var AWS = require('aws-sdk');
AWS.config.update({region: process.env.AWS_REGION});
var ddb = new AWS.DynamoDB.DocumentClient({apiVersion: '2012-08-10'});
let response;
let err;

/**
 * Lambda function for fetching user details.
*/
exports.lambdaHandler = function(event, context, callback) {
    try{
        console.log('checking event data for userId and bookingId');
        console.log(JSON.stringify(event));

        //get query string values
        let pgId = event.queryStringParameters.pgId + '_users';
        let userId =  event.pathParameters.user;
        let bookingId = event.queryStringParameters.bookingId;

        console.log('pgId, userId, bookingId', pgId, userId, bookingId);

        if(userId != undefined) {
            findDetailsByUserId(pgId, userId, callback)
                .then(callback(null, response));
        } else {
            findDetailsByBookingId(pgId, bookingId);
        }

    } catch(err) {
        console.log(err);
        callback("Error", err);
    }
}

function findDetailsByBookingId(pgId, bookingId){
    console.log('entered find details by bookingId stage...');
    let params = {
        Table: 'smartpg',

    }
}

async function findDetailsByUserId(pgId, userId, callback){
    console.log('entered find details by userId stage...');

    let params = {
        TableName: 'smartpg',
        Key: {
            'ID' : pgId,
            'Metadata' : userId
        }
    }

    console.log('About to execute ddb get call...');
    ddb.get(params, function(err, data) {
       console.log('fetching from ddb stage...');

       if(err) {
           console.log('error encountered when fetching from database');
           return err;
       } else {
           console.log('successfully fetched from database',data);
           response = {
               'statusCode' : 200,
                'headers' : {
                    'cache-control' : 'private, max-age = 3600',
                    'Access-Control-Allow-Origin' : '*',
                    'content-type' : 'application/json',
                },
                'body' : JSON.stringify(data)
           }
           console.log(response);
           return response;
       }
    });
}