import json
import os
import sys
import uuid
import boto3
import time

s3 = boto3.client('s3')

def getUser(users, userId):
    for u in users:
        if(u['user_id'] == userId):
            return u
    return None


def getAccount(accounts, account_id):
    for a in accounts:
        if(a['account_id'] == account_id):
            return a
    return None


def checkTransactionValid(account, transaction):
    if(float(transaction['transaction_amount']) <= 0.0):
        return False
    if(float(account['account_balance']) < float(transaction['transaction_amount'])):
        return False
    return True


def completeTransaction(senderAccount, receiverAccount, transaction):
    receiverAccount['account_balance'] = float(
        receiverAccount['account_balance']) + float(transaction['transaction_amount'])
    senderAccount['account_balance'] = float(
        senderAccount['account_balance']) - float(transaction['transaction_amount'])

def saveConfig(senderAccount, receiverAccount, config):
    config['accounts'] = list([
        senderAccount, receiverAccount])
    bucketName = 'transactionsresults'
    s3 = boto3.resource('s3')
    bucket = s3.Bucket(bucketName)
    path = 'tmp/transaction_result_'+str(time.time())+'.json'
    data = json.dumps(config)
    bucket.put_object(
        ACL='public-read',
        ContentType='application/json',
        Key=path,
        Body=data,
    )

    body = {
        "uploaded": "true",
        "bucket": bucketName,
        "path": path,
    }
    return {
        "statusCode": 200,
        "body": json.dumps(body)
    }


def transaction_handler(event, context):
    bucket = 'transactionstorage'
    key = 'transaction.json'
    response = s3.get_object(Bucket = bucket,Key=key)
    content = response['Body']
    jsontransaction = json.loads(content.read())
    transaction = jsontransaction['transaction']
    with open('./config.json') as conf:
        config = json.load(conf)
    users = config['users']
    accounts = config['accounts']
    sender = getUser(users, transaction['sender_id'])
    receiver = getUser(users, transaction['receiver_id'])
    if((sender == None) or (receiver == None)):
        return {
            'statusCode': 400,
            'body': 'Invalid sender or receiver ID'
        }

    senderAccount = getAccount(accounts, sender['user_account_id'])
    receiverAccount = getAccount(accounts, receiver['user_account_id'])
    if(senderAccount == None):
        return {
            'statusCode': 400,
            'body': 'There\'s no accounts registered for the user '+sender['user_id']
        }
    if(receiverAccount == None):
        return {
            'statusCode': 400,
            'body': 'There\'s no accounts registered for the user '+receiver['user_Id']
        }
    validTransaction = checkTransactionValid(senderAccount, transaction)
    if(validTransaction == False):
        return {
            'statusCode': 400,
            'body': 'Transaction not valid'
        }
    completeTransaction(senderAccount, receiverAccount, transaction)
    saveConfig(senderAccount, receiverAccount, config)