2 files changed, 268 insertions, 0 deletions
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/InvalidJidException.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/InvalidJidException.java
new file mode 100644
index 00000000..3c8dd717
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/InvalidJidException.java
@@ -0,0 +1,49 @@
+package de.thedevstack.conversationsplus.xmpp.jid;
+
+public class InvalidJidException extends Exception {
+
+    // This is probably not the "Java way", but the "Java way" means we'd have a ton of extra tiny,
+    // annoying classes floating around. I like this.
+    public final static String INVALID_LENGTH = "JID must be between 0 and 3071 characters";
+    public final static String INVALID_PART_LENGTH = "JID part must be between 0 and 1023 characters";
+    public final static String INVALID_CHARACTER = "JID contains an invalid character";
+    public final static String STRINGPREP_FAIL = "The STRINGPREP operation has failed for the given JID";
+	public final static String IS_NULL = "JID can not be NULL";
+
+    /**
+     * Constructs a new {@code Exception} that includes the current stack trace.
+     */
+    public InvalidJidException() {
+    }
+
+    /**
+     * Constructs a new {@code Exception} with the current stack trace and the
+     * specified detail message.
+     *
+     * @param detailMessage the detail message for this exception.
+     */
+    public InvalidJidException(final String detailMessage) {
+        super(detailMessage);
+    }
+
+    /**
+     * Constructs a new {@code Exception} with the current stack trace, the
+     * specified detail message and the specified cause.
+     *
+     * @param detailMessage the detail message for this exception.
+     * @param throwable the cause of this exception.
+     */
+    public InvalidJidException(final String detailMessage, final Throwable throwable) {
+        super(detailMessage, throwable);
+    }
+
+    /**
+     * Constructs a new {@code Exception} with the current stack trace and the
+     * specified cause.
+     *
+     * @param throwable the cause of this exception.
+     */
+    public InvalidJidException(final Throwable throwable) {
+        super(throwable);
+    }
+}
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/Jid.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/Jid.java
new file mode 100644
index 00000000..43b0e878
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/Jid.java
@@ -0,0 +1,219 @@
+package de.thedevstack.conversationsplus.xmpp.jid;
+
+import android.util.LruCache;
+
+import net.java.otr4j.session.SessionID;
+
+import java.net.IDN;
+
+import de.thedevstack.conversationsplus.Config;
+import gnu.inet.encoding.Stringprep;
+import gnu.inet.encoding.StringprepException;
+
+/**
+ * The `Jid' class provides an immutable representation of a JID.
+ */
+public final class Jid {
+
+	private static LruCache<String,Jid> cache = new LruCache<>(1024);
+
+	private final String localpart;
+	private final String domainpart;
+	private final String resourcepart;
+
+	// It's much more efficient to store the ful JID as well as the parts instead of figuring them
+	// all out every time (since some characters are displayed but aren't used for comparisons).
+	private final String displayjid;
+
+	public String getLocalpart() {
+		return localpart;
+	}
+
+	public String getDomainpart() {
+		return IDN.toUnicode(domainpart);
+	}
+
+	public String getResourcepart() {
+		return resourcepart;
+	}
+
+	public static Jid fromSessionID(final SessionID id) throws InvalidJidException{
+		if (id.getUserID().isEmpty()) {
+			return Jid.fromString(id.getAccountID());
+		} else {
+			return Jid.fromString(id.getAccountID()+"/"+id.getUserID());
+		}
+	}
+
+	public static Jid fromString(final String jid) throws InvalidJidException {
+		return Jid.fromString(jid, false);
+	}
+
+	public static Jid fromString(final String jid, final boolean safe) throws InvalidJidException {
+		return new Jid(jid, safe);
+	}
+
+	public static Jid fromParts(final String localpart,
+			final String domainpart,
+			final String resourcepart) throws InvalidJidException {
+		String out;
+		if (localpart == null || localpart.isEmpty()) {
+			out = domainpart;
+		} else {
+			out = localpart + "@" + domainpart;
+		}
+		if (resourcepart != null && !resourcepart.isEmpty()) {
+			out = out + "/" + resourcepart;
+		}
+		return new Jid(out, false);
+	}
+
+	private Jid(final String jid, final boolean safe) throws InvalidJidException {
+		if (jid == null) throw new InvalidJidException(InvalidJidException.IS_NULL);
+
+		Jid fromCache = Jid.cache.get(jid);
+		if (fromCache != null) {
+			displayjid = fromCache.displayjid;
+			localpart = fromCache.localpart;
+			domainpart = fromCache.domainpart;
+			resourcepart = fromCache.resourcepart;
+			return;
+		}
+
+		// Hackish Android way to count the number of chars in a string... should work everywhere.
+		final int atCount = jid.length() - jid.replace("@", "").length();
+		final int slashCount = jid.length() - jid.replace("/", "").length();
+
+		// Throw an error if there's anything obvious wrong with the JID...
+		if (jid.isEmpty() || jid.length() > 3071) {
+			throw new InvalidJidException(InvalidJidException.INVALID_LENGTH);
+		}
+
+		// Go ahead and check if the localpart or resourcepart is empty.
+		if (jid.startsWith("@") || (jid.endsWith("@") && slashCount == 0) || jid.startsWith("/") || (jid.endsWith("/") && slashCount < 2)) {
+			throw new InvalidJidException(InvalidJidException.INVALID_CHARACTER);
+		}
+
+		String finaljid;
+
+		final int domainpartStart;
+		final int atLoc = jid.indexOf("@");
+		final int slashLoc = jid.indexOf("/");
+		// If there is no "@" in the JID (eg. "example.net" or "example.net/resource")
+		// or there are one or more "@" signs but they're all in the resourcepart (eg. "example.net/@/rp@"):
+		if (atCount == 0 || (atCount > 0 && slashLoc != -1 && atLoc > slashLoc)) {
+			localpart = "";
+			finaljid = "";
+			domainpartStart = 0;
+		} else {
+			final String lp = jid.substring(0, atLoc);
+			try {
+				localpart = Config.DISABLE_STRING_PREP || safe ? lp : Stringprep.nodeprep(lp);
+			} catch (final StringprepException e) {
+				throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+			}
+			if (localpart.isEmpty() || localpart.length() > 1023) {
+				throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+			}
+			domainpartStart = atLoc + 1;
+			finaljid = lp + "@";
+		}
+
+		final String dp;
+		if (slashCount > 0) {
+			final String rp = jid.substring(slashLoc + 1, jid.length());
+			try {
+				resourcepart = Config.DISABLE_STRING_PREP || safe ? rp : Stringprep.resourceprep(rp);
+			} catch (final StringprepException e) {
+				throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+			}
+			if (resourcepart.isEmpty() || resourcepart.length() > 1023) {
+				throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+			}
+			dp = IDN.toUnicode(jid.substring(domainpartStart, slashLoc), IDN.USE_STD3_ASCII_RULES);
+			finaljid = finaljid + dp + "/" + rp;
+		} else {
+			resourcepart = "";
+			dp = IDN.toUnicode(jid.substring(domainpartStart, jid.length()),
+					IDN.USE_STD3_ASCII_RULES);
+			finaljid = finaljid + dp;
+		}
+
+		// Remove trailing "." before storing the domain part.
+		if (dp.endsWith(".")) {
+			try {
+				domainpart = IDN.toASCII(dp.substring(0, dp.length() - 1), IDN.USE_STD3_ASCII_RULES);
+			} catch (final IllegalArgumentException e) {
+				throw new InvalidJidException(e);
+			}
+		} else {
+			try {
+				domainpart = IDN.toASCII(dp, IDN.USE_STD3_ASCII_RULES);
+			} catch (final IllegalArgumentException e) {
+				throw new InvalidJidException(e);
+			}
+		}
+
+		// TODO: Find a proper domain validation library; validate individual parts, separators, etc.
+		if (domainpart.isEmpty() || domainpart.length() > 1023) {
+			throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+		}
+
+		Jid.cache.put(jid, this);
+
+		this.displayjid = finaljid;
+	}
+
+	public Jid toBareJid() {
+		try {
+			return resourcepart.isEmpty() ? this : fromParts(localpart, domainpart, "");
+		} catch (final InvalidJidException e) {
+			// This should never happen.
+			return null;
+		}
+	}
+
+	public Jid toDomainJid() {
+		try {
+			return resourcepart.isEmpty() && localpart.isEmpty() ? this : fromString(getDomainpart());
+		} catch (final InvalidJidException e) {
+			// This should never happen.
+			return null;
+		}
+	}
+
+	@Override
+	public String toString() {
+		return displayjid;
+	}
+
+	@Override
+	public boolean equals(final Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+
+		final Jid jid = (Jid) o;
+
+		return jid.hashCode() == this.hashCode();
+	}
+
+	@Override
+	public int hashCode() {
+		int result = localpart.hashCode();
+		result = 31 * result + domainpart.hashCode();
+		result = 31 * result + resourcepart.hashCode();
+		return result;
+	}
+
+	public boolean hasLocalpart() {
+		return !localpart.isEmpty();
+	}
+
+	public boolean isBareJid() {
+		return this.resourcepart.isEmpty();
+	}
+
+	public boolean isDomainJid() {
+		return !this.hasLocalpart();
+	}
+}