import assert from "node:assert/strict";
import { spawn } from "node:child_process";
import { mkdtemp, mkdir, readFile, writeFile } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";
export const root = path.resolve(
  path.dirname(fileURLToPath(import.meta.url)),
  "..",
);
export const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
export function options() {
  const opts = {};
  for (let i = 2; i < process.argv.length; i += 2)
    opts[process.argv[i].replace(/^--/, "")] = process.argv[i + 1];
  return opts;
}
export async function harness(opts = {}) {
  const port = Number(opts.port || 4001),
    url = `http://127.0.0.1:${port}`;
  try {
    await fetch(`${url}/api/health`, { signal: AbortSignal.timeout(500) });
    throw Error(
      `Port ${port} is already serving HTTP; choose an unused --port`,
    );
  } catch (error) {
    if (error.message?.includes("already serving")) throw error;
  }
  const data = opts.data
    ? path.resolve(opts.data)
    : await mkdtemp(path.join(os.tmpdir(), "shacraft-server-test-"));
  await mkdir(data, { recursive: true });
  let stderr = "";
  const binary = path.resolve(
    opts.binary || path.join(root, "target/debug/shacraft-server"),
  );
  const child = spawn(
    binary,
    [
      "--listen",
      `127.0.0.1:${port}`,
      "--data",
      data,
      "--client",
      path.join(root, "client"),
      "--packages",
      path.join(root, "packages"),
    ],
    { cwd: root, stdio: ["ignore", "pipe", "pipe"] },
  );
  child.stdout.on("data", (chunk) => (stderr += chunk));
  child.stderr.on("data", (chunk) => (stderr += chunk));
  let failure;
  child.on("error", (e) => (failure = e));
  const running = () =>
    child.exitCode === null && child.signalCode === null && !failure;
  async function kill(signal = "SIGKILL") {
    if (!running()) return;
    const exited = new Promise((resolve) => child.once("exit", resolve));
    async function waitForExit() {
      let timer;
      await Promise.race([
        exited,
        new Promise((resolve) => {
          timer = setTimeout(resolve, 5000);
        }),
      ]);
      clearTimeout(timer);
    }
    child.kill(signal);
    await waitForExit();
    if (running()) {
      child.kill("SIGKILL");
      await waitForExit();
    }
    if (running()) throw Error("Test server did not exit after SIGKILL");
  }
  async function stop() {
    await kill("SIGINT");
  }
  try {
    const deadline = Date.now() + 45000;
    while (true) {
      if (failure) throw failure;
      if (!running()) throw Error(`Server exited: ${stderr}`);
      try {
        if ((await fetch(`${url}/api/health`)).ok) break;
      } catch {}
      if (Date.now() > deadline)
        throw Error(`Server startup timeout: ${stderr}`);
      await delay(100);
    }
  } catch (e) {
    await stop();
    throw e;
  }
  const token = (
    await readFile(path.join(data, "control.token"), "utf8")
  ).trim();
  async function get(route) {
    const r = await fetch(url + route);
    assert.equal(r.status, 200, `${route}: HTTP ${r.status}`);
    return r.json();
  }
  async function control(method, params = {}) {
    const response = await fetch(url + "/api/control", {
      method: "POST",
      headers: {
        Authorization: `Bearer ${token}`,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ method, params }),
    });
    const body = await response.json();
    if (!response.ok || body.error)
      throw Error(`${method}: ${body.error || response.status}`);
    return body.result;
  }
  return {
    url,
    data,
    pid: child.pid,
    binary,
    get,
    control,
    stop,
    kill,
    logs: () => stderr,
    async report(value) {
      const output = opts.output
        ? path.resolve(opts.output)
        : path.join(data, "report.json");
      await mkdir(path.dirname(output), { recursive: true });
      await writeFile(output, JSON.stringify(value, null, 2) + "\n");
      console.log(
        JSON.stringify(
          {
            ...value,
            samples: undefined,
            sample_count: value.samples?.length,
            report_file: output,
            data,
          },
          null,
          2,
        ),
      );
    },
  };
}
export class Client {
  constructor(url) {
    this.ws = new WebSocket(url.replace(/^http/, "ws") + "/ws");
    this.queue = [];
    this.waiters = [];
    this.id = null;
    this.seq = 0;
    this.latest = null;
    this.revision = null;
    this.error = null;
    this.open = new Promise((resolve, reject) => {
      this.ws.addEventListener("open", resolve, { once: true });
      this.ws.addEventListener(
        "error",
        () => reject(Error("WebSocket connection failed")),
        { once: true },
      );
    });
    this.ws.addEventListener("message", (event) => {
      let m;
      try {
        m = JSON.parse(event.data);
      } catch {
        return;
      }
      if (m.type === "state") this.latest = m;
      if (m.type === "welcome") {
        this.id = m.id;
        this.welcome = m;
      }
      if (["welcome", "snapshot", "blocks"].includes(m.type))
        this.revision = m.revision;
      for (let i = 0; i < this.waiters.length; i++) {
        const w = this.waiters[i];
        if (w.predicate(m)) {
          this.waiters.splice(i, 1);
          clearTimeout(w.timer);
          w.resolve(m);
          return;
        }
      }
      this.queue.push(m);
      if (this.queue.length > 500) this.queue.shift();
    });
  }
  send(message) {
    this.ws.send(JSON.stringify(message));
  }
  async join(manifest, world, name = "TestPlayer") {
    await this.open;
    this.send({
      type: "join",
      protocol: 1,
      manifest_hash: manifest.hash,
      world,
      name,
    });
    return this.next("welcome");
  }
  next(type, predicate = () => true, timeout = 10000) {
    return this.wait((m) => m.type === type && predicate(m), timeout);
  }
  wait(predicate, timeout = 10000) {
    const i = this.queue.findIndex(predicate);
    if (i >= 0) return Promise.resolve(this.queue.splice(i, 1)[0]);
    return new Promise((resolve, reject) => {
      const w = {
        predicate,
        resolve,
        timer: setTimeout(() => {
          this.waiters = this.waiters.filter((x) => x !== w);
          reject(Error(`WebSocket message timeout (${timeout} ms)`));
        }, timeout),
      };
      this.waiters.push(w);
    });
  }
  input(fields = {}) {
    const input = {
      type: "input",
      seq: ++this.seq,
      yaw: 0,
      pitch: 0,
      forward: 0,
      strafe: 0,
      jump: false,
      ...fields,
    };
    this.send(input);
    return input.seq;
  }
  async state(predicate = () => true, timeout = 10000) {
    return this.next(
      "state",
      (m) =>
        predicate(
          m.players.find((p) => p.id === this.id),
          m,
        ),
      timeout,
    );
  }
  async close() {
    if (this.ws.readyState === WebSocket.CLOSED) return;
    const closed = new Promise((resolve) =>
      this.ws.addEventListener("close", resolve, { once: true }),
    );
    this.ws.close();
    await Promise.race([closed, delay(2000)]);
  }
}