/*
    *    Copyright 2012-2022 the original author or authors.
    *
    *    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.mybatis.scripting.velocity;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.Locale;
  
  import org.apache.velocity.context.InternalContextAdapter;
  import org.apache.velocity.runtime.directive.Directive;
  import org.apache.velocity.runtime.parser.node.ASTBlock;
  import org.apache.velocity.runtime.parser.node.Node;
  
  public class TrimDirective extends Directive {
  
    @Override
    public String getName() {
      return "trim";
    }
  
    @Override
    public final int getType() {
      return BLOCK;
    }
  
    @Override
    public final boolean render(InternalContextAdapter ica, Writer writer, Node node) throws IOException {
      Params p = getParams(ica, node);
      if (p == null) {
        return false;
      }
      return render(p, writer);
    }
  
    public boolean render(final Params params, final Writer writer) throws IOException {
      int leftIndex = 0;
      int rightIndex = params.maxBody;
      if (rightIndex == 0) {
        return false;
      }
      if (!params.prefixOverrides.isEmpty()) {
        final String LEFT = params.body
            .substring(0, params.maxPrefixLength < params.maxBody ? params.maxPrefixLength : params.maxBody)
            .toUpperCase(Locale.ENGLISH);
        FastLinkedList<String>.Node n = params.prefixOverrides.start();
        while (n != null) {
          if (LEFT.startsWith(n.data)) {
            leftIndex = n.data.length();
            break;
          }
          n = n.next;
        }
      }
      if (!params.suffixOverrides.isEmpty()) {
        final String RIGHT = params.body
            .substring(rightIndex > params.maxSuffixLength ? rightIndex - params.maxSuffixLength : 0)
            .toUpperCase(Locale.ENGLISH);
        FastLinkedList<String>.Node n = params.suffixOverrides.start();
        while (n != null) {
          if (RIGHT.endsWith(n.data)) {
            rightIndex = rightIndex - n.data.length();
            break;
          }
          n = n.next;
        }
      }
      if (rightIndex > leftIndex) {
        String content = params.body.substring(leftIndex, rightIndex).trim();
        if (!"".equals(content)) {
          writer.append(params.prefix).append(' ');
          writer.append(params.body, leftIndex, rightIndex).append(' ');
          writer.append(params.suffix);
        }
      }
      return true;
    }
  
    protected static final class Params {
  
      String prefix = "";
  
      String suffix = "";
  
      FastLinkedList<String> prefixOverrides = new FastLinkedList<>();
  
     FastLinkedList<String> suffixOverrides = new FastLinkedList<>();
 
     String body = "";
 
     int maxPrefixLength = 0;
 
     int maxSuffixLength = 0;
 
     int maxBody = 0;
 
     public String getBody() {
       return this.body;
     }
 
     public void setBody(String value) {
       if (value == null) {
         this.body = "";
       } else {
         this.body = value.trim();
       }
       this.maxBody = this.body.length();
     }
 
     public String getPrefix() {
       return this.prefix;
     }
 
     public void setPrefix(String value) {
       this.prefix = value;
     }
 
     public FastLinkedList<String> getPrefixOverrides() {
       return this.prefixOverrides;
     }
 
     public void setPrefixOverrides(String list) {
       this.maxPrefixLength = fromStringList(list, '|', this.prefixOverrides);
     }
 
     public FastLinkedList<String> getSuffixOverrides() {
       return this.suffixOverrides;
     }
 
     public void setSuffixOverrides(String list) {
       this.maxSuffixLength = fromStringList(list, '|', this.suffixOverrides);
     }
 
     public String getSuffix() {
       return this.suffix;
     }
 
     public void setSuffix(String value) {
       this.suffix = value;
     }
 
   }
 
   protected Params getParams(final InternalContextAdapter context, final Node node) throws IOException {
     final Params params = new Params();
     final int nodes = node.jjtGetNumChildren();
     for (int i = 0; i < nodes; i++) {
       Node child = node.jjtGetChild(i);
       if (child != null) {
         if (!(child instanceof ASTBlock)) {
           if (i == 0) {
             params.setPrefix(String.valueOf(child.value(context)));
           } else if (i == 1) {
             params.setPrefixOverrides(String.valueOf(child.value(context)).toUpperCase(Locale.ENGLISH));
           } else if (i == 2) {
             params.setSuffix(String.valueOf(child.value(context)));
           } else if (i == 3) {
             params.setSuffixOverrides(String.valueOf(child.value(context)).toUpperCase(Locale.ENGLISH));
           } else {
             break;
           }
         } else {
           StringWriter blockContent = new StringWriter();
           child.render(context, blockContent);
           params.setBody(blockContent.toString().trim());
           break;
         }
       }
     }
     return params;
   }
 
   static int fromStringList(final String list, final char sep, final FastLinkedList<String> fll) {
     int max = 0;
     if (list != null) {
       final int n = list.length();
       int i = 0;
       while (i < n) {
         int r = list.indexOf(sep, i);
         if (i < r) {
           fll.add(list.substring(i, r));
           int len = r - i;
           if (len > max) {
             max = len;
           }
           i = r + 1;
         } else {
           break;
         }
       }
       if (i < n) {
         fll.add(list.substring(i));
         int len = n - i;
         if (len > max) {
           max = len;
         }
       }
     }
     return max;
   }
 
 }