index.js

/**
 * The main file for the Food Buddy Alexa Skill. Hosted on AWS Lambda.
 * @authors Christopher Jereza, Michelle Hamilton
 */

//****************************************** ATTRIBUTES **************************************************************

'use strict';
/* The Alexa SDK. */
var Alexa = require('alexa-sdk');

/* String literal used for formatting. */
const WHITESPACE = ' ';

/* The states of this skill, used for separating ambiguous Yes and No intents. */
const STATES = {
    'HELP': '_HELPSTATE',
    'MAIN': '_MAINSTATE',
};

/* The Application ID for this Alexa Skill. */
const APP_ID = 'amzn1.ask.skill.f7574c4a-fe13-47d7-b1a5-34a199aacf04';

/* Default Alexa speech output messages. */
const MESSAGES = {
    'WELCOME': 'Welcome to Food Buddy! Add an ingredient or food item to your meal.',
    'STOP': 'Goodbye!',
    'HELP': 'You can add ingredients to your meal by saying, ADD, and the amount of your ingredient. ' +
    'Say, “what if I add,” followed by your quantity and ingredient, to hear the nutrients and calories you ' +
    'will be adding. Say, “Cancel,” or, “remove,” followed by an ingredient to remove it from your meal. Say “summary” ' +
    'at any point to hear the total nutritional information. ' +
    'Would you like to hear an example?',
    'UNHANDLED': 'I\'m sorry, I didn\'t get that. Please specify a quantity, ' +
    'a unit of measurement, and an ingredient. Or, say \'Summary.\'',
    'START_UNHANDLED': 'Say, \'Open Food Buddy\', to track the nutritional value of your meal.',
    'REPROMPT': 'You can add another item, or ask for your summary.',
    'HELP_UNHANDLED': 'Sorry, I didn\'t get that. Would you like to hear an example? Please say yes or no.'

};

/* File containing functions for accessing the USDA Nutrient Data Laboratory API. */
const DATA = require('./data.js');

//****************************************** FUNCTIONS **************************************************************

/**
 * Add a specified ingredient to the current meal.
 * @param {number} quantity - numerical amount of ingredient added
 * @param {String} unit - unit of measurement (e.g. ounce/ounces, pound/pounds, cup/cups, etc.
 * @param {String} ingredient - food item to add (e.g. chicken, pasta, rice, tofu, etc.)
 * @return emit()
 */
function add(quantity, unit, ingredient) {
    if (this.attributes.meal === undefined) {
        this.attributes.meal = {};
    }
    if (this.attributes.ingredients === undefined) {
        this.attributes.ingredients = {};
    }
    if (this.attributes.addedItems === undefined) {
        this.attributes.addedItems = [];
    }
    DATA.getMacros.call(this, quantity, unit, ingredient, 0);
}

/**
 * Update the session attributes with new ingredient
 * @param {number} quantity - numerical amount of ingredient added
 * @param {String} unit - unit of measurement (e.g. ounce/ounces, pound/pounds, cup/cups, etc.
 * @param {String} ingredient - food item to add (e.g. chicken, pasta, rice, tofu, etc.)
 * @param {object} macros - dictionary object with Calories, Protein, Carbs, and Fat attributes.
 */
function update(quantity, unit, ingredient, macros) {
    if (this.attributes.meal === undefined) {
        this.attributes.meal = {};
    }
    if (this.attributes.ingredients === undefined) {
        this.attributes.ingredients = {};
    }
    if (this.attributes.addedItems === undefined) {
        this.attributes.addedItems = [];
    }
    this.attributes.meal[ingredient] = macros;
    this.attributes.ingredients[ingredient] = [quantity, unit, macros.Calories];
    this.attributes.addedItems.push(ingredient);
    console.log(ingredient + macros.Calories);
    this.emit(':ask', 'Adding ' + stringify.call(this, quantity, unit, ingredient, macros.Calories) + '.', MESSAGES.REPROMPT);
}

/**
 * Return a string with the quantity, unit, and ingredient of the added item.
 * @param {number} quantity - numerical amount of ingredient added
 * @param {String} unit - unit of measurement (e.g. ounce/ounces, pound/pounds, cup/cups, etc.
 * @param {String} ingredient - food item to add (e.g. chicken, pasta, rice, tofu, etc.)
 * @param {number} calories - number of calories contained in the quantity of added ingredient.
 * @return {String}
 */
function stringify(quantity, unit, ingredient, calories) {
    return quantity + WHITESPACE + unit + ' of ' + ingredient + ' with ' + calories + ' calories';
}

/**
 * List every ingredient added so far.
 * @return emit()
 */
function report() {
    const meal = this.attributes.meal;
    if (meal === null || meal === undefined || meal.length <= 0) {
        this.emit(':ask', 'No food items have been added.');
    } else {
        let totalCalories = 0;
        let totalCarbs = 0;
        let totalProtein = 0;
        let totalFat = 0;
        let macros;
        for (let ingredient in meal) {
            if (meal.hasOwnProperty(ingredient) && meal[ingredient] !== undefined) {
                macros = meal[ingredient];
                totalCalories += parseFloat(macros.Calories);
                totalCarbs += parseFloat(macros.Carbs);
                totalProtein += parseFloat(macros.Protein);
                totalFat += parseFloat(macros.Fat);
            }
        }
        let outputSpeech = 'You have a total of ' + totalCalories + ' Calories, ' + totalCarbs + ' grams of carbohydrates, ' +
            totalProtein + ' grams of protein, and ' + totalFat + ' grams of fat.';
        this.emit(':ask', outputSpeech, MESSAGES.REPROMPT);
    }
}

/**
 * Remove the ingredient that was most recently added.
 * @return emit()
 */
function remove() {
    let meal = this.attributes.meal;
    let ingredients = this.attributes.ingredients;
    let addedItems = this.attributes.addedItems;
    if (meal === undefined || meal === null || meal.length === 0) {
        this.emit(':ask', 'You have no ingredients left to remove.', MESSAGES.REPROMPT);
    } else if (ingredients === undefined || ingredients === null || ingredients.length === 0) {
        this.emit(':ask', 'You have no ingredients left to remove.', MESSAGES.REPROMPT);
    } else if (addedItems === undefined || addedItems === null || addedItems.length === 0) {
        this.emit(':ask', 'You have no ingredients left to remove.', MESSAGES.REPROMPT);
    } else {
        let itemToDelete = addedItems[addedItems.length - 1];
        delete meal[itemToDelete];
        delete ingredients[itemToDelete];
        this.attributes.meal = meal;
        this.attributes.ingredients = ingredients;
        this.attributes.addedItems.pop();
        let outputSpeech = 'Removing ' + itemToDelete;
        this.emit(':ask', outputSpeech, MESSAGES.REPROMPT);
    }
}

/**
 * Report a list of all ingredients added so far, along with the Calorie count for each item.
 * @return emit()
 */
function ingredients() {
    let meal = this.attributes.ingredients;
    if (meal === undefined || meal === null || meal.length === 0) {
        this.emit(':ask', 'You have no ingredients left to remove.', MESSAGES.REPROMPT);
    } else if (this.attributes.addedItems === undefined
        || this.attributes.addedItems === null
        || this.attributes.addedItems.length === 0) {
        this.emit(':ask', 'You have no ingredients left to remove.', MESSAGES.REPROMPT);
    } else {
        let outputSpeech = 'You have added: ';
        let ingredients = [];
        for (let ingredient in meal) {
            if (meal.hasOwnProperty(ingredient) && meal[ingredient] !== undefined) {
                ingredients.push(ingredient);
            }
        }
        const len = ingredients.length;
        if (len > 0) {
            let ingredient;
            let quantity;
            let unit;
            let calories;
            for (let i = 0; i < len - 1; i += 1) {
                ingredient = ingredients[i];
                quantity = meal[ingredient][0];
                unit = meal[ingredient][1];
                calories = meal[ingredient][2];
                outputSpeech += stringify.call(this, quantity, unit, ingredient, calories);
                if (i < len - 2 || len > 2) {
                    outputSpeech += ', ';
                } else {
                    outputSpeech += WHITESPACE;
                }
            }
            if (len > 1) {
                outputSpeech += 'and ';
            }
            ingredient = ingredients[len - 1];
            quantity = meal[ingredient][0];
            unit = meal[ingredient][1];
            calories = meal[ingredient][2];
            outputSpeech += stringify.call(this, quantity, unit, ingredient, calories) + '.';
        }
        this.emit(':ask', outputSpeech, MESSAGES.REPROMPT);
    }
}

/**
 * Tell the user the Calories and macro-nutrient counts for INGREDIENT, without adding it to the meal.
 * @param {number} quantity - numerical amount of ingredient added
 * @param {String} unit - unit of measurement (e.g. ounce/ounces, pound/pounds, cup/cups, etc.
 * @param {String} ingredient - food item to add (e.g. chicken, pasta, rice, tofu, etc.)
 * @return call to DATA.getMacros()
 */
function whatIf(quantity, unit, ingredient) {
    if (this.attributes.meal === undefined) {
        this.attributes.meal = {};
    }
    if (this.attributes.ingredients === undefined) {
        this.attributes.ingredients = {};
    }
    DATA.getMacros.call(this, quantity, unit, ingredient, 1);
}

/**
 * Helper function for WhatIfIntent.
 * @param {number} quantity - numerical amount of ingredient added
 * @param {String} unit - unit of measurement (e.g. ounce/ounces, pound/pounds, cup/cups, etc.
 * @param {String} ingredient - food item to add (e.g. chicken, pasta, rice, tofu, etc.)
 * @param {Object} macros - dictionary object with Calories, Protein, Carbs, and Fat attributes.
 * @return emit()
 */
function whatIfHelper(quantity, unit, ingredient, macros) {
    this.emit(':ask', 'Adding ' + quantity + WHITESPACE + unit + ' of ' + ingredient + ' would add ' + macros.Calories +
        ' calories, ' + macros.Carbs + ' grams of carbohydrates, ' + macros.Protein + ' grams of protein, and ' +
        macros.Fat + ' grams of fat to your meal.', MESSAGES.REPROMPT);
}

//****************************************** HANDLERS *************************************************************

/* The initial handler for a new session. */
var handlers = {
    'LaunchRequest': function () {
        this.handler.state = STATES.MAIN;
        this.emitWithState('LaunchRequest');
    },
    'AddIntent': function () {
        this.handler.state = STATES.MAIN;
        this.emitWithState('AddIntent');
    },
    'WhatIfIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('WhatIfIntent');
    },
    'ReportIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('ReportIntent');
    },
    'RemoveIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('RemoveIntent');
    },
    'IngredientsIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('IngredientsIntent');
    },
    'Unhandled': function() {
        this.emit(':tell', MESSAGES.START_UNHANDLED);
    },
    'AMAZON.StopIntent': function() {
        this.emit(':tell', MESSAGES.STOP);
    },
    'AMAZON.CancelIntent': function() {
        this.emit('AMAZON.StopIntent');
    }
};

/* The Main State handler for the Skill during the conversation. */
const mainStateHandler = Alexa.CreateStateHandler(STATES.MAIN, {
    'LaunchRequest': function () {
        this.emit(':ask', MESSAGES.WELCOME);
    },
    'AddIntent': function () {
        const quantity = this.event.request.intent.slots.quantity.value;
        const unit = this.event.request.intent.slots.unit.value;
        const ingredient = this.event.request.intent.slots.ingredient.value;
        add.call(this, quantity, unit, ingredient);
    },
    'WhatIfIntent': function() {
        const quantity = this.event.request.intent.slots.quantity.value;
        const unit = this.event.request.intent.slots.unit.value;
        const ingredient = this.event.request.intent.slots.ingredient.value;
        whatIf.call(this, quantity, unit, ingredient);
    },
    'ReportIntent': function() {
        report.call(this);
    },
    'RemoveIntent': function() {
        remove.call(this);
    },
    'IngredientsIntent': function() {
        ingredients.call(this)
    },
    'Unhandled': function() {
        this.emit(':ask', MESSAGES.UNHANDLED);
    },
    'AMAZON.StopIntent': function() {
        this.emit(':tell', MESSAGES.STOP);
    },
    'AMAZON.HelpIntent': function() {
        this.handler.state = STATES.HELP;
        this.emit(':ask', MESSAGES.HELP);
    },
    'AMAZON.NoIntent': function() {
        this.emit('ReportIntent');
    },
    'AMAZON.YesIntent': function() {
        this.emit(':ask', 'Please add another ingredient, or say \'Summary\'.');
    },
    'StartOverIntent': function() {
        this.attributes.meal = {};
        this.attributes.ingredients = {};
        this.attributes.addedItems = [];
        this.emit('LaunchRequest');
    },
    'AMAZON.CancelIntent': function() {
        this.emit('RemoveIntent');
    }
});

/* Handler for the Help State of the conversation. Used to separate Yes and No intents. */
const helpStateHandler = Alexa.CreateStateHandler(STATES.HELP, {
    'AMAZON.YesIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState(':ask', 'For example, you could say: Add three ounces of chicken, or you could ask: How many calories ' +
            'would five grams of cheese add?', MESSAGES.REPROMPT);
    },
    'AMAZON.NoIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState(':ask', MESSAGES.WELCOME);
    },
    'LaunchRequest': function () {
        this.handler.state = STATES.MAIN;
        this.emitWithState('LaunchRequest');
    },
    'AddIntent': function () {
        this.handler.state = STATES.MAIN;
        this.emitWithState('AddIntent');
    },
    'WhatIfIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('WhatIfIntent');
    },
    'ReportIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('ReportIntent');
    },
    'RemoveIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('RemoveIntent');
    },
    'IngredientsIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('IngredientsIntent');
    },
    'StartOverIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('StartOverIntent');
    },
    'AMAZON.StopIntent': function() {
        this.emit(':tell', MESSAGES.STOP);
    },
    'AMAZON.HelpIntent': function() {
        this.emit(':ask', MESSAGES.HELP);
    },
    'AMAZON.CancelIntent': function() {
        this.handler.state = STATES.MAIN;
        this.emitWithState('AMAZON.YesIntent');
    },
    'Unhandled': function() {
        this.emit(':ask', MESSSAGES.HELP_UNHANDLED);
    },
});

//****************************************** EXPORTS *************************************************************
exports.update = update;
exports.whatIfHelper = whatIfHelper;
exports.handler = function(event, context){
    const alexa = Alexa.handler(event, context);
    alexa.appId = APP_ID;
    alexa.registerHandlers(handlers, mainStateHandler, helpStateHandler);
    alexa.execute();
};