paint

#!/usr/bin/env ruby

# frozen_string_literal: true

require 'json'
require 'optionparser'

KEYWORDS = %i[color metadata glow_in_the_dark coats].freeze
DEFAULTS = {coats: 3, glow_in_the_dark: true}.freeze

Paint = Struct.new *KEYWORDS, keyword_init: true
paint = Paint[DEFAULTS]

options = ARGV.options do |x|
  x.banner = "Usage: #{x.program_name} [options] color [metadata]"
  x.version = '0.0.1'

  x.accept JSON do |json|
    JSON.parse json
  rescue JSON::ParserError => e
    raise OptionParser::InvalidArgument, e.message
  end

  PositiveInteger = /\A\d+(?:_\d+)*\z/
  x.accept PositiveInteger, PositiveInteger, &:to_i

  x.on '-m', '--metadata=JSON', JSON, 'JSON metadata'
  x.on '-c', '--coats=COUNT', PositiveInteger, "Number of coats of paint (default: #{paint.coats})"
  x.on '--[no-]glow_in_the_dark', "Glow in the dark paint (default: #{paint.glow_in_the_dark})"
end.freeze
options.permute! into: paint

paint.color = ARGV.shift
raise ArgumentError, "missing argument: color\n#{options.banner}" unless paint.color

paint.metadata ||= JSON.parse ARGV.shift if ARGV.any?
paint.metadata ||= JSON.parse STDIN.gets unless STDIN.tty?
paint.metadata ||= JSON.parse ENV.fetch 'METADATA' if ENV.key? 'METADATA'
paint.metadata ||= JSON.parse File.read 'metadata.json' if File.exist? 'metadata.json'

p paint

paint_example.sh

paint -v
# paint 0.0.1

paint -h
# Usage: paint [options] color [metadata]
#     -m, --metadata=JSON              JSON metadata
#     -c, --coats=COUNT                Number of coats of paint (default: 3)
#         --[no-]glow_in_the_dark      Glow in the dark paint (default: true)

paint
# Traceback (most recent call last):
# ./paint:34:in `<main>': missing argument: color (ArgumentError)
# Usage: paint [options] color [metadata]

paint red
# #<struct Paint color="red", metadata=nil, glow_in_the_dark=true, coats=3>

paint green -c1 --no-glow
# #<struct Paint color="green", metadata=nil, glow_in_the_dark=false, coats=1>

paint --metadata="[1,2,3]" red
# #<struct Paint color="red", metadata=[1, 2, 3], glow_in_the_dark=true, coats=3>

paint red "[1,2,3]"
# #<struct Paint color="red", metadata=[1, 2, 3], glow_in_the_dark=true, coats=3>

echo "[1,2,3]" | paint red
# #<struct Paint color="red", metadata=[1, 2, 3], glow_in_the_dark=true, coats=3>

METADATA="[1,2,3]" paint red
# #<struct Paint color="red", metadata=[1, 2, 3], glow_in_the_dark=true, coats=3>

echo "[1,2,3]" > metadata.json
paint red
# #<struct Paint color="red", metadata=[1, 2, 3], glow_in_the_dark=true, coats=3>