add: implement DefaultCmabService with decision retrieval and attribute filtering logic

Author: FarhanAnjum-opti

core-api/src/main/java/com/optimizely/ab/cmab/service/DefaultCmabService.java

@@ -0,0 +1,141 @@
+package com.optimizely.ab.cmab.service;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+import org.slf4j.Logger;
+
+import com.optimizely.ab.OptimizelyUserContext;
+import com.optimizely.ab.cmab.client.CmabClient;
+import com.optimizely.ab.config.Attribute;
+import com.optimizely.ab.config.Experiment;
+import com.optimizely.ab.config.ProjectConfig;
+import com.optimizely.ab.internal.DefaultLRUCache;
+import com.optimizely.ab.optimizelydecision.OptimizelyDecideOption;
+
+public class DefaultCmabService implements CmabService {
+    private final DefaultLRUCache<CmabCacheValue> cmabCache;
+    private final CmabClient cmabClient;
+    private final Logger logger;
+
+    public DefaultCmabService(CmabServiceOptions options) {
+        this.cmabCache = options.getCmabCache();
+        this.cmabClient = options.getCmabClient();
+        this.logger = options.getLogger();  
+    }
+    
+    @Override
+    public CmabDecision getDecision(ProjectConfig projectConfig, OptimizelyUserContext userContext, String ruleId, List<OptimizelyDecideOption> options) {
+        return null;
+    }
+
+    private Map<String, Object> filterAttributes(ProjectConfig projectConfig, OptimizelyUserContext userContext, String ruleId) {
+        Map<String, Object> userAttributes = userContext.getAttributes();
+        Map<String, Object> filteredAttributes = new HashMap<>();
+        
+        // Get experiment by rule ID
+        Experiment experiment = projectConfig.getExperimentIdMapping().get(ruleId);
+        if (experiment == null) {
+            if (logger != null) {
+                logger.debug("Experiment not found for rule ID: {}", ruleId);
+            }
+            return filteredAttributes;
+        }
+        
+        // Check if experiment has CMAB configuration
+        // Add null check for getCmab()
+        if (experiment.getCmab() == null) {
+            if (logger != null) {
+                logger.debug("No CMAB configuration found for experiment: {}", ruleId);
+            }
+            return filteredAttributes;
+        }
+
+        List<String> cmabAttributeIds = experiment.getCmab().getAttributeIds();
+        if (cmabAttributeIds == null || cmabAttributeIds.isEmpty()) {
+            return filteredAttributes;
+        }
+        
+        Map<String,Attribute> attributeIdMapping = projectConfig.getAttributeIdMapping();
+        // Add null check for attributeIdMapping
+        if (attributeIdMapping == null) {
+            if (logger != null) {
+                logger.debug("No attribute mapping found in project config for rule ID: {}", ruleId);
+            }
+            return filteredAttributes;
+        }
+        
+        // Filter attributes based on CMAB configuration
+        for (String attributeId : cmabAttributeIds) {
+            Attribute attribute = attributeIdMapping.get(attributeId);
+            if (attribute != null) {
+                if (userAttributes.containsKey(attribute.getKey())) {
+                    filteredAttributes.put(attribute.getKey(), userAttributes.get(attribute.getKey()));
+                } else if (logger != null) {
+                    logger.debug("User attribute '{}' not found for attribute ID '{}'", attribute.getKey(), attributeId);
+                }
+            } else if (logger != null) {
+                logger.debug("Attribute configuration not found for ID: {}", attributeId);
+            }
+        }
+        
+        return filteredAttributes;
+    }
+
+    private String getCacheKey(String userId, String ruleId) {
+        return userId.length() + "-" + userId + "-" + ruleId;
+    }
+    
+    /**
+     * Hash attributes using MD5
+     */
+    private String hashAttributes(Map<String, Object> attributes) {
+        try {
+            // Sort attributes to ensure consistent hashing
+            TreeMap<String, Object> sortedAttributes = new TreeMap<>(attributes);
+            
+            // Create a simple string representation
+            StringBuilder sb = new StringBuilder();
+            sb.append("{");
+            boolean first = true;
+            for (Map.Entry<String, Object> entry : sortedAttributes.entrySet()) {
+                if (!first) {
+                    sb.append(",");
+                }
+                sb.append("\"").append(entry.getKey()).append("\":");
+                if (entry.getValue() instanceof String) {
+                    sb.append("\"").append(entry.getValue()).append("\"");
+                } else {
+                    sb.append(entry.getValue());
+                }
+                first = false;
+            }
+            sb.append("}");
+            
+            // Generate MD5 hash
+            MessageDigest md = MessageDigest.getInstance("MD5");
+            byte[] hash = md.digest(sb.toString().getBytes());
+            
+            // Convert to hex string
+            StringBuilder hexString = new StringBuilder();
+            for (byte b : hash) {
+                String hex = Integer.toHexString(0xff & b);
+                if (hex.length() == 1) {
+                    hexString.append('0');
+                }
+                hexString.append(hex);
+            }
+            return hexString.toString();
+            
+        } catch (NoSuchAlgorithmException e) {
+            if (logger != null) {
+                logger.warn("Failed to hash attributes", e);
+            }
+            return "";
+        }
+    }
+}

core-api/src/main/java/com/optimizely/ab/config/DatafileProjectConfig.java

@@ -92,6 +92,7 @@ public class DatafileProjectConfig implements ProjectConfig {
     private final Map<String, Group> groupIdMapping;
     private final Map<String, Rollout> rolloutIdMapping;
     private final Map<String, List<String>> experimentFeatureKeyMapping;
+    private final Map<String, Attribute> attributeIdMapping;
 
     // other mappings
     private final Map<String, Experiment> variationIdToExperimentMapping;
@@ -253,6 +254,7 @@ public DatafileProjectConfig(String accountId,
         this.experimentIdMapping = ProjectConfigUtils.generateIdMapping(this.experiments);
         this.groupIdMapping = ProjectConfigUtils.generateIdMapping(groups);
         this.rolloutIdMapping = ProjectConfigUtils.generateIdMapping(this.rollouts);
+        this.attributeIdMapping = ProjectConfigUtils.generateIdMapping(this.attributes);
 
         // Generate experiment to featureFlag list mapping to identify if experiment is AB-Test experiment or Feature-Test Experiment.
         this.experimentFeatureKeyMapping = ProjectConfigUtils.generateExperimentFeatureMapping(this.featureFlags);
@@ -539,6 +541,11 @@ public Map<String, Attribute> getAttributeKeyMapping() {
         return attributeKeyMapping;
     }
 
+    @Override
+    public Map<String, Attribute> getAttributeIdMapping() {
+        return this.attributeIdMapping;
+    }
+
     @Override
     public Map<String, EventType> getEventNameMapping() {
         return eventNameMapping;

core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java

@@ -101,6 +101,8 @@ Experiment getExperimentForKey(@Nonnull String experimentKey,
 
     Map<String, Attribute> getAttributeKeyMapping();
 
+    Map<String, Attribute> getAttributeIdMapping();
+
     Map<String, EventType> getEventNameMapping();
 
     Map<String, Audience> getAudienceIdMapping();