/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * 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
    * https://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.htmlunit.javascript.host.css;
  
  import java.io.IOException;
  import java.io.StringReader;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.corejs.javascript.VarScope;
  import org.htmlunit.css.CssStyleSheet;
  import org.htmlunit.cssparser.dom.AbstractCSSRuleImpl;
  import org.htmlunit.cssparser.dom.CSSCharsetRuleImpl;
  import org.htmlunit.cssparser.dom.CSSRuleListImpl;
  import org.htmlunit.cssparser.parser.InputSource;
  import org.htmlunit.javascript.JavaScriptEngine;
  import org.htmlunit.javascript.configuration.JsxClass;
  import org.htmlunit.javascript.configuration.JsxConstructor;
  import org.htmlunit.javascript.configuration.JsxFunction;
  import org.htmlunit.javascript.configuration.JsxGetter;
  import org.htmlunit.javascript.host.html.HTMLElement;
  import org.w3c.dom.DOMException;
  
  /**
   * A JavaScript object for {@code CSSStyleSheet}.
   *
   * @see <a href="http://msdn2.microsoft.com/en-us/library/ms535871.aspx">MSDN doc</a>
   * @author Marc Guillemot
   * @author Daniel Gredler
   * @author Ahmed Ashour
   * @author Ronald Brill
   * @author Guy Burton
   * @author Frank Danek
   * @author Carsten Steul
   */
  @JsxClass
  public class CSSStyleSheet extends StyleSheet {
  
      private static final Log LOG = LogFactory.getLog(CSSStyleSheet.class);
  
      /** The parsed stylesheet which this host object wraps. */
      private CssStyleSheet styleSheet_;
  
      /** The collection of rules defined in this style sheet. */
      private CSSRuleList cssRules_;
      private List<Integer> cssRulesIndexFix_;
  
      /**
       * Creates a new empty stylesheet.
       */
      public CSSStyleSheet() {
          super(null);
          styleSheet_ = new CssStyleSheet(null, (InputSource) null, null);
      }
  
      /**
       * Creates a new empty stylesheet.
       */
      @Override
      @JsxConstructor
      public void jsConstructor() {
          super.jsConstructor();
          styleSheet_ = new CssStyleSheet(null, (InputSource) null, null);
      }
  
      /**
       * Creates a new stylesheet representing the CSS stylesheet for the specified input source.
       * @param element the owning node
       * @param source the input source which contains the CSS stylesheet which this stylesheet host object represents
       * @param uri this stylesheet's URI (used to resolved contained @import rules)
       */
      public CSSStyleSheet(final HTMLElement element, final InputSource source, final String uri) {
          super(element);
  
          setParentScope(getTopLevelScope(element.getParentScope()));
          setPrototype(getPrototype(CSSStyleSheet.class));
  
          styleSheet_ = new CssStyleSheet(element.getDomNodeOrDie(), source, uri);
      }
  
      /**
       * Creates a new stylesheet representing the CSS stylesheet for the specified input source.
       * @param element the owning node
       * @param styleSheet the source which contains the CSS stylesheet which this stylesheet host object represents
       * @param uri this stylesheet's URI (used to resolved contained @import rules)
      */
     public CSSStyleSheet(final HTMLElement element, final String styleSheet, final String uri) {
         super(element);
 
         CssStyleSheet css = null;
         try (InputSource source = new InputSource(new StringReader(styleSheet))) {
             css = new CssStyleSheet(element.getDomNodeOrDie(), source, uri);
         }
         catch (final IOException e) {
             LOG.error(e.getMessage(), e);
         }
 
         setParentScope(element.getParentScope());
         setPrototype(getPrototype(CSSStyleSheet.class));
 
         styleSheet_ = css;
     }
 
     /**
      * Creates a new stylesheet representing the specified CSS stylesheet.
      * @param element the owning node
      * @param parentScope the parent scope
      * @param cssStyleSheet the CSS stylesheet which this stylesheet host object represents
      */
     public CSSStyleSheet(final HTMLElement element, final VarScope parentScope,
             final CssStyleSheet cssStyleSheet) {
         super(element);
 
         setParentScope(parentScope);
         setPrototype(getPrototype(CSSStyleSheet.class));
         styleSheet_ = cssStyleSheet;
     }
 
     /**
      * Returns the wrapped stylesheet.
      * @return the wrapped stylesheet
      */
     public CssStyleSheet getCssStyleSheet() {
         return styleSheet_;
     }
 
     /**
      * Retrieves the collection of rules defined in this style sheet.
      * @return the collection of rules defined in this style sheet
      */
     @JsxGetter
     public CSSRuleList getRules() {
         return getCssRules();
     }
 
     /**
      * Returns the collection of rules defined in this style sheet.
      * @return the collection of rules defined in this style sheet
      */
     @JsxGetter
     public CSSRuleList getCssRules() {
         initCssRules();
         return cssRules_;
     }
 
     /**
      * Inserts a new rule.
      * @param rule the CSS rule
      * @param position the position at which to insert the rule
      * @see <a href="http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-CSSStyleSheet">DOM level 2</a>
      * @return the position of the inserted rule
      */
     @JsxFunction
     public int insertRule(final String rule, final int position) {
         try {
             initCssRules();
             getCssStyleSheet().getWrappedSheet().insertRule(rule, fixIndex(position));
             refreshCssRules();
             return position;
         }
         catch (final DOMException e) {
             // in case of error try with an empty rule
             final int pos = rule.indexOf('{');
             if (pos > -1) {
                 final String newRule = rule.substring(0, pos) + "{}";
                 try {
                     getCssStyleSheet().getWrappedSheet().insertRule(newRule, fixIndex(position));
                     refreshCssRules();
                     return position;
                 }
                 catch (final DOMException ex) {
                     throw JavaScriptEngine.asJavaScriptException(getWindow(), ex.getMessage(), ex.code);
                 }
             }
             throw JavaScriptEngine.asJavaScriptException(getWindow(), e.getMessage(), e.code);
         }
     }
 
     private void refreshCssRules() {
         if (cssRules_ == null) {
             return;
         }
 
         cssRules_.clearRules();
         cssRulesIndexFix_.clear();
 
         final CSSRuleListImpl ruleList = getCssStyleSheet().getWrappedSheet().getCssRules();
         final List<AbstractCSSRuleImpl> rules = ruleList.getRules();
         int pos = 0;
         for (final AbstractCSSRuleImpl rule : rules) {
             if (rule instanceof CSSCharsetRuleImpl) {
                 cssRulesIndexFix_.add(pos);
                 continue;
             }
 
             final CSSRule cssRule = CSSRule.create(this, rule);
             if (null == cssRule) {
                 cssRulesIndexFix_.add(pos);
             }
             else {
                 cssRules_.addRule(cssRule);
             }
             pos++;
         }
 
         // reset our index also
         getCssStyleSheet().getWrappedSheet().resetRuleIndex();
     }
 
     private int fixIndex(int index) {
         for (final int fix : cssRulesIndexFix_) {
             if (fix > index) {
                 return index;
             }
             index++;
         }
         return index;
     }
 
     /**
      * Deletes an existing rule.
      * @param position the position of the rule to be deleted
      * @see <a href="http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-CSSStyleSheet">DOM level 2</a>
      */
     @JsxFunction
     public void deleteRule(final int position) {
         try {
             initCssRules();
             getCssStyleSheet().getWrappedSheet().deleteRule(fixIndex(position));
             refreshCssRules();
         }
         catch (final DOMException e) {
             throw JavaScriptEngine.asJavaScriptException(getWindow(), e.getMessage(), e.code);
         }
     }
 
     /**
      * Adds a new rule.
      * @see <a href="http://msdn.microsoft.com/en-us/library/aa358796.aspx">MSDN</a>
      * @param selector the selector name
      * @param rule the rule
      * @return always return -1 as of MSDN documentation
      */
     @JsxFunction
     public int addRule(final String selector, final String rule) {
         String completeRule = selector + " {" + rule + "}";
         try {
             initCssRules();
             getCssStyleSheet().getWrappedSheet().insertRule(completeRule,
                     getCssStyleSheet().getWrappedSheet().getCssRules().getLength());
             refreshCssRules();
         }
         catch (final DOMException e) {
             // in case of error try with an empty rule
             completeRule = selector + " {}";
             try {
                 getCssStyleSheet().getWrappedSheet().insertRule(completeRule,
                         getCssStyleSheet().getWrappedSheet().getCssRules().getLength());
                 refreshCssRules();
             }
             catch (final DOMException ex) {
                 throw JavaScriptEngine.asJavaScriptException(getWindow(), ex.getMessage(), ex.code);
             }
         }
         return -1;
     }
 
     /**
      * Deletes an existing rule.
      * @param position the position of the rule to be deleted
      * @see <a href="http://msdn.microsoft.com/en-us/library/ms531195(v=VS.85).aspx">MSDN</a>
      */
     @JsxFunction
     public void removeRule(final int position) {
         try {
             initCssRules();
             getCssStyleSheet().getWrappedSheet().deleteRule(fixIndex(position));
             refreshCssRules();
         }
         catch (final DOMException e) {
             throw JavaScriptEngine.throwAsScriptRuntimeEx(e);
         }
     }
 
     /**
      * Returns this stylesheet's URI (used to resolved contained @import rules).
      * For inline styles this is the page uri.
      * @return this stylesheet's URI (used to resolved contained @import rules)
      */
     @Override
     public String getUri() {
         return getCssStyleSheet().getUri();
     }
 
     private void initCssRules() {
         if (cssRules_ == null) {
             cssRules_ = new CSSRuleList(this);
             cssRulesIndexFix_ = new ArrayList<>();
             refreshCssRules();
         }
     }
 }