from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.database import get_db
from app.models.test import Answer, Question, Test
from app.schemas.test import TestCreate, TestListItem, TestOut

router = APIRouter(prefix="/api/tests", tags=["tests"])


@router.get("", response_model=list[TestListItem])
async def list_tests(db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(Test)
        .options(selectinload(Test.questions))
        .where(Test.is_active == True)
        .order_by(Test.created_at.desc())
    )
    tests = result.scalars().all()

    items = []
    for test in tests:
        item = TestListItem.model_validate(test)
        item.questions_count = len(test.questions)
        items.append(item)

    return items


@router.get("/{test_id}", response_model=TestOut)
async def get_test(test_id: int, db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(Test)
        .options(selectinload(Test.questions).selectinload(Question.answers))
        .where(Test.id == test_id, Test.is_active == True)
    )
    test = result.scalar_one_or_none()
    if not test:
        raise HTTPException(status_code=404, detail="Тест не найден")
    return test


@router.post("", response_model=TestOut, status_code=201)
async def create_test(data: TestCreate, db: AsyncSession = Depends(get_db)):
    test = Test(
        title=data.title,
        description=data.description,
        passing_score=data.passing_score,
        time_limit=data.time_limit,
        allow_navigation_back=data.allow_navigation_back,
    )
    db.add(test)
    await db.flush()

    for order, q_data in enumerate(data.questions):
        question = Question(test_id=test.id, text=q_data.text, order=order)
        db.add(question)
        await db.flush()

        for a_data in q_data.answers:
            db.add(Answer(
                question_id=question.id,
                text=a_data.text,
                is_correct=a_data.is_correct,
            ))

    await db.commit()

    # Перезагружаем с вложенными связями
    result = await db.execute(
        select(Test)
        .options(selectinload(Test.questions).selectinload(Question.answers))
        .where(Test.id == test.id)
    )
    return result.scalar_one()