import { expect, test } from 'vitest';

import { readCreationAgentSessionFromSse } from './creationAgentSse';

function createChunkedStreamResponse(chunks: Uint8Array[]) {
  const stream = new ReadableStream<Uint8Array>({
    start(controller) {
      for (const chunk of chunks) {
        controller.enqueue(chunk);
      }
      controller.close();
    },
  });

  return new Response(stream, {
    headers: {
      'Content-Type': 'text/event-stream; charset=utf-8',
    },
  });
}

test('readCreationAgentSessionFromSse flushes decoder tail and handles CRLF boundaries', async () => {
  const encoder = new TextEncoder();
  const prefix = encoder.encode('event: reply_delta\r\ndata: {"text":"');
  const replyTextBytes = encoder.encode('你好，潮雾列岛');
  const suffix = encoder.encode(
    '"}\r\n\r\nevent: session\r\ndata: {"session":{"sessionId":"session-1","title":"世界共创"}}\r\n\r\n',
  );
  const splitIndex = replyTextBytes.length - 1;

  const chunks = [
    new Uint8Array([...prefix, ...replyTextBytes.slice(0, splitIndex)]),
    new Uint8Array([...replyTextBytes.slice(splitIndex), ...suffix]),
  ];

  const updates: string[] = [];
  const session = await readCreationAgentSessionFromSse<{
    sessionId: string;
    title: string;
  }>(createChunkedStreamResponse(chunks), {
    fallbackMessage: '发送失败',
    incompleteMessage: '结果不完整',
    onUpdate: (text) => {
      updates.push(text);
    },
  });

  expect(updates).toEqual(['你好，潮雾列岛']);
  expect(session).toEqual({
    sessionId: 'session-1',
    title: '世界共创',
  });
});