from dataclasses import FrozenInstanceError

import pytest

from tht.execute import ExecResult, PlanSummary
from tht.mschema.models import PhysicalSchema
from tht.ports.dwh import (
    DwhAdapter,
    DwhCapabilities,
    DwhHealth,
    DistinctValues,
    UnsupportedCapability,
)


class FakeDwhAdapter:
    capabilities = DwhCapabilities()

    def health(self) -> DwhHealth:
        return DwhHealth(ok=True)

    def introspect(self) -> PhysicalSchema:
        raise NotImplementedError

    def run_query(self, sql: str, *, limit: int) -> ExecResult:
        raise NotImplementedError

    def explain(self, sql: str) -> PlanSummary:
        raise NotImplementedError

    def sample_column(self, table: str, column: str, *, limit: int) -> list[object]:
        raise NotImplementedError

    def distinct_values(self, table: str, column: str) -> DistinctValues:
        raise NotImplementedError


def test_fake_adapter_satisfies_runtime_protocol():
    adapter = FakeDwhAdapter()

    assert isinstance(adapter, DwhAdapter)
    assert adapter.capabilities.explain is True
    assert adapter.health().ok is True


def test_contract_types_are_public_and_capabilities_are_immutable():
    capabilities = DwhCapabilities()

    assert capabilities.introspection is True
    assert capabilities.sampling is True
    assert capabilities.distinct_values is True
    assert issubclass(UnsupportedCapability, Exception)
    with pytest.raises(FrozenInstanceError):
        capabilities.explain = False


def test_all_contract_types_are_exported_from_public_package():
    from tht.ports import DistinctValues as PublicDistinctValues

    result = PublicDistinctValues(values=["a"], truncated=True)
    assert result.values == ["a"]
    assert result.truncated is True