import uuid
from typing import Sequence

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.milestone import Milestone
from app.schemas.project_milestone import ProjectMilestoneUpdate

PROJECT_MILESTONE_TYPE = "SETUP_PROJECT_MILESTONE"


async def list_project_milestones(db: AsyncSession, study_id: uuid.UUID) -> Sequence[Milestone]:
    stmt = (
        select(Milestone)
        .where(
            Milestone.study_id == study_id,
            Milestone.type == PROJECT_MILESTONE_TYPE,
        )
        .order_by(Milestone.planned_date.asc().nulls_last(), Milestone.created_at.asc())
    )
    result = await db.execute(stmt)
    return result.scalars().all()


async def get_project_milestone(db: AsyncSession, study_id: uuid.UUID, milestone_id: uuid.UUID) -> Milestone | None:
    result = await db.execute(
        select(Milestone).where(
            Milestone.id == milestone_id,
            Milestone.study_id == study_id,
            Milestone.type == PROJECT_MILESTONE_TYPE,
        )
    )
    return result.scalar_one_or_none()


async def update_project_milestone(db: AsyncSession, milestone: Milestone, data: ProjectMilestoneUpdate) -> Milestone:
    milestone.adjusted_start_date = data.adjusted_start_date
    milestone.adjusted_end_date = data.adjusted_end_date
    milestone.actual_start_date = data.actual_start_date
    milestone.actual_end_date = data.actual_end_date
    milestone.actual_date = data.actual_end_date
    milestone.notes = data.notes

    if milestone.actual_end_date:
        milestone.status = "DONE"
    elif milestone.actual_start_date:
        milestone.status = "IN_PROGRESS"
    else:
        milestone.status = "NOT_STARTED"

    await db.commit()
    await db.refresh(milestone)
    return milestone