from __future__ import annotations

import os
from concurrent.futures import ThreadPoolExecutor

import pytest
from sqlalchemy import create_engine, text
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session

from app.core.common.identifiers import new_governance_uid
from app.core.data_rules.repository import DataRuleRepository


def _claim(url, receipt, actor):
    engine = create_engine(url)
    try:
        with Session(engine) as session:
            try:
                value = DataRuleRepository(session).begin_dataflow_create(
                    receipt, actor_uid=actor
                )
                session.commit()
                return value
            except ValueError as exc:
                session.rollback()
                return {"status": str(exc)}
    finally:
        engine.dispose()


def test_real_postgres_saga_fk_expiry_concurrent_claim_replay_and_lease_recovery():
    url = os.environ.get("DATA_RULE_POSTGRES_ACCEPTANCE_URL")
    if not url:
        pytest.skip("real PostgreSQL acceptance URL is not configured")
    engine = create_engine(url)
    created_ids = []
    actor = new_governance_uid()
    try:
        with Session(engine) as session:
            session.execute(
                text(
                    "INSERT INTO public.users "
                    "(id, username, display_name, password_hash, status) "
                    "VALUES (CAST(:id AS uuid), :username, "
                    "'Saga Acceptance', 'not-a-login-hash', 'active')"
                ),
                {"id": actor, "username": f"saga-{actor}"},
            )
            session.commit()
            receipt = DataRuleRepository(session).reserve_dataflow_draft(
                actor_uid=actor
            )
            created_ids.append(receipt["reservation_id"])
            session.commit()

        closed = {
            key: receipt[key]
            for key in ("reservation_id", "dataflow_uid", "nonce")
        }
        with ThreadPoolExecutor(max_workers=2) as pool:
            outcomes = list(
                pool.map(lambda _index: _claim(url, closed, actor), range(2))
            )
        claimed = [value for value in outcomes if value["status"] == "claimed"]
        assert len(claimed) == 1
        assert sorted(value["status"] for value in outcomes) == [
            "claimed",
            "dataflow_create_in_progress",
        ]

        result = {"id": 73, "uid": receipt["dataflow_uid"]}
        with Session(engine) as session:
            repository = DataRuleRepository(session)
            assert repository.complete_dataflow_create(
                reservation_id=receipt["reservation_id"],
                dataflow_uid=receipt["dataflow_uid"],
                lease_token=claimed[0]["lease_token"],
                dataflow_node_id=73,
                result=result,
            ) == result
            session.commit()
        replay = _claim(url, closed, actor)
        assert replay["status"] == "completed"
        assert replay["result"] == result

        with Session(engine) as session:
            expired = DataRuleRepository(session).reserve_dataflow_draft(
                actor_uid=actor
            )
            created_ids.append(expired["reservation_id"])
            session.execute(
                text(
                    "UPDATE public.dataflow_draft_reservations "
                    "SET created_at = CURRENT_TIMESTAMP - INTERVAL '2 seconds', "
                    "expires_at = CURRENT_TIMESTAMP - INTERVAL '1 second' "
                    "WHERE id = CAST(:id AS uuid)"
                ),
                {"id": expired["reservation_id"]},
            )
            session.commit()
        expired_closed = {
            key: expired[key]
            for key in ("reservation_id", "dataflow_uid", "nonce")
        }
        assert _claim(url, expired_closed, actor)["status"] == (
            "draft_reservation_refresh_required"
        )

        with Session(engine) as session:
            recoverable = DataRuleRepository(session).reserve_dataflow_draft(
                actor_uid=actor
            )
            created_ids.append(recoverable["reservation_id"])
            session.commit()
            first = DataRuleRepository(session).begin_dataflow_create(
                {
                    key: recoverable[key]
                    for key in ("reservation_id", "dataflow_uid", "nonce")
                },
                actor_uid=actor,
                lease_seconds=10,
            )
            session.commit()
            session.execute(
                text(
                    "UPDATE public.dataflow_draft_reservations "
                    "SET lease_expires_at = CURRENT_TIMESTAMP - INTERVAL '1 second' "
                    "WHERE id = CAST(:id AS uuid)"
                ),
                {"id": recoverable["reservation_id"]},
            )
            session.commit()
        recovered = _claim(
            url,
            {
                key: recoverable[key]
                for key in ("reservation_id", "dataflow_uid", "nonce")
            },
            actor,
        )
        assert first["attempt"] == 1
        assert recovered["status"] == "claimed"
        assert recovered["attempt"] == 2

        with Session(engine) as session:
            with pytest.raises(IntegrityError):
                DataRuleRepository(session).reserve_dataflow_draft(
                    actor_uid=new_governance_uid()
                )
                session.commit()
            session.rollback()
    finally:
        with Session(engine) as session:
            session.execute(
                text(
                    "DELETE FROM public.dataflow_draft_reservations "
                    "WHERE id = ANY(CAST(:ids AS uuid[]))"
                ),
                {"ids": created_ids},
            )
            session.execute(
                text(
                    "DELETE FROM public.users WHERE id = CAST(:id AS uuid)"
                ),
                {"id": actor},
            )
            session.commit()
        engine.dispose()