const CONTROL_COMMANDS = Object.freeze({
  run: "PROGRAM_RUN",
  pause: "PROGRAM_PAUSE",
  resume: "PROGRAM_RESUME",
  abort: "PROGRAM_ABORT",
  mdi: "COMMAND",
  jogStart: "JOG_START",
  jogStop: "JOG_STOP",
  home: "HOME",
  override: "SET_OVERRIDE",
  estop: "ESTOP",
  recover: "IO_RECOVER",
});

function operationId(kind, payload, counter) {
  const identity = JSON.stringify(payload, Object.keys(payload ?? {}).sort()).replace(/[^A-Za-z0-9]+/g, "-").slice(0, 40);
  return `ui-${kind.toLowerCase()}-${counter}${identity ? `-${identity}` : ""}`;
}

export class CommandController {
  constructor(client) {
    if (!client || typeof client.send !== "function") throw new Error("command_client_required");
    this.client = client;
    this.counter = 0;
    this.busy = new Set();
  }

  async execute(action, payload = {}, { operationId: supplied = null } = {}) {
    const kind = CONTROL_COMMANDS[action];
    if (!kind) throw new Error("command_action_unknown");
    const id = supplied ?? operationId(kind, payload, ++this.counter);
    if (this.busy.has(id)) throw new Error("command_operation_busy");
    this.busy.add(id);
    try {
      return await this.client.send(kind, payload, { operationId: id });
    } finally {
      this.busy.delete(id);
    }
  }
}

export { CONTROL_COMMANDS };