module Honeybadger::Config::Yaml

def self.dotify_keys(hash, key_prefix = nil)
  {}.tap do |new_hash|
    hash.each_pair do |k,v|
      k = [key_prefix, k].compact.join('.')
      if v.kind_of?(Hash)
        new_hash.update(dotify_keys(v, k))
      else
        next if DISALLOWED_KEYS.include?(k.to_sym)
        new_hash[k.to_sym] = v
      end
    end
  end
end

def self.load_yaml(path)
  begin
    # This uses `YAML.unsafe_load` to support loading arbitrary Ruby
    # classes, such as !ruby/regexp. This was the default behavior prior
    # to Psych 4. https://bugs.ruby-lang.org/issues/17866
    method = YAML.respond_to?(:unsafe_load) ? :unsafe_load : :load
    yaml = YAML.send(method, ERB.new(path.read).result)
  rescue => e
    config_error = ConfigError.new(e.to_s)
    if e.backtrace
      backtrace = e.backtrace.map do |line|
        if line.start_with?('(erb)'.freeze)
          line.gsub('(erb)'.freeze, path.to_s)
        else
          line
        end
      end
      config_error.set_backtrace(backtrace)
    end
    raise config_error
  end
  case yaml
  when Hash
    yaml
  when NilClass, FalseClass
    {}
  else
    raise ConfigError, "The configuration file #{path} is invalid."
  end
end

def self.new(path, env = 'production')
  path = path.kind_of?(Pathname) ? path : Pathname.new(path)
  if !path.exist?
    raise ConfigError, "The configuration file #{path} was not found."
  elsif !path.file?
    raise ConfigError, "The configuration file #{path} is not a file."
  elsif !path.readable?
    raise ConfigError, "The configuration file #{path} is not readable."
  end
  yaml = load_yaml(path)
  yaml.merge!(yaml[env]) if yaml[env].kind_of?(Hash)
  dotify_keys(yaml)
end