exercise-04-function_refactoring.js

main();

function main() {
  const transactions = [
    {
      id: "t1",
      type: "PAYMENT",
      status: "OPEN",
      method: "CREDIT_CARD",
      amount: "23.99",
    },
    {
      id: "t2",
      type: "PAYMENT",
      status: "OPEN",
      method: "PAYPAL",
      amount: "100.43",
    },
    {
      id: "t3",
      type: "REFUND",
      status: "OPEN",
      method: "CREDIT_CARD",
      amount: "10.99",
    },
    {
      id: "t4",
      type: "PAYMENT",
      status: "CLOSED",
      method: "PLAN",
      amount: "15.99",
    },
  ];

  processTransactions(transactions);
}

function processTransactions(transactions) {
  if (transactions && transactions.length > 0) {
    for (const transaction of transactions) {
      if (transaction.type === "PAYMENT") {
        if (transaction.status === "OPEN") {
          if (transaction.method === "CREDIT_CARD") {
            processCreditCardPayment(transaction);
          } else if (transaction.method === "PAYPAL") {
            processPayPalPayment(transaction);
          } else if (transaction.method === "PLAN") {
            processPlanPayment(transaction);
          }
        } else {
          console.log("Invalid transaction type!");
        }
      } else if (transaction.type === "REFUND") {
        if (transaction.status === "OPEN") {
          if (transaction.method === "CREDIT_CARD") {
            processCreditCardRefund(transaction);
          } else if (transaction.method === "PAYPAL") {
            processPayPalRefund(transaction);
          } else if (transaction.method === "PLAN") {
            processPlanRefund(transaction);
          }
        } else {
          console.log("Invalid transaction type!", transaction);
        }
      } else {
        console.log("Invalid transaction type!", transaction);
      }
    }
  } else {
    console.log("No transactions provided!");
  }
}

function processCreditCardPayment(transaction) {
  console.log(
    "Processing credit card payment for amount: " + transaction.amount
  );
}

function processCreditCardRefund(transaction) {
  console.log(
    "Processing credit card refund for amount: " + transaction.amount
  );
}

function processPayPalPayment(transaction) {
  console.log("Processing PayPal payment for amount: " + transaction.amount);
}

function processPayPalRefund(transaction) {
  console.log("Processing PayPal refund for amount: " + transaction.amount);
}

function processPlanPayment(transaction) {
  console.log("Processing plan payment for amount: " + transaction.amount);
}

function processPlanRefund(transaction) {
  console.log("Processing plan refund for amount: " + transaction.amount);
}

/* Refactor */

function processTransactions(transactions) {
  if (isEmpty(transactions)) {
    showErrorMessage("No transactions provided!");
    return;
  }

  for (const transaction of transactions) {
    processTransaction(transaction)
  }
}

function showErrorMessage(message) {
  console.log(message);
}

function isEmpty(transactions) {
  return !transactions || transactions.length === 0;
}

function processTransaction(transaction) {
  if (!isOpen(transaction)) {
    showErrorMessage("Invalid transaction type!");
    return;
  }

  if (!validTransaction(transaction)) {
    showErrorMessage("Invalid transaction type!")
    return
  }

  processTransactionType(transaction)

}

function processTransactionType(transaction) {
    const processors = getTransactionProcess(transaction)

    if (transaction.type === "PAYMENT") {
        processors.processPayment(transaction)
    } else {
        processors.processRefund
    }
}

function getTransactionProcess(transaction) {
    let processors = {
        processPayment: null,
        processRefund: null
    }

    if (transaction.method === "CREDIT_CARD"){
        processors.processPayment = processCreditCardPayment
        processors.processRefund = processCreditCardRefund
    } else if (transaction.method === "PAYPAL") {
        processors.processPayment = processPayPalPayment
        processors.processRefund = processPayPalRefund
    } else if (transaction.method === "PLAN") {
        processors.processPayment = processPlanPayment
        processors.processRefund = processPlanRefund
    }

    return processors
}

function isOpen(transaction) {
    return transaction.status === "OPEN"
}

function validTransaction(transaction) {
    if (['PAYMENT', 'REFUND'].includes(transaction.type))
}

function processCreditCardPayment(transaction) {
  console.log(
    "Processing credit card payment for amount: " + transaction.amount
  );
}

function processCreditCardRefund(transaction) {
  console.log(
    "Processing credit card refund for amount: " + transaction.amount
  );
}

function processPayPalPayment(transaction) {
  console.log("Processing PayPal payment for amount: " + transaction.amount);
}

function processPayPalRefund(transaction) {
  console.log("Processing PayPal refund for amount: " + transaction.amount);
}

function processPlanPayment(transaction) {
  console.log("Processing plan payment for amount: " + transaction.amount);
}

function processPlanRefund(transaction) {
  console.log("Processing plan refund for amount: " + transaction.amount);
}