class Ougai::Logger

def self.broadcast(logger)
  Module.new do |mdl|
    ::Logger::Severity.constants.each do |severity|
      method_name = severity.downcase.to_sym
      mdl.send(:define_method, method_name) do |*args|
        logger.send(method_name, *args)
        super(*args)
      end
    end
  end
end

def build_log(args)
  @with_fields.merge(to_item(args))
end

def create_formatter
  Formatters::Bunyan.new
end

def create_item_with_1arg(msg)
  item = {}
  if msg.is_a?(Exception)
    item[:msg] = msg.to_s
    set_exc(item, msg)
  elsif msg.is_a?(Hash)
    item[:msg] = @default_message unless msg.key?(:msg)
    item.merge!(msg)
  else
    item[:msg] = msg.to_s
  end
  item
end

def create_item_with_2args(msg, ex)
  item = {}
  if ex.is_a?(Exception)
    item[:msg] = msg.to_s
    set_exc(item, ex)
  elsif ex.is_a?(Hash)
    item.merge!(ex)
    if msg.is_a?(Exception)
      set_exc(item, msg)
    else
      item[:msg] = msg.to_s
    end
  end
  item
end

def create_item_with_3args(msg, ex, data)
  item = {}
  set_exc(item, ex) if ex.is_a?(Exception)
  item.merge!(data) if data.is_a?(Hash)
  item[:msg] = msg.to_s
  item
end

def debug(message = nil, ex = nil, data = nil, &block)
  return true if level > DEBUG
  args = block ? yield : [message, ex, data]
  add(DEBUG, build_log(args))
end

def error(message = nil, ex = nil, data = nil, &block)
  return true if level > ERROR
  args = block ? yield : [message, ex, data]
  add(ERROR, build_log(args))
end

def fatal(message = nil, ex = nil, data = nil, &block)
  return true if level > FATAL
  args = block ? yield : [message, ex, data]
  add(FATAL, build_log(args))
end

def info(message = nil, ex = nil, data = nil, &block)
  return true if level > INFO
  args = block ? yield : [message, ex, data]
  add(INFO, build_log(args))
end

def initialize(*args)
  super(*args)
  @default_message = 'No message'
  @exc_key = :err
  @formatter = create_formatter
  @with_fields = {}
end

def set_exc(item, exc)
  item[@exc_key] = @formatter.serialize_exc(exc)
end

def to_item(args)
  msg, ex, data = args
  if ex.nil?
    create_item_with_1arg(msg)
  elsif data.nil?
    create_item_with_2args(msg, ex)
  elsif msg
    create_item_with_3args(msg, ex, data)
  else # No args
    { msg: @default_message }
  end
end

def unknown(message = nil, ex = nil, data = nil, &block)
  args = block ? yield : [message, ex, data]
  add(UNKNOWN, build_log(args))
end

def warn(message = nil, ex = nil, data = nil, &block)
  return true if level > WARN
  args = block ? yield : [message, ex, data]
  add(WARN, build_log(args))
end