"""ack.py DTO 单元测试。

覆盖 ``AckPolicy`` / ``AckStage`` 枚举与 ``AckDecision`` 的字段赋值、
不可变语义与 ``__post_init__`` 校验逻辑。
"""

from __future__ import annotations

import dataclasses

import pytest
from yuxi.channels.contract.dtos.ack import (
    AckDecision,
    AckPolicy,
    AckStage,
)
from yuxi.channels.contract.errors import ValidationError

pytestmark = pytest.mark.unit


@pytest.mark.unit
class TestAckPolicy:
    """ACK 策略枚举测试。"""

    def test_enum_values_are_correct(self):
        # Arrange
        # Act
        # Assert
        assert AckPolicy.AFTER_RECORD == "after_record"
        assert AckPolicy.AFTER_AGENT_DISPATCH == "after_agent_dispatch"
        assert AckPolicy.AFTER_PERSIST == "after_persist"
        assert AckPolicy.MANUAL == "manual"

    def test_enum_inherits_from_str(self):
        # Arrange
        # Act
        # Assert
        assert issubclass(AckPolicy, str)
        assert isinstance(AckPolicy.MANUAL, str)

    def test_enum_has_four_members(self):
        # Arrange
        # Act
        members = list(AckPolicy)
        # Assert
        assert len(members) == 4


@pytest.mark.unit
class TestAckStage:
    """ACK 阶段枚举测试。"""

    def test_enum_values_are_correct(self):
        # Arrange
        # Act
        # Assert
        assert AckStage.RECORD == "record"
        assert AckStage.DISPATCH == "dispatch"
        assert AckStage.PERSIST == "persist"
        assert AckStage.MANUAL == "manual"

    def test_enum_inherits_from_str(self):
        # Arrange
        # Act
        # Assert
        assert issubclass(AckStage, str)
        assert isinstance(AckStage.RECORD, str)

    def test_enum_has_four_members(self):
        # Arrange
        # Act
        members = list(AckStage)
        # Assert
        assert len(members) == 4


@pytest.mark.unit
class TestAckDecision:
    """ACK 决策 DTO 测试。"""

    def test_fields_are_assigned(self):
        # Arrange
        # Act
        decision = AckDecision(decision="ack", stage=AckStage.RECORD)
        # Assert
        assert decision.decision == "ack"
        assert decision.stage is AckStage.RECORD
        assert decision.idempotency_key is None

    def test_with_idempotency_key(self):
        # Arrange
        # Act
        decision = AckDecision(
            decision="nack",
            stage=AckStage.DISPATCH,
            idempotency_key="idem-1",
        )
        # Assert
        assert decision.idempotency_key == "idem-1"

    @pytest.mark.parametrize("action", ["ack", "nack", "retry", "pending"])
    def test_valid_decisions(self, action):
        # Arrange
        # Act
        decision = AckDecision(decision=action, stage=AckStage.RECORD)
        # Assert
        assert decision.decision == action

    def test_invalid_decision_raises_validation_error(self):
        # Arrange
        # Act / Assert - decision 不在合法取值集合中
        with pytest.raises(ValidationError) as exc_info:
            AckDecision(decision="invalid", stage=AckStage.RECORD)  # type: ignore[arg-type]
        assert exc_info.value.field == "decision"

    def test_is_frozen(self):
        # Arrange
        decision = AckDecision(decision="ack", stage=AckStage.RECORD)
        # Act / Assert
        with pytest.raises(dataclasses.FrozenInstanceError):
            decision.decision = "nack"  # type: ignore[misc]