package io.smallrye.opentracing.arquillian;

import java.util.HashSet;
import java.util.Set;

import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import javax.servlet.annotation.HandlesTypes;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.Path;
import javax.ws.rs.core.Application;
import javax.ws.rs.ext.Provider;

import org.jboss.resteasy.core.AsynchronousDispatcher;
import org.jboss.resteasy.plugins.server.servlet.HttpServlet30Dispatcher;
import org.jboss.resteasy.plugins.server.servlet.ResteasyContextParameters;

/**
 * This is a fixed replacement for <a href=
 * "https://github.com/resteasy/Resteasy/blob/master/resteasy-servlet-initializer/src/main/java/org/jboss/resteasy/plugins/servlet/ResteasyServletInitializer.java">ResteasyServletInitializer.java</a>.
 * See also <a href="https://issues.jboss.org/browse/RESTEASY-1922">RESTEASY-1922</a>.
 */
@HandlesTypes({ Application.class, Path.class, Provider.class })
public class FixedResteasyServletInitializer implements ServletContainerInitializer {

    final static Set<String> IGNORED_PACKAGES = new HashSet<String>();

    static {
        IGNORED_PACKAGES.add(AsynchronousDispatcher.class.getPackage().getName());
    }

    @Override
    public void onStartup(Set<Class<?>> classes, ServletContext servletContext) throws ServletException {
        if (classes == null || classes.size() == 0)
            return;
        for (ServletRegistration reg : servletContext.getServletRegistrations().values()) {
            if (reg.getInitParameter("javax.ws.rs.Application") != null) {
                return; // there's already a servlet mapping, do nothing
            }
        }

        Set<Class<?>> appClasses = new HashSet<Class<?>>();
        Set<Class<?>> providers = new HashSet<Class<?>>();
        Set<Class<?>> resources = new HashSet<Class<?>>();

        for (Class<?> clazz : classes) {
            // FIXED: Ignore client proxy interfaces
            if (clazz.isInterface() || IGNORED_PACKAGES.contains(clazz.getPackage().getName()))
                continue;
            if (clazz.isAnnotationPresent(Path.class)) {
                resources.add(clazz);
            } else if (clazz.isAnnotationPresent(Provider.class)) {
                providers.add(clazz);
            } else {
                appClasses.add(clazz);
            }
        }
        if (appClasses.size() == 0 && resources.size() == 0)
            return;

        if (appClasses.size() == 0) {
            // todo make sure we can do this on all servlet containers
            //       handleNoApplicationClass(providers, resources, servletContext);
            return;
        }

        for (Class<?> app : appClasses) {
            register(app, providers, resources, servletContext);
        }
    }

    protected void handleNoApplicationClass(Set<Class<?>> providers, Set<Class<?>> resources, ServletContext servletContext) {
        ServletRegistration defaultApp = null;
        for (ServletRegistration reg : servletContext.getServletRegistrations().values()) {
            if (reg.getName().equals(Application.class.getName())) {
                defaultApp = reg;
            }
        }
        if (defaultApp == null)
            return;
        throw new IllegalStateException("Default application not implemented yet");

    }

    protected void register(Class<?> applicationClass, Set<Class<?>> providers, Set<Class<?>> resources,
            ServletContext servletContext) {
        ApplicationPath path = applicationClass.getAnnotation(ApplicationPath.class);
        if (path == null) {
            // todo we don't support this yet, i'm not sure if partial deployments are supported in all servlet containers
            return;
        }
        ServletRegistration.Dynamic reg = servletContext.addServlet(applicationClass.getName(), HttpServlet30Dispatcher.class);
        reg.setLoadOnStartup(1);
        reg.setAsyncSupported(true);
        reg.setInitParameter("javax.ws.rs.Application", applicationClass.getName());

        if (path != null) {
            String mapping = path.value();
            if (!mapping.startsWith("/"))
                mapping = "/" + mapping;
            String prefix = mapping;
            if (!prefix.equals("/") && prefix.endsWith("/"))
                prefix = prefix.substring(0, prefix.length() - 1);
            if (!mapping.endsWith("/*")) {
                if (mapping.endsWith("/"))
                    mapping += "*";
                else
                    mapping += "/*";
            }
            // resteasy.servlet.mapping.prefix
            reg.setInitParameter("resteasy.servlet.mapping.prefix", prefix);
            reg.addMapping(mapping);
        }

        if (resources.size() > 0) {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (Class resource : resources) {
                if (first) {
                    first = false;
                } else {
                    builder.append(",");
                }

                builder.append(resource.getName());
            }
            reg.setInitParameter(ResteasyContextParameters.RESTEASY_SCANNED_RESOURCES, builder.toString());
        }
        if (providers.size() > 0) {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (Class provider : providers) {
                if (first) {
                    first = false;
                } else {
                    builder.append(",");
                }
                builder.append(provider.getName());
            }
            reg.setInitParameter(ResteasyContextParameters.RESTEASY_SCANNED_PROVIDERS, builder.toString());
        }

    }
}
