from __future__ import annotations

import sys
import unittest
from pathlib import Path
from types import SimpleNamespace

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from core.loop import AgentLoop, _is_empty_response  # noqa: E402


def _resp_empty(content=None):
    """空响应桩:无 tool_calls,content 为空/None/空白。"""
    msg = SimpleNamespace(tool_calls=[], content=content)
    return SimpleNamespace(choices=[SimpleNamespace(message=msg)], usage=None)


def _resp_text(text):
    """正常文本收尾桩:无 tool_calls 但有正文。"""
    msg = SimpleNamespace(tool_calls=[], content=text)
    return SimpleNamespace(choices=[SimpleNamespace(message=msg)], usage=None)


def _resp_tool():
    """纯 tool_call 轮桩:有 tool_calls、content 空 —— 不算空响应。"""
    tc = SimpleNamespace(function=SimpleNamespace(name="glob", arguments='{"pattern":"*"}'))
    msg = SimpleNamespace(tool_calls=[tc], content=None)
    return SimpleNamespace(choices=[SimpleNamespace(message=msg)], usage=None)


def _make_loop(stream_results, nonstream_results):
    loop = object.__new__(AgentLoop)
    loop.caps = SimpleNamespace(reliable_context=64_000, family="test", variant="t")
    loop.session = SimpleNamespace(messages=[], task_id="test-task")
    loop.user_id = "test-user"  # 无 DB:_log_empty_response 落库路径静默跳过
    loop.events = []
    loop._emit = loop.events.append
    calls = {"stream": 0, "nonstream": 0}

    def collect_stream_once(llm_messages):
        calls["stream"] += 1
        return stream_results.pop(0), False

    def nonstream_once(llm_messages):
        calls["nonstream"] += 1
        return nonstream_results.pop(0)

    loop._collect_stream_once = collect_stream_once
    loop._nonstream_once = nonstream_once
    return loop, calls


class TestIsEmptyResponse(unittest.TestCase):
    def test_empty_empty_is_empty(self):
        self.assertTrue(_is_empty_response(_resp_empty(None)))
        self.assertTrue(_is_empty_response(_resp_empty("")))
        self.assertTrue(_is_empty_response(_resp_empty("   \n\t ")))

    def test_text_answer_not_empty(self):
        self.assertFalse(_is_empty_response(_resp_text("这是最终回答")))

    def test_pure_tool_call_round_not_empty(self):
        # 纯工具调用轮(content 空但有 tool_calls)是正常轮,绝不能误判为空响应
        self.assertFalse(_is_empty_response(_resp_tool()))

    def test_malformed_response_shape_is_safe(self):
        # 畸形 / 缺字段的桩不应抛,只返 False
        self.assertFalse(_is_empty_response(SimpleNamespace(choices=[])))
        self.assertFalse(_is_empty_response(SimpleNamespace()))


class TestEmptyResponseRetry(unittest.TestCase):
    def test_empty_stream_falls_back_to_nonstream(self):
        """空响应首败即降级非流式,重发拿到正文 → 恢复,1 条 warn 提「非流式」。"""
        loop, calls = _make_loop([_resp_empty()], [_resp_text("ok")])
        resp, cancelled = loop._stream_llm()
        self.assertFalse(cancelled)
        self.assertFalse(_is_empty_response(resp))
        self.assertEqual(calls, {"stream": 1, "nonstream": 1})
        warns = [e for e in loop.events if e.get("type") == "warn"]
        self.assertEqual(len(warns), 1)
        self.assertIn("空响应", warns[0]["msg"])
        self.assertIn("非流式", warns[0]["msg"])
        # 每 attempt 重发 llm_start,让前端占位段重建
        starts = [e for e in loop.events if e.get("type") == "llm_start"]
        self.assertEqual(len(starts), 2)

    def test_all_attempts_empty_returns_empty(self):
        """全部尝试仍空 → 返回最后一次空 response(交 run() 收尾分支 warn 自停),不死循环。"""
        n_nonstream = AgentLoop._MAX_MALFORMED_ATTEMPTS - 1
        loop, calls = _make_loop([_resp_empty()], [_resp_empty()] * n_nonstream)
        resp, cancelled = loop._stream_llm()
        self.assertFalse(cancelled)
        self.assertTrue(_is_empty_response(resp))
        self.assertEqual(calls, {"stream": 1, "nonstream": n_nonstream})
        warns = [e for e in loop.events if e.get("type") == "warn"]
        self.assertEqual(len(warns), AgentLoop._MAX_MALFORMED_ATTEMPTS)

    def test_clean_text_no_retry(self):
        """正常文本收尾轮不触发重试。"""
        loop, calls = _make_loop([_resp_text("done")], [])
        resp, cancelled = loop._stream_llm()
        self.assertFalse(cancelled)
        self.assertEqual(calls, {"stream": 1, "nonstream": 0})
        self.assertEqual([e for e in loop.events if e.get("type") == "warn"], [])


if __name__ == "__main__":
    unittest.main()