# Mentorenwahl: A fullstack application for assigning mentors to students based on their whishes.
# Copyright (C) 2022  Dominic Grimm

# 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 3 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, see <https://www.gnu.org/licenses/>.

module Backend
  module Db
    # User model
    class User < Granite::Base
      table users

      has_one :teacher
      has_one :student

      # User's ID
      column id : Int64, primary: true

      # User's LDAP username
      column username : String

      # User's role
      column role : String

      # User is admin
      column admin : Bool = false

      # User's first name
      def firstname : String
        Ldap.user(Ldap.uid(@username.not_nil!)).first["givenName"].first
      end

      # User's last name
      def lastname : String
        Ldap.user(Ldap.uid(@username.not_nil!)).first["sn"].first
      end

      # User's full name
      def name : String
        Ldap.user(Ldap.uid(@username.not_nil!)).first["cn"].first
      end

      # User's email
      def email : String
        Ldap.user(Ldap.uid(@username.not_nil!)).first["mail"].first
      end

      validate :role, "needs to be a valid role" do |user|
        UserRole.parse(user.role).in?(UserRole.values)
      end

      validate :role, "user external needs to be a valid role" do |user|
        if user.teacher.nil? && user.student.nil?
          true
        else
          !!case UserRole.parse(user.role)
          when .teacher?
            user.teacher && user.student.nil?
          when .student?
            user.teacher.nil? && user.student
          else
            false
          end
        end
      end
    end
  end
end