index.js

// configure environment variables in .env
require('dotenv').config()

// import alexa software development kit
const Alexa = require('alexa-sdk')

// import aws software development kit for our database
const awsSDK = require('aws-sdk')
awsSDK.config.update({
  region: 'us-east-1',
  endpoint: 'https://dynamodb.us-east-1.amazonaws.com',
  accessKeyId: process.env.KEY,
  secretAccessKey: process.env.SECRET_KEY
})

// start an instance of our DynamoDB
const docClient = new awsSDK.DynamoDB.DocumentClient()

const table = 'PillsDB'

const pill_brand = 'generic'

const params = {
  TableName: table,
  Key: {
    'pill_brand': pill_brand
  }
}

exports.handler = function (event, context, callback) {
  // create alexa object
  const alexa = Alexa.handler(event, context, callback)
  // our application id
  alexa.appId = process.env.APP_ID
  // register intents for our skill
  alexa.registerHandlers(handlers)
  // after configuration, run alexa
  alexa.execute()
}

const handlers = {
  'HelloWorldIntent': function () {
    // emit response directly
    this.emit(':tell', 'Hello World!')
  },
  'ResetPillCountIntent': function () {
    const self = this
    const count = 10;
    let params = {
      TableName: table,
      Item: {
        "pill_count": count,
        "pill_brand": pill_brand
      }
    };
    console.log("Adding new item...");
    docClient.put(params, function (err, data) {
      if (err) {
        console.error("Unable to add item. Error JSON:", JSON.stringify(err, null, 2));
      } else {
        console.log("Added item:", JSON.stringify(params, null, 2));
      }
    });
    params = {
      TableName: table,
      Item: {
        "pill_count": count,
        "pill_brand": 'greenpill'
      }
    };
    console.log("Adding new item...");
    docClient.put(params, function (err, data) {
      if (err) {
        console.error("Unable to add item. Error JSON:", JSON.stringify(err, null, 2));
      } else {
        console.log("Added item:", JSON.stringify(params, null, 2));
        self.emit(':tell', 'Pill count reset to ' + count);
      }
    });
  },
  'PillCountIntent': function () {
    const self = this
    docClient.get(params, function (err, data) {
      if (err) {
        console.error('Unable to read item. Error JSON:', JSON.stringify(err, null, 2))
      } else {
        console.log('GetItem succeeded:', JSON.stringify(data, null, 2))
        // emit response directly
        self.emit(':tell', 'You currently have ' + data.Item.pill_count + ' red pills')
      }
    })
  },
  'GreenPillCountIntent': function () {
    const self = this
    const pill_brand = 'greenpill'

    const params = {
      TableName: table,
      Key: {
        'pill_brand': pill_brand
      }
    }
    docClient.get(params, function (err, data) {
      if (err) {
        console.error('Unable to read item. Error JSON:', JSON.stringify(err, null, 2))
      } else {
        console.log('GetItem succeeded:', JSON.stringify(data, null, 2))
        // emit response directly
        self.emit(':tell', 'You currently have ' + data.Item.pill_count + ' green pills')
      }
    })
  },
  'PillDispenseIntent': function () {
    const self = this
    docClient.get(params, function (err, data) {
      if (err) {
        console.error('Unable to read item. Error JSON:', JSON.stringify(err, null, 2))
      } else {
        console.log('GetItem succeeded:', JSON.stringify(data, null, 2))
        if (data.Item.pill_count === 0) {
          self.emit(':tell', 'Out of pills! Please restock');
          return;
        }
        // add update query
        params.UpdateExpression = 'set pill_count = :new_count'
        params.ExpressionAttributeValues = {
          ':new_count': data.Item.pill_count - 1
        }
        params.ReturnValues = 'UPDATED_NEW'
        console.log('Updating the item...')

        // update the database
        docClient.update(params, function (err, data) {
          if (err) {
            console.error('Unable to update item. Error JSON:', JSON.stringify(err, null, 2))
          } else {
            console.log('UpdateItem succeeded:', JSON.stringify(data, null, 2))
            // emit response directly
            if (data.Attributes.pill_count === 1) {
              self.emit(':tell', 'Pill dispensed. You now have ' + data.Attributes.pill_count + ' red pill');
              return;
            }
            self.emit(':tell', 'Pill dispensed. You now have ' + data.Attributes.pill_count + ' red  pills')
          }
        })
      }
    })
  },
  'GreenPillDispenseIntent': function () {
    const self = this
    const pill_brand = 'greenpill'

    const params = {
      TableName: table,
      Key: {
        'pill_brand': pill_brand
      }
    }
    docClient.get(params, function (err, data) {
      if (err) {
        console.error('Unable to read item. Error JSON:', JSON.stringify(err, null, 2))
      } else {
        console.log('GetItem succeeded:', JSON.stringify(data, null, 2))
        if (data.Item.pill_count === 0) {
          self.emit(':tell', 'Out of pills! Please restock');
          return;
        }
        // add update query
        params.UpdateExpression = 'set pill_count = :new_count'
        params.ExpressionAttributeValues = {
          ':new_count': data.Item.pill_count - 1
        }
        params.ReturnValues = 'UPDATED_NEW'
        console.log('Updating the item...')

        // update the database
        docClient.update(params, function (err, data) {
          if (err) {
            console.error('Unable to update item. Error JSON:', JSON.stringify(err, null, 2))
          } else {
            console.log('UpdateItem succeeded:', JSON.stringify(data, null, 2))
            // emit response directly
            if (data.Attributes.pill_count === 1) {
              self.emit(':tell', 'Pill dispensed. You now have ' + data.Attributes.pill_count + ' green pill');
              return;
            }
            self.emit(':tell', 'Pill dispensed. You now have ' + data.Attributes.pill_count + ' green pills')
          }
        })
      }
    })
  }
}