import asyncio
import json
import unittest
from unittest.mock import patch

import backend.main as main


def parse_sse(event):
    assert event.startswith("data: ")
    return json.loads(event[6:].strip())


class AnalyzeProcessStreamTest(unittest.TestCase):
    def test_analysis_stream_emits_visible_process_steps_before_content(self):
        async def fake_stream(report, question=""):
            yield "分析结论"

        async def collect_events():
            main._last_diagnosis = {"score": 80}
            main._last_report = "diagnosis report"
            with patch.object(main, "analyze_with_ai_stream", fake_stream):
                response = await main.analyze_stream(question="关注严重问题")
                return [parse_sse(event) async for event in response.body_iterator]

        events = asyncio.run(collect_events())
        process_events = [event for event in events if event["type"] == "process"]

        self.assertEqual(
            [event["status"] for event in process_events],
            ["running", "done", "running", "done", "running", "done", "running", "done"],
        )
        self.assertEqual(
            [event["title"] for event in process_events[::2]],
            ["读取诊断报告", "识别关键风险", "生成修复方案", "整理分析结论"],
        )
        first_chunk_index = next(i for i, event in enumerate(events) if event["type"] == "chunk")
        final_process_index = max(i for i, event in enumerate(events) if event["type"] == "process")
        self.assertLess(final_process_index, first_chunk_index)
        self.assertEqual(events[-1]["type"], "done")


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