import assert from "node:assert/strict";
import { spawn } from "node:child_process";
import type { ChildProcessWithoutNullStreams } from "node:child_process";
import { once } from "node:events";
import { createServer } from "node:net";
import { fileURLToPath } from "node:url";
import test from "node:test";

import { TestWebSocketPeer } from "./websocket-peer.ts";

const repositoryRoot = fileURLToPath(new URL("..", import.meta.url));
const executable = fileURLToPath(
  new URL("../bin/codex-app-server-bridge.js", import.meta.url),
);

type RunningBridge = Readonly<{
  child: ChildProcessWithoutNullStreams;
  stdout: string[];
  stderr: string[];
}>;

function startBridge(port: number, arguments_: string[] = ["app-server"]): RunningBridge {
  const child = spawn(process.execPath, [executable, ...arguments_], {
    cwd: repositoryRoot,
    env: {
      ...process.env,
      CODEX_APP_SERVER_URL: `ws://127.0.0.1:${port}`,
    },
    stdio: ["pipe", "pipe", "pipe"],
  });
  const stdout: string[] = [];
  const stderr: string[] = [];
  child.stdout.setEncoding("utf8");
  child.stderr.setEncoding("utf8");
  child.stdout.on("data", (chunk: string) => stdout.push(chunk));
  child.stderr.on("data", (chunk: string) => stderr.push(chunk));
  return { child, stdout, stderr };
}

async function waitForExit(bridge: RunningBridge): Promise<{
  code: number | null;
  signal: NodeJS.Signals | null;
}> {
  const [code, signal] = await once(bridge.child, "exit");
  return { code: code as number | null, signal: signal as NodeJS.Signals | null };
}

async function unusedPort(): Promise<number> {
  const server = createServer();
  server.listen(0, "127.0.0.1");
  await once(server, "listening");
  const address = server.address();
  if (address === null || typeof address === "string") {
    throw new Error("temporary server did not receive a TCP port");
  }
  const { port } = address;
  server.close();
  await once(server, "close");
  return port;
}

test("unsupported arguments fail without opening a socket", async (context) => {
  const peer = await TestWebSocketPeer.start();
  context.after(async () => peer.stop());

  for (const arguments_ of [[], ["other"], ["app-server", "extra"]]) {
    const bridge = startBridge(peer.port, arguments_);
    const result = await waitForExit(bridge);
    assert.equal(result.code, 1);
    assert.match(bridge.stderr.join(""), /Usage: codex-app-server-bridge app-server/);
  }
  assert.equal(peer.connections.length, 0);
});

test("startup input is preserved and duplex payload text stays ordered", async (context) => {
  const peer = await TestWebSocketPeer.start({ handshakeDelayMs: 100 });
  context.after(async () => peer.stop());
  const bridge = startBridge(peer.port);
  const initialize = '{"jsonrpc":"2.0","id":1,"method":"initialize"}';
  const logout = '{"jsonrpc":"2.0","id":2,"method":"account/logout","secret":"never-log-me"}';

  bridge.child.stdin.write(`${initialize}\n\n   \n${logout}\n`);
  const connection = await peer.nextConnection();
  await once(connection, "text");
  if (connection.textFrames.length < 2) {
    await once(connection, "text");
  }
  assert.deepEqual(connection.textFrames, [initialize, logout]);

  const responseOne = '{"jsonrpc":"2.0","id":1,"result":{"ready":true}}';
  const responseTwo = '{"jsonrpc":"2.0","id":2,"result":null}';
  connection.sendText(responseOne);
  connection.sendText(responseTwo);
  while (!bridge.stdout.join("").includes(responseTwo)) {
    await once(bridge.child.stdout, "data");
  }
  assert.equal(bridge.stdout.join(""), `${responseOne}\n${responseTwo}\n`);

  bridge.child.stdin.end();
  const result = await waitForExit(bridge);
  assert.equal(result.code, 0);
  assert.equal(bridge.stderr.join(""), "");
});

test("binary frames are private fatal protocol errors", async (context) => {
  const peer = await TestWebSocketPeer.start();
  context.after(async () => peer.stop());
  const bridge = startBridge(peer.port);
  const connection = await peer.nextConnection();

  connection.sendBinary(Buffer.from("binary-secret"));
  const result = await waitForExit(bridge);
  assert.equal(result.code, 1);
  assert.equal(bridge.stdout.join(""), "");
  assert.match(bridge.stderr.join(""), /binary WebSocket frames are not supported/);
  assert.doesNotMatch(bridge.stderr.join(""), /binary-secret/);
});

test("unexpected remote closure is nonzero and does not reconnect", async (context) => {
  const peer = await TestWebSocketPeer.start();
  context.after(async () => peer.stop());
  const bridge = startBridge(peer.port);
  const connection = await peer.nextConnection();

  connection.close();
  const result = await waitForExit(bridge);
  assert.equal(result.code, 1);
  assert.match(bridge.stderr.join(""), /connection closed unexpectedly/);
  await new Promise((resolve) => setTimeout(resolve, 50));
  assert.equal(peer.connections.length, 1);
});

test("connection refusal is sanitized and nonzero", async () => {
  const port = await unusedPort();
  const bridge = startBridge(port);
  bridge.child.stdin.write('{"secret":"must-not-appear"}\n');
  const result = await waitForExit(bridge);

  assert.equal(result.code, 1);
  assert.match(bridge.stderr.join(""), new RegExp(`connection error for ws://127\\.0\\.0\\.1:${port}`));
  assert.doesNotMatch(bridge.stderr.join(""), /must-not-appear/);
});

test("a stalled handshake fails at the five-second startup deadline", async (context) => {
  const peer = await TestWebSocketPeer.start({ completeHandshake: false });
  context.after(async () => peer.stop());
  const bridge = startBridge(peer.port);
  const startedAt = Date.now();
  bridge.child.stdin.write('{"id":1,"secret":"timeout-secret"}\n');
  const result = await waitForExit(bridge);
  const elapsed = Date.now() - startedAt;

  assert.equal(result.code, 1);
  assert.ok(elapsed >= 4_800, `timeout fired too early after ${elapsed} ms`);
  assert.ok(elapsed < 7_000, `timeout fired too late after ${elapsed} ms`);
  assert.match(bridge.stderr.join(""), /startup timeout after 5000 ms/);
  assert.doesNotMatch(bridge.stderr.join(""), /timeout-secret/);
  assert.equal(peer.connections.length, 0);
});

test("stdin EOF stays successful when the peer aborts during local close", async (context) => {
  const peer = await TestWebSocketPeer.start();
  context.after(async () => peer.stop());
  const bridge = startBridge(peer.port);
  const connection = await peer.nextConnection();
  connection.abortOnCloseFrame = true;

  bridge.child.stdin.end();
  const result = await waitForExit(bridge);
  assert.equal(result.code, 0);
  assert.equal(result.signal, null);
  assert.equal(bridge.stderr.join(""), "");
});

for (const signal of ["SIGINT", "SIGTERM"] as const) {
  test(`${signal} closes locally with a zero exit`, async (context) => {
    const peer = await TestWebSocketPeer.start();
    context.after(async () => peer.stop());
    const bridge = startBridge(peer.port);
    const connection = await peer.nextConnection();
    const closeFrame = once(connection, "closeFrame");

    bridge.child.kill(signal);
    await closeFrame;
    const result = await waitForExit(bridge);
    assert.equal(result.code, 0);
    assert.equal(result.signal, null);
    assert.equal(bridge.stderr.join(""), "");
  });
}

test("two bridge processes use distinct connections and leave the peer alive", async (context) => {
  const peer = await TestWebSocketPeer.start();
  context.after(async () => peer.stop());
  const first = startBridge(peer.port);
  const second = startBridge(peer.port);

  first.child.stdin.write("first\n");
  second.child.stdin.write("second\n");
  while (peer.connections.length < 2) {
    await once(peer, "connection");
  }
  while (peer.connections.some((connection) => connection.textFrames.length === 0)) {
    await Promise.race(peer.connections.map(async (connection) => once(connection, "text")));
  }

  assert.equal(peer.connections.length, 2);
  assert.deepEqual(
    peer.connections.flatMap((connection) => connection.textFrames).sort(),
    ["first", "second"],
  );
  first.child.stdin.end();
  second.child.stdin.end();
  const [firstResult, secondResult] = await Promise.all([
    waitForExit(first),
    waitForExit(second),
  ]);
  assert.equal(firstResult.code, 0);
  assert.equal(secondResult.code, 0);
  assert.equal(peer.server.listening, true);
});