/*******************************************************************************
 * 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.ofbiz.widget.screen;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.TimeZone;

import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.Perl5Matcher;
import org.ofbiz.base.util.Debug;
import org.ofbiz.base.util.GeneralException;
import org.ofbiz.base.util.ObjectType;
import org.ofbiz.base.util.PatternFactory;
import org.ofbiz.base.util.UtilGenerics;
import org.ofbiz.base.util.UtilValidate;
import org.ofbiz.base.util.UtilXml;
import org.ofbiz.base.util.collections.FlexibleMapAccessor;
import org.ofbiz.base.util.string.FlexibleStringExpander;
import org.ofbiz.entity.GenericValue;
import org.ofbiz.entityext.permission.EntityPermissionChecker;
import org.ofbiz.minilang.operation.BaseCompare;
import org.ofbiz.security.Security;
import org.ofbiz.service.DispatchContext;
import org.ofbiz.service.GenericServiceException;
import org.ofbiz.service.LocalDispatcher;
import org.ofbiz.service.ModelService;
import org.ofbiz.service.ServiceUtil;
import org.w3c.dom.Element;

/**
 * Widget Library - Screen model condition class
 */
@SuppressWarnings("serial")
public class ModelScreenCondition implements Serializable {
    public static final String module = ModelScreenCondition.class.getName();

    protected ModelScreen modelScreen;
    protected ScreenCondition rootCondition;

    public ModelScreenCondition(ModelScreen modelScreen, Element conditionElement) {
        this.modelScreen = modelScreen;
        Element firstChildElement = UtilXml.firstChildElement(conditionElement);
        this.rootCondition = readCondition(modelScreen, firstChildElement);
    }

    public boolean eval(Map<String, Object> context) {
        if (rootCondition == null) {
            return true;
        }
        return rootCondition.eval(context);
    }

    public static abstract class ScreenCondition implements Serializable {
        protected ModelScreen modelScreen;

        public ScreenCondition(ModelScreen modelScreen, Element conditionElement) {
            this.modelScreen = modelScreen;
        }

        public abstract boolean eval(Map<String, Object> context);
    }

    public static List<ScreenCondition> readSubConditions(ModelScreen modelScreen, Element conditionElement) {
        List<? extends Element> subElementList = UtilXml.childElementList(conditionElement);
        List<ScreenCondition> condList = new ArrayList<ScreenCondition>(subElementList.size());
        for (Element subElement: subElementList) {
            condList.add(readCondition(modelScreen, subElement));
        }
        return condList;
    }

    public static ScreenCondition readCondition(ModelScreen modelScreen, Element conditionElement) {
        if (conditionElement == null) {
            return null;
        }
        if ("and".equals(conditionElement.getNodeName())) {
            return new And(modelScreen, conditionElement);
        } else if ("xor".equals(conditionElement.getNodeName())) {
            return new Xor(modelScreen, conditionElement);
        } else if ("or".equals(conditionElement.getNodeName())) {
            return new Or(modelScreen, conditionElement);
        } else if ("not".equals(conditionElement.getNodeName())) {
            return new Not(modelScreen, conditionElement);
        } else if ("if-service-permission".equals(conditionElement.getNodeName())) {
            return new IfServicePermission(modelScreen, conditionElement);
        } else if ("if-has-permission".equals(conditionElement.getNodeName())) {
            return new IfHasPermission(modelScreen, conditionElement);
        } else if ("if-validate-method".equals(conditionElement.getNodeName())) {
            return new IfValidateMethod(modelScreen, conditionElement);
        } else if ("if-compare".equals(conditionElement.getNodeName())) {
            return new IfCompare(modelScreen, conditionElement);
        } else if ("if-compare-field".equals(conditionElement.getNodeName())) {
            return new IfCompareField(modelScreen, conditionElement);
        } else if ("if-regexp".equals(conditionElement.getNodeName())) {
            return new IfRegexp(modelScreen, conditionElement);
        } else if ("if-empty".equals(conditionElement.getNodeName())) {
            return new IfEmpty(modelScreen, conditionElement);
        } else if ("if-entity-permission".equals(conditionElement.getNodeName())) {
            return new IfEntityPermission(modelScreen, conditionElement);
        } else if ("if-empty-section".equals(conditionElement.getNodeName())) {
            return new IfEmptySection(modelScreen, conditionElement);
        } else {
            throw new IllegalArgumentException("Condition element not supported with name: " + conditionElement.getNodeName());
        }
    }

    public static class And extends ScreenCondition {
        protected List<ScreenCondition> subConditions;

        public And(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.subConditions = readSubConditions(modelScreen, condElement);
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            // return false for the first one in the list that is false, basic and algo
            for (ScreenCondition subCondition: this.subConditions) {
                if (!subCondition.eval(context)) {
                    return false;
                }
            }
            return true;
        }
    }

    public static class Xor extends ScreenCondition {
        protected List<ScreenCondition> subConditions;

        public Xor(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.subConditions = readSubConditions(modelScreen, condElement);
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            // if more than one is true stop immediately and return false; if all are false return false; if only one is true return true
            boolean foundOneTrue = false;
            for (ScreenCondition subCondition: this.subConditions) {
                if (subCondition.eval(context)) {
                    if (foundOneTrue) {
                        // now found two true, so return false
                        return false;
                    } else {
                        foundOneTrue = true;
                    }
                }
            }
            return foundOneTrue;
        }
    }

    public static class Or extends ScreenCondition {
        protected List<ScreenCondition> subConditions;

        public Or(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.subConditions = readSubConditions(modelScreen, condElement);
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            // return true for the first one in the list that is true, basic or algo
            for (ScreenCondition subCondition: this.subConditions) {
                if (subCondition.eval(context)) {
                    return true;
                }
            }
            return false;
        }
    }

    public static class Not extends ScreenCondition {
        protected ScreenCondition subCondition;

        public Not(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            Element firstChildElement = UtilXml.firstChildElement(condElement);
            this.subCondition = readCondition(modelScreen, firstChildElement);
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            return !this.subCondition.eval(context);
        }
    }

    public static class IfServicePermission extends ScreenCondition {
        protected FlexibleStringExpander serviceExdr;
        protected FlexibleStringExpander actionExdr;
        protected FlexibleStringExpander ctxMapExdr;
        protected FlexibleStringExpander resExdr;

        public IfServicePermission(ModelScreen modelScreen, Element condElement) {
            super(modelScreen, condElement);
            this.serviceExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("service-name"));
            this.actionExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("main-action"));
            this.ctxMapExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("context-map"));
            this.resExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("resource-description"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            // if no user is logged in, treat as if the user does not have permission
            GenericValue userLogin = (GenericValue) context.get("userLogin");
            if (userLogin != null) {
                String serviceName = serviceExdr.expandString(context);
                String mainAction = actionExdr.expandString(context);
                String contextMap = ctxMapExdr.expandString(context);
                String resource = resExdr.expandString(context);
                if (UtilValidate.isEmpty(resource)) {
                    resource = serviceName;
                }

                if (UtilValidate.isEmpty(serviceName)) {
                    Debug.logWarning("No permission service-name specified!", module);
                    return false;
                }

                Map<String, Object> serviceContext = UtilGenerics.toMap(context.get(contextMap));
                if (serviceContext != null) {
                    // copy the required internal fields
                    serviceContext.put("userLogin", context.get("userLogin"));
                    serviceContext.put("locale", context.get("locale"));
                } else {
                    serviceContext = context;
                }

                // get the service objects
                LocalDispatcher dispatcher = this.modelScreen.getDispatcher(context);
                DispatchContext dctx = dispatcher.getDispatchContext();

                // get the service
                ModelService permService;
                try {
                    permService = dctx.getModelService(serviceName);
                } catch (GenericServiceException e) {
                    Debug.logError(e, module);
                    return false;
                }

                if (permService != null) {
                    // build the context
                    Map<String, Object> svcCtx = permService.makeValid(serviceContext, ModelService.IN_PARAM);
                    svcCtx.put("resourceDescription", resource);
                    if (UtilValidate.isNotEmpty(mainAction)) {
                        svcCtx.put("mainAction", mainAction);
                    }

                    // invoke the service
                    Map<String, Object> resp;
                    try {
                        resp = dispatcher.runSync(permService.name,  svcCtx, 300, true);
                    } catch (GenericServiceException e) {
                        Debug.logError(e, module);
                        return false;
                    }
                    if (ServiceUtil.isError(resp) || ServiceUtil.isFailure(resp)) {
                        Debug.logError(ServiceUtil.getErrorMessage(resp), module);
                        return false;
                    }
                    Boolean hasPermission = (Boolean) resp.get("hasPermission");
                    if (hasPermission != null) {
                        return hasPermission.booleanValue();
                    }
                }
            }
            return false;
        }
    }

    public static class IfHasPermission extends ScreenCondition {
        protected FlexibleStringExpander permissionExdr;
        protected FlexibleStringExpander actionExdr;

        public IfHasPermission(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.permissionExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("permission"));
            this.actionExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("action"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            // if no user is logged in, treat as if the user does not have permission
            GenericValue userLogin = (GenericValue) context.get("userLogin");
            if (userLogin != null) {
                String permission = permissionExdr.expandString(context);
                String action = actionExdr.expandString(context);
                Security security = (Security) context.get("security");
                if (UtilValidate.isNotEmpty(action)) {
                    // run hasEntityPermission
                    if (security.hasEntityPermission(permission, action, userLogin)) {
                        return true;
                    }
                } else {
                    // run hasPermission
                    if (security.hasPermission(permission, userLogin)) {
                        return true;
                    }
                }
            }
            return false;
        }
    }

    public static class IfValidateMethod extends ScreenCondition {
        protected FlexibleMapAccessor<Object> fieldAcsr;
        protected FlexibleStringExpander methodExdr;
        protected FlexibleStringExpander classExdr;

        public IfValidateMethod(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field"));
            if (this.fieldAcsr.isEmpty()) this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field-name"));
            this.methodExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("method"));
            this.classExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("class"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            String methodName = this.methodExdr.expandString(context);
            String className = this.classExdr.expandString(context);

            Object fieldVal = this.fieldAcsr.get(context);
            String fieldString = null;
            if (fieldVal != null) {
                try {
                    fieldString = (String) ObjectType.simpleTypeConvert(fieldVal, "String", null, (TimeZone) context.get("timeZone"), (Locale) context.get("locale"), true);
                } catch (GeneralException e) {
                    Debug.logError(e, "Could not convert object to String, using empty String", module);
                }
            }

            // always use an empty string by default
            if (fieldString == null) fieldString = "";

            Class<?>[] paramTypes = new Class[] {String.class};
            Object[] params = new Object[] {fieldString};

            Class<?> valClass;
            try {
                valClass = ObjectType.loadClass(className);
            } catch (ClassNotFoundException cnfe) {
                Debug.logError("Could not find validation class: " + className, module);
                return false;
            }

            Method valMethod;
            try {
                valMethod = valClass.getMethod(methodName, paramTypes);
            } catch (NoSuchMethodException cnfe) {
                Debug.logError("Could not find validation method: " + methodName + " of class " + className, module);
                return false;
            }

            Boolean resultBool = Boolean.FALSE;
            try {
                resultBool = (Boolean) valMethod.invoke(null, params);
            } catch (Exception e) {
                Debug.logError(e, "Error in IfValidationMethod " + methodName + " of class " + className + ", defaulting to false ", module);
            }

            return resultBool.booleanValue();
        }
    }

    public static class IfCompare extends ScreenCondition {
        protected FlexibleMapAccessor<Object> fieldAcsr;
        protected FlexibleStringExpander valueExdr;

        protected String operator;
        protected String type;
        protected FlexibleStringExpander formatExdr;

        public IfCompare(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field"));
            if (this.fieldAcsr.isEmpty()) this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field-name"));
            this.valueExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("value"));

            this.operator = condElement.getAttribute("operator");
            this.type = condElement.getAttribute("type");

            this.formatExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("format"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            String value = this.valueExdr.expandString(context);
            String format = this.formatExdr.expandString(context);

            Object fieldVal = this.fieldAcsr.get(context);

            // always use an empty string by default
            if (fieldVal == null) {
                fieldVal = "";
            }

            List<Object> messages = new LinkedList<Object>();
            Boolean resultBool = BaseCompare.doRealCompare(fieldVal, value, operator, type, format, messages, null, null, true);
            if (messages.size() > 0) {
                messages.add(0, "Error with comparison in if-compare between field [" + fieldAcsr.toString() + "] with value [" + fieldVal + "] and value [" + value + "] with operator [" + operator + "] and type [" + type + "]: ");

                StringBuilder fullString = new StringBuilder();
                for (Object item: messages) {
                    fullString.append(item.toString());
                }
                Debug.logWarning(fullString.toString(), module);

                throw new IllegalArgumentException(fullString.toString());
            }

            return resultBool.booleanValue();
        }
    }

    public static class IfCompareField extends ScreenCondition {
        protected FlexibleMapAccessor<Object> fieldAcsr;
        protected FlexibleMapAccessor<Object> toFieldAcsr;

        protected String operator;
        protected String type;
        protected FlexibleStringExpander formatExdr;

        public IfCompareField(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field"));
            if (this.fieldAcsr.isEmpty()) this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field-name"));
            this.toFieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("to-field"));
            if (this.toFieldAcsr.isEmpty()) this.toFieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("to-field-name"));

            this.operator = condElement.getAttribute("operator");
            this.type = condElement.getAttribute("type");

            this.formatExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("format"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            String format = this.formatExdr.expandString(context);

            Object fieldVal = this.fieldAcsr.get(context);
            Object toFieldVal = this.toFieldAcsr.get(context);

            // always use an empty string by default
            if (fieldVal == null) {
                fieldVal = "";
            }

            List<Object> messages = new LinkedList<Object>();
            Boolean resultBool = BaseCompare.doRealCompare(fieldVal, toFieldVal, operator, type, format, messages, null, null, false);
            if (messages.size() > 0) {
                messages.add(0, "Error with comparison in if-compare-field between field [" + fieldAcsr.toString() + "] with value [" + fieldVal + "] and to-field [" + toFieldAcsr.toString() + "] with value [" + toFieldVal + "] with operator [" + operator + "] and type [" + type + "]: ");

                StringBuilder fullString = new StringBuilder();
                for (Object item: messages) {
                    fullString.append(item.toString());
                }
                Debug.logWarning(fullString.toString(), module);

                throw new IllegalArgumentException(fullString.toString());
            }

            return resultBool.booleanValue();
        }
    }

    public static class IfRegexp extends ScreenCondition {
        protected FlexibleMapAccessor<Object> fieldAcsr;
        protected FlexibleStringExpander exprExdr;

        public IfRegexp(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field"));
            if (this.fieldAcsr.isEmpty()) this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field-name"));
            this.exprExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("expr"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            Object fieldVal = this.fieldAcsr.get(context);
            String expr = this.exprExdr.expandString(context);
            Pattern pattern;

            try {
                pattern = PatternFactory.createOrGetPerl5CompiledPattern(expr, true);
            } catch (MalformedPatternException e) {
                String errMsg = "Error in evaluation in if-regexp in screen: " + e.toString();
                Debug.logError(e, errMsg, module);
                throw new IllegalArgumentException(errMsg);
            }

            String fieldString = null;
            try {
                fieldString = (String) ObjectType.simpleTypeConvert(fieldVal, "String", null, (TimeZone) context.get("timeZone"), (Locale) context.get("locale"), true);
            } catch (GeneralException e) {
                Debug.logError(e, "Could not convert object to String, using empty String", module);
            }
            // always use an empty string by default
            if (fieldString == null) fieldString = "";

            PatternMatcher matcher = new Perl5Matcher();
            return matcher.matches(fieldString, pattern);
        }
    }

    public static class IfEmpty extends ScreenCondition {
        protected FlexibleMapAccessor<Object> fieldAcsr;

        public IfEmpty(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field"));
            if (this.fieldAcsr.isEmpty()) this.fieldAcsr = FlexibleMapAccessor.getInstance(condElement.getAttribute("field-name"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            Object fieldVal = this.fieldAcsr.get(context);
            return ObjectType.isEmpty(fieldVal);
        }
    }
    public static class IfEntityPermission extends ScreenCondition {
        protected EntityPermissionChecker permissionChecker;

        public IfEntityPermission(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.permissionChecker = new EntityPermissionChecker(condElement);
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            return permissionChecker.runPermissionCheck(context);
        }
    }

    public static class IfEmptySection extends ScreenCondition {
        protected FlexibleStringExpander sectionExdr;

        public IfEmptySection(ModelScreen modelScreen, Element condElement) {
            super (modelScreen, condElement);
            this.sectionExdr = FlexibleStringExpander.getInstance(condElement.getAttribute("section-name"));
        }

        @Override
        public boolean eval(Map<String, Object> context) {
            Map<String, Object> sectionsList = UtilGenerics.toMap(context.get("sections"));
            return !sectionsList.containsKey(this.sectionExdr.expandString(context));
        }
    }
}