require 'rundock'
require 'logger'
require 'ansi/code'

module Rundock
  module Logger
    class LogEntity
      attr_accessor :severity
      attr_accessor :datetime
      attr_accessor :progname
      attr_accessor :message
      attr_accessor :indent_depth

      def initialize(severity, datetime, progname, msg, indent_depth, formatter)
        @severity = severity
        @datetime = datetime
        @progname = progname
        @message  = msg
        @indent_depth = indent_depth
        @formatter = formatter
      end

      def formatted_message
        @message unless @formatter
        @formatter.formatted_message(@severity, @datetime, @progname, @message)
      end
    end

    class Formatter
      attr_accessor :colored
      attr_accessor :indent_depth
      attr_accessor :color
      attr_accessor :show_header
      attr_accessor :short_header
      attr_accessor :date_header
      attr_accessor :buffer

      def initialize(*args)
        super
        @indent_depth = 0
        @buffer = []
        @rec = false
        @lock = false
      end

      def call(severity, datetime, progname, msg)
        out = formatted_message(severity, datetime, progname, msg)
        @buffer << LogEntity.new(severity, datetime, progname, msg, indent_depth, self) if @rec

        if colored
          colorize(out, severity)
        else
          out
        end
      end

      def indent
        add_indent
        yield
      ensure
        reduce_indent
      end

      def add_indent
        @indent_depth += 1
      end

      def reduce_indent
        @indent_depth -= 1 if @indent_depth > 0
      end

      def color(code)
        prev_color = @color
        @color = code
        yield
      ensure
        @color = prev_color
      end

      def flush
        return nil if @lock
        ret = @buffer.dup
        @buffer.clear
        ret
      end

      def on_rec
        @rec = true unless @lock
      end

      def off_rec
        @rec = false unless @lock
      end

      def rec_lock
        @lock = true
      end

      def rec_unlock
        @lock = false
      end

      def formatted_message(severity, datetime, progname, msg)
        out = if !@show_header
                "%s\n" % [msg2str(msg)]
              elsif !@date_header
                "%5s: %s%s\n" % [
                  severity,
                  ' ' * 2 * indent_depth,
                  msg2str(msg)
                ]
              elsif @short_header
                "%s: %s%s\n" % [severity[0, 1], ' ' * 2 * indent_depth, msg2str(msg)]
              else
                "[%s] %5s: %s%s\n" % [
                  datetime.strftime('%Y-%m-%dT%H:%M:%S.%L'),
                  severity,
                  ' ' * 2 * indent_depth,
                  msg2str(msg)
                ]
              end

        out
      end

      private

      def msg2str(msg)
        case msg
        when ::String
          msg
        when ::Exception
          "#{msg.message} (#{msg.class})\n" << (msg.backtrace || []).join("\n")
        else
          msg.inspect
        end
      end

      def colorize(msg, severity)
        col = if @color
                @color
              else
                case severity
                when 'INFO'
                  :clear
                when 'WARN'
                  :yellow
                when 'ERROR'
                  :red
                else
                  :clear
                end
              end

        ANSI.public_send(col) { msg }
      end
    end

    class << self
      def logger
        @logger ||= create_logger
      end

      private

      def create_logger
        ::Logger.new($stdout).tap do |logger|
          logger.formatter = Formatter.new
        end
      end

      def respond_to_missing?(method, include_private = false)
        logger.respond_to?(method)
      end

      def method_missing(method, *args, &block)
        logger.public_send(method, *args, &block)
      end
    end
  end
end