import { NodeSSH } from "node-ssh";

const SSH_TIMEOUT = 15000;
const sshConnections = new Map();

async function getConnection(host, username = "root") {
  const key = username + "@" + host;
  if (sshConnections.has(key)) {
    const conn = sshConnections.get(key);
    if (conn.isConnected()) return conn;
    sshConnections.delete(key);
  }
  const ssh = new NodeSSH();
  await ssh.connect({
    host,
    username,
    privateKeyPath: "/root/.ssh/id_ed25519",
    readyTimeout: SSH_TIMEOUT
  });
  sshConnections.set(key, ssh);
  return ssh;
}

const SE_APPMANIFEST = "/opt/spaceengineers/appdata/space-engineers/bins/SpaceEngineersDedicated/steamapps/appmanifest_298740.acf";

async function getSpaceEngineersVersion(server) {
  const ssh = await getConnection(server.host, server.sshUser);
  const result = await ssh.execCommand(`cat ${SE_APPMANIFEST} 2>/dev/null`);
  const text = result.stdout || "";
  if (!text) return null;

  const buildidMatch = text.match(/"buildid"\s*"([^"]+)"/);
  const lastUpdatedMatch = text.match(/"LastUpdated"\s*"([^"]+)"/);
  const targetBuildMatch = text.match(/"TargetBuildID"\s*"([^"]+)"/);

  const buildid = buildidMatch ? buildidMatch[1] : null;
  const lastUpdatedUnix = lastUpdatedMatch ? parseInt(lastUpdatedMatch[1], 10) : null;
  const targetBuild = targetBuildMatch ? targetBuildMatch[1] : null;

  if (!buildid) return null;

  return {
    version: buildid,
    lastUpdated: lastUpdatedUnix ? new Date(lastUpdatedUnix * 1000).toISOString() : null,
    updatePending: targetBuild && targetBuild !== "0" && targetBuild !== buildid ? targetBuild : null,
    source: "steam-appmanifest"
  };
}

const versionHandlers = {
  spaceengineers: getSpaceEngineersVersion
};

const versionCache = new Map();
const CACHE_TTL_MS = 60_000;

export function supportsVersionInfo(serverType) {
  return !!versionHandlers[serverType];
}

export function invalidateVersionCache(serverId) {
  versionCache.delete(serverId);
}

export async function getVersionInfo(server) {
  const handler = versionHandlers[server.type];
  if (!handler) return null;

  const cached = versionCache.get(server.id);
  if (cached && Date.now() - cached.fetchedAt < CACHE_TTL_MS) {
    return cached.data;
  }

  const data = await handler(server);
  if (data) {
    versionCache.set(server.id, { data, fetchedAt: Date.now() });
  }
  return data;
}