module Guard

  # The UI class helps to format messages for the user.
  #
  module UI

    ANSI_ESCAPE_BRIGHT = "1"

    ANSI_ESCAPE_BLACK   = "30"
    ANSI_ESCAPE_RED     = "31"
    ANSI_ESCAPE_GREEN   = "32"
    ANSI_ESCAPE_YELLOW  = "33"
    ANSI_ESCAPE_BLUE    = "34"
    ANSI_ESCAPE_MAGENTA = "35"
    ANSI_ESCAPE_CYAN    = "36"
    ANSI_ESCAPE_WHITE   = "37"

    ANSI_ESCAPE_BGBLACK   = "40"
    ANSI_ESCAPE_BGRED     = "41"
    ANSI_ESCAPE_BGGREEN   = "42"
    ANSI_ESCAPE_BGYELLOW  = "43"
    ANSI_ESCAPE_BGBLUE    = "44"
    ANSI_ESCAPE_BGMAGENTA = "45"
    ANSI_ESCAPE_BGCYAN    = "46"
    ANSI_ESCAPE_BGWHITE   = "47"

    class << self

      color_enabled = nil

      # Show an info message.
      #
      # @param [String] message the message to show
      # @param [Hash] options the options
      # @option options [Boolean] reset whether to clean the output before
      #
      def info(message, options = {})
        unless ENV["GUARD_ENV"] == "test"
          reset_line if options[:reset]
          puts color(message) if message != ''
        end
      end

      # Show a red error message that is prefixed with ERROR.
      #
      # @param [String] message the message to show
      # @param [Hash] options the options
      # @option options [Boolean] reset whether to clean the output before
      #
      def error(message, options = {})
        unless ENV["GUARD_ENV"] == "test"
          reset_line if options[:reset]
          puts color('ERROR: ', :red) + message
        end
      end

      # Show a red deprecation message that is prefixed with DEPRECATION.
      #
      # @param [String] message the message to show
      # @param [Hash] options the options
      # @option options [Boolean] reset whether to clean the output before
      #
      def deprecation(message, options = {})
        unless ENV["GUARD_ENV"] == "test"
          reset_line if options[:reset]
          puts color('DEPRECATION: ', :red) + message
        end
      end

      # Show a debug message that is prefixed with DEBUG and a timestampe.
      #
      # @param [String] message the message to show
      # @param [Hash] options the options
      # @option options [Boolean] reset whether to clean the output before
      #
      def debug(message, options={ })
        unless ENV["GUARD_ENV"] == "test"
          reset_line if options[:reset]
          puts color("DEBUG (#{Time.now.strftime('%T')}): ", :yellow) + message if ::Guard.options && ::Guard.options[:debug]
        end
      end

      # Reset a line.
      #
      def reset_line
        print(color_enabled? ? "\r\e[0m" : "\r\n")
      end

      # Clear the output.
      #
      def clear
        system("clear;")
      end

      private

      # Reset a color sequence.
      #
      # @deprecated
      # @param [String] text the text
      #
      def reset_color(text)
        deprecation('UI.reset_color(text) is deprecated, please use color(text, "") instead.')
        color(text, "")
      end

      # Colorizes a text message.
      #
      # @example
      #   color("Hello World", :red, :bright)
      #
      # @param [String] the text to colorize
      # @param [Array] color_options
      #
      def color(text, *color_options)
        color_code = ""
        color_options.each do |color_option|
          color_option = color_option.to_s
          if color_option != ""
            if !(color_option =~ /\d+/)
              color_option = const_get("ANSI_ESCAPE_#{ color_option.upcase }")
            end
            color_code += ";" + color_option
          end
        end
        color_enabled? ? "\e[0#{ color_code }m#{ text }\e[0m" : text
      end

      # Checks if color output can be enabled.
      #
      # @return [Boolean] whether color is enabled or not
      #
      def color_enabled?
        if @color_enabled.nil?
          if RbConfig::CONFIG['target_os'] =~ /mswin|mingw/i
            if ENV['ANSICON']
              @color_enabled = true
            else
              begin
                require 'rubygems' unless ENV['NO_RUBYGEMS']
                require 'Win32/Console/ANSI'
                @color_enabled = true
              rescue LoadError
                @color_enabled = false
                info "You must 'gem install win32console' to use color on Windows"
              end
            end
          else
            @color_enabled = true
          end
        end

        @color_enabled
      end

    end
  end
end