"""ResultSummarizer 单元测试（FakeOllama，不依赖真实 Ollama）

覆盖：
- summarize 正常：调用 ollama，prompt 含 query 与 hits 文本，返回 strip 后的 summary
- summarize 无 hits：返回空串且不调 ollama
- summarize ollama 异常：返回空串
- _build_context 拼接格式：编号 / title / section_path / 文本
- 取前 settings.result_summary_max_hits 条：超量 hits 只取前 N 条进入 prompt
"""

import pytest

from app.config import settings
from app.core.result_summarizer import ResultSummarizer
from app.models.search import SearchHit


class FakeOllama:
    """记录调用并返回固定响应的假 OllamaClient"""

    def __init__(self, response: str = "这是总结") -> None:
        self.response = response
        self.calls: list[dict] = []

    async def generate(self, prompt: str, json_mode: bool = False) -> str:
        self.calls.append({"prompt": prompt, "json_mode": json_mode})
        return self.response


class FailingOllama:
    """generate 抛异常的假 OllamaClient，用于测试容错降级"""

    async def generate(self, prompt: str, json_mode: bool = False) -> str:
        raise RuntimeError("ollama 不可用")


def _hit(idx: int, title: str = "", section_path: str = "") -> SearchHit:
    """构造测试用 SearchHit"""
    return SearchHit(
        text=f"文本内容-{idx}",
        doc_id=f"doc-{idx}",
        title=title or f"标题-{idx}",
        section_path=section_path,
        score=0.1 * idx,
    )


class TestSummarize:
    """ResultSummarizer.summarize 主流程"""

    async def test_summarize_normal(self):
        """正常总结：调用 ollama，prompt 含 query 与 hits 文本，返回 strip 后的 summary"""
        ollama = FakeOllama(response="  这是 AI 总结  ")
        summarizer = ResultSummarizer(ollama=ollama)  # type: ignore[arg-type]
        hits = [_hit(1, "文档A", "章节A"), _hit(2, "文档B", "章节B")]

        result = await summarizer.summarize("安装步骤是什么", hits)

        assert result == "这是 AI 总结"
        assert len(ollama.calls) == 1
        prompt = ollama.calls[0]["prompt"]
        assert "安装步骤是什么" in prompt
        assert "文本内容-1" in prompt
        assert "文本内容-2" in prompt
        assert "文档A" in prompt
        assert "文档B" in prompt
        assert "章节A" in prompt
        assert "章节B" in prompt

    async def test_summarize_empty_hits_returns_empty(self):
        """无 hits：返回空串且不调用 ollama"""
        ollama = FakeOllama()
        summarizer = ResultSummarizer(ollama=ollama)  # type: ignore[arg-type]

        result = await summarizer.summarize("任何问题", [])

        assert result == ""
        assert ollama.calls == []

    async def test_summarize_ollama_error_returns_empty(self):
        """ollama.generate 抛异常：返回空串（容错降级）"""
        summarizer = ResultSummarizer(ollama=FailingOllama())  # type: ignore[arg-type]
        hits = [_hit(1)]

        result = await summarizer.summarize("问题", hits)

        assert result == ""


class TestBuildContext:
    """_build_context 拼接格式：编号 / title / section_path / 文本"""

    def test_build_context_format(self):
        hits = [
            _hit(1, "文档A", "第一章"),
            _hit(2, "文档B", "第二章"),
        ]
        context = ResultSummarizer._build_context(hits)

        # 每条带编号、title、section_path
        assert "[1] / 文档A / 第一章" in context
        assert "[2] / 文档B / 第二章" in context
        # 文本内容拼接
        assert "文本内容-1" in context
        assert "文本内容-2" in context
        # 分隔符
        assert "---" in context

    def test_build_context_empty_title_and_section(self):
        """title 与 section_path 为空时头部仅保留编号"""
        hit = SearchHit(text="纯文本", doc_id="d1", title="", section_path="", score=1.0)
        context = ResultSummarizer._build_context([hit])
        assert context.strip().startswith("[1]")
        assert "纯文本" in context


class TestMaxHitsLimit:
    """取前 settings.result_summary_max_hits 条命中"""

    async def test_only_first_n_hits_in_prompt(self, monkeypatch: pytest.MonkeyPatch):
        """构造超过 max_hits 的 hits，验证 prompt 只含前 N 条文本"""
        max_hits = 3
        monkeypatch.setattr(settings, "result_summary_max_hits", max_hits)
        ollama = FakeOllama(response="总结")
        summarizer = ResultSummarizer(ollama=ollama)  # type: ignore[arg-type]

        # 构造 max_hits + 5 条 hits
        hits = [_hit(i) for i in range(max_hits + 5)]
        await summarizer.summarize("问题", hits)

        assert len(ollama.calls) == 1
        prompt = ollama.calls[0]["prompt"]
        # 前 max_hits 条文本出现在 prompt 中
        for i in range(max_hits):
            assert f"文本内容-{i}" in prompt
        # 超出的文本不出现在 prompt 中
        for i in range(max_hits, max_hits + 5):
            assert f"文本内容-{i}" not in prompt