ioBroker: Sync Lovelace and Alexa Shopping Lists

syncShoppingLists.js

const shoppingListId = 'lovelace.0.control.shopping_list';
const alexa2BaseId = 'alexa2.0.Lists.SHOPPING_LIST'; //important. Needed for delete & update also.
const alexaAddToList = alexa2BaseId + '.#New';
const alexaListId = alexa2BaseId + '.json';

//switch off to silence:
const printDebug = true;

function debug(msg) {
    if (printDebug) {
        log(msg)
    }
}

const TodoItemStatus = {
    NeedsAction: 'needs_action',
    Completed: 'completed',
};

/**
 * @typedef lovelaceItem
 * @type {object}
 * @property {string} summary
 * @property {string} status
 * @property {string} uid
 * @property {boolean} [found] - keep track if found or not.
 */

/**
 * @typedef alexaItem
 * @type {object}
 * @property {string} value
 * @property {string} id
 * @property {boolean} completed
 * @property {number} updatedDateTime
 * @proerpty {boolean} [found] - keep track if found or not.
 */

/**
 * Compare alexaItem complete and lovelaceItem status -> returns true if same status.
 * @param {Array<alexaItem>} alexaList
 * @param {Array<lovelaceItem>} list
 * @returns {boolean} true if same status.
*/
function compareCompleted(alexaItem, lovelaceItem) {
    if (alexaItem.completed && lovelaceItem.status !== TodoItemStatus.Completed) {
        return false;
    }
    if (!alexaItem.completed && lovelaceItem.status !== TodoItemStatus.NeedsAction) {
        return false;
    }
    return true;
}

/**
 * sync lists
 * @param {Array<alexaItem>} alexaList
 * @param {Array<lovelaceItem>} list
 * @param {number} timestampLovelace
 * @returns {Array<lovelaceItem>} new lovelace List
 */
function syncLists(alexaList, list, timestampLovelace) {
    const newLovelaceList = [];
    for (const alexaItem of alexaList) {
        for (const lovelaceItem of list) {
            if (lovelaceItem.uid === alexaItem.id) {
                alexaItem.found = true;
                lovelaceItem.found = true;

                //found item. Update completed state from 'newer' list:            
                if (alexaItem.updatedDateTime > timestampLovelace) {
                    if (alexaItem.value !== lovelaceItem.summary || !compareCompleted(alexaItem, lovelaceItem)) {
                        debug('Updating ' + lovelaceItem.name + ' from alexa');
                    }
                    //update lovelace:
                    newLovelaceList.push({
                        summary: alexaItem.value,
                        status: alexaItem.completed ? TodoItemStatus.Completed : TodoItemStatus.NeedsAction,
                        uid: alexaItem.id
                    });
                } else {
                    //keep lovelace:
                    newLovelaceList.push({
                        summary: lovelaceItem.summary,
                        status: lovelaceItem.status,
                        uid: alexaItem.id
                    });

                    //update alexa:
                    if (!compareCompleted(alexaItem, lovelaceItem)) {
                        debug('Update ' + alexaItem.value + ' to ' + (lovelaceItem.status === TodoItemStatus.Completed ? 'done' : 'undone') + ' from lovelace.');
                        setState(`${alexa2BaseId}.items.${alexaItem.id}.completed`, lovelaceItem.status === TodoItemStatus.Completed);
                    }
                    if (alexaItem.value !== lovelaceItem.summary) {
                        debug('Update ' + alexaItem.value + ' to ' + lovelaceItem.summary + ' from lovelace');
                        setState(`${alexa2BaseId}.items.${alexaItem.id}.value`, lovelaceItem.summary);
                    }
                }
            }
        }

        if (!alexaItem.found) {
            //alexa item not found:
            if (alexaItem.completed) {
                //if completed and not in lovelace -> remove.
                debug('Delete ' + alexaItem.value + ' because done and not in lovelace list.');
                setState(`${alexa2BaseId}.items.${alexaItem.id}.#delete`, true);
            } else {
                debug('Add ' + alexaItem.value + ' to lovelace list');
                newLovelaceList.push({
                    summary: alexaItem.value,
                    status: alexaItem.completed ? TodoItemStatus.Completed : TodoItemStatus.NeedsAction,
                    uid: alexaItem.id
                });
            }
        }
    }

    for (const lovelaceItem of list) {
        if (!lovelaceItem.found) {
            if (lovelaceItem.status === TodoItemStatus.Completed) {
                debug('Delete ' + lovelaceItem.summary + ' because done and not on alexa list');
            } else {
                //this will add a new entry to alexa list.
                //of course ids won't match. So we will not keep the item in lovelace at this place
                //but it will be re-added once it traveled through the alexa ecosystem.
                debug('Adding ' + lovelaceItem.summary + ' to alexa list.');
                setState(alexaAddToList, lovelaceItem.summary);
            }
        }
    }

    return newLovelaceList;
}

function doSync() {
    const alexaList = JSON.parse(getState(alexaListId).val);
    const state = getState(shoppingListId);
    const lovelaceList = JSON.parse(state.val);
    const newList = syncLists(alexaList, lovelaceList, state.ts);
    setState(shoppingListId, JSON.stringify(newList));
}


on({id: shoppingListId, ack: true}, e => {
    debug('Got shopping list update: ' + e.state.val);
    doSync();
});

on({id: alexaListId, ack: true}, e => {
    debug('Got alexa shopping list update.');
    doSync();
});

doSync();

Known issue: You can not delete uncompleted items, they will be added again and again.

Updated to new ioBroker.lovelace version (4.x)