ONOS-1479 -- GUI - augmenting topology view for extensibility: WIP.
- Major refactoring of TopologyViewMessageHandler and related classes.

Change-Id: I920f7f9f7317f3987a9a8da35ac086e9f8cab8d3
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/topo/BiLink.java b/web/gui/src/main/java/org/onosproject/ui/impl/topo/BiLink.java
new file mode 100644
index 0000000..5ab4e0e
--- /dev/null
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/topo/BiLink.java
@@ -0,0 +1,244 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.onosproject.ui.impl.topo;
+
+import org.onosproject.net.Link;
+import org.onosproject.net.LinkKey;
+import org.onosproject.net.statistic.Load;
+import org.onosproject.ui.topo.LinkHighlight;
+
+import static org.onosproject.ui.topo.LinkHighlight.Flavor.NO_HIGHLIGHT;
+import static org.onosproject.ui.topo.LinkHighlight.Flavor.PRIMARY_HIGHLIGHT;
+import static org.onosproject.ui.topo.LinkHighlight.Flavor.SECONDARY_HIGHLIGHT;
+
+/**
+ * Representation of a link and its inverse, and any associated traffic data.
+ * This class understands how to generate {@link LinkHighlight}s for sending
+ * back to the topology view.
+ */
+public class BiLink {
+
+    private static final String EMPTY = "";
+
+    private final LinkKey key;
+    private final Link one;
+    private Link two;
+
+    private boolean hasTraffic = false;
+    private long bytes = 0;
+    private long rate = 0;
+    private long flows = 0;
+    private boolean isOptical = false;
+    private LinkHighlight.Flavor taggedFlavor = NO_HIGHLIGHT;
+    private boolean antMarch = false;
+
+    /**
+     * Constructs a bilink for the given key and initial link.
+     *
+     * @param key canonical key for this bilink
+     * @param link first link
+     */
+    public BiLink(LinkKey key, Link link) {
+        this.key = key;
+        this.one = link;
+    }
+
+    /**
+     * Sets the second link for this bilink.
+     *
+     * @param link second link
+     */
+    public void setOther(Link link) {
+        this.two = link;
+    }
+
+    /**
+     * Sets the optical flag to the given value.
+     *
+     * @param b true if an optical link
+     */
+    public void setOptical(boolean b) {
+        isOptical = b;
+    }
+
+    /**
+     * Sets the ant march flag to the given value.
+     *
+     * @param b true if marching ants required
+     */
+    public void setAntMarch(boolean b) {
+        antMarch = b;
+    }
+
+    /**
+     * Tags this bilink with a link flavor to be used in visual rendering.
+     *
+     * @param flavor the flavor to tag
+     */
+    public void tagFlavor(LinkHighlight.Flavor flavor) {
+        this.taggedFlavor = flavor;
+    }
+
+    /**
+     * Adds load statistics, marks the bilink as having traffic.
+     *
+     * @param load load to add
+     */
+    public void addLoad(Load load) {
+        addLoad(load, 0);
+    }
+
+    /**
+     * Adds load statistics, marks the bilink as having traffic, if the
+     * load rate is greater than the given threshold.
+     *
+     * @param load load to add
+     * @param threshold threshold to register traffic
+     */
+    public void addLoad(Load load, double threshold) {
+        if (load != null) {
+            this.hasTraffic = hasTraffic || load.rate() > threshold;
+            this.bytes += load.latest();
+            this.rate += load.rate();
+        }
+    }
+
+    /**
+     * Adds the given count of flows to this bilink.
+     *
+     * @param count count of flows
+     */
+    public void addFlows(int count) {
+        this.flows += count;
+    }
+
+    /**
+     * Generates a link highlight entity, based on state of this bilink.
+     *
+     * @param type the type of statistics to use to interpret the data
+     * @return link highlight data for this bilink
+     */
+    public LinkHighlight generateHighlight(LinkStatsType type) {
+        switch (type) {
+            case FLOW_COUNT:
+                return highlightForFlowCount(type);
+
+            case FLOW_STATS:
+            case PORT_STATS:
+                return highlightForStats(type);
+
+            case TAGGED:
+                return highlightForTagging(type);
+
+            default:
+                throw new IllegalStateException("unexpected case: " + type);
+        }
+    }
+
+    private LinkHighlight highlightForStats(LinkStatsType type) {
+        return new LinkHighlight(linkId(), SECONDARY_HIGHLIGHT)
+                .setLabel(generateLabel(type));
+    }
+
+    private LinkHighlight highlightForFlowCount(LinkStatsType type) {
+        LinkHighlight.Flavor flavor = flows() > 0 ?
+                PRIMARY_HIGHLIGHT : SECONDARY_HIGHLIGHT;
+        return new LinkHighlight(linkId(), flavor)
+                .setLabel(generateLabel(type));
+    }
+
+    private LinkHighlight highlightForTagging(LinkStatsType type) {
+        LinkHighlight hlite = new LinkHighlight(linkId(), flavor())
+                .setLabel(generateLabel(type));
+        if (isOptical()) {
+            hlite.addMod(LinkHighlight.MOD_OPTICAL);
+        }
+        if (isAntMarch()) {
+            hlite.addMod(LinkHighlight.MOD_ANIMATED);
+        }
+        return hlite;
+    }
+
+    // Generates a link identifier in the form that the Topology View on the
+    private String linkId() {
+        return TopoUtils.compactLinkString(one);
+    }
+
+    // Generates a string representation of the load, to be used as a label
+    private String generateLabel(LinkStatsType type) {
+        switch (type) {
+            case FLOW_COUNT:
+                return TopoUtils.formatFlows(flows());
+
+            case FLOW_STATS:
+                return TopoUtils.formatBytes(bytes());
+
+            case PORT_STATS:
+                return TopoUtils.formatBitRate(rate());
+
+            case TAGGED:
+                return hasTraffic() ? TopoUtils.formatBytes(bytes()) : EMPTY;
+
+            default:
+                return "?";
+        }
+    }
+
+    // === ----------------------------------------------------------------
+    // accessors
+
+    public LinkKey key() {
+        return key;
+    }
+
+    public Link one() {
+        return one;
+    }
+
+    public Link two() {
+        return two;
+    }
+
+    public boolean hasTraffic() {
+        return hasTraffic;
+    }
+
+    public boolean isOptical() {
+        return isOptical;
+    }
+
+    public boolean isAntMarch() {
+        return antMarch;
+    }
+
+    public LinkHighlight.Flavor flavor() {
+        return taggedFlavor;
+    }
+
+    public long bytes() {
+        return bytes;
+    }
+
+    public long rate() {
+        return rate;
+    }
+
+    public long flows() {
+        return flows;
+    }
+}