participants_controller.rb

require 'portable_csv'

class ParticipantsController < ApplicationController
  include PointVisualisation
  before_action :set_organization, only: [:index]

  def index
    if @organization.nil?
      authorize! :view, :participants_list
      courses = Course.all
      users = User.all
    else
      authorize! :view_participant_list, @organization
      add_organization_breadcrumb
      courses = Course.where(organization: @organization)
      users = User.organization_students(@organization)
    end
    add_breadcrumb 'Participants'

    @ordinary_fields = %w(username email)
    @extra_fields = UserField.all
    valid_fields = @ordinary_fields + @extra_fields.map(&:name) + ['include_administrators']

    @filter_params = params_starting_with('filter_', valid_fields, remove_prefix: true)
    @raw_filter_params = params_starting_with('filter_', valid_fields, remove_prefix: false)

    @column_params = params_starting_with('column_', valid_fields, remove_prefix: true)
    @raw_column_params = params_starting_with('column_', valid_fields, remove_prefix: false)
    @visible_columns =
      if @column_params.empty?
        @ordinary_fields + @extra_fields.select(&:show_in_participant_list?).map(&:name)
      else
        @column_params.keys
      end

    @courses = courses.order(:name).to_a

    unless params['group_completion_course_id'].blank?
      @group_completion_course = courses.find(params['group_completion_course_id'])
      @group_completion = @group_completion_course.exercise_group_completion_by_user
    end

    @participants = users.filter_by(@filter_params).order(:login)

    if @group_completion && params['show_with_no_points'].blank?
      @participants = @participants.includes(:awarded_points).to_a.select do |user|
        user.awarded_points.to_a.any? { |ap| ap.course_id == @group_completion_course.id }
      end
    end

    respond_to do |format|
      format.html
      format.json do
        render json: index_json_data
      end
      format.csv do
        render_csv(text: index_csv, filename: 'participants.csv')
      end
    end
  end

  def show
    @user = User.find(params[:id])
    authorize! :view_participant_information, @user

    if current_user.administrator?
      add_breadcrumb 'Participants', :participants_path
      add_breadcrumb @user.username, participant_path(@user)
    else
      add_breadcrumb 'My stats', participant_path(@user)
    end

    define_point_stats(@user)

    if current_user.administrator? || current_user.id == @user.id
      @submissions = @user.submissions.order('created_at DESC').includes(:user).includes(:course)
    else # teacher and assistant sees only submissions for own teacherd courses
      @submissions = @user.submissions.order('created_at DESC').includes(:user, :course).where(course: current_user.teaching_in_courses)
    end
    @submission_count = @submissions.count
    @submissions = @submissions.limit(100) unless !!params[:view_all]

    Submission.eager_load_exercises(@submissions)
  end

  def me
    authorize! :view_participant_information, current_user
    redirect_to participant_path(current_user)
  end

  private

  def index_json_data
    result = []
    @participants.each do |user|
      record = { id: user.id, username: user.login, email: user.email }
      @extra_fields.each do |field|
        if @visible_columns.include?(field.name)
          record[field.name] = user.field_ruby_value(field)
        end
      end

      if @group_completion
        record[:groups] = {}
        for group, group_data in @group_completion
          record[:groups][group] = {
            points: group_data[:points_by_user][user.id] || 0,
            total: group_data[:available_points]
          }
        end
      end

      result << record
    end

    {
      api_version: ApiVersion::API_VERSION,
      participants: result
    }
  end

  def index_csv
    PortableCSV.generate(force_quotes: true) do |csv|
      title_row = (@ordinary_fields + @extra_fields.map(&:name)).select { |f| @visible_columns.include?(f) }.map(&:humanize)

      if @group_completion
        completion_cols = @group_completion.keys.sort { |a, b| Natcmp.natcmp(a, b) }
        title_row += completion_cols
      end

      csv << title_row

      @participants.each do |user|
        row = []
        for field in @ordinary_fields
          if @visible_columns.include?(field)
            row << user.send(field)
          end
        end
        for field in @extra_fields
          if @visible_columns.include?(field.name)
            row << user.field_ruby_value(field)
          end
        end

        if @group_completion
          for group in completion_cols
            group_data = @group_completion[group]
            points = group_data[:points_by_user][user.id] || 0
            total = group_data[:available_points]
            percentage = sprintf('%.3f%%', (points.to_f / total.to_f) * 100)
            row << percentage
          end
        end

        csv << row
      end
    end
  end

  private

  def set_organization
    @organization = Organization.find_by(slug:params[:organization_id]) unless params[:organization_id].nil?
  end
end