/*

  * Copyright 2011 The Kuali Foundation Licensed under the Educational Community

  * License, Version 1.0 (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.opensource.org/licenses/ecl1.php 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.kuali.rice.krad.uif.history;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.kuali.rice.krad.service.DataObjectMetaDataService;

 import org.kuali.rice.krad.service.KRADServiceLocatorWeb;

 import org.kuali.rice.krad.uif.UifConstants;

 import org.kuali.rice.krad.uif.container.View;

 import org.kuali.rice.krad.uif.util.ObjectPropertyUtils;

 import org.kuali.rice.krad.uif.util.ViewModelUtils;

 import org.kuali.rice.krad.web.form.UifFormBase;

 import javax.servlet.http.HttpServletRequest;

 import java.io.Serializable;

 import java.io.UnsupportedEncodingException;

 import java.net.URLDecoder;

 import java.net.URLEncoder;

 import java.util.ArrayList;

 import java.util.Enumeration;

 import java.util.List;

 /**

  * History class used to keep track of views visited so they can be displayed in the ui

  * as breadcrumbs - both as homeward path and history path interpretations

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class History implements Serializable {

     private static final long serialVersionUID = -8279297694371557335L;

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

     public static final String ENTRY_TOKEN = "$";

     public static final String VAR_TOKEN = ",";

     private boolean appendHomewardPath;

     private boolean appendPassedHistory;

     private HistoryEntry current;

     private List<HistoryEntry> homewardPath;

     private List<HistoryEntry> historyEntries;

     public History() {

         historyEntries = new ArrayList<HistoryEntry>();

     }

     /**

      * Gets the predetermined homeward path for this view's history.

      * This is set by the same property in the view's Breadcrumbs configuration.

      *

      * @return the homewardPath

      */

     public List<HistoryEntry> getHomewardPath() {

         return this.homewardPath;

     }

     /**

      * @param homewardPath the homewardPath to set

      */

     public void setHomewardPath(List<HistoryEntry> homewardPath) {

         this.homewardPath = homewardPath;

     }

     /**

      * Gets a list of the current HistoryEntries not including the current entry.

      * This list does not include the "&history=" query parameter on each HistoryEntry's

      * url variable.  For HistoryEntries that include history information to be passed to the

      * view they are retrieving, getGeneratedBreadcrumbs is used.

      *

      * @return the history

      */

     public List<HistoryEntry> getHistoryEntries() {

         return this.historyEntries;

     }

     /**

      * @param history the history to set

      */

     public void setHistoryEntries(List<HistoryEntry> history) {

         this.historyEntries = history;

     }

     /**

      * Gets the current view's HistoryEntry.

      * This does not include the "&history=" query parameter on its

      * url variable.  For the HistoryEntry that includes history information to be passed

      * on the url it is retrieving, getGeneratedCurrentBreadcrumb is used.

      *

      * @return the current

      */

     public HistoryEntry getCurrent() {

         return this.current;

     }

     /**

      * @param current the current to set

      */

     private void setCurrent(String viewId, String pageId, String title, String url, String formKey) {

         HistoryEntry entry = new HistoryEntry(viewId, pageId, title, url, formKey);

         current = entry;

     }

     /**

      * @param current the current to set

      */

     public void setCurrent(HistoryEntry current) {

         this.current = current;

     }

     /**

      * Takes in the encoded history query parameter string passed on the url and parses it to create

      * the list of historyEntries.  It will also append any homeward path if appendHomewardPath is true.  This

      * append will happen after the passedHistory entries are appended so it will not make sense to use both settings

      * in

      * most cases.

      *

      * @param parameterString

      */

     public void buildHistoryFromParameterString(String parameterString) {

         if (StringUtils.isNotEmpty(parameterString)) {

             try {

                 parameterString = URLDecoder.decode(parameterString, "UTF-8");

             } catch (UnsupportedEncodingException e) {

                 LOG.error("Error decoding history param", e);

             }

             historyEntries = new ArrayList<HistoryEntry>();

             if (appendPassedHistory) {

                 String[] historyTokens = parameterString.split("\\" + ENTRY_TOKEN);

                 for (String token : historyTokens) {

                     String[] params = token.split(VAR_TOKEN);

                     pushToHistory(params[0], params[1], params[2], params[3], params[4]);

                 }

             }

         }

         if (appendHomewardPath) {

             historyEntries.addAll(homewardPath);

         }

     }

     /**

      * Gets the encoded and tokenized history parameter string that is representative of the HistoryEntries

      * currently in History and includes the current view's HistoryEntry.  This parameter should be appended on any

      * appropriate links which perform view swapping.

      *

      * @return

      */

     public String getHistoryParameterString() {

         String historyString = "";

         for (HistoryEntry e : historyEntries) {

             if (historyEntries.indexOf(e) == 0) {

                 historyString = historyString + e.toParam();

             } else {

                 historyString = historyString + ENTRY_TOKEN + e.toParam();

             }

         }

         // add current

         if (historyString.equals("")) {

             historyString = historyString + current.toParam();

         } else {

             historyString = historyString + ENTRY_TOKEN + current.toParam();

         }

         try {

             historyString = URLEncoder.encode(historyString, "UTF-8");

         } catch (Exception e) {

             LOG.error("Error encoding history param", e);

         }

         return historyString;

     }

     /**

      * Generates a list of HistoryEntries that can be used as breadcrumbs by the breadcrumb widget.  This

      * method appends the appropriate history information on the HistoryEntry url variables so when a view is requested

      * its history can be regenerated for use in its breadcrumbs.  It also sets the the passed showHome variable to

      * false

      * to prevent showing the homeward path more than once (as it is passed through the history variable backwards).

      * This does not include the current HistoryEntry as a breadcrumb.

      *

      * @return

      */

     public List<HistoryEntry> getGeneratedBreadcrumbs() {

         List<HistoryEntry> breadcrumbs = new ArrayList<HistoryEntry>();

         for (int i = 0; i < historyEntries.size(); i++) {

             if (i == 0) {

                 breadcrumbs.add(copyEntry(historyEntries.get(i)));

             } else {

                 HistoryEntry breadcrumb = copyEntry(historyEntries.get(i));

                 String historyParam = "";

                 for (int j = 0; j < i; j++) {

                     historyParam = historyParam + ENTRY_TOKEN + historyEntries.get(j).toParam();

                 }

                 historyParam = historyParam.replaceFirst("\\" + ENTRY_TOKEN, "");

                 try {

                     historyParam = URLEncoder.encode(historyParam, "UTF-8");

                 } catch (Exception e) {

                     LOG.error("Error encoding history param", e);

                 }

                 String url = "";

                 if (breadcrumb.getUrl().contains("?")) {

                     url = breadcrumb.getUrl() + "&" + UifConstants.UrlParams.HISTORY + "=" + historyParam;

                 } else {

                     url = breadcrumb.getUrl() + "?" + UifConstants.UrlParams.HISTORY + "=" + historyParam;

                 }

                 breadcrumb.setUrl(url);

                 breadcrumbs.add(breadcrumb);

             }

         }

         return breadcrumbs;

     }

     /**

      * Gets the current HistoryEntry in the breadcrumb format described in getGeneratedBreadcrumbs.

      *

      * @return

      */

     public HistoryEntry getGeneratedCurrentBreadcrumb() {

         HistoryEntry breadcrumb = copyEntry(current);

         String historyParam = "";

         for (int j = 0; j < historyEntries.size(); j++) {

             historyParam = historyParam + ENTRY_TOKEN + historyEntries.get(j).toParam();

         }

         historyParam = historyParam.replaceFirst("\\" + ENTRY_TOKEN, "");

         try {

             historyParam = URLEncoder.encode(historyParam, "UTF-8");

         } catch (Exception e) {

             LOG.error("Error encoding history param", e);

         }

         String url = "";

         if (breadcrumb.getUrl().contains("?")) {

             url = breadcrumb.getUrl() + "&" + UifConstants.UrlParams.HISTORY + "=" + historyParam;

         } else {

             url = breadcrumb.getUrl() + "?" + UifConstants.UrlParams.HISTORY + "=" + historyParam;

         }

         breadcrumb.setUrl(url);

         return breadcrumb;

     }

     /**

      * Copies a HistoryEntry, for use during breadcrumb generation.

      *

      * @param e

      * @return

      */

     private HistoryEntry copyEntry(HistoryEntry e) {

         return new HistoryEntry(e.getViewId(), e.getPageId(), e.getTitle(), e.getUrl(), e.getFormKey());

     }

     /**

      * Pushes the information passed in to history.

      * Note: currently only used internally in the class - be cautious about its external use.

      *

      * @param viewId

      * @param pageId

      * @param title

      * @param url

      * @param formKey

      */

     public void pushToHistory(String viewId, String pageId, String title, String url, String formKey) {

         HistoryEntry entry = new HistoryEntry(viewId, pageId, title, url, formKey);

         historyEntries.add(entry);

     }

     /**

      * When this is set to true, the homeward path will be appended.

      * Note:  For most cases this should only be on during the first view load.

      * This setting is set automatically in most cases.

      *

      * @param appendHomewardPath the appendHomewardPath to set

      */

     public void setAppendHomewardPath(boolean appendHomewardPath) {

         this.appendHomewardPath = appendHomewardPath;

     }

     /**

      * @return the appendHomewardPath

      */

     public boolean isAppendHomewardPath() {

         return appendHomewardPath;

     }

     /**

      * Appends the passed history as each different view is shown.  This setting should be used when displaying

      * passed history is relevant to the user (ie inquiry/lookup chains).  This setting is set automatically in

      * most cases.

      *

      * @param appendPassedHistory the appendPassedHistory to set

      */

     public void setAppendPassedHistory(boolean appendPassedHistory) {

         this.appendPassedHistory = appendPassedHistory;

     }

     /**

      * @return the appendPassedHistory

      */

     public boolean isAppendPassedHistory() {

         return appendPassedHistory;

     }

     /**

      * Sets the current HistoryEntry using information from the form and the request.  This history parameter is

      * extracted out of the url inorder for a "clean" url to be used in history parameter and

      * breadcrumb generation, as passing history history through the nested urls is unnecessary.

      *

      * @param form

      * @param request

      */

     @SuppressWarnings("unchecked")

     public void setCurrent(UifFormBase form, HttpServletRequest request) {

         if (!request.getMethod().equals("POST")) {

             boolean showHomeValue = false;

             boolean pageIdValue = false;

             boolean formKeyValue = false;

             String queryString = "";

             String url = request.getRequestURL().toString();

             //remove history attribute

             Enumeration<String> params = request.getParameterNames();

             while (params.hasMoreElements()) {

                 String key = params.nextElement();

                 if (!key.equals(UifConstants.UrlParams.HISTORY)) {

                     for (String value : request.getParameterValues(key)) {

                         queryString = queryString + "&" + key + "=" + value;

                     }

                 } else if (key.equals(UifConstants.UrlParams.PAGE_ID)) {

                     pageIdValue = true;

                 } else if (key.equals(UifConstants.UrlParams.SHOW_HOME)) {

                     showHomeValue = true;

                 } else if (key.equals(UifConstants.UrlParams.FORM_KEY)) {

                     formKeyValue = true;

                 }

             }

             //add formKey and pageId to url

             if (StringUtils.isNotBlank(form.getFormKey()) && !formKeyValue) {

                 queryString = queryString + "&" + UifConstants.UrlParams.FORM_KEY + "=" + form.getFormKey();

             }

             if (StringUtils.isNotBlank(form.getPageId()) && !pageIdValue) {

                 queryString = queryString + "&" + UifConstants.UrlParams.PAGE_ID + "=" + form.getPageId();

             }

             if (!showHomeValue) {

                 queryString = queryString + "&" + UifConstants.UrlParams.SHOW_HOME + "=false";

             }

             queryString = queryString.replaceFirst("&", "");

             if (StringUtils.isNotEmpty(queryString)) {

                 url = url + "?" + queryString;

             }

             this.setCurrent(form.getViewId(), form.getPageId(), buildViewTitle(form), url, form.getFormKey());

         }

     }

     /**

      * Builds the title for the view to display in history (for example breadcrumbs)

      *

      * <p>

      * Retrieves the viewLabelFieldPropertyName from the view if configured, otherwise attempts

      * to find the title attribute for the default data object. If view label property is found the

      * corresponding property value is retrieved and appended to the title for the view

      * </p>

      *

      * TODO: Possibly move so it can be used for the actual view title, not just history

      *

      * @param form - form instance containing the view and view data

      * @return String title string to use

      */

     protected String buildViewTitle(UifFormBase form) {

         View view = form.getView();

         String title = view.getTitle();

         // may move this into view logic instead in the future if it is required for the view's title (not just breadcrumb)

         // if so remove this and just use getTitle - this logic would be in performFinalize instead

         String viewLabelPropertyName = view.getViewLabelFieldPropertyName();

         // if view label property name given, try to retrieve the title attribute for the main data object

         if (StringUtils.isBlank(viewLabelPropertyName)) {

             Class<?> dataObjectClass;

             if (StringUtils.isNotBlank(view.getDefaultBindingObjectPath())) {

                 dataObjectClass = ObjectPropertyUtils.getPropertyType(form, view.getDefaultBindingObjectPath());

             } else {

                 dataObjectClass = view.getFormClass();

             }

             DataObjectMetaDataService mds = KRADServiceLocatorWeb.getDataObjectMetaDataService();

             if (dataObjectClass != null) {

                 viewLabelPropertyName = mds.getTitleAttribute(dataObjectClass);

             }

         }

         String viewLabelPropertyPath = "";

         if (StringUtils.isNotBlank(viewLabelPropertyName)) {

             // adjust binding prefix

             if (!viewLabelPropertyName.startsWith(UifConstants.NO_BIND_ADJUST_PREFIX)) {

                 if (StringUtils.isNotBlank(view.getDefaultBindingObjectPath())) {

                     viewLabelPropertyPath = view.getDefaultBindingObjectPath() + "." + viewLabelPropertyName;

                 }

             } else {

                 viewLabelPropertyPath = StringUtils.removeStart(viewLabelPropertyName,

                         UifConstants.NO_BIND_ADJUST_PREFIX);

             }

         }

         else {

             // attempt to get title attribute

             Class<?> dataObjectClass;

             if (StringUtils.isNotBlank(view.getDefaultBindingObjectPath())) {

                 dataObjectClass = ViewModelUtils.getObjectClassForMetadata(view, form,

                         view.getDefaultBindingObjectPath());

             } else {

                 dataObjectClass = view.getFormClass();

             }

             DataObjectMetaDataService mds = KRADServiceLocatorWeb.getDataObjectMetaDataService();

             if (dataObjectClass != null) {

                 String titleAttribute = mds.getTitleAttribute(dataObjectClass);

                 if (StringUtils.isNotBlank(titleAttribute)) {

                   viewLabelPropertyPath = view.getDefaultBindingObjectPath() + "." + titleAttribute;

                 }

             }

         }

         Object viewLabelPropertyValue = null;

         if (StringUtils.isNotBlank(viewLabelPropertyPath)) {

             viewLabelPropertyValue = ObjectPropertyUtils.getPropertyValue(form, viewLabelPropertyPath);

         }

         String titleAppend = "";

         if (viewLabelPropertyValue != null) {

             titleAppend = viewLabelPropertyValue.toString();

         }

         if (StringUtils.isNotBlank(titleAppend) && view.getAppendOption() != null) {

             if (view.getAppendOption().equalsIgnoreCase(UifConstants.TitleAppendTypes.DASH)) {

                 title = title + " - " + titleAppend;

             } else if (view.getAppendOption().equalsIgnoreCase(UifConstants.TitleAppendTypes.PARENTHESIS)) {

                 title = title + "(" + titleAppend + ")";

             } else if (view.getAppendOption().equalsIgnoreCase(UifConstants.TitleAppendTypes.REPLACE)) {

                 title = titleAppend;

             }

             //else it is none or blank so no title modification will be used

         }

         return title;

     }

 }