# 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 Api
    module Schema
      @[GraphQL::Object]
      # User model
      class User < GraphQL::BaseObject
        include Helpers::DbObject

        db_object Db::User

        @[GraphQL::Field]
        # User's first name
        def firstname : String
          find!.firstname
        end

        @[GraphQL::Field]
        # User's last name
        def lastname : String
          find!.lastname
        end

        @[GraphQL::Field]
        # User's full name
        def name : String
          find!.name
        end

        @[GraphQL::Field]
        # User's LDAP username
        def username : String
          find!.username
        end

        @[GraphQL::Field]
        # User's email
        def email : String
          find!.email
        end

        @[GraphQL::Field]
        # User is admin
        def admin : Bool
          find!.admin
        end

        @[GraphQL::Field]
        # User's role
        def role : UserRole
          role = Db::UserRole.parse(find!.role)
          case role
          when .teacher?
            UserRole::Teacher
          when .student?
            UserRole::Student
          else
            raise "Unknown role: #{role}"
          end
        end

        @[GraphQL::Field]
        # User's external ID
        def external_id : Int32?
          case Db::UserRole.parse(find!.role)
          when .teacher?
            find!.teacher
          when .student?
            find!.student
          end.not_nil!.id.not_nil!.to_i
        rescue NilAssertionError
          nil
        end

        @[GraphQL::Field]
        # User's external teacher object
        def teacher : Teacher?
          teacher = find!.teacher
          if teacher
            Teacher.new(teacher)
          end
        end

        @[GraphQL::Field]
        # User's external student object
        def student : Student?
          student = find!.student
          if student
            Student.new(student)
          end
        end
      end

      @[GraphQL::InputObject]
      # User creation input
      class UserCreateInput < GraphQL::BaseInputObject
        getter username
        getter role

        @[GraphQL::Field]
        def initialize(
          @username : String,
          @role : UserRole
        )
        end
      end

      @[GraphQL::Object]
      # Login payload returned after successful login
      class LoginPayload < GraphQL::BaseObject
        # Logged in user
        property user

        # JWT token
        property token

        def initialize(
          @user : User,
          @token : String
        )
        end

        @[GraphQL::Field]
        # Logged in user
        def user : User
          @user
        end

        @[GraphQL::Field]
        # Raw bearer token
        def token : String
          @token
        end

        @[GraphQL::Field]
        # Ready to use bearer token
        def bearer : String
          Auth::BEARER + @token
        end
      end
    end
  end
end