_unset=True)

    if "status" in update_data:
        if update_data["status"] == TaskStatus.COMPLETED:
            update_data["is_completed"] = True
        elif update_data["status"] != TaskStatus.COMPLETED and db_task.is_completed:
            update_data["is_completed"] = False

    if "is_completed" in update_data and update_data["is_completed"]:
        update_data["status"] = TaskStatus.COMPLETED

    for field, value in update_data.items():
        setattr(db_task, field, value)

    db.commit()
    db.refresh(db_task)
    return db_task


def delete_task(db: Session, task_id: int, user_id: int) -> bool:
    db_task = get_task_by_id(db, task_id, user_id)
    if not db_task:
        return False

    db.delete(db_task)
    db.commit()
    return True


def get_tasks_by_status(db: Session, user_id: int, status: TaskStatus) -> List[Task]:
    return db.query(Task).filter(Task.owner_id == user_id, Task.status == status).all()