class Dependabot::PullRequestCreator::BranchNamer::Base

def initialize(dependencies:, files:, target_branch:, separator: "/",
               prefix: "dependabot", max_length: nil)
  @dependencies      = dependencies
  @files             = files
  @target_branch     = target_branch
  @separator         = separator
  @prefix            = prefix
  @max_length        = max_length
end

def new_branch_name
  raise NotImplementedError
end

def sanitize_branch_name(ref_name)
  # General git ref validation
  sanitized_name = sanitize_ref(ref_name)
  # Some users need branch names without slashes
  sanitized_name = sanitized_name.gsub("/", separator)
  # Shorten the ref in case users refs have length limits
  if max_length && (sanitized_name.length > T.must(max_length))
    sha = T.must(Digest::SHA1.hexdigest(sanitized_name)[0, T.must(max_length)])
    sanitized_name[[T.must(max_length) - sha.size, 0].max..] = sha
  end
  sanitized_name
end

def sanitize_ref(ref)
  # This isn't a complete implementation of git's ref validation, but it
  # covers most cases that crop up. Its list of allowed characters is a
  # bit stricter than git's, but that's for cosmetic reasons.
  ref.
    # Remove forbidden characters (those not already replaced elsewhere)
    gsub(%r{[^A-Za-z0-9/\-_.(){}]}, "").
    # Slashes can't be followed by periods
    gsub(%r{/\.}, "/dot-").squeeze(".").squeeze("/").
    # Trailing periods are forbidden
    sub(/\.$/, "")
end