/*
******************************************************************************
* Copyright (C) 2007, International Business Machines Corporation and   *
* others. All Rights Reserved.                                               *
******************************************************************************
*/

package com.ibm.icu.impl.duration.impl;

import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;

import com.ibm.icu.lang.UCharacter;

public class XMLRecordWriter implements RecordWriter {
  private Writer w;
  private List nameStack;

  public XMLRecordWriter(Writer w) {
    this.w = w;
    this.nameStack = new ArrayList();
  }

  public boolean open(String title) {
    newline();
    writeString("<" + title + ">");
    nameStack.add(title);
    return true;
  }

  public boolean close() {
    int ix = nameStack.size() - 1;
    if (ix >= 0) {
      String name = (String) nameStack.remove(ix);
      newline();
      writeString("</" + name + ">");
      return true;
    }
    return false;
  }

  public void flush() {
    try {
      w.flush();
    }
    catch (IOException e) {
    }
  }

  public void bool(String name, boolean value) {
    internalString(name, String.valueOf(value));
  }

  public void boolArray(String name, boolean[] values) {
    if (values != null) {
      String[] stringValues = new String[values.length];
      for (int i = 0; i < values.length; ++i) {
        stringValues[i] = String.valueOf(values[i]);
      }
      stringArray(name, stringValues);
    }
  }

  private static String ctos(char value) {
    if (value == '<') {
      return "&lt;";
    }
    if (value == '&') {
      return "&amp;";
    }
    return String.valueOf(value);
  }

  public void character(String name, char value) {
    if (value != '\uffff') {
      internalString(name, ctos(value));
    }
  }

  public void characterArray(String name, char[] values) {
    if (values != null) {
      String[] stringValues = new String[values.length];
      for (int i = 0; i < values.length; ++i) {
        char value = values[i];
        if (value == '\uffff') {
          stringValues[i] = NULL_NAME;
        } else {
          stringValues[i] = ctos(value);
        }
      }
      internalStringArray(name, stringValues);
    }
  }

  public void namedIndex(String name, String[] names, int value) {
    if (value >= 0) {
      internalString(name, names[value]);
    }
  }

  public void namedIndexArray(String name, String[] names, byte[] values) {
    if (values != null) {
      String[] stringValues = new String[values.length];
      for (int i = 0; i < values.length; ++i) {
        int value = values[i];
        if (value < 0) {
          stringValues[i] = NULL_NAME;
        } else {
          stringValues[i] = names[value];
        }
      }
      internalStringArray(name, stringValues);
    }
  }

  public static String normalize(String str) {
    if (str == null) {
      return null;
    }
    StringBuffer sb = null;
    boolean inWhitespace = false;
    char c = '\0';
    boolean special = false;
    for (int i = 0; i < str.length(); ++i) {
      c = str.charAt(i);
      if (UCharacter.isWhitespace(c)) {
        if (sb == null && (inWhitespace || c != ' ')) {
          sb = new StringBuffer(str.substring(0, i));
        }
        if (inWhitespace) {
          continue;
        }
        inWhitespace = true;
        special = false;
        c = ' ';
      } else {
        inWhitespace = false;
        special = c == '<' || c == '&';
        if (special && sb == null) {
          sb = new StringBuffer(str.substring(0, i));
        }
      }
      if (sb != null) {
        if (special) {
          sb.append(c == '<' ? "&lt;" : "&amp;");
        } else {
          sb.append(c);
        }
      }
    }
    if (sb != null) {
      /*
      if (c == ' ') {
        int len = sb.length();
        if (len == 0) {
          return " ";
        }
        if (len > 1 && c == ' ') {
          sb.deleteCharAt(len - 1);
        }
      }
      */
      return sb.toString();
    }
    return str;
  }

  private void internalString(String name, String normalizedValue) {
    if (normalizedValue != null) {
      newline();
      writeString("<" + name + ">" + normalizedValue + "</" + name + ">");
    }
  }

  private void internalStringArray(String name, String[] normalizedValues) {
    if (normalizedValues != null) {
      push(name + "List");
      for (int i = 0; i < normalizedValues.length; ++i) {
        String value = normalizedValues[i];
        if (value == null) {
          value = NULL_NAME;
        }
        string(name, value);
      }
      pop();
    }
  }
    
  public void string(String name, String value) {
    internalString(name, normalize(value));
  }

  public void stringArray(String name, String[] values) {
    if (values != null) {
      push(name + "List");
      for (int i = 0; i < values.length; ++i) {
        String value = normalize(values[i]);
        if (value == null) {
          value = NULL_NAME;
        }
        internalString(name, value);
      }
      pop();
    }
  }

  public void stringTable(String name, String[][] values) {
    if (values != null) {
      push(name + "Table");
      for (int i = 0; i < values.length; ++i) {
        String[] rowValues = values[i];
        if (rowValues == null) {
          internalString(name + "List", NULL_NAME);
        } else {
          stringArray(name, rowValues);
        }
      }
      pop();
    }
  }

  private void push(String name) {
    newline();
    writeString("<" + name + ">");
    nameStack.add(name);
  }

  private void pop() {
    int ix = nameStack.size() - 1;
    String name = (String) nameStack.remove(ix);
    newline();
    writeString("</" + name + ">");
  }

  private void newline() {
      writeString("\n");
      for (int i = 0; i < nameStack.size(); ++i) {
        writeString(INDENT);
      }
  }

  private void writeString(String str) {
    if (w != null) {
      try {
        w.write(str);
      }
      catch (IOException e) {
        // if there's a problem, record it and stop writing
        System.err.println(e.getMessage());
        w = null;
      }
    }
  }

  static final String NULL_NAME = "Null";
  private static final String INDENT = "    ";
}