/**
 * 验证 stdio 模式的标准输出只包含合法 JSON-RPC 消息，不混入诊断文本。
 *
 * @packageDocumentation
 */

import assert from "node:assert/strict";
import { spawn } from "node:child_process";
import path from "node:path";
import test from "node:test";
import { fileURLToPath } from "node:url";

test("stdio protocol mode writes only JSON-RPC messages to stdout", async () => {
  const packageRoot = path.resolve(fileURLToPath(new URL("..", import.meta.url)));
  const child = spawn(process.execPath, ["--import", "tsx", "test/stdioFixture.ts"], {
    cwd: packageRoot,
    shell: false,
    windowsHide: true,
    stdio: ["pipe", "pipe", "pipe"],
  });
  let stdout = "";
  let stderr = "";
  child.stdout.setEncoding("utf8").on("data", (chunk) => { stdout += String(chunk); });
  child.stderr.setEncoding("utf8").on("data", (chunk) => { stderr += String(chunk); });
  const messages = [
    { jsonrpc: "2.0", id: 1, method: "initialize", params: { protocolVersion: "2025-11-25", capabilities: {}, clientInfo: { name: "stdio-test", version: "1.0.0" } } },
    { jsonrpc: "2.0", method: "notifications/initialized" },
    { jsonrpc: "2.0", id: 2, method: "tools/list", params: { cursor: "next" } },
  ];
  child.stdin.write(messages.map((message) => JSON.stringify(message)).join("\n") + "\n");
  await waitFor(() => stdout.split(/\r?\n/).filter(Boolean).some((line) => {
    try { return (JSON.parse(line) as { id?: number }).id === 2; } catch { return false; }
  }), 3000);
  child.stdin.end();
  await new Promise<void>((resolve) => {
    const timeout = setTimeout(() => { child.kill(); resolve(); }, 1000);
    child.once("close", () => { clearTimeout(timeout); resolve(); });
  });
  const lines = stdout.split(/\r?\n/).filter(Boolean);
  assert.ok(lines.length >= 2);
  const parsed = lines.map((line) => JSON.parse(line) as { jsonrpc: string; id?: number; result?: unknown });
  assert.ok(parsed.every((message) => message.jsonrpc === "2.0"));
  assert.ok(parsed.some((message) => message.id === 1));
  assert.ok(parsed.some((message) => message.id === 2));
  assert.equal(stderr, "");
});

async function waitFor(predicate: () => boolean, timeoutMs: number): Promise<void> {
  const started = Date.now();
  while (!predicate()) {
    if (Date.now() - started > timeoutMs) throw new Error("timed out waiting for stdio response");
    await new Promise((resolve) => setTimeout(resolve, 10));
  }
}