package org.springframework.security.ui;

import org.springframework.util.Assert;

import java.util.Map;
import java.util.LinkedHashMap;

/**
 * Stores the default order numbers of all Spring Security filters for use in configuration.
 *
 * @author Luke Taylor
 * @version $Id$
 */
public abstract class FilterChainOrder {
    /**
     * The first position at which a Spring Security filter will be found. Any filter with an order less than this will
     * be guaranteed to be placed before the Spring Security filters in the stack.
     */
    public static final int FILTER_CHAIN_FIRST = 0;
    private static final int INTERVAL = 100;
    private static int i = 1;

    public static final int CHANNEL_FILTER              = FILTER_CHAIN_FIRST;
    public static final int CONCURRENT_SESSION_FILTER   = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int HTTP_SESSION_CONTEXT_FILTER = FILTER_CHAIN_FIRST + INTERVAL * i++;    
    public static final int LOGOUT_FILTER               = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int X509_FILTER                 = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int PRE_AUTH_FILTER             = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int CAS_PROCESSING_FILTER       = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int AUTHENTICATION_PROCESSING_FILTER = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int OPENID_PROCESSING_FILTER    = FILTER_CHAIN_FIRST + INTERVAL * i++;    
    public static final int LOGIN_PAGE_FILTER           = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int BASIC_PROCESSING_FILTER     = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int SERVLET_API_SUPPORT_FILTER = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int REMEMBER_ME_FILTER          = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int ANONYMOUS_FILTER = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int EXCEPTION_TRANSLATION_FILTER = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int NTLM_FILTER                 = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int SESSION_FIXATION_FILTER     = FILTER_CHAIN_FIRST + INTERVAL * i++;    
    public static final int FILTER_SECURITY_INTERCEPTOR = FILTER_CHAIN_FIRST + INTERVAL * i++;
    public static final int SWITCH_USER_FILTER          = FILTER_CHAIN_FIRST + INTERVAL * i++;

    private static final Map filterNameToOrder = new LinkedHashMap();

    static {
        filterNameToOrder.put("FIRST", new Integer(Integer.MIN_VALUE));
        filterNameToOrder.put("CHANNEL_FILTER", new Integer(CHANNEL_FILTER));
        filterNameToOrder.put("CONCURRENT_SESSION_FILTER", new Integer(CONCURRENT_SESSION_FILTER));
        filterNameToOrder.put("LOGOUT_FILTER", new Integer(LOGOUT_FILTER));
        filterNameToOrder.put("X509_FILTER", new Integer(X509_FILTER));
        filterNameToOrder.put("PRE_AUTH_FILTER", new Integer(PRE_AUTH_FILTER));
        filterNameToOrder.put("CAS_PROCESSING_FILTER", new Integer(CAS_PROCESSING_FILTER));
        filterNameToOrder.put("AUTHENTICATION_PROCESSING_FILTER", new Integer(AUTHENTICATION_PROCESSING_FILTER));
        filterNameToOrder.put("OPENID_PROCESSING_FILTER", new Integer(OPENID_PROCESSING_FILTER));
        filterNameToOrder.put("BASIC_PROCESSING_FILTER", new Integer(BASIC_PROCESSING_FILTER));
        filterNameToOrder.put("SERVLET_API_SUPPORT_FILTER", new Integer(SERVLET_API_SUPPORT_FILTER));
        filterNameToOrder.put("REMEMBER_ME_FILTER", new Integer(REMEMBER_ME_FILTER));
        filterNameToOrder.put("ANONYMOUS_FILTER", new Integer(ANONYMOUS_FILTER));
        filterNameToOrder.put("EXCEPTION_TRANSLATION_FILTER", new Integer(EXCEPTION_TRANSLATION_FILTER));
        filterNameToOrder.put("NTLM_FILTER", new Integer(NTLM_FILTER));
        filterNameToOrder.put("SESSION_CONTEXT_INTEGRATION_FILTER", new Integer(HTTP_SESSION_CONTEXT_FILTER));        
        filterNameToOrder.put("FILTER_SECURITY_INTERCEPTOR", new Integer(FILTER_SECURITY_INTERCEPTOR));
        filterNameToOrder.put("SWITCH_USER_FILTER", new Integer(SWITCH_USER_FILTER));
        filterNameToOrder.put("LAST", new Integer(Integer.MAX_VALUE));
    }

    /** Allows filters to be used by name in the XSD file without explicit reference to Java constants */
    public static int getOrder(String filterName) {
        Integer order = (Integer) filterNameToOrder.get(filterName);

        Assert.notNull(order, "Unable to match filter name " + filterName);

        return order.intValue();
    }
}
