/*
 * Copyright (c) 2011, 2017 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.servlet;


import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import javax.servlet.MultipartConfigElement;
import javax.servlet.Servlet;
import javax.servlet.ServletSecurityElement;
import org.glassfish.grizzly.utils.ArraySet;

Allows customization of a Servlet registered with the WebappContext. 
Since:
2.2/**
 * Allows customization of a {@link javax.servlet.Servlet} registered with the {@link WebappContext}.
 *
 * @since 2.2
 */
public class ServletRegistration extends Registration
        implements javax.servlet.ServletRegistration.Dynamic, Comparable<ServletRegistration> {

    protected Class<? extends Servlet> servletClass;
    protected final ArraySet<String> urlPatterns = new ArraySet<String>(String.class);
    protected Servlet servlet;
    protected int loadOnStartup = -1;
    protected ExpectationHandler expectationHandler;
    protected boolean isAsyncSupported;

    
The run-as identity for this servlet.
/**
     * The run-as identity for this servlet.
     */
    private String runAs = null;

    // ------------------------------------------------------------ Constructors


    
Creates a new ServletRegistration associated with the specified WebappContext. 
Params:
ctx – the owning WebappContext.
name – the name of the Filter.
servletClassName – the fully qualified class name of the Servlet implementation./**
     * Creates a new ServletRegistration associated with the specified
     * {@link WebappContext}.
     *
     * @param ctx the owning {@link WebappContext}.
     * @param name the name of the Filter.
     * @param servletClassName the fully qualified class name of the {@link Servlet}
     *  implementation.
     */
    protected ServletRegistration(final WebappContext ctx,
                                  final String name,
                                  final String servletClassName) {

        super(ctx, name, servletClassName);
        this.name = name;

    }

    
Creates a new ServletRegistration associated with the specified WebappContext. 
Params:
ctx – the owning WebappContext.
name – the name of the Filter.
servlet – the Servlet instance./**
     * Creates a new ServletRegistration associated with the specified
     * {@link WebappContext}.
     *
     * @param ctx the owning {@link WebappContext}.
     * @param name the name of the Filter.
     * @param servlet the {@link Servlet} instance.
     */
    protected ServletRegistration(final WebappContext ctx,
                                  final String name,
                                  final Servlet servlet) {

        this(ctx, name, servlet.getClass());
        this.servlet = servlet;

    }

    
Creates a new ServletRegistration associated with the specified WebappContext. 
Params:
ctx – the owning WebappContext.
name – the name of the Filter.
servletClass – the class of the Servlet implementation./**
     * Creates a new ServletRegistration associated with the specified
     * {@link WebappContext}.
     *
     * @param ctx the owning {@link WebappContext}.
     * @param name the name of the Filter.
     * @param servletClass the class of the {@link Servlet} implementation.
     */
    protected ServletRegistration(final WebappContext ctx,
                                  final String name,
                                  final Class<? extends Servlet> servletClass) {

        this(ctx, name, servletClass.getName());
        this.servletClass = servletClass;

    }


    // ---------------------------------------------------------- Public Methods


    
Adds a servlet mapping with the given URL patterns for the Servlet
represented by this ServletRegistration.
If any of the specified URL patterns are already mapped to a
different Servlet, no updates will be performed.
If this method is called multiple times, each successive call
adds to the effects of the former.
Params:
urlPatterns – the URL patterns of the servlet mapping
Throws:
IllegalArgumentException – if urlPatterns is null
or empty
IllegalStateException – if the ServletContext from which this
ServletRegistration was obtained has already been initialized
Returns:
the (possibly empty) Set of URL patterns that are already
mapped to a different Servlet/**
     * Adds a servlet mapping with the given URL patterns for the Servlet
     * represented by this ServletRegistration.
     *
     * <p>If any of the specified URL patterns are already mapped to a
     * different Servlet, no updates will be performed.
     *
     * <p>If this method is called multiple times, each successive call
     * adds to the effects of the former.
     *
     * @param urlPatterns the URL patterns of the servlet mapping
     *
     * @return the (possibly empty) Set of URL patterns that are already
     * mapped to a different Servlet
     *
     * @throws IllegalArgumentException if <tt>urlPatterns</tt> is null
     * or empty
     * @throws IllegalStateException if the ServletContext from which this
     * ServletRegistration was obtained has already been initialized
     */
    @Override
    public Set<String> addMapping(String... urlPatterns) {
        if (ctx.deployed) {
            throw new IllegalStateException("WebappContext has already been deployed");
        }
        if (urlPatterns == null || urlPatterns.length == 0) {
            throw new IllegalArgumentException("'urlPatterns' cannot be null or zero-length");
        }
        this.urlPatterns.addAll(urlPatterns);
        return Collections.emptySet(); // TODO - need to comply with the spec at some point
    }

    
Gets the currently available mappings of the
Servlet represented by this ServletRegistration.
If permitted, any changes to the returned Collection must not
affect this ServletRegistration.
Returns:
a (possibly empty) Collection of the currently
available mappings of the Servlet represented by this
ServletRegistration/**
     * Gets the currently available mappings of the
     * Servlet represented by this <code>ServletRegistration</code>.
     *
     * <p>If permitted, any changes to the returned <code>Collection</code> must not
     * affect this <code>ServletRegistration</code>.
     *
     * @return a (possibly empty) <code>Collection</code> of the currently
     * available mappings of the Servlet represented by this
     * <code>ServletRegistration</code>
     */
    @Override
    public Collection<String> getMappings() {
        return Collections.unmodifiableList(
                Arrays.asList(urlPatterns.getArrayCopy()));
    }

    
Sets the loadOnStartup priority on the Servlet
represented by this dynamic ServletRegistration.

A loadOnStartup value of greater than or equal to zero indicates to the container the initialization priority of the Servlet. In this case, the container must instantiate and initialize the Servlet during the initialization phase of the WebappContext, that is, after it has invoked all of the ServletContextListener objects configured for the WebappContext at their ServletContextListener.contextInitialized method. 

If loadOnStartup is a negative integer, the container
is free to instantiate and initialize the Servlet lazily.

The default value for loadOnStartup is -1.

A call to this method overrides any previous setting.
Params:
loadOnStartup – the initialization priority of the Servlet
Throws:
IllegalStateException – if the ServletContext from which
                              this ServletRegistration was obtained has already been initialized/**
     * Sets the <code>loadOnStartup</code> priority on the Servlet
     * represented by this dynamic ServletRegistration.
     * <p/>
     * <p>A <tt>loadOnStartup</tt> value of greater than or equal to
     * zero indicates to the container the initialization priority of
     * the Servlet. In this case, the container must instantiate and
     * initialize the Servlet during the initialization phase of the
     * WebappContext, that is, after it has invoked all of the
     * ServletContextListener objects configured for the WebappContext
     * at their {@link javax.servlet.ServletContextListener#contextInitialized}
     * method.
     * <p/>
     * <p>If <tt>loadOnStartup</tt> is a negative integer, the container
     * is free to instantiate and initialize the Servlet lazily.
     * <p/>
     * <p>The default value for <tt>loadOnStartup</tt> is <code>-1</code>.
     * <p/>
     * <p>A call to this method overrides any previous setting.
     *
     * @param loadOnStartup the initialization priority of the Servlet
     * @throws IllegalStateException if the ServletContext from which
     *                               this ServletRegistration was obtained has already been initialized
     */
    @Override
    public void setLoadOnStartup(int loadOnStartup) {
        if (ctx.deployed) {
            throw new IllegalStateException("WebappContext has already been deployed");
        }
        if (loadOnStartup < 0) {
            this.loadOnStartup = -1;
        } else {
            this.loadOnStartup = loadOnStartup;
        }
    }

    
Get the ExpectationHandler responsible for processing Expect: header (for example "Expect: 100-Continue").
Returns:
the ExpectationHandler responsible for processing Expect: header (for example "Expect: 100-Continue")./**
     * Get the {@link ExpectationHandler} responsible for processing
     * <tt>Expect:</tt> header (for example "Expect: 100-Continue").
     * 
     * @return the {@link ExpectationHandler} responsible for processing
     * <tt>Expect:</tt> header (for example "Expect: 100-Continue").
     */
    public ExpectationHandler getExpectationHandler() {
        return expectationHandler;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public Set<String> setServletSecurity(ServletSecurityElement constraint) {
        return Collections.emptySet();
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public void setMultipartConfig(MultipartConfigElement multipartConfig) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public String getRunAsRole() {
        return runAs;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public void setRunAsRole(String roleName) {
        this.runAs = roleName;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public void setAsyncSupported(boolean isAsyncSupported) {
        this.isAsyncSupported = isAsyncSupported;
    }
    
    
Set the ExpectationHandler responsible for processing Expect: header (for example "Expect: 100-Continue").
Params:
expectationHandler –  the ExpectationHandler responsible for processing Expect: header (for example "Expect: 100-Continue")./**
     * Set the {@link ExpectationHandler} responsible for processing
     * <tt>Expect:</tt> header (for example "Expect: 100-Continue").
     * 
     * @param expectationHandler  the {@link ExpectationHandler} responsible
     * for processing <tt>Expect:</tt> header (for example "Expect: 100-Continue").
     */
    public void setExpectationHandler(ExpectationHandler expectationHandler) {
        this.expectationHandler = expectationHandler;
    }
    
    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append("ServletRegistration");
        sb.append("{ servletName=").append(name);
        sb.append(", servletClass=").append(className);
        sb.append(", urlPatterns=").append(Arrays.toString(urlPatterns.getArray()));
        sb.append(", loadOnStartup=").append(loadOnStartup);
        sb.append(", isAsyncSupported=").append(isAsyncSupported);
        sb.append(" }");
        return sb.toString();
    }


    // ------------------------------------------------- Methods from Comparable


    @Override
    public int compareTo(ServletRegistration o) {
        if (loadOnStartup == o.loadOnStartup) {
            return 0;
        }
        if (loadOnStartup < 0 && o.loadOnStartup < 0) {
            return -1;
        }
        if (loadOnStartup >= 0 && o.loadOnStartup >= 0) {
            if (loadOnStartup < o.loadOnStartup) {
                return -1;
            }
        }
        return 1;
    }
}