// @vitest-environment node
// sse/parser.test.js —— SSE 解析器单测（多行 data / 注释帧 / 无 event 名 / CRLF / 分块 UTF-8）
import { describe, it, expect, vi } from 'vitest';
import { parseFrame, SseParser, consumeSseStream } from '../../../../ui/src/sse/parser.js';

describe('parseFrame', () => {
  it('解析单行 data 与 event 名', () => {
    const ev = parseFrame('event: progress\ndata: {"phase":"planning"}\n');
    expect(ev.event).toBe('progress');
    expect(ev.data).toEqual({ phase: 'planning' });
  });

  it('多行 data 按 \\n 合并后 JSON 解析', () => {
    const ev = parseFrame('data: {"a":1,\ndata: "b":2}\n');
    expect(ev.data).toEqual({ a: 1, b: 2 });
    expect(ev.dataStr).toBe('{"a":1,\n"b":2}');
  });

  it('注释帧（keepalive）返回 null', () => {
    expect(parseFrame(': ping\n')).toBeNull();
    expect(parseFrame(': 任何注释\n: 再来一行\n')).toBeNull();
  });

  it('无 event 名时默认 message', () => {
    const ev = parseFrame('data: {"x":1}\n');
    expect(ev.event).toBe('message');
    expect(ev.data).toEqual({ x: 1 });
  });

  it('CRLF 行尾与空行容忍', () => {
    const ev = parseFrame('event: complete\r\ndata: {"ok":true}\r\n');
    expect(ev.event).toBe('complete');
    expect(ev.data).toEqual({ ok: true });
  });

  it('非 JSON data 保留原字符串', () => {
    const ev = parseFrame('data: 纯文本\n');
    expect(ev.data).toBe('纯文本');
    expect(ev.dataStr).toBe('纯文本');
  });

  it('无 data 行返回 null；冒号后仅去一个空格', () => {
    expect(parseFrame('event: progress\n')).toBeNull();
    const ev = parseFrame('data:  保留多余空格\n');
    expect(ev.dataStr).toBe(' 保留多余空格');
  });
});

describe('SseParser（增量）', () => {
  it('跨 chunk 截断的完整帧', () => {
    const got = [];
    const p = new SseParser({ onEvent: (ev) => got.push(ev) });
    p.feed('event: progress\nda');
    p.feed('ta: {"phase":"planning"}\n\n');
    p.end();
    expect(got).toHaveLength(1);
    expect(got[0].event).toBe('progress');
    expect(got[0].data).toEqual({ phase: 'planning' });
  });

  it('多字节 UTF-8 字符跨 chunk 不丢字', () => {
    const got = [];
    const p = new SseParser({ onEvent: (ev) => got.push(ev) });
    const text = JSON.stringify({ label: '证据审核完成' });
    const bytes = new TextEncoder().encode(`data: ${text}\n\n`);
    p.feed(bytes.slice(0, 5));
    p.feed(bytes.slice(5));
    p.end();
    expect(got[0].data.label).toBe('证据审核完成');
  });

  it('注释帧被忽略、CRLF 帧正常', () => {
    const got = [];
    const p = new SseParser({ onEvent: (ev) => got.push(ev) });
    p.feed(': ping\n\n');
    p.feed('event: timeout\r\ndata: {"message":"检索超时"}\r\n\r\n');
    p.end();
    expect(got).toHaveLength(1);
    expect(got[0].event).toBe('timeout');
    expect(got[0].data.message).toBe('检索超时');
  });

  it('一 chunk 多帧', () => {
    const got = [];
    const p = new SseParser({ onEvent: (ev) => got.push(ev) });
    p.feed('data: {"a":1}\n\ndata: {"b":2}\n\n: ping\n\n');
    p.end();
    expect(got.map((e) => e.data)).toEqual([{ a: 1 }, { b: 2 }]);
  });
});

describe('consumeSseStream', () => {
  const chunkStream = (chunks) => {
    const enc = new TextEncoder();
    let i = 0;
    return {
      body: {
        getReader() {
          return {
            read: vi.fn(async () => (i < chunks.length ? { done: false, value: enc.encode(chunks[i++]) } : { done: true })),
            releaseLock: vi.fn(),
          };
        },
      },
    };
  };

  it('消费完整流并逐帧回调', async () => {
    const got = [];
    const resp = chunkStream([
      'event: progress\ndata: {"phase":"planning"}\n\n',
      ': ping\n\n',
      'event: complete\ndata: {"answer":"好"}\n\n',
    ]);
    await consumeSseStream(resp, (ev) => got.push(ev));
    expect(got.map((e) => e.event)).toEqual(['progress', 'complete']);
    expect(got[1].data.answer).toBe('好');
  });

  it('非流响应抛错', async () => {
    await expect(consumeSseStream({ body: null }, () => {})).rejects.toThrow(/readable stream/);
  });
});