/**
 * @author Keesun Baik(Whiteship)
 * @author Seongyoon Kim(Is윤군)
 */
public class AnnotationContextLoader extends AbstractContextLoader {

    private static final String JAVA_FILE_SUFFIX = ".java";
    private static final String APP_CONFIG_FILE_PREFIX = "AppConfig";

    @Override
    public String getResourceSuffix() {
        return APP_CONFIG_FILE_PREFIX + JAVA_FILE_SUFFIX;
    }

    @Override
    protected String[] generateDefaultLocations(Class<?> clazz) {
        Assert.notNull(clazz, "Class must not be null");
        String suffix = getResourceSuffix();
        Assert.hasText(suffix, "Resource suffix must not be empty");
        return new String[] { clazz.getName() + suffix };
    }

    @Override
    protected String[] modifyLocations(Class<?> clazz, String... locations) {
        String[] modifiedLocations = new String[locations.length];
        for (int i = 0; i < locations.length; i++) {
            String path = locations[i];

            if(path.endsWith("/"))
                path = path.substring(0, path.length() - 1);

            if (path.startsWith("/")) {
                modifiedLocations[i] = ClassUtils.convertResourcePathToClassName(path.substring(1));
            }
            else if (!ResourcePatternUtils.isUrl(path)) {
                modifiedLocations[i] = getClassName(clazz, path);
            }
            else {
                throw new UnsupportedOperationException();
            }
        }
        return modifiedLocations;
    }

    private String getClassName(Class clazz, String path) {
        return ClassUtils.convertResourcePathToClassName(
            StringUtils.cleanPath(ClassUtils.classPackageAsResourcePath(clazz) + "/" + path));
    }

    public final ConfigurableApplicationContext loadContext(String... locations) throws Exception {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
        prepareContext(context);
        customizeBeanFactory(context.getDefaultListableBeanFactory());
        context.register(getAppConfigClasses(context.getClassLoader(), locations));
        context.scan(getAppConfigPackages(context.getClassLoader(), locations));
        AnnotationConfigUtils.registerAnnotationConfigProcessors(context);
        context.refresh();
        context.registerShutdownHook();
        return context;
    }

    private String[] getAppConfigPackages(ClassLoader classLoader, String[] locations) {
        List<String> packages = new ArrayList<String>();
        for(String location : locations){
            if(!location.contains(JAVA_FILE_SUFFIX))
                packages.add(location);
        }
        return packages.toArray(new String[packages.size()]);
    }

    private Class<?>[] getAppConfigClasses(ClassLoader classLoader, String[] locations) throws ClassNotFoundException {
        List<Class<?>> classes = new ArrayList<Class<?>>();
        for(String location : locations){
            if(location.contains(JAVA_FILE_SUFFIX))
                classes.add(ClassUtils.forName(location.replace(JAVA_FILE_SUFFIX, ""), classLoader));
        }
        return classes.toArray(new Class<?>[classes.size()]);
    }

    protected void prepareContext(GenericApplicationContext context) {
    }
    protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory) {
    }
    protected void customizeContext(GenericApplicationContext context) {
    }