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, *, limit: int) -> 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 DwhAdapter as PublicDwhAdapter
    from tht.ports import DwhCapabilities as PublicDwhCapabilities
    from tht.ports import DwhHealth as PublicDwhHealth
    from tht.ports import DistinctValues as PublicDistinctValues
    from tht.ports import UnsupportedCapability as PublicUnsupportedCapability

    result = PublicDistinctValues(values=["a"], truncated=True)
    assert result.values == ["a"]
    assert result.truncated is True
    assert PublicDwhAdapter is DwhAdapter
    assert PublicDwhCapabilities is DwhCapabilities
    assert PublicDwhHealth is DwhHealth
    assert PublicUnsupportedCapability is UnsupportedCapability