Fixes #976 Now uses GitHub to retrieve most current version

Reworked whole Version Checker with an extensible interface to add any other service later on easier.
The version checker now has its own config file, to collect the different options and extract them from the main config file.
In that you can specify how fine the versions should be checked.

src/main/java/appeng/services/version/VersionParser.java

@@ -0,0 +1,132 @@
+package appeng.services.version;
+
+
+import java.security.InvalidParameterException;
+import java.util.Scanner;
+import java.util.regex.Pattern;
+
+
+/**
+ * can parse a version in form of rv2-beta-8 or rv2.beta.8
+ */
+public final class VersionParser
+{
+	private static final Pattern PATTERN_DOT = Pattern.compile( "\\." );
+	private static final Pattern PATTERN_DASH = Pattern.compile( "-" );
+	private static final Pattern PATTERN_REVISION = Pattern.compile( "[^0-9]+" );
+	private static final Pattern PATTERN_BUILD = Pattern.compile( "[^0-9]+" );
+	private static final Pattern PATTERN_NATURAL = Pattern.compile( "[0-9]+" );
+	private static final Pattern PATTERN_VALID_REVISION = Pattern.compile( "^rv\\d+$" );
+
+	/**
+	 * Parses the {@link Version} out of a String
+	 *
+	 * @param raw String in form of rv2-beta-8 or rv2.beta.8
+	 *
+	 * @return {@link Version} encoded in the raw String
+	 *
+	 * @throws AssertionError if raw String does not match pattern of a {@link Version}
+	 */
+	public Version parse( String raw )
+	{
+		final String transformed = this.transformDelimiter( raw );
+		final String[] split = transformed.split( "_" );
+
+		return this.parseVersion( split );
+	}
+
+	/**
+	 * Replaces all "." and "-" into "_" to make them uniform
+	 *
+	 * @param raw raw version string containing "." or "-"
+	 *
+	 * @return transformed raw, where "." and "-" are replaced by "_"
+	 */
+	private String transformDelimiter( String raw )
+	{
+		assert raw.contains( "." ) || raw.contains( "-" );
+
+		final String withoutDot = PATTERN_DOT.matcher( raw ).replaceAll( "_" );
+		final String withoutDash = PATTERN_DASH.matcher( withoutDot ).replaceAll( "_" );
+
+		return withoutDash;
+	}
+
+	/**
+	 * parses the {@link Version} out of the split.
+	 * The split must have a length of 3,
+	 * representing revision, channel and build.
+	 *
+	 * @param splitRaw raw version split with length of 3
+	 *
+	 * @return {@link Version} represented by the splitRaw
+	 */
+	private Version parseVersion( String[] splitRaw )
+	{
+		assert splitRaw.length == 3;
+
+		final String rawRevision = splitRaw[0];
+		final String rawChannel = splitRaw[1];
+		final String rawBuild = splitRaw[2];
+
+		final int revision = this.parseRevision( rawRevision );
+		final Channel channel = this.parseChannel( rawChannel );
+		final int build = this.parseBuild( rawBuild );
+
+		return new DefaultVersion( revision, channel, build );
+	}
+
+	/**
+	 * A revision starts with the keyword "rv", followed by a natural number
+	 *
+	 * @param rawRevision String containing the revision number
+	 *
+	 * @return revision number
+	 */
+	private int parseRevision( String rawRevision )
+	{
+		assert PATTERN_VALID_REVISION.matcher( rawRevision ).matches();
+
+		final int revision = new Scanner( rawRevision ).useDelimiter( PATTERN_REVISION ).nextInt();
+
+		return revision;
+	}
+
+	/**
+	 * A channel is atm either one of {@link Channel#Alpha}, {@link Channel#Beta} or {@link Channel#Release}
+	 *
+	 * @param rawChannel String containing the channel
+	 *
+	 * @return matching {@link Channel} to the String
+	 */
+	private Channel parseChannel( String rawChannel )
+	{
+		assert rawChannel.equalsIgnoreCase( Channel.Alpha.name() ) || rawChannel.equalsIgnoreCase( Channel.Beta.name() ) || rawChannel.equalsIgnoreCase( Channel.Release.name() );
+
+		for ( Channel channel : Channel.values() )
+		{
+			if ( channel.name().equalsIgnoreCase( rawChannel ) )
+			{
+				return channel;
+			}
+		}
+
+		throw new InvalidParameterException( "Raw channel did not contain any of the pre-programmed types." );
+	}
+
+	/**
+	 * A build is just a natural number
+	 *
+	 * @param rawBuild String containing the build number
+	 *
+	 * @return build number
+	 */
+	private int parseBuild( String rawBuild )
+	{
+		assert PATTERN_NATURAL.matcher( rawBuild ).matches();
+
+		final int build = new Scanner( rawBuild ).useDelimiter( PATTERN_BUILD ).nextInt();
+
+		return build;
+	}
+}