aws_rock_paper_scissors_lambda_function.py

from __future__ import print_function

import boto3
import json
import logging
from boto3.dynamodb.conditions import Attr 


print('Loading function')

logger = logging.getLogger()
logger.setLevel(logging.INFO)

sns = boto3.client('sns')
dynamodb = boto3.resource('dynamodb', region_name='us-west-2')

def lambda_handler(event, context):
    
    # Find the current player
    serialNumber = event['serialNumber']
    table = dynamodb.Table('eric_lambda_rps')
    getplayer = table.get_item( Key={'playerid':serialNumber})
    player = getplayer['Item']
    logger.info('Player data: ' + json.dumps(player))
    
    # Get the player's roll - convert from clickType to RPS
    rpsroll = convertRoll(event['clickType'])
    logger.info('Rolled: ' + rpsroll)
    
    #Update current player's roll and set "rolled" to True
    table.update_item(
        Key={ 'playerid':serialNumber},
        UpdateExpression='SET rolled = :val1, lastroll = :val2',
        ExpressionAttributeValues={ ':val1': True, ':val2': rpsroll }
    )
    
    #See if both players have "true" as rolled
    response = table.scan(
        FilterExpression=Attr('rolled').eq(True)
    )
    players = response['Items']
    if len(players) == 2:
        player1 = players[0]
        player2 = players[1]
        p1_roll = player1['lastroll']
        p2_roll = player2['lastroll']
        winner = checkWinner(p1_roll, p2_roll)
        sendMessage(winner, p1_roll, p2_roll, player1, player2)
        # now reset them back to both false
        table.update_item(
            Key={
                'playerid': player1['playerid']          
            },
            UpdateExpression = 'SET rolled = :val1',
            ExpressionAttributeValues={
                ':val1': False
            }
        )
        table.update_item(
            Key={
                'playerid': player2['playerid']          
            },
            UpdateExpression = 'SET rolled = :val1',
            ExpressionAttributeValues={
                ':val1': False
            }
        )
    else:
        sendWaitingMessage(player)

    logger.info('Received event: ' + json.dumps(event))

def sendWaitingMessage(player):
    message = "You are {}, waiting for other player...".format(player['name'])
    sns.publish(PhoneNumber=player['phonenumber'], Message=message)
    

def sendMessage(winner, p1roll, p2roll, player1, player2):
    message = ""
    if winner == 0:
        message = "TIE\nYou both played {}".format(p1roll)
        sns.publish(PhoneNumber=player1['phonenumber'], Message=message)
        sns.publish(PhoneNumber=player2['phonenumber'], Message=message)
    if winner == 1:
        message = "{}\n\n{} played {}\n{} played {}".format("You win!", player1['name'], p1roll, player2['name'], p2roll)
        sns.publish(PhoneNumber=player1['phonenumber'], Message=message)
        message = "{}\n\n{} played {}\n{} played {}".format("You lose!", player1['name'], p1roll, player2['name'], p2roll)
        sns.publish(PhoneNumber=player2['phonenumber'], Message=message)
    if winner == 2:
        message = "{}\n\n{} played {}\n{} played {}".format("You win!", player1['name'], p1roll, player2['name'], p2roll)
        sns.publish(PhoneNumber=player2['phonenumber'], Message=message)
        message = "{}\n\n{} played {}\n{} played {}".format("You lose!", player1['name'], p1roll, player2['name'], p2roll)
        sns.publish(PhoneNumber=player1['phonenumber'], Message=message)


def convertRoll(clickType):
    if clickType == 'SINGLE':
        return "rock"
    if clickType == 'DOUBLE':
        return "scissors"
    if clickType == 'LONG':
        return "paper"
    return "#fail"
    
    
def checkWinner(p1roll, p2roll):
    if p1roll == p2roll:
        return 0
    if p1roll == 'rock':
        if p2roll == 'paper':
            return 2
        else:
            return 1
    if p1roll == 'paper':
        if p2roll == 'scissors':
            return 2
        else:
            return 1
    if p1roll == 'scissors':
        if p2roll == 'rock':
            return 2
        else:
            return 1
    return 0