require 'stringio'

class Cl
  module Ui
    def self.new(ctx, opts)
      const = Test if ctx.test?
      const ||= Silent if opts[:silent]
      const ||= Tty if $stdout.tty?
      const ||= Pipe
      const.new(opts)
    end

    class Base < Struct.new(:opts)
      attr_writer :stdout

      def stdout
        @stdout ||= opts[:stdout] || $stdout
      end

      def puts(*str)
        stdout.puts(*str)
      end
    end

    class Silent < Base
      %i(announce info notice warn error success cmd).each do |name|
        define_method (name) { |*| }
      end
    end

    class Test < Base
      %i(announce info notice warn error success cmd).each do |name|
        define_method (name) do |*args|
          puts ["[#{name}]", *args.map(&:inspect)].join(' ')
        end
      end

      def stdout
        @stdout ||= StringIO.new
      end
    end

    class Pipe < Base
      %i(announce info notice warn error).each do |name|
        define_method (name) do |msg, args = nil, _ = nil|
          puts format_msg(msg, args)
        end
      end

      %i(success cmd).each do |name|
        define_method (name) { |*| }
      end

      private

        def format_msg(msg, args)
          msg = [msg, args].flatten.map(&:to_s)
          msg = msg.map { |str| quote_spaced(str) }
          msg.join(' ').strip
        end

        def quote_spaced(str)
          str.include?(' ') ? %("#{str}") : str
        end
    end

    module Colors
      COLORS = {
        red:    "\e[31m",
        green:  "\e[32m",
        yellow: "\e[33m",
        blue:   "\e[34m",
        gray:   "\e[37m",
        reset:  "\e[0m"
      }

      def colored(color, str)
        [COLORS[color], str, COLORS[:reset]].join
      end
    end

    class Tty < Base
      include Colors

      def announce(msg, args = [], msgs = [])
        msg = format_msg(msg, args, msgs)
        puts colored(:green, with_spacing(msg, true))
      end

      def info(msg, args = [], msgs = [])
        msg = format_msg(msg, args, msgs)
        puts colored(:blue, with_spacing(msg, true))
      end

      def notice(msg, args = [], msgs = [])
        msg = format_msg(msg, args, msgs)
        puts colored(:gray, with_spacing(msg, false))
      end

      def warn(msg, args = [], msgs = [])
        msg = format_msg(msg, args, msgs)
        puts colored(:yellow, with_spacing(msg, false))
      end

      def error(msg, args = [], msgs = [])
        msg = format_msg(msg, args, msgs)
        puts colored(:red, with_spacing(msg, true))
      end

      def success(msg)
        announce(msg)
        puts
      end

      def cmd(msg)
        notice("$ #{msg}")
      end

      private

        def colored(color, str)
          opts[:color] ? super : str
        end

        def format_msg(msg, args, msgs)
          msg = msgs[msg] % args if msg.is_a?(Symbol)
          msg.strip
        end

        def with_spacing(str, space)
          str = "\n#{str}" if space && !@last
          @last = space
          str
        end
    end
  end
end