package net.sf.jasperreports.engine.util;

import java.awt.Color;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import net.sf.jasperreports.engine.JRExpression;

public class JRXmlWriteHelper {
  private final Writer writer;
  
  private final List indents;
  
  private int indent;
  
  private final List elementStack;
  
  private StringBuffer buffer;
  
  private StackElement lastElement;
  
  protected static class Attribute {
    String name;
    
    String value;
    
    Attribute(String name, String value) {
      this.name = name;
      this.value = value;
    }
  }
  
  protected static class StackElement {
    String name;
    
    List atts;
    
    boolean hasChildren;
    
    StackElement(String name) {
      this.name = name;
      this.atts = new ArrayList();
      this.hasChildren = false;
    }
    
    void addAttribute(String attName, String value) {
      this.atts.add(new JRXmlWriteHelper.Attribute(attName, value));
    }
  }
  
  public JRXmlWriteHelper(Writer writer) {
    this.writer = writer;
    this.indents = new ArrayList();
    this.indent = 0;
    this.elementStack = new ArrayList();
    this.lastElement = null;
    clearBuffer();
  }
  
  public void writeProlog(String encoding) throws IOException {
    this.writer.write("<?xml version=\"1.0\" encoding=\"" + encoding + "\"?>\n");
  }
  
  public void writePublicDoctype(String rootElement, String description, String dtdLocation) throws IOException {
    this.writer.write("<!DOCTYPE " + rootElement + " PUBLIC \"" + description + "\" \"" + dtdLocation + "\">\n\n");
  }
  
  public void startElement(String name) {
    this.indent++;
    this.lastElement = new StackElement(name);
    this.elementStack.add(this.lastElement);
  }
  
  protected void writeParents(boolean content) throws IOException {
    int stackSize = this.elementStack.size();
    int startWrite = stackSize - 1;
    while (startWrite >= 0) {
      StackElement element = this.elementStack.get(startWrite);
      if (element.hasChildren)
        break; 
      if (startWrite < stackSize - 1) {
        element.hasChildren = true;
      } else {
        element.hasChildren |= content;
      } 
      startWrite--;
    } 
    for (int i = startWrite + 1; i < stackSize; i++) {
      StackElement element = this.elementStack.get(i);
      writeElementAttributes(element, i);
    } 
  }
  
  public void writeCDATA(String data) throws IOException {
    if (data != null) {
      writeParents(true);
      this.buffer.append(getIndent(this.indent));
      this.buffer.append("<![CDATA[");
      this.buffer.append(data);
      this.buffer.append("]]>\n");
      flushBuffer();
    } 
  }
  
  public void writeCDATAElement(String name, String data) throws IOException {
    if (data != null) {
      writeParents(true);
      this.buffer.append(getIndent(this.indent));
      this.buffer.append('<');
      this.buffer.append(name);
      this.buffer.append("><![CDATA[");
      this.buffer.append(data);
      this.buffer.append("]]></");
      this.buffer.append(name);
      this.buffer.append(">\n");
      flushBuffer();
    } 
  }
  
  public void writeCDATAElement(String name, String data, String attName, String attValue) throws IOException {
    writeCDATAElement(name, data, attName, attValue);
  }
  
  public void writeCDATAElement(String name, String data, String attName, Object attValue) throws IOException {
    if (data != null) {
      writeParents(true);
      this.buffer.append(getIndent(this.indent));
      this.buffer.append('<');
      this.buffer.append(name);
      if (attValue != null) {
        this.buffer.append(' ');
        this.buffer.append(attName);
        this.buffer.append("=\"");
        this.buffer.append(attValue);
        this.buffer.append("\"");
      } 
      this.buffer.append("><![CDATA[");
      this.buffer.append(data);
      this.buffer.append("]]></");
      this.buffer.append(name);
      this.buffer.append(">\n");
      flushBuffer();
    } 
  }
  
  protected void writeElementAttributes(StackElement element, int level) throws IOException {
    this.buffer.append(getIndent(level));
    this.buffer.append('<');
    this.buffer.append(element.name);
    for (Iterator i = element.atts.iterator(); i.hasNext(); ) {
      Attribute att = i.next();
      this.buffer.append(' ');
      this.buffer.append(att.name);
      this.buffer.append("=\"");
      this.buffer.append(att.value);
      this.buffer.append('"');
    } 
    if (element.hasChildren) {
      this.buffer.append(">\n");
    } else {
      this.buffer.append("/>\n");
    } 
    flushBuffer();
  }
  
  public void closeElement() throws IOException {
    closeElement(false);
  }
  
  public void closeElement(boolean skipIfEmpty) throws IOException {
    this.indent--;
    if (skipIfEmpty && this.lastElement.atts.size() == 0 && !this.lastElement.hasChildren) {
      clearBuffer();
    } else {
      writeParents(false);
      if (this.lastElement.hasChildren) {
        this.buffer.append(getIndent(this.indent));
        this.buffer.append("</");
        this.buffer.append(this.lastElement.name);
        this.buffer.append(">\n");
        flushBuffer();
      } 
    } 
    this.elementStack.remove(this.indent);
    this.lastElement = (this.indent > 0) ? this.elementStack.get(this.indent - 1) : null;
  }
  
  protected char[] getIndent(int level) {
    if (level >= this.indents.size())
      for (int i = this.indents.size(); i <= level; i++) {
        char[] str = new char[i];
        Arrays.fill(str, '\t');
        this.indents.add(str);
      }  
    return this.indents.get(level);
  }
  
  protected void flushBuffer() throws IOException {
    this.writer.write(this.buffer.toString());
    clearBuffer();
  }
  
  protected void clearBuffer() {
    this.buffer = new StringBuffer();
  }
  
  public void writeExpression(String name, JRExpression expression, boolean writeClass) throws IOException {
    writeExpression(name, expression, writeClass, null);
  }
  
  public void writeExpression(String name, JRExpression expression, boolean writeClass, String defaultClassName) throws IOException {
    if (expression != null)
      if (writeClass && (defaultClassName == null || !defaultClassName.equals(expression.getValueClassName()))) {
        writeCDATAElement(name, expression.getText(), "class", expression.getValueClassName());
      } else {
        writeCDATAElement(name, expression.getText());
      }  
  }
  
  protected void writeAttribute(String name, String value) {
    this.lastElement.addAttribute(name, value);
  }
  
  public void addAttribute(String name, String value) {
    if (value != null)
      writeAttribute(name, value); 
  }
  
  public void addEncodedAttribute(String name, String value) {
    if (value != null)
      writeAttribute(name, JRStringUtil.xmlEncode(value)); 
  }
  
  public void addAttribute(String name, String value, String defaultValue) {
    if (value != null && !value.equals(defaultValue))
      writeAttribute(name, value); 
  }
  
  public void addEncodedAttribute(String name, String value, String defaultValue) {
    if (value != null && !value.equals(defaultValue))
      writeAttribute(name, JRStringUtil.xmlEncode(value)); 
  }
  
  public void addAttribute(String name, Object value) {
    if (value != null)
      writeAttribute(name, String.valueOf(value)); 
  }
  
  public void addAttribute(String name, int value) {
    writeAttribute(name, String.valueOf(value));
  }
  
  public void addAttributePositive(String name, int value) {
    if (value > 0)
      writeAttribute(name, String.valueOf(value)); 
  }
  
  public void addAttribute(String name, float value) {
    writeAttribute(name, String.valueOf(value));
  }
  
  public void addAttribute(String name, float value, float defaultValue) {
    if (value != defaultValue)
      writeAttribute(name, String.valueOf(value)); 
  }
  
  public void addAttribute(String name, double value) {
    writeAttribute(name, String.valueOf(value));
  }
  
  public void addAttribute(String name, double value, double defaultValue) {
    if (value != defaultValue)
      writeAttribute(name, String.valueOf(value)); 
  }
  
  public void addAttribute(String name, int value, int defaultValue) {
    if (value != defaultValue)
      addAttribute(name, value); 
  }
  
  public void addAttribute(String name, boolean value) {
    writeAttribute(name, String.valueOf(value));
  }
  
  public void addAttribute(String name, boolean value, boolean defaultValue) {
    if (value != defaultValue)
      addAttribute(name, value); 
  }
  
  public void addAttribute(String name, Color color) {
    if (color != null)
      writeAttribute(name, "#" + JRColorUtil.getColorHexa(color)); 
  }
  
  public void addAttribute(String name, Color value, Color defaultValue) {
    if (value != null && value.getRGB() != defaultValue.getRGB())
      addAttribute(name, value); 
  }
  
  public void addAttribute(String name, byte value, Map xmlValues) {
    String xmlValue = (String)xmlValues.get(new Byte(value));
    writeAttribute(name, xmlValue);
  }
  
  public void addAttribute(String name, int value, Map xmlValues) {
    String xmlValue = (String)xmlValues.get(new Integer(value));
    writeAttribute(name, xmlValue);
  }
  
  public void addAttribute(String name, byte value, Map xmlValues, byte defaultValue) {
    if (value != defaultValue)
      addAttribute(name, value, xmlValues); 
  }
  
  public void addAttribute(String name, Object value, Map xmlValues) {
    if (value != null) {
      String xmlValue = (String)xmlValues.get(value);
      writeAttribute(name, xmlValue);
    } 
  }
  
  public void addAttribute(String name, Object value, Map xmlValues, Object defaultValue) {
    if (!value.equals(defaultValue))
      addAttribute(name, value, xmlValues); 
  }
}