from __future__ import annotations

import types as t

import pytest

from genesis.inference.engine import InferenceEngine
from genesis.inference.token import approximate_token_count
from genesis.qa.guardrails import (
    DEFAULT_MAX_QA_ROUNDS,
    QALoopController,
    resolve_qa_model,
)
from tests.inference_helpers import FakeLLMClient


class QAModels:
    """模拟 config.InferenceModels：primary=deepseek / fallback=qwen。"""

    def __init__(self):
        self.primary = t.SimpleNamespace(name="deepseek-chat", provider="deepseek")
        self.fallback = t.SimpleNamespace(name="qwen-max", provider="qwen")


class QAModelsNoFallback:
    """无 fallback 配置（覆盖 None 分支）。"""

    def __init__(self):
        self.primary = t.SimpleNamespace(name="deepseek-chat")
        self.fallback = None


class QAModelsFallbackEmptyName:
    """fallback 存在但 name 为空字符串（覆盖 name 假值分支）。"""

    def __init__(self):
        self.primary = t.SimpleNamespace(name="deepseek-chat")
        self.fallback = t.SimpleNamespace(name="")


# ---------- resolve_qa_model（OV6：强制 fallback，防自校验盲区） ----------

def test_resolve_qa_model_returns_fallback_name():
    assert resolve_qa_model(QAModels()) == "qwen-max"


def test_resolve_qa_model_never_returns_primary():
    """关键护栏：QA 不得返回主模型名（否则 DeepSeek 校验 DeepSeek 盲区）。"""
    models = QAModels()
    assert resolve_qa_model(models) != getattr(models.primary, "name", None)


def test_resolve_qa_model_no_fallback_returns_none():
    """无 fallback 时返回 None，迫使调用方显式指定独立校验模型。"""
    assert resolve_qa_model(QAModelsNoFallback()) is None


def test_resolve_qa_model_fallback_empty_name_returns_none():
    """fallback 存在但 name 为空时返回 None（不静默回退到 primary）。"""
    assert resolve_qa_model(QAModelsFallbackEmptyName()) is None


def test_resolve_qa_model_none_models_returns_none():
    assert resolve_qa_model(None) is None


# ---------- QALoopController（OV6：循环边界防无限） ----------

def test_loop_default_max_rounds():
    ctrl = QALoopController()
    assert ctrl.max_rounds == DEFAULT_MAX_QA_ROUNDS


def test_loop_stops_at_max_rounds():
    ctrl = QALoopController(max_rounds=3)
    assert ctrl.can_continue()
    ctrl.advance()
    ctrl.advance()
    ctrl.advance()
    assert ctrl.round == 3
    assert ctrl.is_exhausted()
    assert not ctrl.can_continue()


def test_loop_exhausted_cannot_continue():
    ctrl = QALoopController(max_rounds=1)
    ctrl.advance()
    assert ctrl.is_exhausted()
    assert not ctrl.can_continue()


# ---------- 集成：QA 调用强制走 fallback 模型 ----------

@pytest.mark.anyio
async def test_qa_call_uses_fallback_not_primary():
    client = FakeLLMClient([("ok", "QA 通过")])
    models = QAModels()
    eng = InferenceEngine(
        client=client,
        models=models,
        estimator=approximate_token_count,
    )
    qa_model = resolve_qa_model(models)
    assert qa_model == "qwen-max"
    await eng.chat(
        session_id="qa1",
        prompt="请校验以下章节",
        variables={},
        model=qa_model,
    )
    called_models = [c["model"] for c in client.calls]
    # 实际 LLM 调用必须用 fallback，绝不可落到 primary
    assert called_models == ["qwen-max"]
    assert "deepseek-chat" not in called_models