Generated by XState Viz: https://xstate.js.org/viz

machine.js

  // Available variables:
  // - Machine
  // - interpret
  // - assign
  // - send
  // - sendParent
  // - spawn
  // - raise
  // - actions
  // - XState (all XState exports)
const ProgramChangeEvents = {
    UserChanged: "USER_CHANGED",
    DeviceChanged: "DEVICE_CHANGED",
    Error: "UNKNOWN_MESSAGE",
}  

const {log} = actions;

const initialDeviceState = "All-Around";
const initialAppState = "All-Around";

const ProgramSyncMachine = Machine({
        id: "ProgramSyncMachine",
        initial: "idle",
        context: {
            device: initialDeviceState,
            app: initialAppState,
        },
        states: {
            idle: {
                on: {
                    [ProgramChangeEvents.UserChanged]: 'pending',
                    [ProgramChangeEvents.DeviceChanged]: {
                        target: "idle",
                        actions: ["assignDevice", "notifyDeviceChanged"],
                    }
                },
            },
            pending: {
                entry: ['assignApp', "updateDevice"],
                on: {
                    [ProgramChangeEvents.UserChanged]: {
                        target: 'pending', // external will re-trigger entry
                    },
                    [ProgramChangeEvents.DeviceChanged]: {
                        target: 'committed',
                        actions: 'assignDevice'
                    },
                    [ProgramChangeEvents.Error]: 'failed',
                }
            },
            committed: {
                on: {
                    "": [{
                        target: 'idle',
                        cond: "stateSynced",
                    }, {
                        target: 'pending',
                        cond: "stateMismatch",
                    }]
                }
            },
            failed: {
                on: {
                    [ProgramChangeEvents.UserChanged]: 'pending',
                    [ProgramChangeEvents.DeviceChanged]: {
                        target: "idle",
                        actions: ["notifyDeviceChanged", "assignDevice"],
                    }
                }
            },
        },
    }, {
        guards: {
            stateMismatch: (context) => {
                return context.app !== context.device
            },
            stateSynced: (context => {
                return context.app === context.device
            }),
        }, actions: {
            assignDevice: assign((context, event) => {
                console.log("assignDevice", event);
                if (event.type === ProgramChangeEvents.DeviceChanged) {
                    return ({device: event.program});
                }
                return context;
            }),
            assignApp: assign((context, event) => {
                console.log("assignApp", event);
                if (event.type === ProgramChangeEvents.UserChanged) {
                    return ({app: event.program});
                }
                return context;
            }),
            updateDevice: (context, event) => {
                //    TODO use hearing aid to set program
                console.log("updateDevice", event);
                if (context.device !== context.app) {
                    console.log(`Set device program: ${context.app}`);
                    // HearingAidBridge.setProgram(context.app);
                    new LivelyBridgeManager().setProgram(context.app)
                }
            },
            notifyDeviceChanged: log((context, event) => {
                //    TODO use event.program to notify the device is out of sync with app
                if (event.type === ProgramChangeEvents.DeviceChanged) {
                    return `Device changed: ${context.device} -> ${event.program}`;
                }
                return "No change"
            }),
        },
    });
    

const ProgramSwitchEvents ={
    SwitchProgram : "SWITCH_PROGRAM",
    ApplyProgram : "APPLY_PROGRAM",
    DeviceChanged : "DEVICE_CHANGED_PROGRAM",
    Error : "UNKNOWN_MESSAGE",
}

const State ={
    Active : "Active",
    Selected : "Selected",
    Selecting : "Selecting",
    WaitingForDevice : "WaitingForDevice",
    DeviceChanged : "DeviceChanged",
    DeviceDisconnected : "DeviceDisconnected",
    FailedToApply : "FailedToApply",
}

const Actions ={
    ApplySelectedProgram : "ApplySelectedProgram",
    UpdateActiveProgram : "UpdateActiveProgram",
}

const Guard = {
    NotAppliedYet : "NotAppliedYet",
    InSync : "InSync",
    OutOfSync : "OutOfSync",
}

    
    const ProgramSwitchingMachine = Machine({
        id: "ProgramSwitchMachine",
        initial: "idle",
        context: {
            device: initialDeviceState,
            app: initialAppState,
        },
        invoke: {
            id: "syncProgram",
            src: () => ProgramSyncMachine,
        },
        states: {
          idle: {},
        },
    });