// The AI-SDK streaming shape exactly: response.body → TextDecoderStream →
// EventSourceParserStream (the real eventsource-parser package, embedded)
// → for await, against the harness's local SSE route. Byte-exact vs Node.
import { EventSourceParserStream } from "eventsource-parser/stream";

const out = (line) => process.stdout.write(line + "\n");

export function runSse(base) {
  (async () => {
    const res = await fetch(base + "/sse");
    out(`sse ${res.status} ${res.headers.get("content-type")}`);
    const events = res.body
      .pipeThrough(new TextDecoderStream())
      .pipeThrough(new EventSourceParserStream());
    for await (const ev of events) {
      out(`event ${JSON.stringify(ev.event === undefined ? null : ev.event)} ${JSON.stringify(ev.data)} ${JSON.stringify(ev.id === undefined ? null : ev.id)}`);
    }
    out("sse-done");
  })().catch((e) => {
    out(`FATAL ${e}`);
  });
}