MeetingAssembler.java

package assemblers;

import java.util.ArrayList;
import java.util.List;

import org.joda.time.DateTime;

import models.Attendee;
import models.Meeting;
import models.User;
import results.RenderCustomJson;
import utils.GsonFactory;
import DTO.MeetingDTO;

import com.google.gson.*;

/**
 * Assembler for the MeetingDTO and Meeting classes.
 * 
 * @see MeetingDTO
 * @see Meeting
 * @author Alex Jarvis axj7@aber.ac.uk
 */
public class MeetingAssembler {
	
	/**
	 * Writes a MeetingDTO from a Meeting object.
	 * @param meeting
	 * @return
	 */
	public static MeetingDTO writeDTO(Meeting meeting) {
		MeetingDTO meetingDTO = new MeetingDTO();
		meetingDTO.id = meeting.id;
		meetingDTO.time = new DateTime(meeting.time);
		meetingDTO.place = CoordinateAssembler.writeDTO(meeting.place);
		meetingDTO.attendees = AttendeeAssembler.writeDTOs(meeting.attendees);
		meetingDTO.owner = UserSummaryAssembler.writeDTO(meeting.owner);
		meetingDTO.title = meeting.title;
		meetingDTO.description = meeting.description;
		
		return meetingDTO;
	}
	
	/**
	 * Writes a List of MeetingDTOs from the meetings that a User is related to 
	 * (where they have an Attendee object).
	 * @param user
	 * @return
	 */
	public static List<MeetingDTO> writeDTOs(User user) {
		ArrayList<MeetingDTO> meetings = new ArrayList<MeetingDTO>();
		for (Attendee attendee : user.meetingsRelated) {
			meetings.add(writeDTO(attendee.meeting));
		}
		return meetings;
	}
	
	/**
	 * Creates a Meeting for the specified User and returns a MeetingDTO that
	 * represents this newly created Meeting.
	 * 
	 * Also creates the attendees for the meeting based on the data inside the
	 * MeetingDTO.
	 * @param meetingDTO
	 * @param user
	 * @return
	 */
	public static MeetingDTO createMeeting(MeetingDTO meetingDTO, User user) {
		Meeting meeting = new Meeting();
		meeting.time = meetingDTO.time.toDate();
		if (meetingDTO.place != null) {
			meeting.place = CoordinateAssembler.createCoordinate(meetingDTO.place);
		}
		meeting.owner = user;
		meeting.title = meetingDTO.title;
		meeting.description = meetingDTO.description;
		
		// The Attendee is the owning side of the relationship, so the meeting must be saved first.
		meeting.create();
		if (meetingDTO.attendees != null) {
			AttendeeAssembler.createAttendees(meetingDTO.attendees, meeting);
		}
		
		return writeDTO(meeting);
	}
	
	/**
	 * Updates a Meeting, using the data from a MeetingDTO
	 * @param meetingDTO
	 * @return
	 */
	public static MeetingDTO updateMeeting(MeetingDTO meetingDTO) {
		Meeting meeting = Meeting.findById(meetingDTO.id);
		if (meeting != null) {
			if (meetingDTO.time != null) {
				meeting.time = meetingDTO.time.toDate();
			}
			if (meetingDTO.place != null) {
				meeting.place = CoordinateAssembler.updateCoordinate(meetingDTO.place);
			}
			if (meetingDTO.title != null) {
				meeting.title = meetingDTO.title;
			}
			if (meetingDTO.description != null) {
				meeting.description = meetingDTO.description;
			}
			if (meetingDTO.attendees != null) {
				AttendeeAssembler.updateAttendees(meeting, meetingDTO.attendees);
			}
			
			return writeDTO(meeting);
		}
		return null;
	}
	
	/**
	 * Updates the meeting with a JsonObject
	 * @param jsonObject
	 * @return
	 */
	public static MeetingDTO updateMeetingWithJsonObject(JsonObject jsonObject) {
		MeetingDTO meetingDTO = meetingDTOWithJsonObject(jsonObject);
		meetingDTO = updateMeeting(meetingDTO);
		return meetingDTO;
	}
	
	/**
	 * Returns a MeetingDTO object from a JsonObject
	 * @param jsonObject
	 * @return
	 */
	public static MeetingDTO meetingDTOWithJsonObject(JsonObject jsonObject) {
		GsonBuilder gsonBuilder = GsonFactory.gsonBuilder();
		MeetingDTO meetingDTO = gsonBuilder.create().fromJson(jsonObject, MeetingDTO.class);
		return meetingDTO;
	}
	
	/**
	 * Returns a MeetingDTO object from a Json string
	 * @param jsonString
	 * @return
	 */
	public static MeetingDTO meetingDTOWithJsonString(String jsonString) {
		GsonBuilder gsonBuilder = GsonFactory.gsonBuilder();
		MeetingDTO meetingDTO = gsonBuilder.create().fromJson(jsonString, MeetingDTO.class);
		return meetingDTO;
	}

}