/**
 * Returns the max supported source version.
 * Returns {@link SourceVersion#latest()} by default,
 * subclasses may override or may use the {@link SupportedSourceVersion} annotation.
 * @return the max supported source version
 */
@Override
public SourceVersion getSupportedSourceVersion() {
    SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class);
    SourceVersion sv = null;
    if (ssv == null) {
        return SourceVersion.latest();
    } else {
        return ssv.value();
    }
}
 

/**
 * If the subclass itself does not define SupportedSourceVersion, assume latest(). If it does
 * (was recommended prior to 9.17), returns the subclass' value for compatibility.
 * @return max supported source version.
 * @since 9.17
 */
@Override
public SourceVersion getSupportedSourceVersion() {
    SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class);
    SourceVersion sv;
    if (ssv == null) {
        sv = SourceVersion.latest();
    } else
        sv = ssv.value();
    return sv;
}
 

/**
 * If the subclass itself does not define SupportedSourceVersion, assume latest(). If it does
 * (was recommended prior to 8.40), returns the subclass' value.
 * @return max supported source version.
 * @since 8.40
 */
@Override
public SourceVersion getSupportedSourceVersion() {
    SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class);
    SourceVersion sv;
    if (ssv == null) {
        sv = SourceVersion.latest();
    } else
        sv = ssv.value();
    return sv;
}
 

@Override
public SourceVersion getSupportedSourceVersion() {
  @Nullable SupportedSourceVersion sourceVersion = this.getClass().getAnnotation(SupportedSourceVersion.class);
  if (sourceVersion != null) {
    return sourceVersion.value();
  }
  return SourceVersion.latestSupported();
}
 

/**
 * Warns on incorrect @{@link SupportedSourceVersion} annotation. The hint triggers in
 * following cases, if the class does <b>not</b> override {@link javax.annotation.processing.Processor#getSupportedSourceVersion()}.
 * <ul>
 * <li>Class derived from AbstractProcessor with no annotation at all: defaults to 1.6, which
 * is almost certainly wrong.
 * <li>Declares {@code @SupportedSourceVersion} earlier than the project's source level.
 * </ul>
 * Offers a hint to declare a {@code @SupportedSourceVersion} or to override the {@code getSupportedSourceVersion}
 * to return {@link SourceVersion#latest()}.
 * @param ctx
 * @return 
 */
@Hint(
    category = "rules15",
    displayName = "#DN_AnnoProcessor_ObsoleteSupportedSource",
    description = "#DESC_AnnoProcessor_ObsoleteSupportedSource",
    id = "obsoleteAnnotationSupportedSource",
    suppressWarnings = "ObsoleteAnnotationSupportedSource"
)
@TriggerPattern(
    value = "$modifiers$ class $name extends $superClass$ implements $superInterfaces$ { $body$; }", 
        constraints = @ConstraintVariableType(
            variable = "$superInterfaces",
            type = "javax.annotation.processing.Processor"
    )
)
@NbBundle.Messages({
    "DN_AnnoProcessor_ObsoleteSupportedSource=Missing or obsolete @SupportedSourceVersion",
    "HINT_AnnoProcessor_DeclaredSourceObsolete=Annoration declares older source version than the project source level.",
    "HINT_AnnoProcessor_NoSupportedSource=No @SupportedSourceVersion is declared, the default (1.6) is older than project source level."
})
public static ErrorDescription annotatedByObsoleteSource(HintContext ctx) {
    CompilationInfo info = ctx.getInfo();
    ProcessorHintSupport helper = new ProcessorHintSupport(ctx.getInfo(), ctx.getPath());
    if (!helper.initialize()) {
        return null;
    }
    // not an AbstractProcessor; or overrides the getSupported method.
    if (!helper.canOverrideAbstract(true)) {
        return null;
    }
    SupportedSourceVersion ssv = helper.getProcessor().getAnnotation(SupportedSourceVersion.class);
    SourceVersion current = info.getSourceVersion();
    if (ssv != null) {
        SourceVersion declared = ssv.value();
        if (declared.compareTo(current) >= 0) {
            // OK
            return null;
        }
        TreePath rewriteAt = helper.findSupportedAnnotation();
        if (rewriteAt == null) {
            return null;
        }
        
        return ErrorDescriptionFactory.forTree(ctx, rewriteAt, 
                Bundle.HINT_AnnoProcessor_DeclaredSourceObsolete(), 
                // suggest to generate latest()
                new OverrideReturnLatest(info, helper.getProcessorPath(), false).toEditorFix(),
                new OverrideReturnLatest(info, helper.getProcessorPath(), true).toEditorFix(),
                // suggest change to the current version
                changeToCurrentSource(ctx, helper, info.getSourceVersion())
        );
    } else {
        TreePath path = helper.getProcessorPath();
        return ErrorDescriptionFactory.forTree(ctx, path, 
                Bundle.HINT_AnnoProcessor_NoSupportedSource(), 
                new OverrideReturnLatest(info, path, false).toEditorFix(),
                new OverrideReturnLatest(info, path, true).toEditorFix(),
                new DeclareCurrentSourceFix(info, path, info.getSourceVersion()).toEditorFix()
        );
    }
}