package org.jboss.windup.rules.apps.javaee.rules;


import org.jboss.windup.ast.java.data.TypeReferenceLocation;
import org.jboss.windup.config.AbstractRuleProvider;
import org.jboss.windup.config.GraphRewrite;
import org.jboss.windup.config.loader.RuleLoaderContext;
import org.jboss.windup.config.metadata.RuleMetadata;
import org.jboss.windup.config.operation.Iteration;
import org.jboss.windup.config.operation.iteration.AbstractIterationOperation;
import org.jboss.windup.config.phase.InitialAnalysisPhase;
import org.jboss.windup.rules.apps.java.condition.JavaClass;
import org.jboss.windup.rules.apps.java.model.AbstractJavaSourceModel;
import org.jboss.windup.rules.apps.java.model.JavaClassModel;
import org.jboss.windup.rules.apps.java.scan.ast.JavaTypeReferenceModel;
import org.jboss.windup.rules.apps.java.scan.ast.annotations.JavaAnnotationLiteralTypeValueModel;
import org.jboss.windup.rules.apps.java.scan.ast.annotations.JavaAnnotationTypeReferenceModel;
import org.jboss.windup.rules.apps.java.scan.ast.annotations.JavaAnnotationTypeValueModel;
import org.jboss.windup.rules.apps.java.scan.ast.AnalyzeJavaFilesRuleProvider;
import org.jboss.windup.rules.apps.javaee.service.JaxRSWebServiceModelService;
import org.ocpsoft.rewrite.config.Configuration;
import org.ocpsoft.rewrite.config.ConfigurationBuilder;
import org.ocpsoft.rewrite.context.EvaluationContext;

/**
 * Scans for classes with JAX-RS related annotations, and adds JAX-RS related metadata for these.
 *
 * @author <a href="mailto:bradsdavis@gmail.com">Brad Davis</a>
 */
@RuleMetadata(phase = InitialAnalysisPhase.class, after = AnalyzeJavaFilesRuleProvider.class)
public class DiscoverJaxRsAnnotationsRuleProvider extends AbstractRuleProvider {
    private static final String JAXRS_ANNOTATIONS = "jaxrsAnnotations";

    @Override
    public Configuration getConfiguration(RuleLoaderContext ruleLoaderContext) {
        String ruleIDPrefix = getClass().getSimpleName();
        return ConfigurationBuilder
                .begin()
                .addRule()
                .when(JavaClass
                        .references("javax.ws.rs.Path")
                        .at(TypeReferenceLocation.ANNOTATION)
                        .as(JAXRS_ANNOTATIONS))
                .perform(Iteration.over(JAXRS_ANNOTATIONS).perform(new AbstractIterationOperation<JavaTypeReferenceModel>() {
                    @Override
                    public void perform(GraphRewrite event, EvaluationContext context, JavaTypeReferenceModel payload) {
                        extractMetadata(event, payload);
                    }
                }).endIteration())
                .withId(ruleIDPrefix + "_JAXRSAnnotationRule");
    }

    private void extractMetadata(GraphRewrite event, JavaTypeReferenceModel typeReference) {
        typeReference.getFile().setGenerateSourceReport(true);
        JavaAnnotationTypeReferenceModel jaxRSAnnotationTypeReference = (JavaAnnotationTypeReferenceModel) typeReference;

        String path = getAnnotationLiteralValue(jaxRSAnnotationTypeReference, "value");
        JavaClassModel implementationClass = getJavaClass(typeReference);

        JaxRSWebServiceModelService service = new JaxRSWebServiceModelService(event.getGraphContext());
        service.getOrCreate(typeReference.getFile().getApplication(), path, implementationClass);
    }

    private String getAnnotationLiteralValue(JavaAnnotationTypeReferenceModel model, String name) {
        JavaAnnotationTypeValueModel valueModel = model.getAnnotationValues().get(name);
        if (valueModel instanceof JavaAnnotationLiteralTypeValueModel) {
            JavaAnnotationLiteralTypeValueModel literalTypeValue = (JavaAnnotationLiteralTypeValueModel) valueModel;
            return literalTypeValue.getLiteralValue();
        } else {
            return null;
        }
    }

    private JavaClassModel getJavaClass(JavaTypeReferenceModel javaTypeReference) {
        JavaClassModel result = null;
        AbstractJavaSourceModel javaSource = javaTypeReference.getFile();
        for (JavaClassModel javaClassModel : javaSource.getJavaClasses()) {
            // there can be only one public one, and the annotated class should be public
            if (javaClassModel.isPublic() != null && javaClassModel.isPublic()) {
                result = javaClassModel;
                break;
            }
        }

        if (result == null) {
            // no public classes found, so try to find any class (even non-public ones)
            result = javaSource.getJavaClasses().iterator().next();
        }

        return result;
    }

    @Override
    public String toString() {
        return "DiscoverEJBAnnotatedClasses";
    }
}