openproject/app/models/projects/hierarchy.rb

# frozen_string_literal: true

#-- copyright
# OpenProject is an open source project management software.
# Copyright (C) the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2013 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See COPYRIGHT and LICENSE files for more details.
#++

module Projects::Hierarchy
  extend ActiveSupport::Concern

  class_methods do
    # builds up a project hierarchy helper structure for use with #project_tree_from_hierarchy
    #
    # it expects a simple list of projects with a #lft column (awesome_nested_set)
    # and returns a hierarchy based on #lft
    #
    # the result is a nested list of root level projects that contain their child projects
    # but, each entry is actually a ruby hash wrapping the project and child projects
    # the keys are :project and :children where :children is in the same format again
    #
    #   result = [ root_level_project_info_1, root_level_project_info_2, ... ]
    #
    # where each entry has the form
    #
    #   project_info = { project: the_project, children: [ child_info_1, child_info_2, ... ] }
    #
    # if a project has no children the :children array is just empty
    #
    def build_projects_hierarchy(projects) # rubocop:disable Metrics/AbcSize
      ancestors = []
      result = []

      projects.sort_by(&:lft).each do |project|
        while ancestors.any? && !project.is_descendant_of?(ancestors.last[:project])
          # before we pop back one level, we sort the child projects by name
          ancestors.last[:children] = sort_by_name(ancestors.last[:children])
          ancestors.pop
        end

        current_hierarchy = { project:, children: [] }
        current_tree = ancestors.any? ? ancestors.last[:children] : result

        current_tree << current_hierarchy
        ancestors << current_hierarchy
      end

      # When the last project is deeply nested, we need to sort
      # all layers we are in.
      ancestors.each do |level|
        level[:children] = sort_by_name(level[:children])
      end
      # we need one extra element to ensure sorting at the end
      # at the end the root level must be sorted as well
      sort_by_name(result)
    end

    def project_tree_from_hierarchy(projects_hierarchy, level, &)
      projects_hierarchy.each do |hierarchy|
        project = hierarchy[:project]
        children = hierarchy[:children]
        yield project, level
        # recursively show children
        project_tree_from_hierarchy(children, level + 1, &) if children.any?
      end
    end

    # Yields the given block for each project with its level in the tree
    def project_tree(projects, &)
      projects_hierarchy = build_projects_hierarchy(projects)
      project_tree_from_hierarchy(projects_hierarchy, 0, &)
    end

    private

    def sort_by_name(project_hashes)
      project_hashes.sort_by { |h| h[:project].name&.downcase }
    end
  end

  included do
    acts_as_nested_set order_column: :lft, dependent: :destroy

    # Keep the siblings sorted after naming changes to ensure lft sort includes name sorting
    before_save :remember_reorder
    after_save :reorder_by_name, if: -> { @reorder_nested_set }

    # Returns an array of projects that are in this project's hierarchy
    #
    # Example: parents, children, siblings
    def hierarchy
      parents = project.self_and_ancestors || []
      descendants = project.descendants || []
      parents | descendants # Set union
    end

    def has_subprojects?
      !leaf?
    end

    # Returns an array of active subprojects.
    def active_subprojects
      project.descendants.where(active: true)
    end

    def reorder_by_name
      @reorder_nested_set = nil
      return unless siblings.any?

      left_neighbor = left_neighbor_by_name_order

      if left_neighbor
        move_to_right_of(left_neighbor)
      elsif self != self_and_siblings.first
        move_to_left_of(self_and_siblings.first)
      end
    end

    ##
    # Find the sibling for which the current project's name is smaller.
    # Since we sort ascending, start from the back.
    # Returns:
    #   - nil, if the current project does not have a left neighbor (should be added as first)
    #   - the project sibling for which the project should be appended to the right to
    def left_neighbor_by_name_order
      siblings
        .reverse_each
        .detect { |project| project.name.casecmp(name) == -1 }
    end

    # We need to remember if we want to reorder as nested_set
    # will perform another save directly in +after_save+ if a parent was set
    # and that clear new_record? as well as previous_new_record?
    def remember_reorder
      @reorder_nested_set = new_record? || name_changed?
    end

    # Returns a :conditions SQL string that can be used to find the issues associated with this project.
    #
    # Examples:
    #   project.with_subprojects(true)  => "(projects.id = 1 OR (projects.lft > 1 AND projects.rgt < 10))"
    #   project.with_subprojects(false) => "projects.id = 1"
    def with_subprojects(with_subprojects)
      projects_table = Project.arel_table

      stmt = projects_table[:id].eq(id)
      if with_subprojects && has_subprojects?
        stmt = stmt.or(projects_table[:lft].gt(lft).and(projects_table[:rgt].lt(rgt)))
      end
      stmt
    end

    def allowed_parent_workspace_types = Project::ALLOWED_PARENT_WORKSPACE_TYPES[workspace_type] || []

    def parent_allowed?
      allowed_parent_workspace_types.any?
    end
  end
end