MoodleRestMessage.java

package in.co.praveenkumar.mdroid.moodlerest;

import in.co.praveenkumar.mdroid.helper.GsonExclude;
import in.co.praveenkumar.mdroid.model.MoodleMessage;
import in.co.praveenkumar.mdroid.model.MoodleMessages;

import java.io.Reader;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import android.util.Log;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;

public class MoodleRestMessage {
	private final String DEBUG_TAG = "MoodleRestMessage";
	private String mUrl;
	private String token;
	private String error;

	public MoodleRestMessage(String mUrl, String token) {
		this.mUrl = mUrl;
		this.token = token;
	}

	/**
	 * Sends a message to a Moodle user.
	 * 
	 * @param message
	 *            Message to send with the required params (touserid, text at
	 *            the least) set
	 * 
	 * @return status - true if success. false if failed.
	 */
	public Boolean sendMessage(MoodleMessage message) {
		String format = MoodleRestOption.RESPONSE_FORMAT;
		String function = MoodleRestOption.FUNCTION_SEND_MESSAGE;
		ArrayList<MoodleMessage> mMessages = new ArrayList<>();

		if (message == null) {
			Log.d(DEBUG_TAG, "Message not setup correctly");
			error = "Message not setup correctly. Report to developer";
			return false;
		}

		try {
			// Adding all parameters.
			String params = "" + URLEncoder.encode("", "UTF-8");

			params += "&messages[0][touserid]="
					+ URLEncoder.encode(String.valueOf(message.getTouserid()),
							"UTF-8");
			params += "&messages[0][text]="
					+ URLEncoder.encode(message.getText(), "UTF-8");
			params += "&messages[0][textformat]="
					+ URLEncoder.encode(
							String.valueOf(message.getTextformat()), "UTF-8");
			if (message.getClientmsgid() != null)
				params += "&messages[0][clientmsgid]="
						+ URLEncoder.encode(message.getClientmsgid(), "UTF-8");

			// Build a REST call url to make a call.
			String restUrl = mUrl + "/webservice/rest/server.php" + "?wstoken="
					+ token + "&wsfunction=" + function
					+ "&moodlewsrestformat=" + format;

			// Fetch content now.
			MoodleRestCall mrc = new MoodleRestCall();
			Reader reader = mrc.fetchContent(restUrl, params);
			GsonExclude ex = new GsonExclude();
			Gson gson = new GsonBuilder()
					.addDeserializationExclusionStrategy(ex)
					.addSerializationExclusionStrategy(ex).create();
			mMessages = gson.fromJson(reader,
					new TypeToken<List<MoodleMessage>>() {
					}.getType());
			reader.close();

			if (mMessages == null)
				return false;

			if (mMessages.isEmpty())
				return false;

			MoodleMessage mMessage = mMessages.get(0);
			if (mMessage.getMsgid() == -1) {
				/**
				 * Don't show error when moodle gives null error. Some issue on
				 * Moodle end. Report and wait for a fix. Till then, say sent
				 * because messages are actually being sent in this case.
				 */
				if (mMessage.getErrormessage() == null
						|| mMessage.getErrormessage().contentEquals("null"))
					return true;
				error = mMessage.getErrormessage();
				return false;
			}

		} catch (Exception e) {
			Log.d(DEBUG_TAG, "URL encoding failed");
			error = "Check internet connection!";
			e.printStackTrace();
			return false;
		}

		return true;
	}

	/**
	 * Error while sending last message.
	 * 
	 * @return error
	 */
	public String getError() {
		return error;
	}

	/**
	 * Get all the messages exchanged by two users. User MUST have the required
	 * permissions (user who logged into this account) or an access denied
	 * exception may occur.
	 * 
	 * @param useridto
	 *            userid of the user who received these messages
	 * @param useridfrom
	 *            userid of the user who sent these messages
	 * @param read
	 *            read - only read messages. 0 - only unread messages.
	 * @return MoodleMessages
	 * 
	 * <br/>
	 *         <b>Note:<b/> <br/>
	 *         1. To get list of messages received by a user, set useridfrom to
	 *         0 <br/>
	 *         2. To get list of messages sent by a user, set useridto to 0 <br/>
	 *         3. Due to Moodle API limitation you need make 2 calls - read = 0
	 *         and read = 1 to get all messages.<br/>
	 */
	public MoodleMessages getMessages(int useridto, int useridfrom, int read) {
		MoodleMessages mMessages = null;
		String format = MoodleRestOption.RESPONSE_FORMAT;
		String function = MoodleRestOption.FUNCTION_GET_MESSAGES;

		try {
			// Adding all parameters.
			String params = "";

			params += "&useridto="
					+ URLEncoder.encode(String.valueOf(useridto), "UTF-8");
			params += "&useridfrom="
					+ URLEncoder.encode(String.valueOf(useridfrom), "UTF-8");
			params += "&read="
					+ URLEncoder.encode(String.valueOf(read), "UTF-8");

			// Build a REST call url to make a call.
			String restUrl = mUrl + "/webservice/rest/server.php" + "?wstoken="
					+ token + "&wsfunction=" + function
					+ "&moodlewsrestformat=" + format;

			// Fetch content now.
			MoodleRestCall mrc = new MoodleRestCall();
			Reader reader = mrc.fetchContent(restUrl, params);
			GsonExclude ex = new GsonExclude();
			Gson gson = new GsonBuilder()
					.addDeserializationExclusionStrategy(ex)
					.addSerializationExclusionStrategy(ex).create();
			mMessages = gson.fromJson(reader, MoodleMessages.class);
		} catch (Exception e) {
			Log.d(DEBUG_TAG, "URL encoding failed");
			e.printStackTrace();
		}

		return mMessages;
	}
}