discourse/app/controllers/groups_controller.rb

class GroupsController < ApplicationController

  before_filter :ensure_logged_in, only: [
    :set_notifications,
    :mentionable,
    :update,
    :messages,
    :histories
  ]

  skip_before_filter :preload_json, :check_xhr, only: [:posts_feed, :mentions_feed]

  def index
    page_size = 30
    page = params[:page]&.to_i || 0

    groups = Group.order(user_count: :desc, name: :asc)
      .where(visible: true)
      .offset(page * page_size)
      .limit(page_size)

    render json: {
      groups: serialize_data(groups, BasicGroupSerializer),
      total_rows_groups: Group.count,
      load_more_groups: groups_path(page: page + 1)
    }
  end

  def show
    render_serialized(find_group(:id), GroupShowSerializer, root: 'basic_group')
  end

  def edit
  end

  def update
    group = Group.find(params[:id])
    guardian.ensure_can_edit!(group)

    if group.update_attributes(group_params)
      GroupActionLogger.new(current_user, group).log_change_group_settings

      render json: success_json
    else
      render_json_error(group)
    end
  end

  def posts
    group = find_group(:group_id)
    posts = group.posts_for(guardian, params[:before_post_id]).limit(20)
    render_serialized posts.to_a, GroupPostSerializer
  end

  def posts_feed
    group = find_group(:group_id)
    @posts = group.posts_for(guardian).limit(50)
    @title = "#{SiteSetting.title} - #{I18n.t("rss_description.group_posts", group_name: group.name)}"
    @link = Discourse.base_url
    @description = I18n.t("rss_description.group_posts", group_name: group.name)
    render 'posts/latest', formats: [:rss]
  end

  def topics
    group = find_group(:group_id)
    posts = group.posts_for(guardian, params[:before_post_id]).where(post_number: 1).limit(20)
    render_serialized posts.to_a, GroupPostSerializer
  end

  def mentions
    group = find_group(:group_id)
    posts = group.mentioned_posts_for(guardian, params[:before_post_id]).limit(20)
    render_serialized posts.to_a, GroupPostSerializer
  end

  def mentions_feed
    group = find_group(:group_id)
    @posts = group.mentioned_posts_for(guardian).limit(50)
    @title = "#{SiteSetting.title} - #{I18n.t("rss_description.group_mentions", group_name: group.name)}"
    @link = Discourse.base_url
    @description = I18n.t("rss_description.group_mentions", group_name: group.name)
    render 'posts/latest', formats: [:rss]
  end

  def messages
    group = find_group(:group_id)
    posts = if guardian.can_see_group_messages?(group)
      group.messages_for(guardian, params[:before_post_id]).where(post_number: 1).limit(20).to_a
    else
      []
    end
    render_serialized posts, GroupPostSerializer
  end

  def members
    group = find_group(:group_id)

    limit = (params[:limit] || 20).to_i
    offset = params[:offset].to_i
    dir = (params[:desc] && !params[:desc].blank?) ? 'DESC' : 'ASC'
    order = {}

    if params[:order] && %w{last_posted_at last_seen_at}.include?(params[:order])
      order.merge!(params[:order] => dir)
    end

    total = group.users.count
    members = group.users
      .order('NOT group_users.owner')
      .order(order)
      .order(:username_lower => dir)
      .limit(limit)
      .offset(offset)

    owners = group.users
      .order(order)
      .order(:username_lower => dir)
      .where('group_users.owner')

    render json: {
      members: serialize_data(members, GroupUserSerializer),
      owners: serialize_data(owners, GroupUserSerializer),
      meta: {
        total: total,
        limit: limit,
        offset: offset
      }
    }
  end

  def add_members
    group = Group.find(params[:id])
    group.public ? ensure_logged_in : guardian.ensure_can_edit!(group)

    users =
      if params[:usernames].present?
        User.where(username: params[:usernames].split(","))
      elsif params[:user_ids].present?
        User.find(params[:user_ids].split(","))
      elsif params[:user_emails].present?
        User.where(email: params[:user_emails].split(","))
      else
        raise Discourse::InvalidParameters.new(
          'user_ids or usernames or user_emails must be present'
        )
      end

    raise Discourse::NotFound if users.blank?

    if group.public
      if !guardian.can_log_group_changes?(group) && current_user != users.first
        raise Discourse::InvalidAccess
      end

      unless current_user.staff?
        RateLimiter.new(current_user, "public_group_membership", 3, 1.minute).performed!
      end
    end

    users.each do |user|
      if !group.users.include?(user)
        group.add(user)
        GroupActionLogger.new(current_user, group).log_add_user_to_group(user)
      else
        return render_json_error I18n.t('groups.errors.member_already_exist', username: user.username)
      end
    end

    if group.save
      render json: success_json
    else
      render_json_error(group)
    end
  end

  def mentionable
    group = find_group(:name)

    if group
      render json: { mentionable: Group.mentionable(current_user).where(id: group.id).present? }
    else
      raise Discourse::InvalidAccess.new
    end
  end

  def remove_member
    group = Group.find(params[:id])
    group.public ? ensure_logged_in : guardian.ensure_can_edit!(group)

    user =
      if params[:user_id].present?
        User.find_by(id: params[:user_id])
      elsif params[:username].present?
        User.find_by_username(params[:username])
      elsif params[:user_email].present?
        User.find_by_email(params[:user_email])
      else
        raise Discourse::InvalidParameters.new('user_id or username must be present')
      end

    raise Discourse::NotFound unless user

    if group.public
      if !guardian.can_log_group_changes?(group) && current_user != user
        raise Discourse::InvalidAccess
      end

      unless current_user.staff?
        RateLimiter.new(current_user, "public_group_membership", 3, 1.minute).performed!
      end
    end

    user.primary_group_id = nil if user.primary_group_id == group.id

    group.remove(user)
    GroupActionLogger.new(current_user, group).log_remove_user_from_group(user)

    if group.save && user.save
      render json: success_json
    else
      render_json_error(group)
    end

  end

  def set_notifications
    group = find_group(:id)
    notification_level = params.require(:notification_level)

    GroupUser.where(group_id: group.id)
             .where(user_id: current_user.id)
             .update_all(notification_level: notification_level)

    render json: success_json
  end

  def histories
    group = find_group(:group_id)
    guardian.ensure_can_edit!(group)

    page_size = 25
    offset = (params[:offset] && params[:offset].to_i) || 0

    group_histories = GroupHistory.with_filters(group, params[:filters])
      .limit(page_size)
      .offset(offset * page_size)

    render_json_dump(
      logs: serialize_data(group_histories, BasicGroupHistorySerializer),
      all_loaded: group_histories.count < page_size
    )
  end

  private

  def group_params
    params.require(:group).permit(
      :flair_url,
      :flair_bg_color,
      :flair_color,
      :bio_raw,
      :full_name,
      :public,
      :allow_membership_requests
    )
  end

  def find_group(param_name)
    name = params.require(param_name)
    group = Group.find_by("lower(name) = ?", name.downcase)
    guardian.ensure_can_see!(group)
    group
  end

end