// harness/tests/fake_pi/test_fake_pi_contract.mjs  — run: node --test
import test from "node:test";
import assert from "node:assert";
import { spawn } from "node:child_process";
import path from "node:path";

function drive(scriptPath, commands) {
  return new Promise((resolve) => {
    const fp = spawn("node", [path.join(import.meta.dirname, "fake_pi_rpc.mjs"), scriptPath]);
    const events = []; let buf = "";
    fp.stdout.on("data", (c) => {
      buf += c.toString("utf8");
      for (let nl; (nl = buf.indexOf("\n")) !== -1; ) {
        const line = buf.slice(0, nl).replace(/\r$/, ""); buf = buf.slice(nl + 1);
        if (line) events.push(JSON.parse(line));
      }
    });
    fp.on("exit", () => resolve(events));
    for (const cmd of commands) fp.stdin.write(JSON.stringify(cmd) + "\n");
    setTimeout(() => fp.stdin.end(), 300);
  });
}

test("on prompt emette il widget F1; on response avanza", async () => {
  const sp = path.join(import.meta.dirname, "scripts/f1_disambiguation.json");
  const events = await drive(sp, [
    { type: "prompt", message: "/nuova-domanda \"x\"" },
    { type: "extension_ui_response", id: "u1",
      value: JSON.stringify({ id: "u1", choices: ["a"], decision: { type: "concept_clarified" } }) },
  ]);
  const widget = events.find((e) => e.type === "extension_ui_request");
  assert.equal(widget.method, "input");          // shape nativa di Pi
  assert.equal(widget.id, "u1");
  const descriptor = JSON.parse(widget.title);    // il descriptor viaggia nel title
  assert.equal(descriptor.widget, "select");
  assert.equal(descriptor.id, "u1");
  assert.ok(events.some((e) => e.type === "agent_end"));
});