# frozen_string_literal: true

module Packages
  class GroupPackagesFinder
    attr_reader :current_user, :group, :params

    InvalidPackageTypeError = Class.new(StandardError)

    def initialize(current_user, group, params = { exclude_subgroups: false, order_by: 'created_at', sort: 'asc' })
      @current_user = current_user
      @group = group
      @params = params
    end

    def execute
      return ::Packages::Package.none unless group

      packages_for_group_projects
    end

    private

    def packages_for_group_projects
      packages = ::Packages::Package
        .for_projects(group_projects_visible_to_current_user)
        .processed
        .has_version
        .sort_by_attribute("#{params[:order_by]}_#{params[:sort]}")

      packages = filter_by_package_type(packages)
      packages = filter_by_package_name(packages)
      packages
    end

    def group_projects_visible_to_current_user
      ::Project
        .in_namespace(groups)
        .public_or_visible_to_user(current_user, Gitlab::Access::REPORTER)
        .with_project_feature
        .select { |project| Ability.allowed?(current_user, :read_package, project) }
    end

    def package_type
      params[:package_type].presence
    end

    def groups
      return [group] if exclude_subgroups?

      group.self_and_descendants
    end

    def exclude_subgroups?
      params[:exclude_subgroups]
    end

    def filter_by_package_type(packages)
      return packages unless package_type
      raise InvalidPackageTypeError unless Package.package_types.key?(package_type)

      packages.with_package_type(package_type)
    end

    def filter_by_package_name(packages)
      return packages unless params[:package_name].present?

      packages.search_by_name(params[:package_name])
    end
  end
end