javascript

var banks = {
	SBI: 'SBI',
	HDFC: 'HDFC'
};

var transactionTypes = {
	MONEY_TRANSFER: 'MONEY_TRANSFER',
	CARD: 'CARD',
	NETBANKING: 'NETBANKING'
};


var utils = {
	HDFC : {
		toNumberFomINRFormat(str){
			str = str.replace(/,/g, '');
			return parseFloat(str, 10);
		}
	}
};

var subTypes = {
	CARD: {
		DEBIT: 'DEBIT',
		CREDIT: 'CREDIT'
	},
	
	MONEY_TRANSFER: {
		NEFT: 'NEFT',
		ITGS: 'ITGS',
		ATM : 'ATM'
	},

	NETBANKING: {
		NETBANKING: 'NETBANKING'
	}
};

class TransactionConverter{
	_extractSBIDebitInfo(body){
		var cardNumberRegExp 	 = /Card ([0-9X]+ for)/;
		var transAmountRegExp 	 = /worth Rs([0-9,]+) on/;
		var altTransAmountRegExp = /for Rs([0-9,]+) on/;
		var handlerRegExp		 = /at ([A-Za-z0-9_.\/\*\? ]+) txn/;

		var extractedAmount = body.match(transAmountRegExp);
		
		if( extractedAmount === null ){
			extractedAmount = body.match(altTransAmountRegExp);
		}



		return {
			transactionTo 		: body.match(handlerRegExp)[1],
			amount 	   			: utils.HDFC.toNumberFomINRFormat( extractedAmount[1] ),
			cardNumberId 		: body.match(cardNumberRegExp)[1],
			transactionType		: transactionTypes.CARD,
			transactionSubType 	: subTypes.CARD.DEBIT,
			bank            	: banks.SBI
		};

	}

	_extractSBINetBankingInfo(body){
		
		var transAmountRegExp = /for Rs.([0-9,]+\.[0-9]+) on/;
		var altTransAmountRegExp = /for Rs.([0-9,]+) on/;
		var dateTimeRegExp = /on ([0-9\/: ]+)/;
		
		var amount = body.match(transAmountRegExp);
		if( amount === null ){
			amount = body.match(altTransAmountRegExp);
		}
		return {
			amount 				: utils.HDFC.toNumberFomINRFormat( amount[1] ),
			timestamp 			: new Date(body.match(dateTimeRegExp)[1]),
			accountNumberId 	: 'self',
			transactionType		: transactionTypes.NETBANKING,
			transactionSubType 	: subTypes.NETBANKING.NETBANKING,
			bank            	: banks.SBI
		};
	
	}

	_extractSBIATMInfo(body){
		
		var transAmountRegExp = /Rs([0-9]+) withdrawn/;
		var transAccountNumber = /A\/c ([0-9x]+) on/;

		return {
			amount			: utils.HDFC.toNumberFomINRFormat( body.match(transAmountRegExp)[1] ),
			accountNumberId 	: body.match(transAccountNumber)[1],
			transactionType		: transactionTypes.MONEY_TRANSFER,
			transactionSubType 	: subTypes.MONEY_TRANSFER.ATM,
			bank            	: banks.SBI
		};

	}
	_extractSBIInfo(message){
		var lowerBody = message.body.toLowerCase();
		console.log(message.body);
		if( lowerBody.indexOf("pleasure to serve") !== -1 ){
			return null;
		}else if( lowerBody.indexOf("withdrawn at") !== -1 ){
			return this._extractSBIATMInfo(message.body);
		}else if( lowerBody.indexOf("state bank internet banking") !== -1 ){
			return this._extractSBINetBankingInfo(message.body);
		}else if( lowerBody.indexOf("sbi debit card") !== -1 ){
			return this._extractSBIDebitInfo(message.body);
		}

		return null;
	}

	_extractHDFCDebitInfo(message){


		var cardNumberRegExp 	 = /ending (\d+)/;
		var transAmountRegExp 	 = /for Rs.([0-9,]+\.[0-9]+) in/;
		var altTransAmountRegExp = /for Rs. ([0-9,]+\.[0-9]+) towards/;
		var handlerRegExp		 = /at ([A-Za-z0-9_.\*\? ]+) on/;
		var dateTimeRegExp		 = /on ([0-9\-:]+)/;

		var extractedAmount = message.body.match(transAmountRegExp);
		
		if( extractedAmount === null ){
			extractedAmount = message.body.match(altTransAmountRegExp);
		}



		return {
			timestamp 		: new Date(message.body.match(dateTimeRegExp)[1]),
			transactionTo 		: message.body.match(handlerRegExp)[1],
			amount 	   		: utils.HDFC.toNumberFomINRFormat( extractedAmount[1] ),
			cardNumberId 		: message.body.match(cardNumberRegExp)[1],
			transactionType		: transactionTypes.CARD,
			transactionSubType 	: subTypes.CARD.DEBIT,
			bank            	: banks.HDFC
		};

	}

	_extractHDFCNetBankingInfo(body){
		var transAmountRegExp = /of Rs.([0-9,]+\.[0-9]+) has/;
		var transAccountNumber = /number ([0-9X]+) for/;
		console.log(body);
		return {
			amount 			: utils.HDFC.toNumberFomINRFormat( body.match(transAmountRegExp)[1] ),
			bank  			: banks.HDFC,
			accountNumberId : body.match(transAccountNumber)[1]
		};
	}

	_extractHDFCNeftInfo(message){

		return _.assign(this._extractHDFCNetBankingInfo(message.body),{
			transactionType 	: transactionTypes.MONEY_TRANSFER,
			transactionSubType 	: subTypes.MONEY_TRANSFER.NEFT
		});
	}

	_extractHDFCOnlineTransactionInfo(message){

		return _.assign(this._extractHDFCNetBankingInfo(message.body),{
			transactionType 	: transactionTypes.NETBANKING,
			transactionSubType 	: subTypes.NETBANKING.NETBANKING
		});

	}

	_extractHDFCInfo(message){
		
		var lowerBody = message.body.toLowerCase();
		console.log(message);

		if( lowerBody.indexOf("online payment txn") !== -1 ){
		
			return this._extractHDFCOnlineTransactionInfo(message);
		
		}if( lowerBody.indexOf("neft txn") !== -1 ){
			
			return this._extractHDFCNeftInfo(message);

		}else if( lowerBody.indexOf("debit/atm")  !== -1 ){
		
			return this._extractHDFCDebitInfo(message);
		
		}
		
		return null;
	}

	convertMessageToTransaction(message){
		var bank = '', info = null;

		console.log("probing new message");
		
		if( message.address.toLowerCase().indexOf("sbi") != -1 ){
			console.log("Found an SBI message");
			bank = banks.SBI;
		}else if( message.address.toLowerCase().indexOf("hdfc") != -1){
			console.log("Found an HDFC Bank Message");
			bank = banks.HDFC;
		}
		
		switch(bank){
			
			case banks.SBI:
				console.log("Extracting Info from SBI");
				info = this._extractSBIInfo(message);
				break;
			
			case banks.HDFC:
				console.log("Extracting info from HDFC");
				info = this._extractHDFCInfo(message);
				break;

			default:
				console.log("Unknown bank");
		}
		
		if( info ){
			info = _.assign(info,{
				messageTimestamp : new Date(+message.date),
				hashed			 : sha256(JSON.stringify(message))
			});
		}
		console.log("Returning Object", info);
		return info;
	}

	convertMessagesToTransactions(smsArray){
		console.log("Beginning to process", smsArray.length, "messages");
		var transactions = smsArray.map(this.convertMessageToTransaction.bind(this))
								.filter(x => !!x);
		console.log("Processed ", smsArray.length, "messages and found", transactions.length, "transactions");
		return transactions;
	}

}