package de.is24.deadcode4j.analyzer;

import com.google.common.base.Optional;
import com.google.common.collect.Iterables;

import javax.annotation.Nonnull;

import static com.google.common.base.Optional.absent;
import static com.google.common.base.Optional.of;

/**
 * Analyzes Spring XML files:
 * <ul>
 * <li>lists the <code>bean</code> classes being referenced</li>
 * <li>lists the classes being referenced by a <a href="http://docs.spring.io/autorepo/docs/spring-framework/3.2.x/javadoc-api/org/springframework/beans/factory/config/MethodInvokingFactoryBean.html">
 * MethodInvokingFactoryBean</a>; note however that the <tt>staticMethod</tt> property is not supported, but the
 * more verbose approach using the <tt>targetClass</tt> and <tt>targetMethod</tt> properties</li>
 * <li>lists the <a href="http://cxf.apache.org/schemas/jaxws.xsd">CXF <code>endpoint</code></a> implementor classes
 * being referenced</li>
 * <li>lists the classes executed by Quartz via
 * <a href="http://docs.spring.io/spring/docs/3.0.x/reference/scheduling.html#scheduling-quartz-jobdetail">JobDetailBean</a></li> or
 * <a href="http://docs.spring.io/spring/docs/4.0.x/spring-framework-reference/html/scheduling.html#scheduling-quartz-jobdetail">JobDetailFactoryBean</a>
 * <li>lists the view class used by
 * <a href="http://docs.spring.io/spring/docs/3.0.x/reference/view.html#view-tiles-url">
 * <code>UrlBasedViewResolver</code></a> and subclasses</li>
 * </ul>
 *
 * @since 1.1.0
 */
public class SpringXmlAnalyzer extends ExtendedXmlAnalyzer {

    private static void registerPropertyValueAsClass(@Nonnull Path beanPath, @Nonnull String propertyName) {
        Path propertyPath = beanPath.anyElementNamed("property").withAttributeValue("name", propertyName);
        propertyPath.registerAttributeAsClass("value");
        propertyPath.anyElementNamed("value").registerTextAsClass();
    }

    private static Optional<String> extractClassName(Optional<String> staticMethodCallNotation) {
        if (!staticMethodCallNotation.isPresent()) {
            return absent();
        }
        int lastDot = staticMethodCallNotation.get().lastIndexOf('.');
        if (lastDot < 1) {
            return absent();
        }
        return of(staticMethodCallNotation.get().substring(0, lastDot));
    }

    public SpringXmlAnalyzer() {
        super("_Spring-XML_", ".xml", "beans");
        // regular spring beans
        anyElementNamed("bean").registerAttributeAsClass("class");
        // MethodInvokingFactoryBean
        Path methodInvokingFactoryBean = beanOfClass("org.springframework.beans.factory.config.MethodInvokingFactoryBean");
        registerPropertyValueAsClass(methodInvokingFactoryBean, "targetClass");
        Path staticMethodProperty = methodInvokingFactoryBean.anyElementNamed("property").withAttributeValue("name", "staticMethod");
        staticMethodProperty.registerDependeeExtractor(new DependeeExtractor() {
            @Nonnull
            @Override
            public Optional<String> extractDependee(@Nonnull Iterable<XmlElement> xmlElements, @Nonnull Optional<String> containedText) {
                return extractClassName(Iterables.getLast(xmlElements).getAttribute("value"));
            }
        });
        staticMethodProperty.anyElementNamed("value").registerDependeeExtractor(new DependeeExtractor() {
            @Nonnull
            @Override
            public Optional<String> extractDependee(@Nonnull Iterable<XmlElement> xmlElements, @Nonnull Optional<String> containedText) {
                return extractClassName(containedText);
            }
        });
        // CXF endpoints
        anyElementNamed("endpoint").registerAttributeAsClass("implementor");
        anyElementNamed("endpoint").anyElementNamed("implementor").registerTextAsClass();
        anyElementNamed("endpoint").registerAttributeAsClass("implementorClass");
        // JobDetailBean
        registerPropertyValueAsClass(
                beanOfClass("org.springframework.scheduling.quartz.JobDetailBean"),
                "jobClass");
        // JobDetailFactoryBean
        registerPropertyValueAsClass(
                beanOfClass("org.springframework.scheduling.quartz.JobDetailFactoryBean"),
                "jobClass");
        // view resolver; this is not restricted to a class bc there are loads of subclasses
        registerPropertyValueAsClass(anyElementNamed("bean"), "viewClass");
    }

    @Nonnull
    private Path beanOfClass(@Nonnull String beanClass) {
        return anyElementNamed("bean").withAttributeValue("class", beanClass);
    }

}