module Ollama::Documents::Cache::Common
  include Ollama::Utils::Math

  attr_writer :prefix # current prefix defined for the cache

  # Returns an array of collection names that match the given prefix.
  #
  # @param prefix [String] a string to search for in collection names
  # @return [Array<Symbol>] an array of matching collection names
  def collections(prefix)
    unique = Set.new
    full_each { |key, _| unique << key[/\A#{prefix}(.*)-/, 1] }
    unique.map(&:to_sym)
  end

  # Returns a string representing the given `key` prefixed with the defined
  # prefix.
  #
  # @param key [String] the key to join with the prefix
  # @return [String] the joined string of prefix and key
  def pre(key)
    [ @prefix, key ].join
  end

  # Returns a string with the prefix removed from the given `key`.
  #
  # @param key [String] the input string containing the prefix.
  # @return [String] the input string without the prefix.
  def unpre(key)
    key.sub(/\A#@prefix/, '')
  end
end