import uuid
from datetime import date

from fastapi import APIRouter, Depends
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.deps import get_db_session, require_study_member
from app.models.milestone import Milestone
from app.models.task import Task
from app.schemas.progress import StudyProgressRead

router = APIRouter()


@router.get("/progress", response_model=StudyProgressRead, dependencies=[Depends(require_study_member())])
async def get_progress(
    study_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
) -> StudyProgressRead:
    # Milestones
    milestone_total_stmt = select(func.count()).select_from(Milestone).where(Milestone.study_id == study_id)
    milestone_done_stmt = select(func.count()).select_from(Milestone).where(
        Milestone.study_id == study_id, Milestone.status == "DONE"
    )
    task_total_stmt = select(func.count()).select_from(Task).where(Task.study_id == study_id)
    task_done_stmt = select(func.count()).select_from(Task).where(Task.study_id == study_id, Task.status == "DONE")
    task_overdue_stmt = select(func.count()).select_from(Task).where(
        Task.study_id == study_id,
        Task.due_date < date.today(),
        Task.status != "DONE",
    )

    milestone_total = (await db.execute(milestone_total_stmt)).scalar_one()
    milestone_done = (await db.execute(milestone_done_stmt)).scalar_one()
    task_total = (await db.execute(task_total_stmt)).scalar_one()
    task_done = (await db.execute(task_done_stmt)).scalar_one()
    task_overdue = (await db.execute(task_overdue_stmt)).scalar_one()

    total_items = milestone_total + task_total
    done_items = milestone_done + task_done
    completion_rate = float(done_items / total_items) if total_items else 0.0

    return StudyProgressRead(
        milestones_total=milestone_total,
        milestones_done=milestone_done,
        tasks_total=task_total,
        tasks_done=task_done,
        tasks_overdue=task_overdue,
        completion_rate=completion_rate,
    )