class Aws::Query::ParamBuilder

def apply(shape, params)
  structure(shape, params, '')
end

def flat?(shape)
  !!shape.metadata('flattened')
end

def format(shape, value, prefix)
  case shape.type
  when 'structure' then structure(shape, value, prefix + '.')
  when 'list'      then list(shape, value, prefix)
  when 'map'       then map(shape, value, prefix)
  when 'blob'      then set(prefix, Base64.strict_encode64(value))
  when 'timestamp'
    set(prefix, shape.format_time(value, 'iso8601').to_s)
  else
    set(prefix, value.to_s)
  end
end

def initialize(param_list)
  @params = param_list
end

def list(list, values, prefix)
  if values.empty?
    set(prefix, '')
    return
  end
  if flat?(list)
    if name = query_name(list.member)
      parts = prefix.split('.')
      parts.pop
      parts.push(name)
      prefix = parts.join('.')
    end
  else
    prefix += '.member'
  end
  values.each.with_index do |value, n|
    format(list.member, value, "#{prefix}.#{n+1}")
  end
end

def map(map, values, prefix)
  prefix += '.entry' unless flat?(map)
  key_name = "%s.%d.#{query_name(map.key, 'key')}"
  value_name  = "%s.%d.#{query_name(map.value, 'value')}"
  values.each.with_index do |(key, value), n|
    format(map.key, key, key_name % [prefix, n + 1])
    format(map.value, value, value_name % [prefix, n + 1])
  end
end

def query_name(shape, default = nil)
  shape.location_name || default
end

def set(name, value)
  params.set(name, value)
end

def structure(structure, values, prefix)
  values.each do |name, value|
    unless value.nil?
      member_shape = structure.member(name)
      format(member_shape, value, prefix + query_name(member_shape))
    end
  end
end