sprinklers3/common/sprinklersRpc/ConnectionState.ts

import { computed, observable } from "mobx";

export class ConnectionState {
    /**
     * Represents if a client is connected to the sprinklers3 server (eg. via websocket)
     * Can be null if there is no client involved
     */
    @observable clientToServer: boolean | null = null;

    /**
     * Represents if the sprinklers3 server is connected to the broker (eg. via mqtt)
     * Can be null if there is no broker involved
     */
    @observable serverToBroker: boolean | null = null;

    /**
     * Represents if the device is connected to the broker and we can communicate with it (eg. via mqtt)
     * Can be null if there is no device involved
     */
    @observable brokerToDevice: boolean | null = null;

    /**
     * Represents if whoever is trying to access this device has permission to access it.
     * Is null if there is no concept of access involved.
     */
    @observable hasPermission: boolean | null = null;

    @computed get noPermission() {
        return this.hasPermission === false;
    }

    @computed get isAvailable(): boolean {
        if (this.hasPermission === false) {
            return false;
        }
        if (this.brokerToDevice != null) {
            return true;
        }
        if (this.serverToBroker != null) {
            return this.serverToBroker;
        }
        if (this.clientToServer != null) {
            return this.clientToServer;
        }
        return false;
    }

    @computed get isDeviceConnected(): boolean | null {
        if (this.hasPermission === false) {
            return false;
        }
        if (this.serverToBroker === false || this.clientToServer === false) {
            return null;
        }
        if (this.brokerToDevice != null) {
            return this.brokerToDevice;
        }
        return null;
    }

    @computed get isServerConnected(): boolean | null {
        if (this.hasPermission === false) {
            return false;
        }
        if (this.serverToBroker != null) {
            return this.serverToBroker;
        }
        if (this.clientToServer != null) {
            return this.brokerToDevice;
        }
        return null;
    }
}