/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.struts2.interceptor.parameter;

import org.apache.commons.lang3.BooleanUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.struts2.ActionContext;
import org.apache.struts2.ActionInvocation;
import org.apache.struts2.ModelDriven;
import org.apache.struts2.StrutsConstants;
import org.apache.struts2.action.NoParameters;
import org.apache.struts2.action.ParameterNameAware;
import org.apache.struts2.action.ParameterValueAware;
import org.apache.struts2.dispatcher.HttpParameters;
import org.apache.struts2.dispatcher.Parameter;
import org.apache.struts2.inject.Inject;
import org.apache.struts2.interceptor.MethodFilterInterceptor;
import org.apache.struts2.ognl.OgnlUtil;
import org.apache.struts2.ognl.ThreadAllowlist;
import org.apache.struts2.security.AcceptedPatternsChecker;
import org.apache.struts2.security.DefaultAcceptedPatternsChecker;
import org.apache.struts2.security.ExcludedPatternsChecker;
import org.apache.struts2.util.ClearableValueStack;
import org.apache.struts2.util.MemberAccessValueStack;
import org.apache.struts2.util.ProxyService;
import org.apache.struts2.util.TextParseUtil;
import org.apache.struts2.util.ValueStack;
import org.apache.struts2.util.ValueStackFactory;
import org.apache.struts2.util.reflection.ReflectionContextState;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.TreeMap;
import java.util.regex.Pattern;

import static java.lang.String.format;
import static java.util.Collections.unmodifiableSet;
import static java.util.stream.Collectors.joining;
import static org.apache.commons.lang3.StringUtils.indexOfAny;
import static org.apache.commons.lang3.StringUtils.normalizeSpace;
import static org.apache.struts2.security.DefaultAcceptedPatternsChecker.NESTING_CHARS;
import static org.apache.struts2.security.DefaultAcceptedPatternsChecker.NESTING_CHARS_STR;
import static org.apache.struts2.util.DebugUtils.logWarningForFirstOccurrence;
import static org.apache.struts2.util.DebugUtils.notifyDeveloperOfError;

/**
 * This interceptor sets all parameters on the value stack.
 */
public class ParametersInterceptor extends MethodFilterInterceptor {

    private static final Logger LOG = LogManager.getLogger(ParametersInterceptor.class);

    protected static final int PARAM_NAME_MAX_LENGTH = 100;

    private static final Pattern DMI_IGNORED_PATTERN = Pattern.compile("^(action|method):.*", Pattern.CASE_INSENSITIVE);

    private int paramNameMaxLength = PARAM_NAME_MAX_LENGTH;
    private boolean devMode = false;
    private boolean dmiEnabled = false;

    protected boolean ordered = false;
    protected boolean requireAnnotations = false;
    protected boolean requireAnnotationsTransitionMode = false;

    private ValueStackFactory valueStackFactory;
    private OgnlUtil ognlUtil;
    protected ThreadAllowlist threadAllowlist;
    private ProxyService proxyService;
    private ExcludedPatternsChecker excludedPatterns;
    private AcceptedPatternsChecker acceptedPatterns;
    private Set<Pattern> excludedValuePatterns = null;
    private Set<Pattern> acceptedValuePatterns = null;

    @Inject
    public void setValueStackFactory(ValueStackFactory valueStackFactory) {
        this.valueStackFactory = valueStackFactory;
    }

    @Inject
    public void setOgnlUtil(OgnlUtil ognlUtil) {
        this.ognlUtil = ognlUtil;
    }

    @Inject
    public void setThreadAllowlist(ThreadAllowlist threadAllowlist) {
        this.threadAllowlist = threadAllowlist;
    }

    @Inject
    public void setProxyService(ProxyService proxyService) {
        this.proxyService = proxyService;
    }

    @Inject(StrutsConstants.STRUTS_DEVMODE)
    public void setDevMode(String mode) {
        this.devMode = BooleanUtils.toBoolean(mode);
    }

    @Inject(value = StrutsConstants.STRUTS_PARAMETERS_REQUIRE_ANNOTATIONS, required = false)
    public void setRequireAnnotations(String requireAnnotations) {
        this.requireAnnotations = BooleanUtils.toBoolean(requireAnnotations);
        if (!this.requireAnnotations) {
            String msg = "@StrutsParameter annotation requirement is disabled!" +
                    " We strongly recommend keeping it enabled to protect against critical vulnerabilities." +
                    " Set the configuration `{}=true` to enable it." +
                    " Please refer to the Struts 7.0 migration guide and security documentation for further information.";
            logWarningForFirstOccurrence("strutsParameter", LOG, msg, StrutsConstants.STRUTS_PARAMETERS_REQUIRE_ANNOTATIONS);
        }
    }

    /**
     * When 'Transition Mode' is enabled, parameters that are not 'nested' will be accepted without annotations. What
     * this means in practice is that all public setters on an Action will be exposed for parameter injection again, and
     * only 'nested' parameters, i.e. public getters on an Action, will require annotations.
     * <p>
     * In this mode, the OGNL auto-allowlisting capability is not degraded in any way, and as such, it offers a
     * convenient option for applications to enable the OGNL allowlist capability whilst they work through the process
     * of annotating all their Action parameters.
     */
    @Inject(value = StrutsConstants.STRUTS_PARAMETERS_REQUIRE_ANNOTATIONS_TRANSITION, required = false)
    public void setRequireAnnotationsTransitionMode(String transitionMode) {
        this.requireAnnotationsTransitionMode = BooleanUtils.toBoolean(transitionMode);
    }

    @Inject
    public void setExcludedPatterns(ExcludedPatternsChecker excludedPatterns) {
        this.excludedPatterns = excludedPatterns;
    }

    @Inject
    public void setAcceptedPatterns(AcceptedPatternsChecker acceptedPatterns) {
        this.acceptedPatterns = acceptedPatterns;
    }

    @Inject(value = StrutsConstants.STRUTS_ENABLE_DYNAMIC_METHOD_INVOCATION, required = false)
    protected void setDynamicMethodInvocation(String dmiEnabled) {
        this.dmiEnabled = Boolean.parseBoolean(dmiEnabled);
    }

    /**
     * If the param name exceeds the configured maximum length it will not be
     * accepted.
     *
     * @param paramNameMaxLength Maximum length of param names
     */
    public void setParamNameMaxLength(int paramNameMaxLength) {
        this.paramNameMaxLength = paramNameMaxLength;
    }

    static private int countOGNLCharacters(String s) {
        int count = 0;
        for (int i = s.length() - 1; i >= 0; i--) {
            char c = s.charAt(i);
            if (c == '.' || c == '[') count++;
        }
        return count;
    }

    /**
     * Compares based on number of '.' and '[' characters (fewer is higher)
     */
    static final Comparator<String> rbCollator = (s1, s2) -> {
        int l1 = countOGNLCharacters(s1);
        int l2 = countOGNLCharacters(s2);
        return l1 < l2 ? -1 : (l2 < l1 ? 1 : s1.compareTo(s2));
    };

    @Override
    public String doIntercept(ActionInvocation invocation) throws Exception {
        Object action = invocation.getAction();
        if (action instanceof NoParameters) {
            return invocation.invoke();
        }

        ActionContext actionContext = invocation.getInvocationContext();
        HttpParameters parameters = retrieveParameters(actionContext);

        if (parameters == null) {
            return invocation.invoke();
        }

        if (LOG.isDebugEnabled()) {
            LOG.debug("Setting params {}", normalizeSpace(getParameterLogMap(parameters)));
        }

        Map<String, Object> contextMap = actionContext.getContextMap();
        batchApplyReflectionContextState(contextMap, true);
        try {
            applyParameters(action, actionContext.getValueStack(), parameters);
        } finally {
            batchApplyReflectionContextState(contextMap, false);
        }

        return invocation.invoke();
    }

    /**
     * Gets the parameter map to apply from wherever appropriate
     *
     * @param actionContext The action context
     * @return The parameter map to apply
     */
    protected HttpParameters retrieveParameters(ActionContext actionContext) {
        return actionContext.getParameters();
    }


    /**
     * Adds the parameters into context's ParameterMap
     * <p>
     * In this class this is a no-op, since the parameters were fetched from the same location. In subclasses both this
     * and {@link #retrieveParameters} should be overridden.
     *
     * @param ac        The action context
     * @param newParams The parameter map to apply
     */
    protected void addParametersToContext(ActionContext ac, Map<String, ?> newParams) {
    }

    protected void applyParameters(final Object action, ValueStack stack, HttpParameters parameters) {
        Map<String, Parameter> acceptableParameters = toAcceptableParameters(parameters, action);

        ValueStack newStack = toNewStack(stack);
        batchApplyReflectionContextState(newStack.getContext(), true);
        applyMemberAccessProperties(newStack);

        applyParametersOnStack(newStack, acceptableParameters, action);

        if (newStack instanceof ClearableValueStack) {
            stack.getActionContext().withConversionErrors(newStack.getActionContext().getConversionErrors());
        }

        addParametersToContext(ActionContext.getContext(), acceptableParameters);
    }

    protected void batchApplyReflectionContextState(Map<String, Object> context, boolean value) {
        ReflectionContextState.setCreatingNullObjects(context, value);
        ReflectionContextState.setDenyMethodExecution(context, value);
        ReflectionContextState.setReportingConversionErrors(context, value);
    }

    protected ValueStack toNewStack(ValueStack stack) {
        ValueStack newStack = valueStackFactory.createValueStack(stack);
        if (newStack instanceof ClearableValueStack clearable) {
            clearable.clearContextValues();
            newStack.getActionContext().withLocale(stack.getActionContext().getLocale()).withValueStack(stack);
        }
        return newStack;
    }

    protected void applyMemberAccessProperties(ValueStack stack) {
        if (!(stack instanceof MemberAccessValueStack accessValueStack)) {
            return;
        }
        accessValueStack.useAcceptProperties(acceptedPatterns.getAcceptedPatterns());
        accessValueStack.useExcludeProperties(excludedPatterns.getExcludedPatterns());
    }

    protected Map<String, Parameter> toAcceptableParameters(HttpParameters parameters, Object action) {
        HttpParameters newParams = initNewHttpParameters(parameters);
        Map<String, Parameter> acceptableParameters = initParameterMap();

        for (Map.Entry<String, Parameter> entry : newParams.entrySet()) {
            String parameterName = entry.getKey();
            Parameter parameterValue = entry.getValue();
            if (isAcceptableParameter(parameterName, action) && isAcceptableParameterValue(parameterValue, action)) {
                acceptableParameters.put(parameterName, parameterValue);
            }
        }
        return acceptableParameters;
    }

    protected Map<String, Parameter> initParameterMap() {
        if (ordered) {
            return new TreeMap<>(getOrderedComparator());
        } else {
            return new TreeMap<>();
        }
    }

    protected HttpParameters initNewHttpParameters(HttpParameters parameters) {
        if (ordered) {
            return HttpParameters.create().withComparator(getOrderedComparator()).withParent(parameters).build();
        } else {
            return HttpParameters.create().withParent(parameters).build();
        }
    }

    protected void applyParametersOnStack(ValueStack stack, Map<String, Parameter> parameters, Object action) {
        for (Map.Entry<String, Parameter> entry : parameters.entrySet()) {
            try {
                stack.setParameter(entry.getKey(), entry.getValue().getObject());
            } catch (RuntimeException e) {
                if (devMode) {
                    notifyDeveloperParameterException(action, entry.getKey(), e.getMessage());
                }
            }
        }
    }

    protected void notifyDeveloperParameterException(Object action, String property, String message) {
        String logMsg = format("Unexpected Exception caught setting '%s' on '%s: %s", property, action.getClass(), message);
        notifyDeveloperOfError(LOG, action, logMsg);
    }

    /**
     * Checks if name of parameter can be accepted or thrown away
     *
     * @param name   parameter name
     * @param action current action
     * @return true if parameter is accepted
     */
    protected boolean isAcceptableParameter(String name, Object action) {
        return isAcceptableName(name) && isAcceptableParameterNameAware(name, action) && isParameterAnnotatedAndAllowlist(name, action);
    }

    protected boolean isAcceptableParameterNameAware(String name, Object action) {
        return !(action instanceof ParameterNameAware nameAware) || nameAware.acceptableParameterName(name);
    }

    /**
     * Checks if the Action class member corresponding to a parameter is appropriately annotated with
     * {@link StrutsParameter} and OGNL allowlists any necessary classes.
     * <p>
     * Note that this logic relies on the use of {@link DefaultAcceptedPatternsChecker#NESTING_CHARS} and may also
     * be adversely impacted by the use of custom OGNL property accessors.
     */
    protected boolean isParameterAnnotatedAndAllowlist(String name, Object action) {
        if (!requireAnnotations) {
            return true;
        }

        long paramDepth = name.codePoints().mapToObj(c -> (char) c).filter(NESTING_CHARS::contains).count();

        if (action instanceof ModelDriven<?> && !ActionContext.getContext().getValueStack().peek().equals(action)) {
            LOG.debug("Model driven Action detected, exempting from @StrutsParameter annotation requirement");
            return true;
        }

        if (requireAnnotationsTransitionMode && paramDepth == 0) {
            LOG.debug("Annotation transition mode enabled, exempting non-nested parameter [{}] from @StrutsParameter annotation requirement", name);
            return true;
        }

        int nestingIndex = indexOfAny(name, NESTING_CHARS_STR);
        String rootProperty = nestingIndex == -1 ? name : name.substring(0, nestingIndex);
        String normalisedRootProperty = Character.toLowerCase(rootProperty.charAt(0)) + rootProperty.substring(1);

        return hasValidAnnotatedMember(normalisedRootProperty, action, paramDepth);
    }

    /**
     * Note that we check for a public field last or only if there is no valid, annotated property descriptor. This is
     * because this check is likely to fail more often than not, as the relative use of public fields is low - so we
     * save computation by checking this last.
     */
    protected boolean hasValidAnnotatedMember(String rootProperty, Object action, long paramDepth) {
        LOG.debug("Checking Action [{}] for a matching, correctly annotated member for property [{}]",
                action.getClass().getSimpleName(), rootProperty);
        BeanInfo beanInfo = getBeanInfo(action);
        if (beanInfo == null) {
            return hasValidAnnotatedField(action, rootProperty, paramDepth);
        }

        Optional<PropertyDescriptor> propDescOpt = Arrays.stream(beanInfo.getPropertyDescriptors())
                .filter(desc -> desc.getName().equals(rootProperty)).findFirst();
        if (propDescOpt.isEmpty()) {
            return hasValidAnnotatedField(action, rootProperty, paramDepth);
        }

        if (hasValidAnnotatedPropertyDescriptor(action, propDescOpt.get(), paramDepth)) {
            return true;
        }

        return hasValidAnnotatedField(action, rootProperty, paramDepth);
    }

    protected boolean hasValidAnnotatedPropertyDescriptor(Object action, PropertyDescriptor propDesc, long paramDepth) {
        Class<?> actionClass = ultimateClass(action);
        Method relevantMethod = paramDepth == 0 ? propDesc.getWriteMethod() : propDesc.getReadMethod();
        if (relevantMethod == null) {
            return false;
        }
        if (getPermittedInjectionDepth(relevantMethod) < paramDepth) {
            String logMessage = format(
                    "Parameter injection for method [%s] on Action [%s] rejected. Ensure it is annotated with @StrutsParameter with an appropriate 'depth'.",
                    relevantMethod.getName(),
                    relevantMethod.getDeclaringClass().getName());
            if (devMode) {
                notifyDeveloperOfError(LOG, action, logMessage);
            } else {
                LOG.debug(logMessage);
            }
            return false;
        }
        LOG.debug("Success: Matching annotated method [{}] found for property [{}] of depth [{}] on Action [{}]",
                relevantMethod.getName(), propDesc.getName(), paramDepth, actionClass.getSimpleName());
        if (paramDepth >= 1) {
            allowlistClass(propDesc.getPropertyType());
        }
        if (paramDepth >= 2) {
            allowlistReturnTypeIfParameterized(relevantMethod);
        }
        return true;
    }

    protected void allowlistReturnTypeIfParameterized(Method method) {
        allowlistParameterizedTypeArg(method.getGenericReturnType());
    }

    protected void allowlistParameterizedTypeArg(Type genericType) {
        if (!(genericType instanceof ParameterizedType)) {
            return;
        }
        Type[] paramTypes = ((ParameterizedType) genericType).getActualTypeArguments();
        allowlistParamType(paramTypes[0]);
        if (paramTypes.length > 1) {
            // Probably useful for Map or Map-like classes
            allowlistParamType(paramTypes[1]);
        }
    }

    protected void allowlistParamType(Type paramType) {
        if (paramType instanceof Class<?> clazz) {
            allowlistClass(clazz);
        }
    }

    protected void allowlistClass(Class<?> clazz) {
        threadAllowlist.allowClassHierarchy(clazz);
    }

    protected boolean hasValidAnnotatedField(Object action, String fieldName, long paramDepth) {
        Class<?> actionClass = ultimateClass(action);
        LOG.debug("No matching annotated method found for property [{}] of depth [{}] on Action [{}], now also checking for public field",
                fieldName, paramDepth, actionClass.getSimpleName());
        Field field;
        try {
            field = actionClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            LOG.debug("Matching field for property [{}] not found on Action [{}]", fieldName, actionClass.getSimpleName());
            return false;
        }
        if (!Modifier.isPublic(field.getModifiers())) {
            LOG.debug("Matching field [{}] is not public on Action [{}]", field.getName(), actionClass.getSimpleName());
            return false;
        }
        if (getPermittedInjectionDepth(field) < paramDepth) {
            String logMessage = format(
                    "Parameter injection for field [%s] on Action [%s] rejected. Ensure it is annotated with @StrutsParameter with an appropriate 'depth'.",
                    field.getName(),
                    actionClass.getName());
            if (devMode) {
                notifyDeveloperOfError(LOG, action, logMessage);
            } else {
                LOG.debug(logMessage);
            }
            return false;
        }
        LOG.debug("Success: Matching annotated public field [{}] found for property of depth [{}] on Action [{}]",
                field.getName(), paramDepth, actionClass.getSimpleName());
        if (paramDepth >= 1) {
            allowlistClass(field.getType());
        }
        if (paramDepth >= 2) {
            allowlistFieldIfParameterized(field);
        }
        return true;
    }

    protected void allowlistFieldIfParameterized(Field field) {
        allowlistParameterizedTypeArg(field.getGenericType());
    }

    /**
     * @return permitted injection depth where -1 indicates not permitted
     */
    protected int getPermittedInjectionDepth(AnnotatedElement element) {
        StrutsParameter annotation = getParameterAnnotation(element);
        if (annotation == null) {
            return -1;
        }
        return annotation.depth();
    }

    /**
     * Annotation retrieval logic. Can be overridden to support extending annotations or some other form of annotation
     * inheritance.
     */
    protected StrutsParameter getParameterAnnotation(AnnotatedElement element) {
        return element.getAnnotation(StrutsParameter.class);
    }

    protected Class<?> ultimateClass(Object action) {
        if (proxyService.isProxy(action)) {
            return proxyService.ultimateTargetClass(action);
        }
        return action.getClass();
    }

    protected BeanInfo getBeanInfo(Object action) {
        Class<?> actionClass = ultimateClass(action);
        try {
            return ognlUtil.getBeanInfo(actionClass);
        } catch (IntrospectionException e) {
            LOG.warn("Error introspecting Action {} for parameter injection validation", actionClass, e);
            return null;
        }
    }

    /**
     * Checks if parameter value can be accepted or thrown away
     *
     * @param param  the parameter
     * @param action current action
     * @return true if parameter is accepted
     */
    protected boolean isAcceptableParameterValue(Parameter param, Object action) {
        return isAcceptableParameterValueAware(param, action) && isAcceptableValue(param.getName(), param.getValue());
    }

    protected boolean isAcceptableParameterValueAware(Parameter param, Object action) {
        return !(action instanceof ParameterValueAware valueAware) || valueAware.acceptableParameterValue(param.getValue());
    }

    /**
     * Gets an instance of the comparator to use for the ordered sorting.  Override this
     * method to customize the ordering of the parameters as they are set to the
     * action.
     *
     * @return A comparator to sort the parameters
     */
    protected Comparator<String> getOrderedComparator() {
        return rbCollator;
    }

    protected String getParameterLogMap(HttpParameters parameters) {
        if (parameters == null) {
            return "NONE";
        }
        return parameters.entrySet().stream()
                .map(entry -> format("%s => %s ", entry.getKey(), entry.getValue().getValue()))
                .collect(joining());
    }

    /**
     * Validates the name passed is:
     * * Within the max length of a parameter name
     * * Is not excluded
     * * Is accepted
     *
     * @param name - Name to check
     * @return true if accepted
     */
    protected boolean isAcceptableName(String name) {
        if (isIgnoredDMI(name)) {
            LOG.trace("DMI is enabled, ignoring DMI method: {}", name);
            return false;
        }
        boolean accepted = isWithinLengthLimit(name) && !isExcluded(name) && isAccepted(name);
        if (devMode && accepted) {
            LOG.debug("Parameter [{}] was accepted and will be appended to action!", name);
        }
        return accepted;
    }

    private boolean isIgnoredDMI(String name) {
        if (!dmiEnabled) {
            return false;
        }
        return DMI_IGNORED_PATTERN.matcher(name).matches();
    }

    /**
     * Validates:
     * * Value is null/blank
     * * Value is not excluded
     * * Value is accepted
     *
     * @param name  - Param name (for logging)
     * @param value - value to check
     * @return true if accepted
     */
    protected boolean isAcceptableValue(String name, String value) {
        boolean accepted = value == null || value.isEmpty() || (!isParamValueExcluded(value) && isParamValueAccepted(value));
        if (!accepted) {
            String message = "Value [{}] of parameter [{}] was not accepted and will be dropped!";
            if (devMode) {
                LOG.warn(message, normalizeSpace(value), normalizeSpace(name));
            } else {
                LOG.debug(message, normalizeSpace(value), normalizeSpace(name));
            }
        }
        return accepted;
    }

    protected boolean isWithinLengthLimit(String name) {
        boolean matchLength = name.length() <= paramNameMaxLength;
        if (!matchLength) {
            if (devMode) {
                LOG.warn("Parameter [{}] is too long, allowed length is [{}]. Use Interceptor Parameter Overriding " +
                        "to override the limit, see more at\n" +
                        "https://struts.apache.org/core-developers/interceptors.html#interceptor-parameter-overriding",
                    name, paramNameMaxLength);
            } else {
                LOG.warn("Parameter [{}] is too long, allowed length is [{}]", name, paramNameMaxLength);
            }
        }
        return matchLength;
    }

    protected boolean isAccepted(String paramName) {
        AcceptedPatternsChecker.IsAccepted result = acceptedPatterns.isAccepted(paramName);
        if (!result.isAccepted()) {
            if (devMode) {
                LOG.warn("Parameter [{}] didn't match accepted pattern [{}]! See Accepted / Excluded patterns at\n" +
                         "https://struts.apache.org/security/#accepted--excluded-patterns",
                        paramName, result.getAcceptedPattern());
            } else {
                LOG.debug("Parameter [{}] didn't match accepted pattern [{}]!", paramName, result.getAcceptedPattern());
            }
            return false;
        }
        return true;
    }

    protected boolean isExcluded(String paramName) {
        ExcludedPatternsChecker.IsExcluded result = excludedPatterns.isExcluded(paramName);
        if (result.isExcluded()) {
            if (devMode) {
                LOG.warn("Parameter [{}] matches excluded pattern [{}]! See Accepted / Excluded patterns at\n" +
                         "https://struts.apache.org/security/#accepted--excluded-patterns",
                        paramName, result.getExcludedPattern());
            } else {
                LOG.debug("Parameter [{}] matches excluded pattern [{}]!", paramName, result.getExcludedPattern());
            }
            return true;
        }
        return false;
    }

    protected boolean isParamValueExcluded(String value) {
        if (!hasParamValuesToExclude()) {
            LOG.debug("'excludedValuePatterns' not defined so anything is allowed");
            return false;
        }
        for (Pattern excludedValuePattern : excludedValuePatterns) {
            if (excludedValuePattern.matcher(value).matches()) {
                if (devMode) {
                    LOG.warn("Parameter value [{}] matches excluded pattern [{}]! See Accepting/Excluding parameter values at\n" +
                             "https://struts.apache.org/core-developers/parameters-interceptor#excluding-parameter-values",
                            value, excludedValuePatterns);
                } else {
                    LOG.debug("Parameter value [{}] matches excluded pattern [{}]", value, excludedValuePattern);
                }
                return true;
            }
        }
        return false;
    }

    protected boolean isParamValueAccepted(String value) {
        if (!hasParamValuesToAccept()) {
            LOG.debug("'acceptedValuePatterns' not defined so anything is allowed");
            return true;
        }
        for (Pattern acceptedValuePattern : acceptedValuePatterns) {
            if (acceptedValuePattern.matcher(value).matches()) {
                return true;
            }
        }
        if (devMode) {
            LOG.warn("Parameter value [{}] didn't match accepted pattern [{}]! See Accepting/Excluding parameter values at\n" +
                     "https://struts.apache.org/core-developers/parameters-interceptor#excluding-parameter-values",
                    value, acceptedValuePatterns);
        } else {
            LOG.debug("Parameter value [{}] was not accepted!", value);
        }
        return false;
    }

    private boolean hasParamValuesToExclude() {
        return excludedValuePatterns != null && !excludedValuePatterns.isEmpty();
    }

    private boolean hasParamValuesToAccept() {
        return acceptedValuePatterns != null && !acceptedValuePatterns.isEmpty();
    }

    /**
     * Whether to order the parameters or not
     *
     * @return True to order
     */
    public boolean isOrdered() {
        return ordered;
    }

    /**
     * Set whether to order the parameters by object depth or not
     *
     * @param ordered True to order them
     */
    public void setOrdered(boolean ordered) {
        this.ordered = ordered;
    }

    /**
     * Sets a comma-delimited list of regular expressions to match
     * parameters that are allowed in the parameter map (aka whitelist).
     * <p>
     * Don't change the default unless you know what you are doing in terms
     * of security implications.
     * </p>
     *
     * @param commaDelim A comma-delimited list of regular expressions
     */
    public void setAcceptParamNames(String commaDelim) {
        acceptedPatterns.setAcceptedPatterns(commaDelim);
    }

    /**
     * Sets a comma-delimited list of regular expressions to match
     * parameters that should be removed from the parameter map.
     *
     * @param commaDelim A comma-delimited list of regular expressions
     */
    public void setExcludeParams(String commaDelim) {
        excludedPatterns.setExcludedPatterns(commaDelim);
    }

    /**
     * Sets a comma-delimited list of regular expressions to match
     * values of parameters that should be accepted and included in the parameter map.
     *
     * @param commaDelimitedPatterns A comma-delimited set of regular expressions
     */
    public void setAcceptedValuePatterns(String commaDelimitedPatterns) {
        Set<String> patterns = TextParseUtil.commaDelimitedStringToSet(commaDelimitedPatterns);
        if (acceptedValuePatterns == null) {
            // Limit unwanted log entries (for 1st call, acceptedValuePatterns null)
            LOG.debug("Sets accepted value patterns to [{}], note this may impact the safety of your application!", patterns);
        } else {
            LOG.warn("Replacing accepted patterns [{}] with [{}], be aware that this may impact safety of your application!",
                    acceptedValuePatterns, patterns);
        }
        acceptedValuePatterns = new HashSet<>(patterns.size());
        try {
            for (String pattern : patterns) {
                acceptedValuePatterns.add(Pattern.compile(pattern, Pattern.CASE_INSENSITIVE));
            }
        } finally {
            acceptedValuePatterns = unmodifiableSet(acceptedValuePatterns);
        }
    }

    /**
     * Sets a comma-delimited list of regular expressions to match
     * values of parameters that should be removed from the parameter map.
     *
     * @param commaDelimitedPatterns A comma-delimited set of regular expressions
     */
    public void setExcludedValuePatterns(String commaDelimitedPatterns) {
        Set<String> patterns = TextParseUtil.commaDelimitedStringToSet(commaDelimitedPatterns);
        if (excludedValuePatterns == null) {
            // Limit unwanted log entries (for 1st call, excludedValuePatterns null)
            LOG.debug("Setting excluded value patterns to [{}]", patterns);
        } else {
            LOG.warn("Replacing excluded value patterns [{}] with [{}], be aware that this may impact safety of your application!",
                    excludedValuePatterns, patterns);
        }
        excludedValuePatterns = new HashSet<>(patterns.size());
        try {
            for (String pattern : patterns) {
                excludedValuePatterns.add(Pattern.compile(pattern, Pattern.CASE_INSENSITIVE));
            }
        } finally {
            excludedValuePatterns = unmodifiableSet(excludedValuePatterns);
        }
    }
}
