retrospring/app/helpers/theme_helper.rb

# frozen_string_literal: true

module ThemeHelper
  ATTRIBUTE_MAP = {
    "primary_color"      => %w[primary primary-rgb],
    "primary_text"       => "primary-text",
    "danger_color"       => "danger",
    "danger_text"        => "danger-text",
    "warning_color"      => "warning",
    "warning_text"       => "warning-text",
    "info_color"         => "info",
    "info_text"          => "info-text",
    "success_color"      => "success",
    "success_text"       => "success-text",
    "dark_color"         => "dark",
    "dark_text"          => "dark-text",
    "light_color"        => "light",
    "light_text"         => "light-text",
    "raised_background"  => %w[raised-bg raised-bg-rgb],
    "raised_text"        => "raised-text",
    "raised_accent"      => %w[raised-accent raised-accent-rgb],
    "raised_accent_text" => "raised-accent-text",
    "background_color"   => "background",
    "body_text"          => "body-text",
    "input_color"        => "input-bg",
    "input_text"         => "input-text",
    "input_placeholder"  => "input-placeholder",
    "muted_text"         => "muted-text",
  }.freeze

  def get_theme_css(theme, wrap = true)
    body = wrap ? ":root {\n" : ""
    body += theme.to_css
    body += "}" if wrap
    body
  end

  def get_color_for_key(key, color)
    hex = get_hex_color_from_theme_value(color)

    if key.include?("text") || key.include?("placeholder") || key.include?("rgb")
      get_decimal_triplet_from_hex(hex)
    else
      "##{hex}"
    end
  end

  def theme_color
    theme = active_theme_user&.active_theme
    if theme
      theme.theme_color
    else
      "#5e35b1"
    end
  end

  def mobile_theme_color
    theme = active_theme_user&.active_theme
    if theme
      theme.mobile_theme_color
    else
      "#f0edf4"
    end
  end

  def active_theme_user
    user = @user || @answer&.user # rubocop:disable Rails/HelperInstanceVariable

    if user&.active_theme.present? && should_show_foreign_theme?
      user
    elsif user_signed_in?
      current_user
    end
  end

  def should_show_foreign_theme? = current_user&.show_foreign_themes || !user_signed_in?

  def get_hex_color_from_theme_value(value)
    "0000000#{value.to_s(16)}"[-6, 6]
  end

  def get_decimal_triplet_from_hex(value)
    hexes = value.split(/(.{2})/).reject(&:empty?)
    hexes.map(&:hex).join(", ")
  end

  def rgb_values_from_hex(value)
    [
      (value & 0xFF0000) >> 16, # R
      (value & 0x00FF00) >> 8, # G
      value & 0x0000FF # B
    ]
  end

  def rgb_to_hex(rgb_values)
    rgb_values.map.with_index { |v, i| v << ((2 - i) * 8) }.reduce(&:+).to_s(16)
  end

  def lighten(value, amount = 0.25)
    rgb_to_hex(rgb_values_from_hex(value).map { |v| [(v + (255 * amount)).round, 255].min })
  end
end