Added version checking code. Complete with unit tests. Oh yeah. :D

build.gradle

@@ -21,6 +21,9 @@ dependencies {
 	compile 'com.github.spullara.mustache.java:compiler:0.8.18'
 	compile 'org.slf4j:slf4j-api:1.7.21'
 	compile 'ch.qos.logback:logback-classic:1.1.7'
+	compile 'com.google.code.gson:gson:2.5'
+	
+	testCompile 'junit:junit:4.12'
 }
 
 run {

src/main/java/de/fabianonline/telegram_backup/CommandLineRunner.java

@@ -17,6 +17,8 @@
 package de.fabianonline.telegram_backup;
 
 import de.fabianonline.telegram_backup.CommandLineController;
+import de.fabianonline.telegram_backup.Utils;
+import de.fabianonline.telegram_backup.Version;
 import org.slf4j.LoggerFactory;
 import ch.qos.logback.classic.Logger;
 import ch.qos.logback.classic.LoggerContext;
@@ -55,6 +57,14 @@ public class CommandLineRunner {
 			((Logger)LoggerFactory.getLogger("com.github.badoualy")).setLevel(Level.TRACE);
 		}
 		
+		Version v = Utils.getNewestVersion();
+		if (v!=null && v.isNewer) {
+			System.out.println("A newer version is vailable!");
+			System.out.println("You are using: " + Config.APP_APPVER);
+			System.out.println("Available:     " + v.version);
+			System.out.println("Get it here:   " + v.url);
+			System.out.println();
+		}
 
 		if (true || CommandLineOptions.cmd_console) {
 			// Always use the console for now.

src/main/java/de/fabianonline/telegram_backup/Utils.java

@@ -19,8 +19,20 @@ import com.github.badoualy.telegram.tl.exception.RpcErrorException;
 import java.io.File;
 import java.util.List;
 import java.util.Vector;
+import com.google.gson.*;
+import java.net.URL;
+import org.apache.commons.io.IOUtils;
+import de.fabianonline.telegram_backup.Version;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class Utils {
+	public static final int VERSIONS_EQUAL = 0;
+	public static final int VERSION_1_NEWER = 1;
+	public static final int VERSION_2_NEWER = 2;
+	
+	private static final Logger logger = (Logger)LoggerFactory.getLogger(Utils.class);
+	
 	static Vector<String> getAccounts() {
 		Vector<String> accounts = new Vector<String>();
 		File folder = new File(Config.FILE_BASE);
@@ -53,4 +65,83 @@ public class Utils {
 		try { Thread.sleep(wait * 60 * 1000); } catch(InterruptedException e2) {}
 		System.out.println("");
 	}
+	
+	static Version getNewestVersion() {
+		try {
+			String data_url = "https://api.github.com/repos/fabianonline/telegram_backup/releases";
+			logger.debug("Requesting current release info from {}", data_url);
+			String json = IOUtils.toString(new URL(data_url));
+			JsonParser parser = new JsonParser();
+			JsonElement root_elm = parser.parse(json);
+			if (root_elm.isJsonArray()) {
+				JsonArray root = root_elm.getAsJsonArray();
+				JsonObject newest_version = null;
+				for (JsonElement e : root) if (e.isJsonObject()) {
+					JsonObject version = e.getAsJsonObject();
+					if (version.getAsJsonPrimitive("prerelease").getAsBoolean() == false) {
+						newest_version = version;
+						break;
+					}
+				}
+				if (newest_version == null) return null;
+				String new_v = newest_version.getAsJsonPrimitive("tag_name").getAsString();
+				logger.debug("Found current release version {}", new_v);
+				String cur_v = Config.APP_APPVER;
+				
+				int result = compareVersions(cur_v, new_v);
+				
+				return new Version(new_v, newest_version.getAsJsonPrimitive("html_url").getAsString(), result == VERSION_2_NEWER);
+			}
+			return null;
+		} catch(Exception e) {
+			return null;
+		}
+	}
+	
+	public static int compareVersions(String v1, String v2) {
+		logger.debug("Comparing versions {} and {}.", v1, v2);
+		if (v1.equals(v2)) return VERSIONS_EQUAL;
+				
+		String[] v1_p = v1.split("-");
+		String[] v2_p = v2.split("-");
+		
+		logger.trace("Parts to compare without suffixes: {} and {}.", v1_p[0], v2_p[0]);
+		
+		String[] v1_p2 = v1_p[0].split("\\.");
+		String[] v2_p2 = v2_p[0].split("\\.");
+		
+		logger.trace("Length of the parts without suffixes: {} and {}.", v1_p2.length, v2_p2.length);
+		
+		int i;
+		for (i=0; i<v1_p2.length && i<v2_p2.length; i++) {
+			int i_1 = Integer.parseInt(v1_p2[i]);
+			int i_2 = Integer.parseInt(v2_p2[i]);
+			logger.trace("Comparing parts: {} and {}.", i_1, i_2);
+			if (i_1 > i_2) {
+				logger.debug("v1 is newer");
+				return VERSION_1_NEWER;
+			} else if (i_2 > i_1) {
+				logger.debug("v2 is newer");
+				return VERSION_2_NEWER;
+			}
+		}
+		logger.trace("At least one of the versions has run out of parts.");
+		if (v1_p2.length > v2_p2.length) {
+			logger.debug("v1 is longer, so it is newer");
+			return VERSION_1_NEWER;
+		} else if (v2_p2.length > v1_p2.length) {
+			logger.debug("v2 is longer, so it is newer");
+			return VERSION_2_NEWER;
+		}
+		
+		if (v1_p.length>1 && v2_p.length==1) {
+			logger.debug("v1 has a suffix, v2 not - so v2 is newer.");
+			return VERSION_2_NEWER;
+		} else if (v1_p.length==1 && v2_p.length>1) {
+			logger.debug("v1 has no suffix, but v2 has - so v1 is newer.");
+			return VERSION_1_NEWER;
+		}
+		logger.debug("We couldn't find a real difference, so we're assuming the versions are equal-ish.");
+		return VERSIONS_EQUAL;
+	}
 }

src/main/java/de/fabianonline/telegram_backup/Version.java

@@ -0,0 +1,29 @@
+/* Telegram_Backup
+ * Copyright (C) 2016 Fabian Schlenz
+ * 
+ * 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 <http://www.gnu.org/licenses/>. */
+
+package de.fabianonline.telegram_backup;
+
+public class Version {
+	public final String version;
+	public final String url;
+	public final boolean isNewer;
+		
+	public Version(String v, String u, boolean n) {
+		this.version = v;
+		this.url = u;
+		this.isNewer = n;
+	}
+}

src/test/java/de/fabianonline/telegram_backup/utils/CompareVersionsTest.java

@@ -0,0 +1,15 @@
+import static org.junit.Assert.*;
+import org.junit.Test;
+import de.fabianonline.telegram_backup.Utils;
+
+public class CompareVersionsTest {
+	@Test
+	public void tests() {
+		assertEquals(Utils.compareVersions("1.0.3", "1.0.4"), Utils.VERSION_2_NEWER);
+		assertEquals(Utils.compareVersions("1.0.4", "1.0.3"), Utils.VERSION_1_NEWER);
+		assertEquals(Utils.compareVersions("1.0.4", "1.0.4.1"), Utils.VERSION_2_NEWER);
+		assertEquals(Utils.compareVersions("1.0.4", "1.0.4-pre.1"), Utils.VERSION_1_NEWER);
+		assertEquals(Utils.compareVersions("1.0.4", "1.0.4"), Utils.VERSIONS_EQUAL);
+		assertEquals(Utils.compareVersions("1.0.4-pre.2", "1.0.4-pre.1"), Utils.VERSIONS_EQUAL);
+	}
+}