Technical Challenge

readme.md

Leave Balance Calculation Challenge

Overview

Tilt works by tracking how much time off an employee has taken. In this exercise an employee may take a maximum of 12 weeks of leave per 12-month period.

Your task is to calculate the number of remaining leave hours from the initial 12-week allocation, using the provided as_of_date.

Tracking Methods

The 12-month period is determined by a given tracking_method.

1. "calendar"

The period is January 1 through December 31 of the year containing the as_of_date.

2. "fixed"

The period begins on the date the employee was hired and resets every 12 months.

Rules and Assumptions

• An employee can take a total of 12-weeks of leave per 12-month period.
• The employee works 40 hours per week (Monday–Friday).
• Leave is taken in full weeks only.
• Each LeaveEvent represents one or more full weeks.
• Each LeaveEvent is in a single 12-month period and will not cross into the next period.
• Ignore holidays.
• All dates are valid and formatted %Y-%m-%d.

Main Task

Implement the calendar tracking method inside:

calculate_remaining_fmla_hours(as_of_date: str) -> float

The function must:

1. Count leave used within that period up to and including as_of_date
2. Return remaining hours

Followup Task

Once the calendar method is working, add support for the fixed method inside calculate_remaining_fmla_hours

main.py

#!/bin/python3

from datetime import date


class Employee:
    def __init__(self, start_date_str):
        self.start_date = date.fromisoformat(start_date_str)


class LeaveEvent:
    def __init__(self, employee, start_date_str, end_date_str):
        self.employee = employee
        self.start_date = date.fromisoformat(start_date_str)
        self.end_date = date.fromisoformat(end_date_str)


class FMLATracker:
    def __init__(self, tracking_method, employee, leave_events):
        self.tracking_method = tracking_method
        self.employee = employee
        self.leave_events = leave_events

    @staticmethod
    def get_date_difference_days(date_from, date_to):
        return (date_to - date_from).days

    def calculate_remaining_fmla_hours(self, as_of_date_str):
        as_of_date = date.fromisoformat(as_of_date_str)
        as_of_date_year = as_of_date.year

        employee_start_date = self.employee.start_date

        cecs = date(as_of_date_year, employee_start_date.month, employee_start_date.day)

        cece = date(
            as_of_date_year + 1,
            employee_start_date.month,
            employee_start_date.day,
        )

        total_starting_time = 12 * 40

        weeks_taked = 0

        for leave in self.leave_events:
            if leave.start_date >= as_of_date:
                continue

            if (
                self.tracking_method == "calendar"
                and as_of_date_year != leave.start_date.year
            ):
                continue

            if self.tracking_method == "fixed" and (
                leave.start_date <= cecs or leave.end_date >= cece
            ):
                continue

            days_taked = FMLATracker.get_date_difference_days(
                leave.start_date, leave.end_date
            )

            weeks_taked += (days_taked + 1) / 7

        total_taked_time = weeks_taked * 40

        return total_starting_time - total_taked_time


if __name__ == "__main__":
    scenarios = [("fixed", 120.0), ("calendar", 40.0)]
    as_of_date_str = "2021-12-01"

    employee = Employee("2020-03-01")
    leave_events = [
        LeaveEvent(employee, "2020-07-05", "2020-07-18"),
        LeaveEvent(employee, "2021-02-07", "2021-02-20"),
        LeaveEvent(employee, "2021-04-04", "2021-04-24"),
        LeaveEvent(employee, "2021-08-01", "2021-09-11"),
    ]
    for scenario in scenarios:
        tracking_method, expected = scenario
        tracker = FMLATracker(
            tracking_method,
            employee,
            leave_events,
        )
        result = tracker.calculate_remaining_fmla_hours(as_of_date_str)

        if result != scenario[1]:
            status_message = "FAILED CASE"
        else:
            status_message = "SUCCESSFUL CASE"

        print(
            f"{status_message}\n"
            f"Tracking Method: {tracking_method}\n"
            f"Expected: {expected}\n"
            f"Actual: {result}\n"
        )