convert images to "squared" PNGs

square_fit

#!/usr/bin/env ruby
# frozen_string_literal: true

#
# INSTALLATION
#
# ln -s ${PWD}/square_fit $(brew --prefix)/bin/
# sudo ln -s ${PWD}/square_fit /usr/local/bin/
#
# PREREQUISITES
#
# brew install media-info
# brew install imagemagick
#

require 'json'

# rubocop:disable Style/BlockDelimiters
# rubocop:disable Style/CharacterLiteral

ARGV.each do |input|
  next unless File.size? input

  output = input.gsub(/#{File.extname(input)}\z/, '_squared.png')

  next if File.size? output

  mediainfo = JSON.parse(`mediainfo --Output=JSON \"#{input}\"`)

  image_track = mediainfo['media']['track'].find { |track|
    track['@type'] == 'Image'
  }

  next unless image_track

  width = image_track['Width'].to_i
  height = image_track['Height'].to_i

  next if width == height

  size = [width, height].max
  border = ENV.fetch('BORDER', '0').to_i
  size += border

  background = ENV.fetch('BG', 'white')

  #
  # for transparent background:
  #
  # -background \"rgba(0,0,0,0)\"
  #

  cmd = <<~"EOCMD".gsub(?\n, ' ')
    convert
    -define png:size=\"#{size}x#{size}\"
    \"#{input}\"
    -background #{background}
    -gravity center
    -extent \"#{size}x#{size}\"
    \"#{output}\"
  EOCMD

  system(cmd)
end

# rubocop:enable Style/CharacterLiteral
# rubocop:enable Style/BlockDelimiters

# That's all Folks!