habit_tracker.py

import calendar
import argparse
from datetime import datetime, timedelta
from PIL import Image, ImageDraw, ImageFont


def generate_calendar(year, filename):

    # Determine the start and end dates of the year
    start_date = datetime(year, 1, 1)
    end_date = datetime(year, 12, 31)

    # Determine the number of days in the year
    days_in_year = (end_date - start_date).days + 1

    # Create an image
    cell_size = 20
    gap = 2
    margin = 40
    weeks_in_year = (days_in_year + start_date.weekday()) // 7 + 1
    img_width = cell_size * weeks_in_year + \
        margin * 2 + gap * (weeks_in_year - 1)
    img_height = cell_size * 7 + margin * 2
    image = Image.new("RGB", (img_width, img_height), "white")
    draw = ImageDraw.Draw(image)

    # Load a font
    try:
        font = ImageFont.truetype("arial.ttf", 12)
    except IOError:
        font = ImageFont.load_default()

    # Draw month labels
    month_starts = {}
    for month in range(1, 13):
        month_start = datetime(year, month, 1)
        month_start_week = (month_start - start_date).days // 7
        month_starts[month] = month_start_week

    for month, week in month_starts.items():
        month_name = calendar.month_abbr[month]
        x_pos = margin + week * (cell_size + gap)
        draw.text((x_pos, margin - 20), month_name, fill="black", font=font)

    # Draw day labels
    days = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    for i, day in enumerate(days):
        y_pos = margin + i * (cell_size + gap)
        draw.text((margin - 30, y_pos + cell_size // 4),
                  day, fill="black", font=font)

    # Fill the calendar with cells
    for day in range(days_in_year):
        current_date = start_date + timedelta(days=day)
        week = (day + start_date.weekday()) // 7
        day_of_week = current_date.weekday()
        x = margin + week * (cell_size + gap)
        y = margin + day_of_week * (cell_size + gap)

        # Draw a rounded rectangle as a cell
        draw.rounded_rectangle([x, y, x + cell_size - 1, y + cell_size - 1],
                               3, fill="white", outline="black")

    # Save the image
    image.save(filename)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("year", type=int, help="The year for the tracker")
    parser.add_argument("--filename", type=str,
                        help="The output filename", default="tracker.png")

    args = parser.parse_args()
    generate_calendar(args.year, args.filename)