@katesthings/smartstate/index.ts

AWS Lambda utilities to store and retrieve in DynamoDB for SmartThings SmartApps

// Import required AWS SDK clients and commands for establishing DynamoDBClient
const { DynamoDBClient, GetItemCommand, PutItemCommand } = require("@aws-sdk/client-dynamodb");
const dbclient = new DynamoDBClient({ region: 'us-west-2' });
const contextTable = 'smartapp-context-store';
const homeSettings = 'smartapp-home-settings';

/*
  Get the value of the specified state variable stored in DynamoDB, returned as string
  */
async function getState( context, name ) {
	// use installedAppId as unique key combined with name for state variable 
	// const appId = context.event.appId;
	const appId = context.installedAppId;
	
	// Set the parameters
	const params = {
  		TableName: 'smartapp-context-store',
  		Key: {
    		appId: { S: appId },
			name: { S: name },
  		},
  		ProjectionExpression: 'stateValue',
	};
  	
	// Return the requested state variable
	try {
		// console.log("Calling DynamoDB application context store to get state variable value");
		const data = await dbclient.send(new GetItemCommand(params));
		return data.Item.stateValue.S;
	} catch (err) {
		console.error('getState - error: ', err);
	}	
};

/*
  Store the value of the specified state variable stored in DynamoDB as string
  */
async function putState( context, name, value ) {
	// use installedAppId as unique key combined with name for state variable 
	// const appId = context.event.appId;
	const appId = context.installedAppId;

	// Set the parameters
	const params = {
  		TableName: 'smartapp-context-store',
  		Item: {
    		appId: { S: appId },
			name: { S: name },
			stateValue: { S: value },
  		},
	};
	
	try {
    		const data = await dbclient.send(new PutItemCommand(params));
    		// console.log('Data stored in DynamoDB: ',data);
  	} catch (err) {
    		console.error('putState - error: ', err);
  	}
};

/*
  Get the value for a given key from a given table
  */
async function getValue( table, key ) {
	// Set the parameters
	const params = {
  		TableName: table,
  		Key: {
    			key: { S: key }
  		},
  		ProjectionExpression: 'keyValue'
	};
  	
	// Return the requested state variable
	try {
		const data = await dbclient.send(new GetItemCommand(params));
		return data.Item.keyValue.S;
	} catch (err) {
		console.error('getValue - error: ', err);
	}	
};

/*
  Store an item in the specified table the value of the specified state variable stored in DynamoDB as string
  */
async function putValue( table, key, value ) {
	// Set the parameters
	const params = {
  		TableName: table,
  		Item: {
    		key: { S: key },
			keyValue: { S: value },
  		},
	};
	
	try {
    		const data = await dbclient.send(new PutItemCommand(params));
    		console.log('Data stored in DynamoDB: ',data);
  	} catch (err) {
		console.error('putValue - error: ', err);
  	}
};

/*
function nextState( appId, currentDateTime ) {
	var nextState = null;

	
	// const today = new Date();
	// const nDayOfWeek = today.getDay();
	const nDayOfWeek = currentDateTime.getDay();
	
	const params = {
  		TableName: 'smartapp-state-machine',
  		Key: {
    			appId: { S: appId }
  		}
	};
  	
	// Return the requested state variable
	try {
		const data = await dbclient.send(new GetItemCommand(params));
		return data.Item.stateValue.S;
	} catch (err) {
		console.log("Error", err);
	}	
	
	
	
	
	var bDayOfWeek = false;
	switch (strDayOfWeek) {
		case 'everyday':
			bDayOfWeek = true;
			break;
		case 'weekdays':
			bDayOfWeek = ( nDayOfWeek >= 1 && nDayOfWeek <= 5 );
			break;
		case 'weekend':
			bDayOfWeek = ( nDayOfWeek==0 || nDayOfWeek==6 );
	}
	return bDayOfWeek;	
	
	
	
	return nexState;
};
*/

async function getHomeMode( homeName, modeType ) {
	// Set the parameters
	const params = {
  		TableName: 'smartapp-home-settings',
  		Key: {
			homeName: { S: homeName },
			modeType: { S: modeType },
  		},
  		ProjectionExpression: 'modeValue',
	};
  	
	// Return the requested mode type value
	try {
		// console.log('Home settings query parameters: ', params);
		const data = await dbclient.send(new GetItemCommand(params));
		return data.Item.modeValue.S;
	} catch (err) {
		console.error('getHomeMode - error: ', err);
	}	
};

async function putHomeMode( homeName, modeType, modeValue ) {
	// Set the mode for the specified type
	const params = {
  		TableName: 'smartapp-home-settings',
  		Item: {
			homeName: { S: homeName },
			modeType: { S: modeType },
			modeValue: { S: modeValue },
  		},
	};
	
	try {
    		const data = await dbclient.send(new PutItemCommand(params));
    		// console.log('Data stored in DynamoDB: ', data);
  	} catch (err) {
		console.error('putHomeMode - error: ', err);
  	}
};

async function isHomeActive( homeName ) {
	// initialize return value to true
	var bActive: boolean;
	
	if (homeName) {
		const homeOccupiedMode = await getHomeMode( homeName, 'occupancy' );
    	// console.log('isHomeActive - home occupied mode: ', homeOccupiedMode, ', home name; ', homeName);
		try {
			bActive = (homeOccupiedMode==='active');
		} catch(err) {
			console.log('isHomeActive - invalid dynamoDB response: ', err);
			bActive = true;  // default to true
		}
	}
	return bActive;	
};

// Export functions
exports.getState = getState;
exports.putState = putState;
exports.getValue = getValue;
exports.putValue = putValue;
// exports.nextState = nextState;
exports.getHomeMode = getHomeMode;
exports.putHomeMode = putHomeMode;
exports.isHomeActive = isHomeActive;