Mailer: register default mailer beans correctly

- even if only mail template record is used
- get rid of unnecessary programmatic lookup in MailTemplateProducer
- fixes quarkusio#43518

extensions/mailer/deployment/src/main/java/io/quarkus/mailer/deployment/MailerProcessor.java

@@ -1,6 +1,8 @@
 package io.quarkus.mailer.deployment;
 
 import java.io.File;
+import java.lang.reflect.Modifier;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -11,8 +13,12 @@
 import jakarta.inject.Singleton;
 
 import org.jboss.jandex.AnnotationInstance;
+import org.jboss.jandex.AnnotationTarget.Kind;
+import org.jboss.jandex.ClassInfo;
 import org.jboss.jandex.ClassType;
 import org.jboss.jandex.DotName;
+import org.jboss.jandex.IndexView;
+import org.jboss.jandex.MethodInfo;
 
 import io.quarkus.arc.deployment.AdditionalBeanBuildItem;
 import io.quarkus.arc.deployment.AnnotationsTransformerBuildItem;
@@ -35,6 +41,7 @@
 import io.quarkus.deployment.builditem.nativeimage.ReflectiveClassBuildItem;
 import io.quarkus.deployment.pkg.builditem.CurateOutcomeBuildItem;
 import io.quarkus.mailer.MailTemplate;
+import io.quarkus.mailer.MailTemplate.MailTemplateInstance;
 import io.quarkus.mailer.Mailer;
 import io.quarkus.mailer.MailerName;
 import io.quarkus.mailer.MockMailbox;
@@ -56,6 +63,7 @@
 public class MailerProcessor {
 
     static final DotName MAIL_TEMPLATE = DotName.createSimple(MailTemplate.class.getName());
+    static final DotName MAIL_TEMPLATE_INSTANCE = DotName.createSimple(MailTemplateInstance.class.getName());
 
     static final DotName MAILER_NAME = DotName.createSimple(MailerName.class);
 
@@ -105,7 +113,7 @@ MailersBuildItem generateMailerSupportBean(MailerRecorder recorder,
                 .anyMatch(i -> i.hasDefaultedQualifier() ||
                 // we inject a MailTemplate and it is not named
                         (MAIL_TEMPLATE.equals(i.getType().name()) && i.getRequiredQualifier(MAILER_NAME) == null))
-                || !index.getIndex().getAnnotations(CheckedTemplate.class).isEmpty();
+                || isTypeSafeMailTemplateFound(index.getIndex());
 
         Set<String> namedMailers = mailerInjectionPoints.stream()
                 .map(i -> i.getRequiredQualifier(MAILER_NAME))
@@ -124,6 +132,35 @@ MailersBuildItem generateMailerSupportBean(MailerRecorder recorder,
         return new MailersBuildItem(hasDefaultMailer, namedMailers);
     }
 
+    private boolean isTypeSafeMailTemplateFound(IndexView index) {
+        // Find all occurences of @CheckedTemplate
+        Collection<AnnotationInstance> checkedTemplates = index.getAnnotations(CheckedTemplate.class);
+        for (AnnotationInstance annotation : checkedTemplates) {
+            if (annotation.target().kind() == Kind.CLASS) {
+                ClassInfo target = annotation.target().asClass();
+                if (target.isRecord()) {
+                    //  Java record that most likely implements MailTemplateInstance
+                    return true;
+                }
+                for (MethodInfo method : target.methods()) {
+                    if (Modifier.isStatic(method.flags()) && method.returnType().name().equals(MAIL_TEMPLATE_INSTANCE)) {
+                        // Target declares a static method that returns MailTemplateInstance
+                        return true;
+                    }
+                }
+            }
+        }
+
+        Collection<ClassInfo> mailTemplateInstances = index.getAllKnownImplementors(MAIL_TEMPLATE_INSTANCE);
+        for (ClassInfo mailTemplateInstance : mailTemplateInstances) {
+            if (mailTemplateInstance.isRecord()) {
+                // Java record that implements MailTemplateInstance found
+                return true;
+            }
+        }
+        return false;
+    }
+
     @Record(ExecutionTime.RUNTIME_INIT)
     @BuildStep
     void generateMailerBeans(MailerRecorder recorder,

extensions/mailer/deployment/src/test/java/io/quarkus/mailer/MailTemplateRecordNoInjectionTest.java

@@ -0,0 +1,39 @@
+package io.quarkus.mailer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.arc.Arc;
+import io.quarkus.mailer.MailTemplate.MailTemplateInstance;
+import io.quarkus.test.QuarkusUnitTest;
+import io.vertx.ext.mail.MailMessage;
+
+public class MailTemplateRecordNoInjectionTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withApplicationRoot(root -> root
+                    .addClasses(confirmation.class)
+                    .addAsResource("mock-config.properties", "application.properties")
+                    .addAsResource(new StringAsset(""
+                            + "<html>{name}</html>"), "templates/MailTemplateRecordNoInjectionTest/confirmation.html"));
+
+    @Test
+    public void testMailTemplateRecord() {
+        // Intentionally use programmatic lookup to obtain the MockMailbox
+        MockMailbox mockMailbox = Arc.container().instance(MockMailbox.class).get();
+        new confirmation("Ondrej").to("[email protected]").from("[email protected]").subject("test mailer")
+                .send().await().indefinitely();
+        assertEquals(1, mockMailbox.getMailMessagesSentTo("[email protected]").size());
+        MailMessage message = mockMailbox.getMailMessagesSentTo("[email protected]").get(0);
+        assertEquals("[email protected]", message.getFrom());
+        assertEquals("<html>Ondrej</html>", message.getHtml());
+    }
+
+    record confirmation(String name) implements MailTemplateInstance {
+    }
+
+}

extensions/mailer/runtime/src/main/java/io/quarkus/mailer/runtime/MailTemplateProducer.java

@@ -4,9 +4,9 @@
 import java.lang.reflect.Field;
 
 import jakarta.enterprise.inject.Any;
+import jakarta.enterprise.inject.Default;
 import jakarta.enterprise.inject.Instance;
 import jakarta.enterprise.inject.Produces;
-import jakarta.enterprise.inject.spi.Annotated;
 import jakarta.enterprise.inject.spi.AnnotatedParameter;
 import jakarta.enterprise.inject.spi.InjectionPoint;
 import jakarta.inject.Singleton;
@@ -31,7 +31,7 @@ public class MailTemplateProducer {
     Instance<Template> template;
 
     @Produces
-    MailTemplate getDefault(InjectionPoint injectionPoint) {
+    MailTemplate getDefault(InjectionPoint injectionPoint, @Any Instance<ReactiveMailer> reactiveMailer) {
 
         final String name;
         if (injectionPoint.getMember() instanceof Field) {
@@ -50,7 +50,7 @@ MailTemplate getDefault(InjectionPoint injectionPoint) {
         return new MailTemplate() {
             @Override
             public MailTemplateInstance instance() {
-                return new MailTemplateInstanceImpl(getReactiveMailer(injectionPoint),
+                return new MailTemplateInstanceImpl(getReactiveMailer(injectionPoint, reactiveMailer),
                         template.select(new LocationLiteral(name)).get().instance());
             }
 
@@ -59,7 +59,7 @@ public MailTemplateInstance instance() {
 
     @Location("ignored")
     @Produces
-    MailTemplate get(InjectionPoint injectionPoint) {
+    MailTemplate get(InjectionPoint injectionPoint, @Any Instance<ReactiveMailer> reactiveMailer) {
         Location path = null;
         for (Annotation qualifier : injectionPoint.getQualifiers()) {
             if (qualifier.annotationType().equals(Location.class)) {
@@ -74,21 +74,18 @@ MailTemplate get(InjectionPoint injectionPoint) {
         return new MailTemplate() {
             @Override
             public MailTemplateInstance instance() {
-                return new MailTemplateInstanceImpl(getReactiveMailer(injectionPoint),
+                return new MailTemplateInstanceImpl(getReactiveMailer(injectionPoint, reactiveMailer),
                         template.select(new LocationLiteral(name)).get().instance());
             }
         };
     }
 
-    public static ReactiveMailer getReactiveMailer(InjectionPoint injectionPoint) {
-        Annotated annotated = injectionPoint.getAnnotated();
-        MailTemplateMailerName mailerName = annotated.getAnnotation(MailTemplateMailerName.class);
-
+    static ReactiveMailer getReactiveMailer(InjectionPoint injectionPoint, Instance<ReactiveMailer> reactiveMailer) {
+        MailTemplateMailerName mailerName = injectionPoint.getAnnotated().getAnnotation(MailTemplateMailerName.class);
         if (mailerName != null) {
-            return Arc.container().instance(ReactiveMailer.class, MailerName.Literal.of(mailerName.value())).get();
+            return reactiveMailer.select(MailerName.Literal.of(mailerName.value())).get();
         }
-
-        return Arc.container().instance(ReactiveMailer.class).get();
+        return reactiveMailer.select(Default.Literal.INSTANCE).get();
     }
 
     /**