fix(classifier): iterate all email candidates per field; document method contract

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

includes/class-classifier.php

@@ -216,6 +216,17 @@ final class Classifier
         return $hits;
     }
 
+    /**
+     * Checks whether any field value contains a syntactically valid email address.
+     *
+     * Used by drop-logic to spare submissions that include any plausible contact email
+     * (any TLD, including gmail.com and custom domains — not limited to RU domains).
+     *
+     * Handles flat string values and one level of array nesting (matches CF7 posted_data
+     * shape). Deeper nesting is intentionally NOT supported.
+     *
+     * @param array<string,string|string[]> $fields CF7 posted_data
+     */
     public static function has_valid_email_anywhere(array $fields): bool
     {
         foreach ($fields as $v) {
@@ -223,8 +234,10 @@ final class Classifier
             foreach ($values as $val) {
                 $val = trim((string)$val);
                 if ($val === '') continue;
-                if (preg_match('/[A-Za-z0-9._%+\-]+@[A-Za-z0-9.\-]+\.[A-Za-z]{2,}/', $val, $m)) {
+                if (preg_match_all('/[A-Za-z0-9._%+\-]+@[A-Za-z0-9.\-]+\.[A-Za-z]{2,}/', $val, $matches)) {
-                    if (is_email($m[0])) return true;
+                    foreach ($matches[0] as $candidate) {
+                        if (is_email($candidate)) return true;
+                    }
                 }
             }
         }

tests/ClassifierDropTest.php

@@ -29,4 +29,18 @@ final class ClassifierDropTest extends Cf7stgTestCase
     {
         self::assertFalse(Classifier::has_valid_email_anywhere([]));
     }
+
+    public function test_has_valid_email_anywhere_finds_email_embedded_in_text(): void
+    {
+        $fields = ['your-message' => 'reach me at user@domain.com thanks'];
+        self::assertTrue(Classifier::has_valid_email_anywhere($fields));
+    }
+
+    public function test_has_valid_email_anywhere_finds_second_email_when_first_invalid(): void
+    {
+        // First candidate is "alice@in" which is not a valid email; second is valid.
+        // Without preg_match_all, the method would return false here.
+        $fields = ['msg' => 'try alice@in or bob@example.com'];
+        self::assertTrue(Classifier::has_valid_email_anywhere($fields));
+    }
 }