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


class TaskCRUD:
    def create_task(self, db: Session, task: TaskCreate) -> Task:
        db_task = Task(**task.model_dump())
        db.add(db_task)
        db.commit()
        db.refresh(db_task)
        return db_task

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

    def get_tasks(
        self,
        db: Session,
        skip: int = 0,
        limit: int = 100,
        completed: Optional[bool] = None,
    ) -> List[Task]:
        query = db.query(Task)
        if completed is not None:
            query = query.filter(Task.completed == completed)
        return query.offset(skip).limit(limit).all()

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

        update_data = task_update.model_dump(exclude_unset=True)
        for field, value in update_data.items():
            setattr(db_task, field, value)

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

    def delete_task(self, db: Session, task_id: int) -> bool:
        db_task = self.get_task(db, task_id)
        if not db_task:
            return False

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

    def get_tasks_by_priority(self, db: Session, priority: str) -> List[Task]:
        return db.query(Task).filter(Task.priority == priority).all()


task_crud = TaskCRUD()