class Aws::Query::Builder

def self.to_query_params(rules, params)
  new(rules).to_query_params(params)
end

def blob(param_list, shape, prefix, value)
  param_list.set(prefix, Base64.strict_encode64(value))
end

def flat?(shape)
  FlatListShape === shape || FlatMapShape === shape
end

def initialize(rules)
  @rules = rules
end

def list(param_list, shape, prefix, values)
  member_shape = shape.members
  if flat?(shape)
    if member_shape.serialized_name
      parts = prefix.split('.')
      parts.pop
      parts.push(member_shape.serialized_name)
      prefix = parts.join('.')
    end
  else
    prefix += '.member'
  end
  values.each_with_index do |value, n|
    member(param_list, member_shape, "#{prefix}.#{n+1}", value)
  end
end

def map(param_list, shape, prefix, values)
  key_shape = shape.keys
  value_shape = shape.members
  prefix += '.entry' unless flat?(shape)
  key_name = "%s.%d.#{key_shape.serialized_name || 'key'}"
  value_name  = "%s.%d.#{value_shape.serialized_name || 'value'}"
  n = 1
  values.each_pair do |key, value|
    member(param_list, key_shape, key_name % [prefix, n], key)
    member(param_list, value_shape, value_name % [prefix, n], value)
    n += 1
  end
end

def member(param_list, shape, prefix, value)
  case shape
  when StructureShape then structure(param_list, shape, prefix, value)
  when ListShape then list(param_list, shape, prefix, value)
  when MapShape then map(param_list, shape, prefix, value)
  when TimestampShape then timestamp(param_list, shape, prefix, value.utc)
  when BlobShape then blob(param_list, shape, prefix, value)
  else param_list.set(prefix, value.to_s)
  end
end

def structure(param_list, shape, prefix, values)
  values.each do |name, value|
    member_shape = shape.members[name]
    param_name = member_shape.serialized_name
    param_name = "#{prefix}.#{param_name}" if prefix
    member(param_list, member_shape, param_name, value)
  end
end

def timestamp(param_list, shape, prefix, value)
  value = case shape
    when Iso8601TimestampShape then value.iso8601
    when Rfc822TimestampShape then value.rfc822
    when UnixTimestampShape then value.to_i.to_s
    else raise "invalid timestamp format `#{shape.class.name}'"
  end
  param_list.set(prefix, value)
end

def to_query_params(params)
  param_list = ParamList.new
  structure(param_list, @rules, nil, params)
  param_list
end