class Bundler::Fetcher::CompactIndex

def self.compact_index_request(method_name)
  method = instance_method(method_name)
  undef_method(method_name)
  define_method(method_name) do |*args, &blk|
    method.bind_call(self, *args, &blk)
  rescue NetworkDownError, CompactIndexClient::Updater::MismatchedChecksumError => e
    raise HTTPError, e.message
  rescue AuthenticationRequiredError, BadAuthenticationError
    # Fail since we got a 401 from the server.
    raise
  rescue HTTPError => e
    Bundler.ui.trace(e)
    nil
  end
end

def api_fetcher?
  true
end

def available?
  unless SharedHelpers.md5_available?
    Bundler.ui.debug("FIPS mode is enabled, bundler can't use the CompactIndex API")
    return nil
  end
  # Read info file checksums out of /versions, so we can know if gems are up to date
  compact_index_client.available?
rescue CompactIndexClient::Updater::MismatchedChecksumError => e
  Bundler.ui.debug(e.message)
  nil
end

def bundle_worker(func = nil)
  @bundle_worker ||= begin
    worker_name = "Compact Index (#{display_uri.host})"
    Bundler::Worker.new(Bundler.settings.processor_count, worker_name, func)
  end
  @bundle_worker.tap do |worker|
    worker.instance_variable_set(:@func, func) if func
  end
end

def cache_path
  Bundler.user_cache.join("compact_index", remote.cache_slug)
end

def client_fetcher
  ClientFetcher.new(self, Bundler.ui)
end

def compact_index_client
  @compact_index_client ||=
    SharedHelpers.filesystem_access(cache_path) do
      CompactIndexClient.new(cache_path, client_fetcher)
    end
end

def fetch_gem_infos(names)
  in_parallel(names) {|name| compact_index_client.info(name) }
rescue TooManyRequestsError # rubygems.org is rate limiting us, slow down.
  @bundle_worker&.stop
  @bundle_worker = nil # reset it.  Not sure if necessary
  compact_index_client.reset!
  names.map {|name| compact_index_client.info(name) }
end

def in_parallel(inputs, &blk)
  func = lambda {|object, _index| blk.call(object) }
  worker = bundle_worker(func)
  inputs.each {|input| worker.enq(input) }
  inputs.map { worker.deq }
end

def specs(gem_names)
  specs_for_names(gem_names)
end

def specs_for_names(gem_names)
  gem_info = []
  complete_gems = []
  remaining_gems = gem_names.dup
  until remaining_gems.empty?
    log_specs { "Looking up gems #{remaining_gems.inspect}" }
    deps = fetch_gem_infos(remaining_gems).flatten(1)
    next_gems = deps.flat_map {|d| d[CompactIndexClient::INFO_DEPS].flat_map(&:first) }.uniq
    deps.each {|dep| gem_info << dep }
    complete_gems.concat(deps.map(&:first)).uniq!
    remaining_gems = next_gems - complete_gems
  end
  @bundle_worker&.stop
  @bundle_worker = nil # reset it.  Not sure if necessary
  gem_info
end