class AwsRecord::Generators::SecondaryIndex

def get_option_value(raw_option)
  case raw_option
  when /hkey\{(\w+)\}/
    return :hash_key, $1
  when /rkey\{(\w+)\}/
    return :range_key, $1
  when /proj_type\{(\w+)\}/
    return :projection_type, $1
  else
    raise ArgumentError.new("Invalid option for secondary index #{raw_option}")
  end
end

def initialize(name, opts)
  raise ArgumentError.new("You must provide a name") if not name
  raise ArgumentError.new("You must provide a hash key") if not opts[:hash_key]
  if opts.key? :projection_type
    raise ArgumentError.new("Invalid projection type #{opts[:projection_type]}") if not PROJ_TYPES.include? opts[:projection_type]
    raise NotImplementedError.new("ALL is the only projection type currently supported") if opts[:projection_type] != "ALL"
  else
    opts[:projection_type] = "ALL"
  end
  if opts[:hash_key] == opts[:range_key]
    raise ArgumentError.new("#{opts[:hash_key]} cannot be both the rkey and hkey for gsi #{name}")
  end
  @name = name
  @hash_key = opts[:hash_key]
  @range_key = opts[:range_key]
  @projection_type = '"' + "#{opts[:projection_type]}" + '"'
end

def parse(key_definition)
  name, index_options = key_definition.split(':')
  index_options = index_options.split(',') if index_options
  opts = parse_raw_options(index_options)
  new(name, opts)
end

def parse_raw_options(raw_opts)
  raw_opts = [] if not raw_opts
  raw_opts.map { |opt| get_option_value(opt) }.to_h
end