"""The few facts the site may state about itself before anybody signs in.

Counts only, and only of published material. No titles, no ids, nothing that
could be walked to enumerate the bank — a landing page needs to say how much
there is, not what it is.

Unauthenticated on purpose: it is read by the page a stranger lands on.
"""
from fastapi import APIRouter, Depends
from sqlalchemy import func
from sqlalchemy.orm import Session

from app.database import get_db
from app.models.article import Article
from app.models.exam import Exam
from app.models.question import Question
from app.models.question_category import QuestionCategory

router = APIRouter()


@router.get("/stats")
def public_stats(db: Session = Depends(get_db)):
    """What the landing page says there is, taken from what there is.

    A number written into the markup is a number that goes stale the week
    after it is written, and nobody notices because nothing breaks.
    """
    questions = db.query(func.count(Question.id)).filter(
        Question.deleted_at.is_(None)).scalar() or 0
    topics = db.query(func.count(QuestionCategory.id)).scalar() or 0
    systems = db.query(func.count(func.distinct(QuestionCategory.system_id))).filter(
        QuestionCategory.system_id.isnot(None)).scalar() or 0
    articles = db.query(func.count(Article.id)).filter(
        Article.status == "published").scalar() or 0
    exams = db.query(func.count(Exam.id)).filter(Exam.is_active == 1).scalar() or 0
    return {
        "questions": questions,
        "topics": topics,
        "systems": systems,
        "articles": articles,
        "exams": exams,
    }