[Blackbird] Fixing Intent purge case (ONOS-1207)

Master needs to remove from the current map.

Change-Id: I30eccbe188997949ef2d63d6dbd37b0d8d4b3f5e
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/phase/PurgeRequest.java b/core/net/src/main/java/org/onosproject/net/intent/impl/phase/PurgeRequest.java
new file mode 100644
index 0000000..b04e05e
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/phase/PurgeRequest.java
@@ -0,0 +1,60 @@
+/*
+ * 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.net.intent.impl.phase;
+
+import org.onosproject.net.intent.IntentData;
+import org.onosproject.net.intent.IntentState;
+import org.slf4j.Logger;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Represents a phase of requesting a purge of an intent.
+ * <p>
+ * Note: The purge will only succeed if the intent is FAILED or WITHDRAWN.
+ * </p>
+ */
+final class PurgeRequest extends FinalIntentProcessPhase {
+
+    private static final Logger log = getLogger(PurgeRequest.class);
+
+    private final IntentData pending;
+    private final IntentData current;
+
+    PurgeRequest(IntentData intentData, IntentData current) {
+        this.pending = checkNotNull(intentData);
+        this.current = checkNotNull(current);
+    }
+
+    private boolean shouldAcceptPurge() {
+        if (current.state() == IntentState.WITHDRAWN
+                || current.state() == IntentState.FAILED) {
+            return true;
+        }
+        log.info("Purge for intent {} is rejected", pending.key());
+        return false;
+    }
+
+    @Override
+    public IntentData data() {
+        if (shouldAcceptPurge()) {
+            return pending;
+        } else {
+            return current;
+        }
+    }
+}