1 files changed, 23 insertions, 0 deletions
diff --git a/app/helpers/colors_helper.rb b/app/helpers/colors_helper.rb
new file mode 100644
index 00000000000..bc72122220a
--- /dev/null
+++ b/app/helpers/colors_helper.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module ColorsHelper
+  HEX_COLOR_PATTERN = /\A\#(?:[0-9A-Fa-f]{3}){1,2}\Z/.freeze
+
+  def hex_color_to_rgb_array(hex_color)
+    raise ArgumentError, "invalid hex color `#{hex_color}`" unless hex_color =~ HEX_COLOR_PATTERN
+
+    hex_color.length == 7 ? hex_color[1, 7].scan(/.{2}/).map(&:hex) : hex_color[1, 4].scan(/./).map { |v| (v * 2).hex }
+  end
+
+  def rgb_array_to_hex_color(rgb_array)
+    raise ArgumentError, "invalid RGB array `#{rgb_array}`" unless rgb_array_valid?(rgb_array)
+
+    "##{rgb_array.map{ "%02x" % _1 }.join}"
+  end
+
+  private
+
+  def rgb_array_valid?(rgb_array)
+    rgb_array.is_a?(Array) && rgb_array.length == 3 && rgb_array.all?{ _1 >= 0 && _1 <= 255 }
+  end
+end