import uuid

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

from app.models.account import Account
from app.models.flow_proposal import FlowProposal
from app.models.l1_walk_session import L1WalkSession
from app.models.user import User


def test_flow_proposal_accepts_l1_session_id_without_source_session():
    p = FlowProposal(
        account_id=uuid.uuid4(),
        l1_session_id=uuid.uuid4(),
        source_session_id=None,
        proposal_type="new_flow",
        title="AI L1 draft",
        proposed_flow_data={"tree_structure": {"id": "root"}},
        source="ai_realtime_l1",
        status="pending",
    )
    assert p.l1_session_id is not None and p.source_session_id is None


@pytest.mark.asyncio
async def test_deleting_l1_session_cascades_proposal_not_check_violation(test_db: AsyncSession):
    """Finding 6: an L1-sourced proposal has source_session_id NULL by the exactly-one
    CHECK. With ondelete=CASCADE the proposal dies with its session; the old SET NULL
    would have NULLed both columns and aborted the DELETE on the CHECK (time bomb)."""
    s = str(uuid.uuid4())[:8]
    account = Account(id=uuid.uuid4(), name=f"Acct {s}", display_code=s.upper())
    test_db.add(account)
    await test_db.flush()
    user = User(
        id=uuid.uuid4(), email=f"u-{uuid.uuid4()}@example.com", name="U",
        account_id=account.id, account_role="l1_tech", role="engineer", is_active=True,
    )
    test_db.add(user)
    await test_db.flush()
    session = L1WalkSession(
        account_id=account.id, created_by_user_id=user.id,
        ticket_id="t-cascade", ticket_kind="internal", session_kind="ai_build",
    )
    test_db.add(session)
    await test_db.flush()
    proposal = FlowProposal(
        account_id=account.id, l1_session_id=session.id, source_session_id=None,
        proposal_type="new_flow", title="AI L1 draft",
        proposed_flow_data={"tree_structure": {"id": "root"}},
        source="ai_realtime_l1", status="pending",
    )
    test_db.add(proposal)
    await test_db.flush()
    pid = proposal.id

    # Delete the session — must succeed and cascade to the proposal.
    await test_db.delete(session)
    await test_db.flush()

    remaining = (await test_db.execute(
        select(FlowProposal).where(FlowProposal.id == pid)
    )).scalar_one_or_none()
    assert remaining is None