"""ImpactAgent RAG 上下文注入测试（RAG 迭代 Task 4）。

验证：
- use_rag=True 时，run_impact 发送给 LLM 的 prompt 文本包含 RAG 检索命中片段与明确小节标题。
- use_rag=False（或默认）时，prompt 文本不含 RAG 小节标题（向后兼容）。
"""
from genesis.impact.impact_agent import ImpactAgent
from genesis.rag.embeddings import FakeEmbedder
from genesis.rag.impact_rag import ImpactRAG
from genesis.rag.store import RagStore


_RAG_SECTION_TITLE = "# 既有系统关联上下文（RAG 检索，辅助判断影响范围）"


class FakeEngine:
    """捕获真实 LLM 方法（chat_structured）收到的 prompt 文本。

    方法名与签名刻意复用本仓库 InferenceEngine.chat_structured 的形参风格，
    以保证 mock 的是真实接口（key=session_id/prompt/variables/schema/retry_count）。
    """

    def __init__(self) -> None:
        self.last_prompt: str | None = None
        self.calls = 0

    def chat_structured(self, *, session_id, prompt, variables, schema, retry_count=2):
        self.last_prompt = prompt
        self.calls += 1
        # 返回结构兼容 ChatResult 的最小占位（测试仅校验 prompt 注入）
        return {"session_id": session_id, "prompt": prompt}


def _make_rag(session_id: str, sources):
    store = RagStore(":memory:")
    rag = ImpactRAG(store, FakeEmbedder())
    rag.index(session_id, sources)
    return store, rag


def test_run_impact_with_rag_injects_context():
    session_id = "sess-rag"
    store, rag = _make_rag(session_id, [("TradeApplication.java", "订单创建调用 MyBatis")])
    try:
        engine = FakeEngine()
        agent = ImpactAgent(engine=engine, rag=rag, use_rag=True)
        agent.run_impact(session_id, requirements_text="创建订单的影响", k=5)
        prompt = engine.last_prompt
        assert prompt is not None
        # 命中片段（含文件名 TradeApplication.java）被注入
        assert "TradeApplication" in prompt
        # 明确小节标题被注入
        assert _RAG_SECTION_TITLE in prompt
    finally:
        store.close()


def test_run_impact_without_rag_no_context():
    session_id = "sess-no-rag"
    store, rag = _make_rag(session_id, [("TradeApplication.java", "订单创建调用 MyBatis")])
    try:
        engine = FakeEngine()
        agent = ImpactAgent(engine=engine, rag=rag, use_rag=False)
        agent.run_impact(session_id, requirements_text="创建订单的影响", k=5)
        prompt = engine.last_prompt
        # 显式关闭 RAG：不含小节标题，也不含检索片段
        assert _RAG_SECTION_TITLE not in prompt
        assert "TradeApplication" not in prompt
    finally:
        store.close()


def test_run_impact_default_no_rag_no_context():
    # 默认 use_rag 为 False（未显式开启），行为与关闭一致
    session_id = "sess-default"
    store, rag = _make_rag(session_id, [("TradeApplication.java", "订单创建调用 MyBatis")])
    try:
        engine = FakeEngine()
        agent = ImpactAgent(engine=engine, rag=rag)  # 不传 use_rag
        agent.run_impact(session_id, requirements_text="创建订单的影响", k=5)
        prompt = engine.last_prompt
        assert _RAG_SECTION_TITLE not in prompt
        assert "TradeApplication" not in prompt
    finally:
        store.close()