import pytest_asyncio
from httpx import AsyncClient, ASGITransport
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

from sqlalchemy import text

from app.main import app
from app.core.database import Base, get_db
from app.core.limiter import limiter

# Echte PostgreSQL Test-Datenbank (kein SQLite – Models nutzen JSONB/UUID)
TEST_DATABASE_URL = "postgresql+asyncpg://timemaster:timemaster_secret_change_me@localhost:5432/timemaster_test"

test_engine = create_async_engine(TEST_DATABASE_URL, echo=False)
TestSessionLocal = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)


_BYPASS = "COALESCE(current_setting('app.bypass_rls', true), 'off') = 'on'"
_CID    = "company_id = NULLIF(current_setting('app.company_id', true), '')::uuid"
_IID    = "id         = NULLIF(current_setting('app.company_id', true), '')::uuid"
_RID    = "reseller_id = NULLIF(current_setting('app.reseller_id', true), '')::uuid"
# Reseller darf User seiner eigenen Firmen verwalten (vgl. Migration 0034)
_USER_RESELLER = (
    "company_id IN (SELECT id FROM companies WHERE "
    "reseller_id = NULLIF(current_setting('app.reseller_id', true), '')::uuid)"
)

def _rls_using_cid():   return f"({_BYPASS} OR {_CID})"
def _rls_using_iid():   return f"({_BYPASS} OR {_IID} OR {_RID})"
def _rls_using_users(): return f"({_BYPASS} OR {_CID} OR {_USER_RESELLER})"
def _rls_using_join(): return (
    f"({_BYPASS} OR user_id IN (SELECT id FROM users WHERE {_CID}))"
)

_COMPANY_COL_TABLES = [
    "absence_comments", "absence_types", "audit_logs", "caldav_company_configs", "departments",
    "hours_payouts", "kiosk_devices", "ldap_configs", "overtime_balances", "smtp_configs",
    "special_assignments", "users", "work_schedules",
]
_USER_JOIN_TABLES = [
    "absences", "caldav_user_configs", "password_resets",
    "sessions", "time_entries", "vacation_balances",
]


async def _apply_rls(conn) -> None:
    """Apply the same RLS policies as migration 0024 to the test database."""
    def enable(table: str, using: str):
        return [
            f"ALTER TABLE {table} ENABLE ROW LEVEL SECURITY",
            f"ALTER TABLE {table} FORCE ROW LEVEL SECURITY",
            f"DROP POLICY IF EXISTS rls_{table}_select ON {table}",
            f"DROP POLICY IF EXISTS rls_{table}_insert ON {table}",
            f"DROP POLICY IF EXISTS rls_{table}_update ON {table}",
            f"DROP POLICY IF EXISTS rls_{table}_delete ON {table}",
            f"CREATE POLICY rls_{table}_select ON {table} FOR SELECT USING {using}",
            f"CREATE POLICY rls_{table}_insert ON {table} FOR INSERT WITH CHECK {using}",
            f"CREATE POLICY rls_{table}_update ON {table} FOR UPDATE USING {using} WITH CHECK {using}",
            f"CREATE POLICY rls_{table}_delete ON {table} FOR DELETE USING {using}",
        ]

    for sql in enable("companies", _rls_using_iid()):
        await conn.execute(text(sql))
    for table in _COMPANY_COL_TABLES:
        using = _rls_using_users() if table == "users" else _rls_using_cid()
        for sql in enable(table, using):
            await conn.execute(text(sql))
    for table in _USER_JOIN_TABLES:
        for sql in enable(table, _rls_using_join()):
            await conn.execute(text(sql))


@pytest_asyncio.fixture(scope="session", loop_scope="session", autouse=True)
async def setup_db():
    # Redis-Test-Keys bereinigen (Login/PIN/TOTP-Lockouts von vorherigen Runs)
    import redis.asyncio as aioredis
    from app.core.config import settings
    async with aioredis.from_url(settings.redis_url) as r:
        patterns = ["login_fails:*", "login_lockout:*", "pin_fails:*", "pin_lockout:*",
                    "totp_fails:*", "totp_lockout:*", "burned_token:*"]
        for pattern in patterns:
            keys = await r.keys(pattern)
            if keys:
                await r.delete(*keys)

    async with test_engine.begin() as conn:
        # Schema komplett neu anlegen – löst circular dependency departments↔users
        await conn.execute(text("DROP SCHEMA public CASCADE"))
        await conn.execute(text("CREATE SCHEMA public"))
        await conn.execute(text("GRANT ALL ON SCHEMA public TO timemaster"))
        await conn.execute(text("GRANT ALL ON SCHEMA public TO public"))
        await conn.run_sync(Base.metadata.create_all)
        await _apply_rls(conn)
    yield
    async with test_engine.begin() as conn:
        await conn.execute(text("DROP SCHEMA public CASCADE"))
        await conn.execute(text("CREATE SCHEMA public"))
        await conn.execute(text("GRANT ALL ON SCHEMA public TO timemaster"))
        await conn.execute(text("GRANT ALL ON SCHEMA public TO public"))


@pytest_asyncio.fixture(scope="session", loop_scope="session")
async def db_session():
    async with TestSessionLocal() as session:
        yield session
        await session.rollback()


@pytest_asyncio.fixture(scope="session", loop_scope="session")
async def client(db_session: AsyncSession):
    async def override_get_db():
        try:
            # Tests use a shared session without a real transaction context per
            # request. Set bypass_rls = 'on' so that all test queries succeed
            # regardless of whether app.company_id is set.
            await db_session.execute(text("SET LOCAL app.bypass_rls = 'on'"))
            yield db_session
            await db_session.commit()
        except Exception:
            await db_session.rollback()
            raise

    app.dependency_overrides[get_db] = override_get_db
    limiter.enabled = False  # Rate-Limiter in Tests deaktivieren

    async with AsyncClient(
        transport=ASGITransport(app=app),
        base_url="http://test",
    ) as ac:
        yield ac

    limiter.enabled = True
    app.dependency_overrides.clear()


@pytest_asyncio.fixture(scope="session", loop_scope="session")
async def registered_user(client: AsyncClient):
    """Register a company + admin user, return tokens + user data."""
    resp = await client.post("/api/v1/auth/register", json={
        "company_name": "Test GmbH",
        "first_name": "Max",
        "last_name": "Mustermann",
        "email": "max@testgmbh.de",
        "password": "Secret123",
    })
    assert resp.status_code == 201
    tokens = resp.json()

    me = await client.get(
        "/api/v1/auth/me",
        headers={"Authorization": f"Bearer {tokens['access_token']}"},
    )
    return {"tokens": tokens, "user": me.json()}
