from sqlalchemy.orm import Session, joinedload
from typing import List, Optional
from . import models, schemas


# Project CRUD
def create_project(db: Session, project: schemas.ProjectCreate) -> models.Project:
    db_project = models.Project(**project.model_dump())
    db.add(db_project)
    db.commit()
    db.refresh(db_project)
    return db_project


def get_project(db: Session, project_id: int) -> Optional[models.Project]:
    return db.query(models.Project).filter(models.Project.id == project_id).first()


def get_projects(db: Session, skip: int = 0, limit: int = 100) -> List[models.Project]:
    return db.query(models.Project).offset(skip).limit(limit).all()


def update_project(
    db: Session, project_id: int, project: schemas.ProjectUpdate
) -> Optional[models.Project]:
    db_project = get_project(db, project_id)
    if not db_project:
        return None

    update_data = project.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_project, key, value)

    db.commit()
    db.refresh(db_project)
    return db_project


def delete_project(db: Session, project_id: int) -> bool:
    db_project = get_project(db, project_id)
    if not db_project:
        return False
    db.delete(db_project)
    db.commit()
    return True


# Task CRUD
def create_task(db: Session, task: schemas.TaskCreate) -> models.Task:
    # Get max sort_order for siblings
    if task.parent_task_id:
        max_order = db.query(models.Task).filter(
            models.Task.parent_task_id == task.parent_task_id
        ).count()
    else:
        max_order = db.query(models.Task).filter(
            models.Task.project_id == task.project_id,
            models.Task.parent_task_id.is_(None)
        ).count()

    task_data = task.model_dump()
    if "sort_order" not in task_data or task_data["sort_order"] == 0:
        task_data["sort_order"] = max_order

    db_task = models.Task(**task_data)
    db.add(db_task)
    db.commit()
    db.refresh(db_task)
    return db_task


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


def get_tasks_by_project(db: Session, project_id: int) -> List[models.Task]:
    return db.query(models.Task).filter(models.Task.project_id == project_id).all()


def get_root_tasks(db: Session, project_id: int) -> List[models.Task]:
    """Get all root-level tasks (no parent) for a project"""
    return db.query(models.Task).filter(
        models.Task.project_id == project_id,
        models.Task.parent_task_id.is_(None)
    ).order_by(models.Task.sort_order).all()


def get_task_with_subtasks(db: Session, task_id: int) -> Optional[models.Task]:
    """Recursively load a task with all its subtasks"""
    return db.query(models.Task).options(
        joinedload(models.Task.subtasks)
    ).filter(models.Task.id == task_id).first()


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

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

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


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


def get_tasks_by_status(db: Session, project_id: int, status: models.TaskStatus) -> List[models.Task]:
    """Get all tasks for a project with a specific status"""
    return db.query(models.Task).filter(
        models.Task.project_id == project_id,
        models.Task.status == status
    ).all()