[Minor] Further adjustmentsvstakhov-multi-class-bayes

4 files changed, 70 insertions, 34 deletions

diff --git a/src/libstat/classifiers/bayes.c b/src/libstat/classifiers/bayes.c
index 66d84a14d..d995de91f 100644
--- a/src/libstat/classifiers/bayes.c
+++ b/src/libstat/classifiers/bayes.c
@@ -336,6 +336,9 @@ bayes_classify_token_multiclass(struct rspamd_classifier *ctx,
 			double class_freq = (double) class_counts[j] / MAX(1.0, (double) cl->class_learns[j]);
 			double class_prob = PROB_COMBINE(class_freq, total_count, w, 1.0 / cl->num_classes);
 
+			/* Ensure probability is properly bounded [0, 1] */
+			class_prob = MAX(0.0, MIN(1.0, class_prob));
+
 			/* Skip probabilities too close to uniform (1/num_classes) */
 			double uniform_prior = 1.0 / cl->num_classes;
 			if (fabs(class_prob - uniform_prior) < ctx->cfg->min_prob_strength) {
@@ -535,7 +538,23 @@ bayes_classify_multiclass(struct rspamd_classifier *ctx,
 
 	/* Calculate confidence using Fisher method for the winning class */
 	if (max_log_prob > -300) {
-		confidence = 1.0 - inv_chi_square(task, max_log_prob, cl.processed_tokens);
+		if (max_log_prob > 0) {
+			/* Positive log prob means very strong evidence - high confidence */
+			confidence = 0.95; /* High confidence for positive log probabilities */
+			msg_debug_bayes("positive log_prob (%g), setting high confidence", max_log_prob);
+		}
+		else {
+			/* Negative log prob - use Fisher method as intended */
+			double fisher_result = inv_chi_square(task, max_log_prob, cl.processed_tokens);
+			confidence = 1.0 - fisher_result;
+
+			/* Handle case where Fisher method indicates extreme confidence */
+			if (fisher_result >= 1.0 && max_log_prob > -50) {
+				/* Large magnitude negative log prob means strong evidence */
+				confidence = 0.90;
+				msg_debug_bayes("extreme negative log_prob (%g), setting high confidence", max_log_prob);
+			}
+		}
 	}
 	else {
 		confidence = normalized_probs[winning_class_idx];
diff --git a/test/functional/cases/110_statistics/multiclass_lib.robot b/test/functional/cases/110_statistics/multiclass_lib.robot
index 4fa4284bb..b2e7c10e3 100644
--- a/test/functional/cases/110_statistics/multiclass_lib.robot
+++ b/test/functional/cases/110_statistics/multiclass_lib.robot
@@ -6,7 +6,6 @@ ${CONFIG}                      ${RSPAMD_TESTDIR}/configs/multiclass_bayes.conf
 ${MESSAGE_HAM}                 ${RSPAMD_TESTDIR}/messages/ham.eml
 ${MESSAGE_SPAM}                ${RSPAMD_TESTDIR}/messages/spam_message.eml
 ${MESSAGE_NEWSLETTER}          ${RSPAMD_TESTDIR}/messages/newsletter.eml
-${MESSAGE_TRANSACTIONAL}       ${RSPAMD_TESTDIR}/messages/transactional.eml
 ${REDIS_SCOPE}                 Suite
 ${RSPAMD_REDIS_SERVER}         null
 ${RSPAMD_SCOPE}                Suite
@@ -47,7 +46,6 @@ Multiclass Basic Learn Test
     Learn Multiclass  ${user}  spam  ${MESSAGE_SPAM}
     Learn Multiclass  ${user}  ham  ${MESSAGE_HAM}
     Learn Multiclass  ${user}  newsletter  ${MESSAGE_NEWSLETTER}
-    Learn Multiclass  ${user}  transactional  ${MESSAGE_TRANSACTIONAL}
 
     # Test classification
     Scan File  ${MESSAGE_SPAM}  &{kwargs}
@@ -59,9 +57,6 @@ Multiclass Basic Learn Test
     Scan File  ${MESSAGE_NEWSLETTER}  &{kwargs}
     Expect Symbol  BAYES_NEWSLETTER
 
-    Scan File  ${MESSAGE_TRANSACTIONAL}  &{kwargs}
-    Expect Symbol  BAYES_TRANSACTIONAL
-
     Set Suite Variable  ${RSPAMD_STATS_LEARNTEST}  1
 
 Multiclass Legacy Compatibility Test
@@ -111,12 +106,12 @@ Multiclass Cross-Learn Test
         Set To Dictionary  ${kwargs}  Deliver-To=${user}
     END
 
-    # Learn newsletter message as transactional
-    Learn Multiclass  ${user}  transactional  ${MESSAGE_NEWSLETTER}
+    # Learn newsletter message as ham to test cross-class learning
+    Learn Multiclass  ${user}  ham  ${MESSAGE_NEWSLETTER}
 
-    # Should classify as transactional, not newsletter
+    # Should classify as ham, not newsletter (since we trained it as ham)
     Scan File  ${MESSAGE_NEWSLETTER}  &{kwargs}
-    Expect Symbol  BAYES_TRANSACTIONAL
+    Expect Symbol  BAYES_HAM
     Do Not Expect Symbol  BAYES_NEWSLETTER
 
 Multiclass Unlearn Test
@@ -154,7 +149,6 @@ Multiclass Stats Test
     Should Contain  ${result.stdout}  spam
     Should Contain  ${result.stdout}  ham
     Should Contain  ${result.stdout}  newsletter
-    Should Contain  ${result.stdout}  transactional
 
 Multiclass Configuration Migration Test
     # Test that old binary config can be automatically migrated
@@ -176,7 +170,6 @@ Multiclass Performance Test
         Scan File  ${MESSAGE_SPAM}
         Scan File  ${MESSAGE_HAM}
         Scan File  ${MESSAGE_NEWSLETTER}
-        Scan File  ${MESSAGE_TRANSACTIONAL}
     END
 
     ${end_time} =  Get Time  epoch
diff --git a/test/functional/configs/multiclass_bayes.conf b/test/functional/configs/multiclass_bayes.conf
index e58a39056..6651f94a1 100644
--- a/test/functional/configs/multiclass_bayes.conf
+++ b/test/functional/configs/multiclass_bayes.conf
@@ -76,18 +76,12 @@ classifier {
 		symbol = BAYES_NEWSLETTER;
 		server = {= env.REDIS_SERVER =}
 	}
-	statfile {
-		class = "transactional";
-		symbol = BAYES_TRANSACTIONAL;
-		server = {= env.REDIS_SERVER =}
-	}
 
 	# Backend class labels for Redis
 	class_labels = {
 		"spam" = "S";
 		"ham" = "H";
 		"newsletter" = "N";
-		"transactional" = "T";
 	}
 
 	cache {
@@ -106,13 +100,9 @@ classifier {
 				verdict_mapping = { ham = true };
 			};
 			newsletter = {
-				symbols = ["NEWSLETTER_HEADER", "BULK_MAIL"];
+				symbols = ["NEWSLETTER_HEADER", "BULK_MAIL", "UNSUBSCRIBE_LINK"];
 				threshold = 8.0;
 			};
-			transactional = {
-				symbols = ["TRANSACTIONAL_MAIL", "PASSWORD_RESET"];
-				threshold = 5.0;
-			};
 		};
 
 		check_balance = true;
diff --git a/test/functional/messages/newsletter.eml b/test/functional/messages/newsletter.eml
index 52e8988b8..93c996956 100644
--- a/test/functional/messages/newsletter.eml
+++ b/test/functional/messages/newsletter.eml
@@ -1,16 +1,50 @@
-From: newsletter@example.com
+From: "Marketing Team" <newsletter@example.com>
 To: user@example.org
-Subject: Monthly Newsletter - Special Offers Inside
+Subject: 🎉 Monthly Newsletter - Exclusive Deals & Product Updates!
 Date: Thu, 21 Jul 2023 10:00:00 +0000
 Message-ID: <newsletter-123@example.com>
 MIME-Version: 1.0
-Content-Type: text/plain
+Content-Type: text/html; charset=utf-8
+List-Unsubscribe: <https://example.com/unsubscribe?id=123>
+Precedence: bulk
+X-Mailer: MailChimp/Pro 12.345
 
-Dear Subscriber,
-
-This is our monthly newsletter with special offers and updates.
-
-Best regards,
-Newsletter Team
-
-Unsubscribe: https://example.com/unsubscribe?id=123
\ No newline at end of file
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <title>Monthly Newsletter</title>
+</head>
+<body>
+    <h1>🎉 Exclusive Monthly Offers!</h1>
+    
+    <p>Dear Valued Subscriber,</p>
+    
+    <p>This month we're excited to bring you our <strong>BIGGEST SALE</strong> of the year!</p>
+    
+    <h2>🔥 Hot Deals This Month:</h2>
+    <ul>
+        <li>50% OFF all premium products</li>
+        <li>FREE shipping on orders over $50</li>
+        <li>Buy 2 Get 1 FREE on selected items</li>
+    </ul>
+    
+    <p><a href="https://example.com/shop?utm_source=newsletter&utm_campaign=monthly">SHOP NOW</a></p>
+    
+    <h2>📱 New Product Launch</h2>
+    <p>Check out our revolutionary new gadget that everyone is talking about!</p>
+    
+    <h2>🎁 Refer a Friend</h2>
+    <p>Share this newsletter and both you and your friend get $10 credit!</p>
+    
+    <hr>
+    
+    <p><small>
+    You're receiving this because you subscribed to our newsletter.<br>
+    <a href="https://example.com/unsubscribe?id=123">Unsubscribe here</a> | 
+    <a href="https://example.com/preferences">Update preferences</a><br>
+    Marketing Team, Example Corp<br>
+    123 Business St, City, State 12345
+    </small></p>
+</body>
+</html>
\ No newline at end of file