/*
 * $Id: JavascriptValidatorTag.java 383908 2006-03-07 15:33:42Z niallp $ 
 *
 * Copyright 2001-2005 The Apache Software Foundation.
 * 
 * Licensed 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.struts.taglib.html;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.StringTokenizer;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.BodyTagSupport;

import org.apache.commons.validator.Field;
import org.apache.commons.validator.Form;
import org.apache.commons.validator.ValidatorAction;
import org.apache.commons.validator.ValidatorResources;
import org.apache.commons.validator.Var;
import org.apache.commons.validator.util.ValidatorUtils;
import org.apache.struts.Globals;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.config.ModuleConfig;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;
import org.apache.struts.validator.Resources;
import org.apache.struts.validator.ValidatorPlugIn;

/**
 * Custom tag that generates JavaScript for client side validation based
 * on the validation rules loaded by the <code>ValidatorPlugIn</code>
 * defined in the struts-config.xml file.
 *
 * @version $Rev: 383908 $ $Date: 2006-03-07 15:33:42 +0000 (Tue, 07 Mar 2006) $
 * @since Struts 1.1
 */
public class JavascriptValidatorTag extends BodyTagSupport {

    /**
     * A Comparator to use when sorting ValidatorAction objects.
     */
    private static final Comparator actionComparator = new Comparator() {
        public int compare(Object o1, Object o2) {

            ValidatorAction va1 = (ValidatorAction) o1;
            ValidatorAction va2 = (ValidatorAction) o2;

            if ((va1.getDepends() == null || va1.getDepends().length() == 0)
                && (va2.getDepends() == null || va2.getDepends().length() == 0)) {
                return 0;

            } else if (
                (va1.getDepends() != null && va1.getDepends().length() > 0)
                    && (va2.getDepends() == null || va2.getDepends().length() == 0)) {
                return 1;

            } else if (
                (va1.getDepends() == null || va1.getDepends().length() == 0)
                    && (va2.getDepends() != null && va2.getDepends().length() > 0)) {
                return -1;

            } else {
                return va1.getDependencyList().size() - va2.getDependencyList().size();
            }
        }
    };

    /**
     * The start of the HTML comment hiding JavaScript from old browsers.
     * @since Struts 1.2
     */
    protected static final String HTML_BEGIN_COMMENT = "\n<!-- Begin \n";

    /**
     * The end of the HTML comment hiding JavaScript from old browsers.
     * @since Struts 1.2
     */
    protected static final String HTML_END_COMMENT = "//End --> \n";

    // ----------------------------------------------------------- Properties

    /**
     * The servlet context attribute key for our resources.
     */
    protected String bundle = Globals.MESSAGES_KEY;

    /**
     * The default locale on our server.
     * @deprecated This variable is no longer used.
     */
    protected static Locale defaultLocale = Locale.getDefault();

    /**
     * The name of the form that corresponds with the action name
     * in struts-config.xml. Specifying a form name places a
     * &lt;script&gt; &lt;/script&gt; around the javascript.
     */
    protected String formName = null;
    
    /**
     * formName is used for both Javascript and non-javascript validations.
     * For the javascript validations, there is the possibility that we will
     * be rewriting the formName (if it is a ValidatorActionForm instead of just
     * a ValidatorForm) so we need another variable to hold the formName just for
     * javascript usage.
     */
    protected String jsFormName = null;

    /**
     * The line ending string.
     */
    protected static String lineEnd = System.getProperty("line.separator");

    /**
     * The current page number of a multi-part form.
     * Only valid when the formName attribute is set.
     */
    protected int page = 0;

    /**
     * This will be used as is for the JavaScript validation method name if it has a value.  This is
     * the method name of the main JavaScript method that the form calls to perform validations.
     */
    protected String methodName = null;

    /**
     * Include language attribute in the &lt;script&gt; element.  This property is
     * ignored in XHTML mode.
     * @since Struts 1.2
     */
    protected boolean scriptLanguage = true;

    /**
     * The static JavaScript methods will only be printed if this is set to "true".
     */
    protected String staticJavascript = "true";

    /**
     * The dynamic JavaScript objects will only be generated if this is set to "true".
     */
    protected String dynamicJavascript = "true";

    /**
     * The src attribute for html script element (used to include an external script
     * resource). The src attribute is only recognized
     * when the formName attribute is specified.
     */
    protected String src = null;

    /**
     * The JavaScript methods will enclosed with html comments if this is set to "true".
     */
    protected String htmlComment = "true";

    /**
     * Hide JavaScript methods in a CDATA section for XHTML when "true".
     */
    protected String cdata = "true";

    /**
     * Gets the key (form name) that will be used
     * to retrieve a set of validation rules to be
     * performed on the bean passed in for validation.
     */
    public String getFormName() {
        return formName;
    }

    /**
     * Sets the key (form name) that will be used
     * to retrieve a set of validation rules to be
     * performed on the bean passed in for validation.
     * Specifying a form name places a
     * &lt;script&gt; &lt;/script&gt; tag around the javascript.
     */
    public void setFormName(String formName) {
        this.formName = formName;
    }

    /**
     * @return Returns the jsFormName.
     */
    public String getJsFormName() {
        return jsFormName;
    }
    /**
     * @param jsFormName The jsFormName to set.
     */
    public void setJsFormName(String jsFormName) {
        this.jsFormName = jsFormName;
    }
    /**
     * Gets the current page number of a multi-part form.
     * Only field validations with a matching page numer
     * will be generated that match the current page number.
     * Only valid when the formName attribute is set.
     */
    public int getPage() {
        return page;
    }

    /**
     * Sets the current page number of a multi-part form.
     * Only field validations with a matching page numer
     * will be generated that match the current page number.
     * Only valid when the formName attribute is set.
     */
    public void setPage(int page) {
        this.page = page;
    }

    /**
     * Gets the method name that will be used for the Javascript
     * validation method name if it has a value.  This overrides
     * the auto-generated method name based on the key (form name)
     * passed in.
     */
    public String getMethod() {
        return methodName;
    }

    /**
     * Sets the method name that will be used for the Javascript
     * validation method name if it has a value.  This overrides
     * the auto-generated method name based on the key (form name)
     * passed in.
     */
    public void setMethod(String methodName) {
        this.methodName = methodName;
    }

    /**
     * Gets whether or not to generate the static
     * JavaScript.  If this is set to 'true', which
     * is the default, the static JavaScript will be generated.
     */
    public String getStaticJavascript() {
        return staticJavascript;
    }

    /**
     * Sets whether or not to generate the static
     * JavaScript.  If this is set to 'true', which
     * is the default, the static JavaScript will be generated.
     */
    public void setStaticJavascript(String staticJavascript) {
        this.staticJavascript = staticJavascript;
    }

    /**
     * Gets whether or not to generate the dynamic
     * JavaScript.  If this is set to 'true', which
     * is the default, the dynamic JavaScript will be generated.
     */
    public String getDynamicJavascript() {
        return dynamicJavascript;
    }

    /**
     * Sets whether or not to generate the dynamic
     * JavaScript.  If this is set to 'true', which
     * is the default, the dynamic JavaScript will be generated.
     */
    public void setDynamicJavascript(String dynamicJavascript) {
        this.dynamicJavascript = dynamicJavascript;
    }

    /**
      * Gets whether or not to delimit the
      * JavaScript with html comments.  If this is set to 'true', which
      * is the default, the htmlComment will be surround the JavaScript.
      */
    public String getHtmlComment() {
        return htmlComment;
    }

    /**
     * Sets whether or not to delimit the
     * JavaScript with html comments.  If this is set to 'true', which
     * is the default, the htmlComment will be surround the JavaScript.
     */
    public void setHtmlComment(String htmlComment) {
        this.htmlComment = htmlComment;
    }

    /**
     * Gets the src attribute's value when defining
     * the html script element.
     */
    public String getSrc() {
        return src;
    }

    /**
     * Sets the src attribute's value when defining
     * the html script element. The src attribute is only recognized
     * when the formName attribute is specified.
     */
    public void setSrc(String src) {
        this.src = src;
    }

    /**
     * Sets the servlet context attribute key for our resources.
     */
    public String getBundle() {
        return bundle;
    }

    /**
     * Gets the servlet context attribute key for our resources.
     */
    public void setBundle(String bundle) {
        this.bundle = bundle;
    }

    /**
     * Render the JavaScript for to perform validations based on the form name.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {

        JspWriter writer = pageContext.getOut();
        try {
            writer.print(this.renderJavascript());

        } catch (IOException e) {
            throw new JspException(e.getMessage());
        }

        return EVAL_BODY_TAG;

    }

    /**
     * Returns fully rendered JavaScript.
     * @since Struts 1.2
     */
    protected String renderJavascript() throws JspException {
        StringBuffer results = new StringBuffer();

        ModuleConfig config = TagUtils.getInstance().getModuleConfig(pageContext);
        ValidatorResources resources =
            (ValidatorResources) pageContext.getAttribute(
                ValidatorPlugIn.VALIDATOR_KEY + config.getPrefix(),
                PageContext.APPLICATION_SCOPE);

        if (resources == null) {
            throw new JspException(
                "ValidatorResources not found in application scope under key \"" 
                + ValidatorPlugIn.VALIDATOR_KEY + config.getPrefix() + "\"");
        }        

        Locale locale = TagUtils.getInstance().getUserLocale(this.pageContext, null);

        Form form = resources.getForm(locale, formName);

        if ("true".equalsIgnoreCase(dynamicJavascript) && form == null)
        {
            throw new JspException("No form found under '"
                                   + formName
                                   + "' in locale '"
                                   + locale
                                   + "'");
        }

        if (form != null) {
            if ("true".equalsIgnoreCase(dynamicJavascript)) {
                results.append(
                        this.createDynamicJavascript(config, resources, locale, form));

            } else if ("true".equalsIgnoreCase(staticJavascript)) {
                results.append(this.renderStartElement());
                if ("true".equalsIgnoreCase(htmlComment)) {
                    results.append(HTML_BEGIN_COMMENT);
                }
            }
        }

        if ("true".equalsIgnoreCase(staticJavascript)) {
            results.append(getJavascriptStaticMethods(resources));
        }

        if (form != null
            && ("true".equalsIgnoreCase(dynamicJavascript)
                || "true".equalsIgnoreCase(staticJavascript))) {

            results.append(getJavascriptEnd());
        }

        return results.toString();
    }

    /**
     * Generates the dynamic JavaScript for the form.
     * @param config
     * @param resources
     * @param locale
     * @param form
     */
    private String createDynamicJavascript(
        ModuleConfig config,
        ValidatorResources resources,
        Locale locale,
        Form form) throws JspException {

        StringBuffer results = new StringBuffer();

        MessageResources messages = 
            TagUtils.getInstance().retrieveMessageResources(pageContext, bundle, true);
 
        HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();
        ServletContext application = pageContext.getServletContext();

        List actions = this.createActionList(resources, form);

        final String methods = this.createMethods(actions, this.stopOnError(config));

        String formName = form.getName();
        jsFormName = formName;
                if(jsFormName.charAt(0) == '/') {
                    String mappingName = TagUtils.getInstance().getActionMappingName(jsFormName);
                    ActionMapping mapping = (ActionMapping) config.findActionConfig(mappingName);
                    if (mapping == null) {
                        JspException e = new JspException(messages.getMessage("formTag.mapping", mappingName));
                        pageContext.setAttribute(Globals.EXCEPTION_KEY, e, PageContext.REQUEST_SCOPE);
                        throw e;
                    }