class Ougai::Logger

def debug(message, ex = nil, data = {})
  super(to_item(message, ex, data))
end

def error(message, ex = nil, data = {})
  super(to_item(message, ex, data))
end

def fatal(message, ex = nil, data = {})
  super(to_item(message, ex, data))
end

def info(message, ex = nil, data = {})
  super(to_item(message, ex, data))
end

def initialize(*args)
  super(*args)
  run_filename = File.basename($0, ".rb")
  hostname = Socket.gethostname
  @formatter = proc do |severity, time, progname, data|
    JSON.generate({
      name: progname || run_filename,
      hostname: hostname,
      pid: $$,
      level: to_level(severity),
      time: time.iso8601(3),
      v: 0
    }.merge(data)) + "\n"
  end
end

def serialize_ex(ex)
  err = {
    name: ex.class.name,
    message: ex.to_s
  }
  if ex.backtrace
    err[:stack] = ex.backtrace.join("\n  ")
  end
  err
end

def to_item(msg, ex, data)
  item = {}
  if ex.nil? && msg.is_a?(Exception)
    item[:msg] = msg.to_s
    item[:err] = serialize_ex(msg)
  elsif ex
    item[:msg] = msg
    if ex.is_a?(Hash)
      item.merge!(ex)
    elsif ex.is_a?(Exception)
      item[:err] = serialize_ex(ex)
      item.merge!(data)
    end
  else
    item[:msg] = msg
    item.merge!(data)
  end
  item
end

def to_level(severity)
  case severity
  when 'INFO'
    30
  when 'WARN'
    40
  when 'ERROR'
    50
  when 'FATAL'
    60
  else # DEBUG
    20
  end
end

def warn(message, ex = nil, data = {})
  super(to_item(message, ex, data))
end