/*
    * 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.devacfr.maven.skins.reflow.snippet;
  
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Iterator;
  
  import org.devacfr.maven.skins.reflow.ISkinConfig;
  import org.devacfr.maven.skins.reflow.snippet.Processor.ShortcodeProcessor;
  import org.devacfr.maven.skins.reflow.snippet.Processor.WebComponentProcessor;
  import org.jsoup.Jsoup;
  import org.jsoup.nodes.Document;
  import org.jsoup.nodes.Element;
  import org.jsoup.select.Elements;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * @author Christophe Friederich
   * @version 2.4
   */
  public class SnippetParser {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(SnippetParser.class);
  
      /** */
      private final ComponentResolver resolver;
  
      /** */
      private final ArrayList<ComponentToken> stack;
  
      /** */
      private Iterator<Element> it;
  
      /** */
      private Processor state = null;
  
      /** */
      private final WebComponentProcessor webComponentProcessor;
  
      /** */
      private final ShortcodeProcessor shortcodeProcessor;
  
      /** */
      private final SnippetContext snippetContext;
  
      /** */
      private ComponentToken currentToken;
  
      public SnippetParser() {
          resolver = new ComponentResolver();
          stack = new ArrayList<>(32);
          snippetContext = new SnippetContext(this);
          webComponentProcessor = new WebComponentProcessor(this);
          shortcodeProcessor = new ShortcodeProcessor(this);
      }
  
      public SnippetParser insertResourcePath(final String path, final int index) {
          snippetContext.insertResourcePath(path, index);
          return this;
      }
  
      public SnippetParser addResourcePath(final String path) {
          snippetContext.addResourcePath(path);
          return this;
      }
  
      public SnippetContext parse(@Nonnull final ISkinConfig config, @Nullable String htmlSource)
              throws IOException {
          requireNonNull(config);
          if (htmlSource == null) {
              htmlSource = "";
          }
  
          snippetContext.reset();
          snippetContext.setConfig(config);
  
         if (LOGGER.isDebugEnabled()) {
             LOGGER.debug("Parse Snippet");
             LOGGER.debug(htmlSource);
         }
 
         // find all snippets
         final Document doc = resolver.normalize(Jsoup.parse(htmlSource));
 
         final Elements elements = resolver.collect(doc);
 
         for (it = elements.iterator(); it.hasNext();) {
             try {
                 parse();
             } catch (final Exception ex) {
                 throw new SnippetParseException(
                         "error on parse token " + currentToken + " when generate file " + config.getFileId(), ex);
             }
         }
         snippetContext.setHtmlSource(doc.html());
         return snippetContext;
     }
 
     protected void parse() {
         if (!it.hasNext()) {
             throw new SnippetParseException("EOF");
         }
         final Element element = it.next();
         currentToken = resolver.create(element);
         if (currentToken == null) {
             throw new SnippetParseException("unknown component: " + element);
         }
         switch (currentToken.type()) {
             case webComponent:
                 state = webComponentProcessor;
                 break;
             case shortcode:
                 state = shortcodeProcessor;
                 break;
             default:
                 throw new SnippetParseException("unknown token type " + currentToken.type());
         }
         parse(currentToken);
         currentToken = null;
     }
 
     protected void parse(final ComponentToken token) {
         state.parse(token);
     }
 
     protected ComponentToken currentToken() {
         final int size = stack.size();
         return size > 0 ? stack.get(size - 1) : null;
     }
 
     protected ComponentToken pop() {
         final int size = stack.size();
         if (LOGGER.isDebugEnabled()) {
             LOGGER.debug("Stack size befor pop: {}", size);
         }
         final ComponentToken element = stack.remove(size - 1);
         if (LOGGER.isDebugEnabled()) {
             LOGGER.debug("Remove component from stack: {}", element);
         }
         return element;
     }
 
     protected void push(final ComponentToken element) {
         stack.add(element);
         if (LOGGER.isDebugEnabled()) {
             LOGGER.debug("Add component to stack: {}", element);
         }
     }
 
     protected SnippetContext getSnippetContext() {
         return snippetContext;
     }
 }