code refactoring + add unit test [memory module] (opensearch-project#4086)

* code refactoring

Signed-off-by: Dhrubo Saha <[email protected]>

* add more unit tests and bug fix

Signed-off-by: Dhrubo Saha <[email protected]>

---------

Signed-off-by: Dhrubo Saha <[email protected]>

Author: dhrubo-os

plugin/src/main/java/org/opensearch/ml/action/memorycontainer/memory/FactSearchResult.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.action.memorycontainer.memory;
+
+/**
+ * Helper class to store fact search results
+ */
+public class FactSearchResult {
+    private final String id;
+    private final String text;
+    private final float score;
+
+    public FactSearchResult(String id, String text, float score) {
+        this.id = id;
+        this.text = text;
+        this.score = score;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    public float getScore() {
+        return score;
+    }
+}

plugin/src/main/java/org/opensearch/ml/action/memorycontainer/memory/MemoryInfo.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.action.memorycontainer.memory;
+
+import org.opensearch.ml.common.memorycontainer.MemoryType;
+
+/**
+ * Helper class to track memory info for response building
+ */
+public class MemoryInfo {
+    private String memoryId;
+    private final String content;
+    private final MemoryType type;
+    private final boolean includeInResponse;
+
+    public MemoryInfo(String memoryId, String content, MemoryType type, boolean includeInResponse) {
+        this.memoryId = memoryId;
+        this.content = content;
+        this.type = type;
+        this.includeInResponse = includeInResponse;
+    }
+
+    public String getMemoryId() {
+        return memoryId;
+    }
+
+    public void setMemoryId(String memoryId) {
+        this.memoryId = memoryId;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public MemoryType getType() {
+        return type;
+    }
+
+    public boolean isIncludeInResponse() {
+        return includeInResponse;
+    }
+}