Example usage

go build -o ./bin/ ./cmd/*
OMISE_PUBLIC_KEY=<SECRET> OMISE_SECRET_KEY=<SECRET> ./bin/gotamboon data/fng.1000-3.csv.rot128

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GO-TAMBOON ไปทำบุญ

This is a small challenge project to see how good you are with Go. Included in this repository is a CSV list of Song-pah-pa (ซองผ้าป่า). It is a white envelope with money inside and the donor name printed on the front. They are usually collected en bulk from multiple people in order to round up money to repair or construct new temple buildings.

The idea is that your donation amount should be kept secret les the activity becomes an act of flaunting your wealth.

But we're a payment gateway, we can do better than that. The envelope will contain, instead, a valid CC number (fake ones, not a real working card) and the desired donation amount. The entire list is also encrypted using NSA-proof variant of the Caesar Cipher 🧌

CONTENTS

• data/fng.csv.rot128 - A ROT-128 encrypted CSV file.
• cipher/rot128.go - Sample ROT-128 encrypt-/decrypter.

EXERCISE

Write a GO command-line module that, when given the CSV list, calls the Charge API to make donations by creating a charge for each row in the file and produce a summary at the end.

Example:

$ cd $GOPATH/omise/go-tamboon
$ go install -v .

$ $GOPATH/bin/go-tamboon test.csv

performing donations...
done.

        total received: THB  210,000.00
  successfully donated: THB  200,000.00
       faulty donation: THB   10,000.00

    average per person: THB      534.23
            top donors: Obi-wan Kenobi
                        Luke Skywalker
                        Kylo Ren

Requirements:

• Decrypt the file using a simple ROT-128 algorithm.
• Make donations by creating a Charge via the Charge API for each row in the decrypted CSV.
• Produce a brief summary at the end.
• Handle errors gracefully, without stopping the entire process.
• Writes readable and maintainable code.

Bonus:

• Have a good Go package structure.
• Be a good internet citizen and throttles the API call if we hit rate limit.
• Run as fast as possible on a multi-core CPU.
• Allocate as little memory as possible.
• Complete the entire process without leaving large trace of Credit Card numbers in memory, or on disk.
• Ensure reproducible builds on your workspace.