#!/usr/bin/env ruby
# Enconding: UTF-8
# Frozen_String_Literal: false
# Warn_Indent: true

# Written by Sourav Goswami <souravgoswami@protonmail.com>

## Future Ruby release may have frozen string literals.
# It's good to keep it false so that our program doesn't crash in the future.

# Version should be floating point number
VERSION = "0.1".freeze

# Make sure sync is enabled
STDOUT.sync = STDERR.sync = true

# Check Ruby version
abort "Error! Atleast Ruby 2.4 is needed! You are running #{RUBY_VERSION} (#{RUBY_PLATFORM})" if RUBY_VERSION.split(?.).first(2).join.to_i < 24

### User definable ###
## Location of the base cursors
BASE = File.join(__dir__, 'oreo_base_cursors')

## Output directory
OUT_DIR = File.join(File.expand_path('..', __dir__), 'src')

## Content of index.theme inside each theme
INDEX_THEME = proc do |x|
	<<~EOF
		[Icon Theme]
		Name=Oreo #{x.split(?_).map(&:capitalize).join(?\s)} Cursors
		Comment=design by varlesh | colour by #{Process.argv0}
	EOF
end

### Code ###

# Monkey Patches for Ruby 2.4 to 2.5
Kernel.class_exec { define_method(:then) { |&block| block === self } } unless Kernel.respond_to?(:then)
Dir.define_singleton_method(:children) { |arg| Dir.entries(arg).drop(2) } unless Dir.respond_to?(:children)

puts "Error with the output directory. Does it exist? Is it writable?" unless File.writable?(OUT_DIR)

class String
	def colourize
		colours, line_length, temp = [], -1, ''
		sample_colour, rev = rand(7), rand < 0.5

		each_line do |c|
			n, i = c.length, -1

			if line_length != n
				step, line_length = 255.0./(n), n
				colours.clear

				while (i += 1) < n
					colours.<<(
						case sample_colour
							when 0 then i.*(step).then { |l| [ l.*(2).to_i.clamp(0, 255), l.to_i.clamp(0, 255), 255.-(l).to_i.clamp(0, 255) ] }
							when 1 then i.*(step).then { |l| [ 255, 255.-(l).to_i.clamp(0, 255), l.to_i.clamp(0, 255) ] }
							when 2 then i.*(step).then { |l| [ l.to_i.clamp(0, 255), 255.-(l).to_i.clamp(0, 255), l.to_i.clamp(0, 255) ] }
							when 3 then i.*(step).then { |l| [ l.*(2).to_i.clamp(0, 255), 255.-(l).to_i.clamp(0, 255), 100.+(l / 2).to_i.clamp(0, 255) ] }
							when 4 then i.*(step).then { |l| [ 30, 255.-(l / 2).to_i.clamp(0, 255), 110.+(l / 2).to_i.clamp(0, 255) ] }
							when 5 then i.*(step).then { |l| [ 255.-(l * 2).to_i.clamp(0, 255), l.to_i.clamp(0, 255), 200 ] }
							when 6 then i.*(step).then { |l| [ 50.+(255 - l).to_i.clamp(0, 255), 255.-(l / 2).to_i.clamp(0, 255), (l * 2).to_i.clamp(0, 255) ] }
							else  i.*(step).then { |l| [ l.*(2).to_i.clamp(0, 255), 255.-(l).to_i.clamp(0, 255), 100.+(l / 2).to_i.clamp(0, 255) ] }
						end
					)
				end

				colours.reverse! if rev
			end

			i = -1
			temp.concat "\e[38;2;#{colours[i][0]};#{colours[i][1]};#{colours[i][2]}m#{c[i]}" while (i += 1) < n
		end

		STDOUT.print(temp, "\e[0m\n".freeze)
	end
end

## Grab arguments

# Show help
if ARGV.any? { |x| x[/\A\-(\-help|h)\Z/] }
	<<~EOF.colourize
		This program is used to generate oreo cursors.
		It can generate cursor of your defined colours.

		\u2B23 Arguments:
			1. --help | -h\t\tShow this help
			2. --config= | -c=\t\tSpecify the configration file
			\t\t\t\t[defaults to colours.conf]
			3. --version | -v\t\tShow version

		\u2B23 Config File:
			You need a config file. A sample file will look like this:

			# Name = Colour LabelColour ShadowColour ShadowOpacity
			black = #424242 #fff #111 #0.4
			spark_violet = #6435C9

			# This is a comment.
			# By default, LabelColour is #ffffff, ShadowColour is #000
			# And ShadowOpacity is 0.3
	EOF

	exit
end

# Grab the -v | --version option
if ARGV.any? { |x| x[/\A\-(\-version|v)\Z/] }
	"You are running #{Process.argv0} version #{VERSION}".colourize
	exit
end

# Grab the configuration file from arguments, defaults to colours.conf
config_file, cf = ARGV.select { |x| x[/\A\-(\-config|c)=.+\Z/] }[-1], nil
cf = config_file.split(?=)[1] if config_file

CONFIG_FILE = if cf && File.readable?(cf)
	cf
elsif cf && !File.readable?(cf)
	puts ":: #{cf} is not readable, using colours.conf"
	sleep 1
	File.join(__dir__, 'colours.conf')
else
	File.join(__dir__, 'colours.conf')
end

require 'io/console'
tw = STDOUT.isatty ? STDOUT.winsize[1] : 80

# Art generated from https://fsymbols.com/generators/carty/
# Used utf-8, editors messes up with the font and makes development harder.
# To generate utf-8 chars to utf-8 codes using String#dump
<<~EOF.lines.map { |x| '//' + ?\s * (tw / 2.0 - x.length / 2 - 2).clamp(0, Float::INFINITY) + x.chomp + ?\s * (tw / 2 - x.length / 2.0 - 2).to_i.clamp(0, Float::INFINITY) + '//' + ?\n}.join.colourize
	#{?- * (tw / 1.25)}

	\u2591\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2588\u2588\u2588\u2557\u2591
	\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u2550\u2550\u255D\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557
	\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2591\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551
	\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u255D\u2591\u2591\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551
	\u255A\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u255A\u2588\u2588\u2588\u2588\u2588\u2554\u255D
	\u2591\u255A\u2550\u2550\u2550\u2550\u255D\u2591\u255A\u2550\u255D\u2591\u2591\u255A\u2550\u255D\u255A\u2550\u2550\u2550\u2550\u2550\u2550\u255D\u2591\u255A\u2550\u2550\u2550\u2550\u255D\u2591

	\u2591\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2557\u2591\u2591\u2591\u2588\u2588\u2557\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2591\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2591\u2588\u2588\u2588\u2588\u2588\u2588\u2557
	\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2551\u2591\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u2550\u2550\u255D\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2554\u2550\u2550\u2550\u2550\u255D
	\u2588\u2588\u2551\u2591\u2591\u255A\u2550\u255D\u2588\u2588\u2551\u2591\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u255A\u2588\u2588\u2588\u2588\u2588\u2557\u2591\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u255A\u2588\u2588\u2588\u2588\u2588\u2557\u2591
	\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2557\u2588\u2588\u2551\u2591\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2591\u255A\u2550\u2550\u2550\u2588\u2588\u2557\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2554\u2550\u2550\u2588\u2588\u2557\u2591\u255A\u2550\u2550\u2550\u2588\u2588\u2557
	\u255A\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u255A\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u255A\u2588\u2588\u2588\u2588\u2588\u2554\u255D\u2588\u2588\u2551\u2591\u2591\u2588\u2588\u2551\u2588\u2588\u2588\u2588\u2588\u2588\u2554\u255D
	\u2591\u255A\u2550\u2550\u2550\u2550\u255D\u2591\u2591\u255A\u2550\u2550\u2550\u2550\u2550\u255D\u2591\u255A\u2550\u255D\u2591\u2591\u255A\u2550\u255D\u255A\u2550\u2550\u2550\u2550\u2550\u255D\u2591\u2591\u255A\u2550\u2550\u2550\u2550\u255D\u2591\u255A\u2550\u255D\u2591\u2591\u255A\u2550\u255D\u255A\u2550\u2550\u2550\u2550\u2550\u255D\u2591

	#{?- * (tw / 1.25)}
EOF

colours = {}
def colour_validation!(colour, i, silent = false)
		# Colours are uppercased
		colour.upcase!

		# Spaces are trimmed
		colour.strip!

		# Make sure all the colour characters are valid hex
		if !!colour[/[^a-fA-F0-9#]/] || ![3, 6].include?(colour.start_with?(?#) ? colour[1..-1].length : colour.length)
			puts %Q(:: Line #{i.next}: "#{colour}" is not a valid colour) unless silent
			return false
		end

		# Make sure colour starts with #
		colour.prepend(?#) unless colour.start_with?(?#)

		# Make sure colour is 6 characters long
		colour.replace(?# + colour.chars[1..-1].map { |y| y + y }.join) if colour.length == 4
		true
end

if File.readable?(CONFIG_FILE)
	puts "Reading configuration file #{CONFIG_FILE}\n\n"

	IO.readlines(CONFIG_FILE).each_with_index do |x, i|
		next if x.start_with?(?#) || x.strip.empty?

		# Label colour
		label = '#fff'
		l = +x.split[3].to_s
		label = l if colour_validation!(l, i, true)
		colour_validation!(label, 0)

		# Shadow colour
		shadow = '#000'
		s = +x.split[4].to_s
		shadow = s if colour_validation!(s, i, true)
		colour_validation!(shadow, 0)

		# Shadow opacity
		shadow_opacity = '0.3'
		so = x.split.map(&:strip).select { |y| y.to_f.to_s == y || y.to_i.to_s == y }[-1]
		shadow_opacity = +so.strip if so

		# Get cursor name and colour
		name, colour = x.split(?=).then { |y| [+y[0].to_s.strip, +y[1].to_s.split[0].to_s.strip] }

		# Make sure colour name is not 0 characters long or too long
		if name.length.zero? || name.length > 512
			puts %Q(:: Line #{i.next}: "#{name}" is not a valid name.)
			next
		end

		next unless colour_validation!(colour, i)

		# Print RGB in the terminal, respective to the config file
		r, g, b = colour[1..2].to_i(16), colour[3..4].to_i(16), colour[5..6].to_i(16)
		lr, lg, lb = label[1..2].to_i(16), label[3..4].to_i(16), label[5..6].to_i(16)
		sr, sg, sb = shadow[1..2].to_i(16), shadow[3..4].to_i(16), shadow[5..6].to_i(16)

		puts ":: Detected: \e[1;38;2;#{r};#{g};#{b}m#{name}:"\
			"\e[0m \e[38;2;#{r};#{g};#{b}m#{colour}"\
			"\e[0m | \e[38;2;#{lr};#{lg};#{lb}mLabel"\
			"\e[0m | \e[38;2;#{sr};#{sg};#{sb}mShadow(#{shadow_opacity})"\
			"\e[0m |"

		colours.merge!(name => [colour, label, shadow, shadow_opacity])
	end
else
	abort ":: Unable to read #{CONFIG_FILE}"
end

begin
	colours.each do |x, y|
		# Make the directory name is the colour name mentioned in the config file
		dirname = File.join(OUT_DIR, "oreo_#{x}_cursors")

		# Make the directory mentioned in the config file
		# We will store svg files here, mapped to colours
		Dir.mkdir(dirname) unless Dir.exist?(dirname)

		# Delete files from dirname if it's not empty. The reason is to get rid of excess files.
		Dir.children(dirname).each do |x|
			file = File.join(dirname, x)
			File.delete(file) if File.file?(file)
		end

		# Iterate over each base files and add colours to them,
		# and write them to the directories fetched from configuration file
		Dir.glob("#{BASE}/*svg.oreo").each do |z|
			if File.file?(z)
				# Destination file has the name.svg converted from name.svg.oreo
				dest_file = File.join(dirname, File.basename(z).split(?..freeze).tap(&:pop).join(?..freeze))

				# Read the base file
				data = IO.read(z)

				# Change Background Colour
				data.gsub!(/\{\{ background \}\}/i, y[0])

				# Change Label Colour
				data.gsub!(/\{\{ label \}\}/i, y[1])

				# Change Shadow Colour
				data.gsub!(/\{\{ shadow \}\}/i, y[2])

				# Change Shadow Opacity
				data.gsub!(/\{\{ shadow\s*opacity \}\}/i, y[3])

				# Write converted data to destination file
				IO.write(dest_file, data, encoding: 'UTF-8'.freeze)
			end
		end

		# Write to index file
		IO.write(File.join(dirname, 'index.theme'.freeze), INDEX_THEME.call(x), encoding: 'UTF-8'.freeze)

		c = y[0]
		r, g, b = c[1..2].to_i(16), c[3..4].to_i(16), c[5..6].to_i(16)

		puts ":: Created \e[38;2;#{r};#{g};#{b}m#{dirname}/\e[0m"
	end
rescue Exception
	puts "\n\nUh oh! Program crashed!\n\t#{$!.backtrace.join(?\n)}\n\t#{$!}".colourize
else
	puts ":: Successfully created src/ files"
end