/*
 * 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.myfaces.extensions.validator.beanval;

import org.apache.myfaces.extensions.validator.beanval.validation.message.interpolator.DefaultMessageInterpolator;
import org.apache.myfaces.extensions.validator.beanval.validation.message.interpolator.ExtValMessageInterpolatorAdapter;
import org.apache.myfaces.extensions.validator.beanval.validation.ModelValidationEntry;
import org.apache.myfaces.extensions.validator.internal.ToDo;
import org.apache.myfaces.extensions.validator.internal.Priority;
import org.apache.myfaces.extensions.validator.core.validation.message.resolver.MessageResolver;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.faces.context.FacesContext;
import javax.faces.component.UIComponent;
import javax.validation.groups.Default;
import javax.validation.MessageInterpolator;
import javax.validation.Validation;
import java.util.Map;
import java.util.List;
import java.util.ArrayList;
import java.util.HashMap;

/**
 * @author Gerhard Petracek
 * @since 1.x.3
 */
public class ExtValBeanValidationContext
{
    protected final Log logger = LogFactory.getLog(getClass());

    private static final String KEY = ExtValBeanValidationContext.class.getName() + ":KEY";

    private static MessageInterpolator defaultMessageInterpolator = new DefaultMessageInterpolator(
            Validation.buildDefaultValidatorFactory().getMessageInterpolator());

    private static MessageResolver messageResolver;

    @ToDo(value = Priority.HIGH, description = "refactor to a pluggable Storage")
    private Map<String, List<Class>> addedGroups = new HashMap<String, List<Class>>();

    @ToDo(value = Priority.HIGH, description = "refactor to a pluggable Storage")
    private Map<String, List<Class>> restrictedGroups = new HashMap<String, List<Class>>();

    @ToDo(value = Priority.HIGH, description = "refactor to a pluggable Storage")
    private Map<String, List<ModelValidationEntry>> modelValidationEntries =
            new HashMap<String, List<ModelValidationEntry>>();

    @ToDo(value = Priority.HIGH, description = "refactor to a pluggable Storage")
    private List<String> componentsOfRequest = new ArrayList<String>();

    private ExtValBeanValidationContext()
    {
    }

    @SuppressWarnings({"unchecked"})
    public static ExtValBeanValidationContext getCurrentInstance()
    {
        FacesContext facesContext = FacesContext.getCurrentInstance();

        Map requestMap = facesContext.getExternalContext().getRequestMap();

        ExtValBeanValidationContext currentContext = (ExtValBeanValidationContext)requestMap.get(KEY);

        if(currentContext == null)
        {
            currentContext = new ExtValBeanValidationContext();
            requestMap.put(KEY, currentContext);
        }

        return currentContext;
    }

    private String getGroupKey(String viewId, String componentId)
    {
        return componentId == null ? viewId : viewId + "@" + componentId;
    }

    public void addGroup(Class groupClass)
    {
        addGroup(groupClass, FacesContext.getCurrentInstance().getViewRoot().getViewId());
    }

    public void addGroup(Class groupClass, String viewId)
    {
        addGroup(groupClass, viewId, null);
    }

    public void addGroup(Class groupClass, String viewId, String componentId)
    {
        addGroupToGroupStorage(groupClass, viewId, componentId, this.addedGroups);
    }

    public void addModelValidationEntry(ModelValidationEntry modelValidationEntry)
    {
        addModelValidationEntry(modelValidationEntry, FacesContext.getCurrentInstance().getViewRoot().getViewId());
    }

    public void addModelValidationEntry(ModelValidationEntry modelValidationEntry, String viewId)
    {
        addModelValidationEntry(modelValidationEntry, viewId, null);
    }

    public void addModelValidationEntry(
            ModelValidationEntry modelValidationEntry, String viewId, UIComponent component)
    {
        modelValidationEntry.setComponent(component);

        String componentId = null;

        if(component != null)
        {
            componentId = component.getClientId(FacesContext.getCurrentInstance());
            this.componentsOfRequest.add(componentId);
        }

        List<ModelValidationEntry> modelValidationEntryList =
                this.modelValidationEntries.get(getGroupKey(viewId, componentId));

        if(modelValidationEntryList == null)
        {
            modelValidationEntryList = new ArrayList<ModelValidationEntry>();
            this.modelValidationEntries.put(getGroupKey(viewId, componentId), modelValidationEntryList);
        }

        if(!modelValidationEntryList.contains(modelValidationEntry))
        {
            modelValidationEntryList.add(modelValidationEntry);
        }
    }

    public void restrictGroup(Class groupClass)
    {
        restrictGroup(groupClass, FacesContext.getCurrentInstance().getViewRoot().getViewId());
    }

    public void restrictGroup(Class groupClass, String viewId)
    {
        restrictGroup(groupClass, viewId, null);
    }

    public void restrictGroup(Class groupClass, String viewId, String componentId)
    {
        addGroupToGroupStorage(groupClass, viewId, componentId, this.restrictedGroups);
    }

    private void addGroupToGroupStorage(Class groupClass, String viewId, String componentId,
                                        Map<String, List<Class>> groupStorage)
    {
        List<Class> groupList = groupStorage.get(getGroupKey(viewId, componentId));

        if(groupList == null)
        {
            groupList = new ArrayList<Class>();
            groupStorage.put(getGroupKey(viewId, componentId), groupList);
        }

        if(!groupList.contains(groupClass))
        {
            groupList.add(groupClass);
        }
    }

    public void resetGroup(String viewId)
    {
        resetGroups(viewId, null);
    }

    public void resetGroups(String viewId, String componentId)
    {
        this.addedGroups.put(getGroupKey(viewId, componentId), new ArrayList<Class>());
    }

    /*
    public Class[] getGroups()
    {
        if(this.addedGroups.size() < 1)
        {
            return new Class[] {Default.class};
        }

        List<Class> fullGroupList = new ArrayList<Class>();

        for(Map.Entry<String, List<Class>> currentGroupEntry : this.addedGroups.entrySet())
        {
            fullGroupList.addAll(currentGroupEntry.getValue());

        }
        return (Class[]) fullGroupList.toArray();
    }
    */

    public Class[] getGroups(String viewId)
    {
        return getGroups(viewId, null);
    }

    public Class[] getAllGroups(String viewId)
    {
        return getGroups(viewId, "*");
    }

    @ToDo(value = Priority.HIGH, description = "change impl. for #getAllGroups - see getModelValidationEntries")
    public Class[] getGroups(String viewId, String componentId)
    {
        if(this.addedGroups.size() < 1)
        {
            if(!"true".equalsIgnoreCase(WebXmlParameter.DEACTIVATE_IMPLICIT_DEFAULT_GROUP_VALIDATION))
            {
                return new Class[] {Default.class};
            }
            return null;
        }

        //add found groups
        String key = getGroupKey(viewId, null);
        List<Class> resultListForPage = buildGroupList(key, this.addedGroups);

        key = getGroupKey(viewId, componentId);
        List<Class> resultListForComponent = buildGroupList(key, this.addedGroups);

        //remove restricted groups
        Class[] resultsForPage = filterGroupList(getGroupKey(viewId, null), resultListForPage);
        Class[] resultsForComponent = filterGroupList(getGroupKey(viewId, componentId), resultListForComponent);

        if(resultsForPage.length == 0)
        {
            if(resultsForComponent.length == 0)
            {
                if(this.logger.isDebugEnabled())
                {
                    this.logger.debug("no groups for group-validation available." +
                            "maybe you restricted all groups or you aren't using groups." +
                            "bean validation will use the default group for validation");
                }
            }
            return resultsForComponent;
        }
        else if(resultsForComponent.length == 0)
        {
            return resultsForPage;
        }

        return mergeResults(resultsForPage, resultsForComponent);
    }

    public List<ModelValidationEntry> getModelValidationEntries(String viewId)
    {
        return getModelValidationEntries(viewId, null);
    }

    public List<ModelValidationEntry> getAllModelValidationEntries(String viewId)
    {
        return getModelValidationEntries(viewId, "*");
    }

    public List<ModelValidationEntry> getModelValidationEntriesOfCurrentRequest(String viewId)
    {
        List<ModelValidationEntry> result = new ArrayList<ModelValidationEntry>();

        for(String currentClientId : this.componentsOfRequest)
        {
            result.addAll(getModelValidationEntries(viewId, currentClientId));
        }

        result.addAll(getModelValidationEntries(viewId));

        return result;
    }

    public List<ModelValidationEntry> getModelValidationEntries(String viewId, String componentId)
    {
        if(this.modelValidationEntries.size() < 1)
        {
            return new ArrayList<ModelValidationEntry>();
        }

        //add found groups
        String key;
        List<ModelValidationEntry> resultListForPage = null;

        if(!"*".equals(componentId))
        {
            key = getGroupKey(viewId, null);
            resultListForPage =
                    buildModelValidationEntryList(key, this.modelValidationEntries);
        }

        key = getGroupKey(viewId, componentId);
        List<ModelValidationEntry> resultListForComponent =
                buildModelValidationEntryList(key, this.modelValidationEntries);

        if(resultListForPage == null || resultListForPage.isEmpty())
        {
            return resultListForComponent;
        }
        else if(resultListForComponent.isEmpty())
        {
            return resultListForPage;
        }

        //merge results
        List<ModelValidationEntry> mergedResult = new ArrayList<ModelValidationEntry>();
        mergedResult.addAll(resultListForPage);
        mergedResult.addAll(resultListForComponent);
        return mergedResult;
    }

    private List<Class> buildGroupList(String key, Map<String, List<Class>> groupStorage)
    {
        List<Class> list = groupStorage.get(key);
        return (list != null) ? list : new ArrayList<Class>();
    }

    private List<ModelValidationEntry> buildModelValidationEntryList(
            String key, Map<String, List<ModelValidationEntry>> groupStorage)
    {
        List<ModelValidationEntry> list;

        if(key != null && key.endsWith("*"))
        {
            list = new ArrayList<ModelValidationEntry>();
            for(Map.Entry<String,List<ModelValidationEntry>> entry : groupStorage.entrySet())
            {
                if(entry.getKey().substring(0, entry.getKey().indexOf("@"))
                        .equals(key.substring(0, key.indexOf("@"))))
                {
                    list.addAll(entry.getValue());
                }
            }
            return list;
        }

        list = groupStorage.get(key);
        return (list != null) ? list : new ArrayList<ModelValidationEntry>();
    }

    private Class[] filterGroupList(String key, List<Class> addedGroups)
    {
        List<Class> restrictedGroups = buildGroupList(key, this.restrictedGroups);
        List<Class> results = new ArrayList<Class>();

        for(Class currentGroup : addedGroups)
        {
            if(!restrictedGroups.contains(currentGroup))
            {
                results.add(currentGroup);
            }
        }

        return results.toArray(new Class[results.size()]);
    }

    private Class[] mergeResults(Class[] resultsForPage, Class[] resultsForComponent)
    {
        Class[] mergedResult = new Class[resultsForPage.length + resultsForComponent.length];

        System.arraycopy(resultsForPage, 0, mergedResult, 0, resultsForPage.length);
        System.arraycopy(resultsForComponent, 0, mergedResult, resultsForPage.length, resultsForComponent.length);

        return mergedResult;
    }

    public void removeGroup(Class groupClass)
    {
        removeGroup(groupClass, FacesContext.getCurrentInstance().getViewRoot().getViewId());
    }

    public void removeGroup(Class groupClass, String viewId)
    {
        removeGroup(groupClass, viewId, null);
    }

    @ToDo(Priority.HIGH)
    public void removeGroup(Class groupClass, String viewId, String componentId)
    {
        this.addedGroups.remove(getGroupKey(viewId, componentId));
    }

    public MessageInterpolator getMessageInterpolator()
    {
        if(messageResolver != null)
        {
            return new ExtValMessageInterpolatorAdapter(defaultMessageInterpolator, messageResolver);
        }

        return defaultMessageInterpolator;
    }

    @ToDo(Priority.HIGH)
    public static void setMessageResolver(MessageResolver customMessageResolver)
    {
        messageResolver = customMessageResolver;
    }
}