ece517-p3/expertiza

# Provides Course functions
# Author: unknown
#
# Last modified: 7/18/2008
# By: ajbudlon

# change access permission from public to private or vice versa
class CourseController < ApplicationController
  autocomplete :user, :name
  require 'fileutils'

  def action_allowed?
    current_role_name.eql?("Instructor")
  end

  def auto_complete_for_user_name
    search = params[:user][:name].to_s
    @users = User.where(role_id: 6) if search.present?
    render inline: "<%= auto_complete_result @users, 'name' %>", layout: false
  end

  # Creates a new course
  # if private is set to 1, then the course will
  # only be available to the instructor who created it.
  def new
    @private = params[:private]
  end

  # Modify an existing course
  def edit
    @course = Course.find(params[:id])
  end

  def update
    @course = Course.find(params[:id])
    if params[:course][:directory_path] && @course.directory_path != params[:course][:directory_path]
      begin
        FileHelper.delete_directory(@course)
      rescue StandardError
        flash[:error] = $ERROR_INFO
      end

      begin
        FileHelper.create_directory_from_path(params[:course][:directory_path])
      rescue StandardError
        flash[:error] = $ERROR_INFO
      end
    end
    @course.name = params[:course][:name]
    @course.institutions_id = params[:course][:institutions_id]
    @course.directory_path = params[:course][:directory_path]
    @course.info = params[:course][:info]
    @course.private = params[:course][:private].nil? ? false : params[:course][:private]
    @course.save
    undo_link("The course \"#{@course.name}\" has been updated successfully.")
    redirect_to controller: 'tree_display', action: 'list'
  end

  def copy
    orig_course = Course.find(params[:id])
    new_course = orig_course.dup
    new_course.instructor_id = session[:user].id
    new_course.name = 'Copy of ' + orig_course.name
    new_course.directory_path = new_course.directory_path + '_copy'
    begin
      new_course.save!
      parent_id = CourseNode.get_parent_id
      if parent_id
        CourseNode.create(node_object_id: new_course.id, parent_id: parent_id)
      else
        CourseNode.create(node_object_id: new_course.id)
      end

      undo_link("The course \"#{orig_course.name}\" has been successfully copied.
        The copy is currently associated with an existing location from the original course.
        This could cause errors for future submissions and it is recommended that the copy be edited as needed.")
      redirect_to controller: 'course', action: 'edit', id: new_course.id
    rescue StandardError
      flash[:error] = 'The course was not able to be copied: ' + $ERROR_INFO
      redirect_to controller: 'tree_display', action: 'list'
    end
  end

  # create a course
  def create
    @course = Course.new
    @course.name = params[:course][:name]
    @course.institutions_id = params[:course][:institutions_id]
    @course.directory_path = params[:course][:directory_path]
    @course.info = params[:course][:info]
    @course.private = params[:course][:private]
    @course.instructor_id = session[:user].id
    begin
      @course.save!
      create_course_node(@course)
      FileHelper.create_directory(@course)
      undo_link("The course \"#{@course.name}\" has been successfully created.")
      redirect_to controller: 'tree_display', action: 'list'
    rescue StandardError
      flash[:error] = $ERROR_INFO # "The following error occurred while saving the course: #"+
      redirect_to action: 'new'
    end
  end

  # delete the course
  def delete
    @course = Course.find(params[:id])
    begin
      FileHelper.delete_directory(@course)
    rescue StandardError
      flash[:error] = $ERROR_INFO
    end
    @course.destroy
    undo_link("The course \"#{@course.name}\" has been successfully deleted.")
    redirect_to controller: 'tree_display', action: 'list'
  end

  def view_teaching_assistants
    @course = Course.find(params[:id])
    @ta_mappings = @course.ta_mappings
  end

  def add_ta
    @course = Course.find(params[:course_id])
    @user = User.find_by(name: params[:user][:name])
    if @user.nil?
      flash.now[:error] = "The user inputted \"" + params[:user][:name] + "\" does not exist."
    elsif !TaMapping.where(ta_id: @user.id, course_id: @course.id).empty?
      flash.now[:error] = "The user inputted \"" + params[:user][:name] + "\" is already a TA for this course."
    else
      @ta_mapping = TaMapping.create(ta_id: @user.id, course_id: @course.id)
      @user.role = Role.find_by name: 'Teaching Assistant'
      @user.save

      @course = @ta_mapping
      undo_link("The TA \"#{@user.name}\" has been successfully added.")
    end
    render action: 'add_ta.js.erb', layout: false
  end

  def remove_ta
    @ta_mapping = TaMapping.find(params[:id])
    @ta = User.find(@ta_mapping.ta_id)

    # if the user does not have any other TA mappings, then the role should be changed to student
    other_ta_mappings_num = TaMapping.where(ta_id: @ta_mapping.ta_id).size - 1
    if other_ta_mappings_num.zero?
      @ta.role = Role.find_by name: 'Student'
      @ta.save
    end
    @ta_mapping.destroy

    @course = @ta_mapping
    undo_link("The TA \"#{@ta.name}\" has been successfully removed.")

    render action: 'remove_ta.js.erb', layout: false
  end

  def create_course_node(course)
    parent_id = CourseNode.get_parent_id
    @course_node = CourseNode.new
    @course_node.node_object_id = course.id
    @course_node.parent_id = parent_id if parent_id
    @course_node.save
  end
end