module Faraday::Utils

def normalize_params(params, name, v = nil)
  name =~ %r(\A[\[\]]*([^\[\]]+)\]*)
  k = $1 || ''
  after = $' || ''
  return if k.empty?
  if after == ""
    if params[k]
      params[k] = Array[params[k]] unless params[k].kind_of?(Array)
      params[k] << v
    else
      params[k] = v
    end
  elsif after == "[]"
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    params[k] << v
  elsif after =~ %r(^\[\]\[([^\[\]]+)\]$) || after =~ %r(^\[\](.+)$)
    child_key = $1
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    if params[k].last.is_a?(Hash) && !params[k].last.key?(child_key)
      normalize_params(params[k].last, child_key, v)
    else
      params[k] << normalize_params({}, child_key, v)
    end
  else
    params[k] ||= {}
    raise TypeError, "expected Hash (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Hash)
    params[k] = normalize_params(params[k], after, v)
  end
  return params
end