render.py

import os
import webbrowser
import math
from datetime import datetime

import typer
from mako.lookup import TemplateLookup
import cairosvg


def compute_svg_settings(unvaccinated: int, vaccinated: int):
    """
    These should have been calculated directly in the view, but for the life of me I couldn't figure out how to 
    pass the calculated values between derived & base.
    Some convoluted info is here:
    https://mako-discuss.narkive.com/DITZe7SV/how-can-i-pass-variable-from-child-to-the-parent-template
    but it doesn't seem to work when using template arguments for the calculations
    :return:
    """
    max_width = 1024

    sprite_height = 60
    sprite_width = 25

    sprite_distance_x = 5
    sprite_distance_y = 5

    x_start = 30
    y_start = 220

    y_bottom_padding = 120
    x_right_padding = 20

    sprites_per_row = math.floor((max_width - x_start - x_right_padding) / (sprite_width + sprite_distance_x))
    sprite_rows = math.ceil((unvaccinated + vaccinated) / sprites_per_row)

    row_height = sprite_height + sprite_distance_y
    max_height = y_start + sprite_rows * row_height + y_bottom_padding

    return {
        'max_width': max_width, 'max_height': max_height,
        'sprite_height': sprite_height, 'sprite_width': sprite_width,
        'sprite_distance_x': sprite_distance_x, 'sprite_distance_y': sprite_distance_y,
        'x_start': x_start, 'y_start': y_start,
        'y_bottom_padding': y_bottom_padding,
        'x_right_padding': x_right_padding,
        'sprites_per_row': sprites_per_row, 'sprite_rows': sprite_rows,
        'row_height': row_height
    }


def main(unvaccinated: int, vaccinated: int, previous: int, svg_file: str = './out/out.svg', png_file: str = './out/out.png'):
    """
    Renders the infographic and opens it in the browser.

    :param unvaccinated: How many deaths of unvaccinated people
    :param vaccinated: How many deaths of vaccinated people
    :param previous: How many deaths out of the total are outside the reference interval (last 24 hrs)
    :return:
    """
    date = datetime.today()
    
    template_dir = './templates'
    lookup = TemplateLookup(directories=[template_dir])
    template = lookup.get_template('derived.mako')

    rendered_content = template.render(unvaccinated=unvaccinated, vaccinated=vaccinated, total_deaths=unvaccinated + vaccinated,
                               previous_deaths=previous,
                               date=date, **compute_svg_settings(unvaccinated, vaccinated))

    with open(svg_file, 'w') as file:
        file.write(rendered_content)

    cairosvg.svg2png(url=svg_file, write_to=png_file)
    webbrowser.open('file://' + os.path.realpath(png_file))


if __name__ == "__main__":
    typer.run(main)