module Gitlab
  module DataBuilder
    module Push
      extend self

      # Produce a hash of post-receive data
      #
      # data = {
      #   before: String,
      #   after: String,
      #   ref: String,
      #   user_id: String,
      #   user_name: String,
      #   user_email: String
      #   project_id: String,
      #   repository: {
      #     name: String,
      #     url: String,
      #     description: String,
      #     homepage: String,
      #   },
      #   commits: Array,
      #   total_commits_count: Fixnum
      # }
      #
      def build(project, user, oldrev, newrev, ref, commits = [], message = nil)
        commits = Array(commits)

        # Total commits count
        commits_count = commits.size

        # Get latest 20 commits ASC
        commits_limited = commits.last(20)

        # For performance purposes maximum 20 latest commits
        # will be passed as post receive hook data.
        commit_attrs = commits_limited.map do |commit|
          commit.hook_attrs(with_changed_files: true)
        end

        type = Gitlab::Git.tag_ref?(ref) ? 'tag_push' : 'push'

        # Hash to be passed as post_receive_data
        {
          object_kind: type,
          event_name: type,
          before: oldrev,
          after: newrev,
          ref: ref,
          checkout_sha: checkout_sha(project.repository, newrev, ref),
          message: message,
          user_id: user.id,
          user_name: user.name,
          user_email: user.email,
          user_avatar: user.avatar_url,
          project_id: project.id,
          project: project.hook_attrs,
          commits: commit_attrs,
          total_commits_count: commits_count,
          # DEPRECATED
          repository: project.hook_attrs.slice(:name, :url, :description, :homepage,
                                               :git_http_url, :git_ssh_url, :visibility_level)
        }
      end

      # This method provide a sample data generated with
      # existing project and commits to test webhooks
      def build_sample(project, user)
        ref = "#{Gitlab::Git::BRANCH_REF_PREFIX}#{project.default_branch}"
        commits = project.repository.commits(project.default_branch.to_s, limit: 3) rescue []

        build(project, user, commits.last&.id, commits.first&.id, ref, commits)
      end

      def checkout_sha(repository, newrev, ref)
        # Checkout sha is nil when we remove branch or tag
        return if Gitlab::Git.blank_ref?(newrev)

        # Find sha for tag, except when it was deleted.
        if Gitlab::Git.tag_ref?(ref)
          tag_name = Gitlab::Git.ref_name(ref)
          tag = repository.find_tag(tag_name)

          if tag
            commit = repository.commit(tag.dereferenced_target)
            commit.try(:sha)
          end
        else
          newrev
        end
      end
    end
  end
end