module LogStuff

# File lib/logstuff.rb, line 33
def self.log(severity = 'info', *args, &block)

  return unless block_given?

  # Ignore if we are not logging this severity
  return unless logger.send("#{severity}?")

  local_fields = {}
  local_tags   = Set.new
  args.each do |arg|
    case arg
      when Hash
        local_fields.merge!(arg)
      when Symbol
        local_tags.add(arg)
      when Array
        local_tags.merge(arg)
    end
  end

  msg = yield

  event = LogStash::Event.new('@source' => source,
                              '@severity' => severity,
                              'message' => msg,
                              '@tags' => get_thread_current(:current_tags).merge(local_tags).to_a,
                              '@fields' => get_thread_current(:current_fields).merge(local_fields)
  )
  logger << event.to_json + "\n"
  true
end

# File lib/logstuff.rb, line 15
def get_thread_current(name)
  Thread.current[NAMESPACE] ||= {
      :current_fields => {},
      :current_tags   => Set.new
  }
  Thread.current[NAMESPACE][name].dup
end

# File lib/logstuff.rb, line 85
def metadata(*pairs, &block)
  original_fields = get_thread_current(:current_fields) || {}
  current_fields  = original_fields.dup
  pairs.flatten.each do |pair|
    pair.each do |k, v|
      current_fields[k.to_sym] = v
    end
  end
  set_thread_current(:current_fields, current_fields)
  yield
  set_thread_current(:current_fields, original_fields)
  true
end

# File lib/logstuff.rb, line 108
def new_logger(path, loglevel)
  if path.class == String
    FileUtils.touch path # prevent autocreate messages in log
  end
  newlogger = Logger.new path
  newlogger.level = loglevel unless loglevel.nil?
  newlogger
end

# File lib/logstuff.rb, line 24
def set_thread_current(name, value)
  Thread.current[NAMESPACE]       ||= {
      :current_fields => {},
      :current_tags   => Set.new
  }
  Thread.current[NAMESPACE][name] = value.dup
end

# File lib/logstuff.rb, line 100
def setup(params)
  require 'logstash-event'
  self.logger_path = params[:path] || "logstuff.json"
  self.logger = params[:logger] || new_logger(self.logger_path, params[:loglevel])
  self.source = params[:source] || 'logstuff'
end

# File lib/logstuff.rb, line 75
def tag(*tags, &block)
  original_tags = get_thread_current(:current_tags)
  current_tags  = original_tags.dup + tags.flatten
  set_thread_current(:current_tags, current_tags)
  yield
  set_thread_current(:current_tags, original_tags)
  true
end