module Faraday::NestedParamsEncoder

def self.decode(query)
  return nil if query == nil
  params = {}
  query.split("&").each do |pair|
    next if pair.empty?
    key, value = pair.split("=", 2)
    key = unescape(key)
    value = unescape(value.gsub(/\+/, ' ')) if value
    subkeys = key.scan(/[^\[\]]+(?:\]?\[\])?/)
    context = params
    subkeys.each_with_index do |subkey, i|
      is_array = subkey =~ /[\[\]]+\Z/
      subkey = $` if is_array
      last_subkey = i == subkeys.length - 1
      if !last_subkey || is_array
        value_type = is_array ? Array : Hash
        if context[subkey] && !context[subkey].is_a?(value_type)
          raise TypeError, "expected %s (got %s) for param `%s'" % [
            value_type.name,
            context[subkey].class.name,
            subkey
          ]
        end
        context = (context[subkey] ||= value_type.new)
      end
      if context.is_a?(Array) && !is_array
        if !context.last.is_a?(Hash) || context.last.has_key?(subkey)
          context << {}
        end
        context = context.last
      end
      if last_subkey
        if is_array
          context << value
        else
          context[subkey] = value
        end
      end
    end
  end
  dehash(params, 0)
end