#!/usr/bin/ruby

require "fileutils"

drive_resources = "/Applications/Google Drive.app/Contents/Resources"

Dir.chdir drive_resources

def remap(filename, suffix = nil)
  suffix = suffix.nil? ? "" : "-#{suffix}"

  filename.sub(/-(?:inverse|dark|light)/, suffix)
end

def inverse
  @inverse ||= Dir["mac-*-inverse{,@2x}.png"]
end

def active
  @active ||= inverse.map { |f| remap(f) }
end

def light
  @light ||= inverse.map { |f| remap(f, "light") }
end

def dark
  @dark ||= inverse.map { |f| remap(f, "dark") }
end

def generate_persistent_assets
  light.each do |persistent|
    next if File.exist? persistent

    source = remap(persistent)
    FileUtils.cp(source, persistent)
  end

  dark.each do |persistent|
    next if File.exist? persistent

    source = remap(persistent, "inverse")
    FileUtils.cp(source, persistent)
  end
end

def copy_assets(mode)
  mapping = case mode
            when "light"
              { dark: "inverse", light: nil }
            when "dark"
              { light: "inverse", dark: nil }
            else fail NotImplementedError
            end

  light.each do |persistent|
    dest = remap(persistent, mapping[:light])
    FileUtils.cp(persistent, dest)
  end

  dark.each do |persistent|
    dest = remap(persistent, mapping[:dark])
    FileUtils.cp(persistent, dest)
  end
end

def remove_persistent_assets
  copy_assets "light"
  (light + dark).each { |f| FileUtils.rm_f(f) }
end

def restart
  %x(killall "Google Drive")
  sleep 30
  %x(open -a "Google Drive")
end

case ARGV[0]
when "dark"
  generate_persistent_assets
  copy_assets "dark"
  restart
when "light"
  generate_persistent_assets
  copy_assets "light"
  restart
when "clean"
  remove_persistent_assets
  restart
else
  $stderr.puts("light or dark?")
  exit 1
end