require 'stringio'

module Gitlab
  module GitalyClient
    class WikiService
      MAX_MSG_SIZE = 128.kilobytes.freeze

      def initialize(repository)
        @gitaly_repo = repository.gitaly_repository
        @repository = repository
      end

      def write_page(name, format, content, commit_details)
        request = Gitaly::WikiWritePageRequest.new(
          repository: @gitaly_repo,
          name: GitalyClient.encode(name),
          format: format.to_s,
          commit_details: gitaly_commit_details(commit_details)
        )

        strio = StringIO.new(content)

        enum = Enumerator.new do |y|
          until strio.eof?
            chunk = strio.read(MAX_MSG_SIZE)
            request.content = GitalyClient.encode(chunk)

            y.yield request

            request = Gitaly::WikiWritePageRequest.new
          end
        end

        response = GitalyClient.call(@repository.storage, :wiki_service, :wiki_write_page, enum)
        if error = response.duplicate_error.presence
          raise Gitlab::Git::Wiki::DuplicatePageError, error
        end
      end

      def delete_page(page_path, commit_details)
        request = Gitaly::WikiDeletePageRequest.new(
          repository: @gitaly_repo,
          page_path: GitalyClient.encode(page_path),
          commit_details: gitaly_commit_details(commit_details)
        )

        GitalyClient.call(@repository.storage, :wiki_service, :wiki_delete_page, request)
      end

      private

      def gitaly_commit_details(commit_details)
        Gitaly::WikiCommitDetails.new(
          name: GitalyClient.encode(commit_details.name),
          email: GitalyClient.encode(commit_details.email),
          message: GitalyClient.encode(commit_details.message)
        )
      end
    end
  end
end