module Gitlab
  module Regex
    extend self

    def username_regex
      default_regex
    end

    def project_name_regex
      /\A[a-zA-Z0-9][a-zA-Z0-9_\-\. ]*\z/
    end

    def name_regex
      /\A[a-zA-Z0-9_\-\. ]*\z/
    end

    def path_regex
      default_regex
    end

    def git_reference_regex
      # Valid git ref regex, see:
      # https://www.kernel.org/pub/software/scm/git/docs/git-check-ref-format.html

      %r{
        (?!
           (?# doesn't begins with)
           \/|                    (?# rule #6)
           (?# doesn't contain)
           .*(?:
              [\/.]\.|            (?# rule #1,3)
              \/\/|               (?# rule #6)
              @\{|                (?# rule #8)
              \\                  (?# rule #9)
           )
        )
        [^\000-\040\177~^:?*\[]+  (?# rule #4-5)
        (?# doesn't end with)
        (?<!\.lock)               (?# rule #1)
        (?<![\/.])                (?# rule #6-7)
      }x
    end

    protected

    def default_regex
      /\A[a-zA-Z0-9][a-zA-Z0-9_\-\.]*(?<!\.git)\z/
    end
  end
end