"""Кто видит тест: автор + назначенные пользователи."""
from __future__ import annotations

from dataclasses import dataclass

from sqlalchemy import exists, select

from ..db import get_session
from ..models import Test, TestAssignment, TestAssignmentTarget, TestAttempt, TestVersion, User


def is_test_author(created_by, user_id) -> bool:
    if created_by is None or user_id is None:
        return False
    return str(created_by) == str(user_id)


@dataclass
class AccessResult:
    ok: bool
    is_author: bool
    not_found: bool


def user_has_test_access(user_id: str, test_id: str) -> AccessResult:
    import uuid as _uuid
    session = get_session()
    try:
        tid = _uuid.UUID(test_id)
        uid = _uuid.UUID(user_id)
    except (ValueError, AttributeError):
        return AccessResult(ok=False, is_author=False, not_found=True)

    test = session.get(Test, tid)
    if not test:
        return AccessResult(ok=False, is_author=False, not_found=True)

    if is_test_author(test.created_by, uid):
        return AccessResult(ok=True, is_author=True, not_found=False)

    # Глобальная политика доступа: любой активный тест доступен всем сотрудникам.
    if bool(test.is_active):
        return AccessResult(ok=True, is_author=False, not_found=False)

    assigned = session.query(
        exists().where(
            TestAssignmentTarget.target_type == 'user',
            TestAssignmentTarget.target_id == uid,
            TestAssignmentTarget.assignment_id == TestAssignment.id,
            TestAssignment.test_version_id == TestVersion.id,
            TestVersion.test_id == tid,
        )
    ).scalar()

    return AccessResult(ok=bool(assigned), is_author=False, not_found=False)


def list_visible_tests(user_id: str) -> list[dict]:
    """В dev-режиме возвращает все активные тесты независимо от назначения."""
    import uuid as _uuid
    session = get_session()
    try:
        uid = _uuid.UUID(user_id)
    except (ValueError, AttributeError):
        uid = None

    rows = (
        session.query(Test, TestVersion, User)
        .join(TestVersion, (TestVersion.test_id == Test.id) & TestVersion.is_active.is_(True))
        .outerjoin(User, User.id == Test.created_by)
        .filter(Test.is_active.is_(True))
        .order_by(Test.updated_at.desc().nullslast(), Test.created_at.desc())
        .all()
    )

    return [
        {
            'id': str(t.id),
            'title': t.title,
            'description': t.description,
            'chain_active': t.is_active,
            'created_at': t.created_at,
            'updated_at': t.updated_at,
            'active_version_id': str(tv.id),
            'version': tv.version,
            'created_by': str(t.created_by) if t.created_by else None,
            'author_full_name': u.full_name if u else '—',
            'has_in_progress_attempt': bool(
                uid and session.query(
                    exists().where(
                        TestAttempt.user_id == uid,
                        TestAttempt.status == 'in_progress',
                        TestAttempt.test_version_id == TestVersion.id,
                        TestVersion.test_id == t.id,
                    )
                ).scalar()
            ),
        }
        for t, tv, u in rows
    ]


def list_hidden_by_author(user_id: str) -> list[dict]:
    import uuid as _uuid
    session = get_session()
    try:
        uid = _uuid.UUID(user_id)
    except (ValueError, AttributeError):
        return []

    rows = (
        session.query(Test, TestVersion, User)
        .join(TestVersion, (TestVersion.test_id == Test.id) & TestVersion.is_active.is_(True))
        .join(User, User.id == Test.created_by)
        .filter(Test.is_active.is_(False), Test.created_by == uid)
        .order_by(Test.updated_at.desc().nullslast(), Test.created_at.desc())
        .all()
    )

    return [
        {
            'id': str(t.id),
            'title': t.title,
            'description': t.description,
            'chain_active': t.is_active,
            'created_at': t.created_at,
            'updated_at': t.updated_at,
            'active_version_id': str(tv.id),
            'version': tv.version,
            'created_by': str(t.created_by),
            'author_full_name': u.full_name,
        }
        for t, tv, u in rows
    ]