"""ImpactAgent RAG 上下文注入测试（RAG 迭代 Task 4，异步形态）。

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）。
- run_impact 为 async def，真实 await 引擎 chat_structured。
"""
import asyncio
import types

import pytest

from genesis.impact.impact_agent import ImpactAgent, _RAG_CONTEXT_TITLE
from genesis.rag.embeddings import FakeEmbedder
from genesis.rag.impact_rag import ImpactRAG
from genesis.rag.store import RagStore


class FakeEngine:
    """捕获真实 LLM 方法（chat_structured，async）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.captured: str | None = None
        self.calls = 0

    async def chat_structured(self, *, session_id, prompt, variables, schema, retry_count=2):
        self.captured = prompt
        self.calls += 1
        # 返回结构兼容 StructuredResult 的最小占位（含 data/raw_text）
        return types.SimpleNamespace(data={}, raw_text=prompt)


def _make_rag(session_id: str, text: str) -> ImpactRAG:
    store = RagStore(":memory:")
    rag = ImpactRAG(store, FakeEmbedder())
    rag.index(session_id, [("TradeApplication.java", text)])
    return rag


def test_run_impact_with_rag_injects_context():
    rag = _make_rag("p1", "订单创建调用 MyBatis")
    engine = FakeEngine()
    agent = ImpactAgent(engine=engine, rag=rag, use_rag=True)
    asyncio.run(agent.run_impact("p1", "创建订单的影响"))
    assert engine.captured is not None
    # 命中片段（含文件名 TradeApplication.java）被注入
    assert "TradeApplication" in engine.captured
    # 明确小节标题被注入
    assert _RAG_CONTEXT_TITLE in engine.captured


def test_run_impact_without_rag_no_context():
    engine = FakeEngine()
    agent = ImpactAgent(engine=engine, rag=_make_rag("p1", "x"), use_rag=False)
    asyncio.run(agent.run_impact("p1", "创建订单的影响"))
    assert _RAG_CONTEXT_TITLE not in engine.captured


def test_run_impact_rag_enabled_but_no_hits():
    # rag 已建但索引在另一 scope，retrieve 命中为空 → 不应注入 RAG 小节
    engine = FakeEngine()
    agent = ImpactAgent(engine=engine, rag=_make_rag("other", "订单创建调用 MyBatis"), use_rag=True)
    asyncio.run(agent.run_impact("p1", "创建订单的影响"))
    assert _RAG_CONTEXT_TITLE not in engine.captured


def test_run_impact_use_rag_none_falls_back_to_instance_default():
    # use_rag=None 时回退实例级 self.use_rag（此处为 True）→ 应注入 RAG 小节
    engine = FakeEngine()
    agent = ImpactAgent(engine=engine, rag=_make_rag("p1", "订单创建调用 MyBatis"), use_rag=True)
    asyncio.run(agent.run_impact("p1", "创建订单的影响", use_rag=None))
    assert _RAG_CONTEXT_TITLE in engine.captured
    assert "TradeApplication" in engine.captured


def test_run_impact_explicit_false_no_context():
    # 显式 use_rag=False（覆盖 use_rag is None 的 False 分支）→ 不注入 RAG 小节
    engine = FakeEngine()
    agent = ImpactAgent(engine=engine, rag=_make_rag("p1", "x"), use_rag=True)
    asyncio.run(agent.run_impact("p1", "创建订单的影响", use_rag=False))
    assert _RAG_CONTEXT_TITLE not in engine.captured


def test_run_impact_requires_engine():
    agent = ImpactAgent()
    with pytest.raises(RuntimeError):
        asyncio.run(agent.run_impact("p1", "x"))