Hi there! 👋

Thanks for your interest in Nowsta :-) we really appreciate you taking the time to work on this coding challenge for us. We expect it to take no longer than a few hours max.

The task

At Nowsta, we do a whole lot with worker timecard data. Sometimes the "business logic" in this domain is actually "legal logic", such as in the case of calculating overtime.

The comprehensive solution for this problem is rather involved so we've split it up into several phases for you. Complete as many as you'd like - getting them all is definitely not necessary, as we prefer quality over quantity.

The goal is to write a function which takes a list of Punchcards (you can assume they are all worked by the same worker), and for each punchcard, it must set its respective regular and overtime hours worked. Each punchcard has the following fields:

day (Integer) - prepopulated (the day index that this punchcard occurred on: 0 = Sun, 1 = Mon, ..., 6 = Sat)
week (Integer) - prepopulated (the week index that this punchcard occurred on: starts at 0, increases thereafter)
regular_hours (Integer) - default nil (will be set by you)
overtime_hours (Integer) - default nil (will be set by you)

One test is included to start you off, but please feel free to modify or add as many as you'd like.

The deliverable is your fork of this repository (no need to create a PR), or zip up your solution and send it via email.

Objectives

Use git! Please commit often so it's easy to follow your train of thought and iterations
Implement as many phases as you'd like, but quality > quantity!
Make the tests pass, and add any tests to cover any change in specification
Try to keep the code as clean, readable, and DRY as possible
Efficiency isn't a main concern here, but a solution is certainly possible in Θ(n + n log(n)) time complexity

Running it

Fork this repository to your personal GitHub account. (It's a private repo, so it won't show up publicly in your profile.) Or, just clone it locally.
Run bundle install in this directory to install the necessary gems (rspec).
Run bundle exec rspec overtime_spec.rb to run the tests (they should fail)
Start with Phase 1 below to make the tests pass!

Phase 1

The federally mandated rule for hourly-wage employees is that after an employee works 40 hours in a week, any work that they do after that within that week must be paid at 1.5x the regular rate.

For this example, we won't care about the rates. We just care about knowing, for each job, how many regular and overtime hours were worked. Here's an example:

	Mon	Tue	Wed	Fri	Sat	Sun	Mon (resets)
Hours Worked	5	8	11	9	12	5	8
Regular	5	8	11	9	7	0	8
Overtime	0	0	0	0	5	5	0

As you can see, the first 7 hours of work done on Saturday brings the employee to over 40 hours, and the rest of the hours worked (5) count towards overtime. On Sunday, since the employee is already over 40 hours, all of the hours they work count as overtime. On the next Monday, the workweek resets, and the hours worked are counted as regular.

Implement this behavior in overtime.rb, making all the tests in overtime_spec.rb pass.

Phase 2

A "punchcard" can be classified as either W-2 (worked as an offical employee of the company) or 1099 (worked as an independent contractor) (the names come from the tax forms that those employees file with the IRS). For the purposes of this example, 1099 jobs do not count at all towards overtime and themselves cannot have overtime hours (only regular).

(N.B. While it's extremely uncommon that one employee works different jobs at different tax classes, one possible scenario is when an employee switches over from one type to another within one workweek!)

Implement and test this behavior.

Phase 3

Some (progressive) states have additional overtime laws around how many hours is regular to be working in a single day. A daily overtime threshold, let's say of 8 hours, requires that any work that's done after 8 hours in one day count towards overtime.

Very important to note is that daily overtime interacts with weekly overtime! The federal rule only applies when an employee works more than 40 regular hours in a week, meaning that with a daily threshold, hours past the daily overtime threshold do not count as hours towards the weekly overtime threshold (since they are not regular hours).

Here's an example. Let's say you work 10 hour days four days in a row. Without daily overtime, on the fifth day, you've already worked 40 hours in the week so far, so any more hours would count as overtime. But, if your state has an 8 hour daily overtime threshold, not so. This is what your hours could look like:

	Mon	Tue	Wed	Thu	Fri	Sat	Sun
Hours Worked	10	10	10	10	5	10	4
Regular	8	8	8	8	5	3	0
Overtime	2	2	2	2	0	7	4

Note that Monday-Thursday, you actually only accrue 8 regular (and 2 overtime) hours each day, meaning that on Friday, you've actually only worked 32 regular hours, and so you haven't yet hit the federal weekly threshold. Thus, the hours on Friday count as regular. Then, the first three hours on Saturday do bring us over the weekly threshold, and so any work for the remainder of the week thus counts as overtime.

Implement and test this behavior by allowing a user of the calculator to specify the double_overtime_threshold.

Phase 4

Some other states (ahem, California) implement a double-daily overtime threshold. If your state has one of, let's say 12 hours, it requires that any work that's done after 12 hours in one day counts towards double-overtime (and is paid at a 2x multiplier). This rule can only be in place with a daily overtime rule. Here's an example, for a company with 8 hour daily overtime, and 12 hour double-daily overtime thresholds:

	Mon	Tue	Wed	Thu	Fri	Sat	Sun
Hours Worked	9	12	14	5	7	6	13
Regular	8	8	8	5	7	4	0
Overtime	1	4	4	0	0	2	12
Double-Overtime	0	0	2	0	0	0	1

These hours are basically treated as overtime hours (they just have a different pay) so they don't interact with federal weekly overtime in any way different than in Phase 3.

Implement and test this behavior by allowing a user of the calculator to specify the double_daily_overtime_threshold.

NYDrewReynolds / overtime