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import { STATUS_TEXT } from "https://deno.land/std@0.89.0/http/http_status.ts";import { Context } from "../models/context.ts";import { assert } from "../deps_test.ts";
export async function acceptSSE(  context: Context,): Promise<(data: string, retry?: number) => Promise<number>> {  const { w: bufWriter } = context.request.serverRequest;
  const headers = context.response.headers;
  headers.append("Content-Type", "text/event-stream");  headers.append("Connection", "keep-alive");  headers.append("Cache-Control", "no-cache");
  const protoMajor = 1;  const protoMinor = 1;  const statusCode = context.response.status || 200;  const statusText = STATUS_TEXT.get(statusCode);
  let out = `HTTP/${protoMajor}.${protoMinor} ${statusCode} ${statusText}\r\n`;
  for (const [key, value] of headers) {    out += `${key}: ${value}\r\n`;  }  out += "\r\n";
  const header = new TextEncoder().encode(out);  let n = await bufWriter.write(header);  assert(header.byteLength == n);
  const encoder = new TextEncoder();  let id = 0;
  async function send(data: string, retry: number = 1000): Promise<number> {    const _data = data.split("\n");
    let msg: string = "";
    msg += `retry: ${retry}\n`;
    _data.forEach((str) => {      msg += `data: ${str}\n`;    });
    msg += `id: ${id}\n\n`;
    const body = encoder.encode(msg);
    try {      const n = await bufWriter.write(body);      await bufWriter.flush();      assert(n == body.byteLength);      id++;      return n;    } catch (err) {      return -1;    }  }
  return send;}