Better UX handling on identity key mismatches.

1) Migrate from GSON to Jackson everywhere.

2) Add support for storing identity key conflicts on message rows.

3) Add limited support for surfacing identity key conflicts in UI.

src/org/thoughtcrime/securesms/database/documents/Document.java

@@ -0,0 +1,10 @@
+package org.thoughtcrime.securesms.database.documents;
+
+import java.util.List;
+
+public interface Document<T> {
+
+  public int size();
+  public List<T> getList();
+
+}

src/org/thoughtcrime/securesms/database/documents/IdentityKeyMismatch.java

@@ -0,0 +1,85 @@
+package org.thoughtcrime.securesms.database.documents;
+
+import android.util.Log;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+import org.thoughtcrime.securesms.util.Base64;
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+
+import java.io.IOException;
+
+public class IdentityKeyMismatch {
+
+  private static final String TAG = IdentityKeyMismatch.class.getSimpleName();
+
+  @JsonProperty(value = "r")
+  private long recipientId;
+
+  @JsonProperty(value = "k")
+  @JsonSerialize(using = IdentityKeySerializer.class)
+  @JsonDeserialize(using = IdentityKeyDeserializer.class)
+  private IdentityKey identityKey;
+
+  public IdentityKeyMismatch() {}
+
+  public IdentityKeyMismatch(long recipientId, IdentityKey identityKey) {
+    this.recipientId = recipientId;
+    this.identityKey = identityKey;
+  }
+
+  public long getRecipientId() {
+    return recipientId;
+  }
+
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == null || !(other instanceof IdentityKeyMismatch)) {
+      return false;
+    }
+
+    IdentityKeyMismatch that = (IdentityKeyMismatch)other;
+    return that.recipientId == this.recipientId && that.identityKey.equals(this.identityKey);
+  }
+
+  @Override
+  public int hashCode() {
+    return (int)recipientId ^ identityKey.hashCode();
+  }
+
+  private static class IdentityKeySerializer extends JsonSerializer<IdentityKey> {
+    @Override
+    public void serialize(IdentityKey value, JsonGenerator jsonGenerator, SerializerProvider serializers)
+        throws IOException
+    {
+      jsonGenerator.writeString(Base64.encodeBytes(value.serialize()));
+    }
+  }
+
+  private static class IdentityKeyDeserializer extends JsonDeserializer<IdentityKey> {
+    @Override
+    public IdentityKey deserialize(JsonParser jsonParser, DeserializationContext ctxt)
+        throws IOException
+    {
+      try {
+        return new IdentityKey(Base64.decode(jsonParser.getValueAsString()), 0);
+      } catch (InvalidKeyException e) {
+        Log.w(TAG, e);
+        throw new IOException(e);
+      }
+    }
+  }
+}

src/org/thoughtcrime/securesms/database/documents/IdentityKeyMismatchList.java

@@ -0,0 +1,31 @@
+package org.thoughtcrime.securesms.database.documents;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class IdentityKeyMismatchList implements Document<IdentityKeyMismatch> {
+
+  @JsonProperty(value = "m")
+  private List<IdentityKeyMismatch> mismatches;
+
+  public IdentityKeyMismatchList() {
+    this.mismatches = new LinkedList<>();
+  }
+
+  public IdentityKeyMismatchList(List<IdentityKeyMismatch> mismatches) {
+    this.mismatches = mismatches;
+  }
+
+  @Override
+  public int size() {
+    if (mismatches == null) return 0;
+    else                    return mismatches.size();
+  }
+
+  @Override
+  public List<IdentityKeyMismatch> getList() {
+    return mismatches;
+  }
+}

src/org/thoughtcrime/securesms/database/documents/NetworkFailure.java

@@ -0,0 +1,32 @@
+package org.thoughtcrime.securesms.database.documents;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class NetworkFailure {
+
+  @JsonProperty(value = "r")
+  private long recipientId;
+
+  public NetworkFailure(long recipientId) {
+    this.recipientId = recipientId;
+  }
+
+  public NetworkFailure() {}
+
+  public long getRecipientId() {
+    return recipientId;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == null || !(other instanceof NetworkFailure)) return false;
+
+    NetworkFailure that = (NetworkFailure)other;
+    return this.recipientId == that.recipientId;
+  }
+
+  @Override
+  public int hashCode() {
+    return (int)recipientId;
+  }
+}

src/org/thoughtcrime/securesms/database/documents/NetworkFailureList.java

@@ -0,0 +1,33 @@
+package org.thoughtcrime.securesms.database.documents;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class NetworkFailureList implements Document<NetworkFailure> {
+
+  @JsonProperty(value = "l")
+  private List<NetworkFailure> failures;
+
+  public NetworkFailureList() {
+    this.failures = new LinkedList<>();
+  }
+
+  public NetworkFailureList(List<NetworkFailure> failures) {
+    this.failures = failures;
+  }
+
+  @Override
+  public int size() {
+    if (failures == null) return 0;
+    else                  return failures.size();
+  }
+
+  @Override
+  @JsonIgnore
+  public List<NetworkFailure> getList() {
+    return failures;
+  }
+}