// Copyright (c) 2001 Hursh Jain (http://www.mollypages.org) 
// The Molly framework is freely distributable under the terms of an
// MIT-style license. For details, see the molly pages web site at:
// http://www.mollypages.org/. Use, modify, have fun !

package fc.util;

import fc.io.*;
import fc.util.*;

import java.util.*;
import java.lang.reflect.*;

/**  
Makes creating <tt>toString</tt> methods easier. (For example, 
provides ability to introspect and write field values). Idea
inspired by a similar apache/jakarta utility.
<p>
Methods of the form append(String, type) imply the name 
specified by the string (typically a field name) is shown
with value specified by type.
<p>
Example usage:<br>
<tt>foo</tt> and <tt>bar</tt> are fields of this object.
<blockquote>
<pre>
public String toString() {
  return new ToString(this).
    <font color="blue">append</font>("foo","some-value").
    <font color="blue">append</font>("bar",123).
    <font color="blue">render</font>();
  }
</pre>
</blockquote>
Another example:<br>
Automatically prints this entire object using reflection.
<blockquote>
<pre>
public String toString() {
  return new ToString(this).<font color="blue">reflect</font>().
  <font color="blue">render</font>();
  }
</pre>
</blockquote>
<i><b>Note</b>: Don't forget the <tt>render()</tt> call at the end.</i>
<p>
The class only needs to be instantiated once so here's a more
efficient approach:
<blockquote>
<pre>
{ //instance initializer
ToString tostr = new ToString(this);
}
public String toString() {
  return tostr.<font color="blue">reflect</font>().
  <font color="blue">render</font>();
  }
</pre>
</blockquote>
<p>

@author hursh jain
**/
public class ToString 
{
private static  final boolean dbg      = false;
private static      Style   defaultStyle = new Style();

Object      client;
Style     style;
StringBuffer  result;
boolean     firstFieldDone;

/**  
Creates a ToString for the specified object, using the
default {@link ToString.Style}.
**/
public ToString(Object obj) {
  this(obj, (Style)null);
  }

/**  
Creates a ToString for the specified object using the
specified style
@param  obj   the target object
@param  style the formatting style
**/
public ToString(Object obj, Style style) 
  {
  Argcheck.notnull(obj, "target object cannot be null");
  client = obj;
  
  if (style == null)
    this.style = defaultStyle;
  else
    this.style = style;
    
  result = new StringBuffer();
  }

/**  
Creates a ToString for the specified object with the
specified visibility level.

@param  obj   the target object
@param  style the formatting style
**/
public ToString(Object obj, Style.VisibleLevel level) 
  {
  Argcheck.notnull(obj, "target object cannot be null");
  client = obj;
  this.style = defaultStyle;
  this.style.reflectVisibleLevel = level;
  result = new StringBuffer();
  }


/** 
Returns the default style object. Changes to this will affect
the default formatting
**/ 
public static ToString.Style getDefaultStyle() 
  {
    return defaultStyle;
    }
   
/** 
Sets the style object to use as the default. This style will
be used by default by all new instances of ToString.

@param   style  the default style
**/
public static void setDefaultStyle(ToString.Style style) 
  {
  Argcheck.notnull(style, "style cannot be null");
  defaultStyle = style;
    } 

/** 
Returns the style being currently used by this instance. 
Modifications to this style this will affect rendering
output appropriately.
**/
public ToString.Style getStyle() {
  return style;
  }
  

/** Returns the internal buffer used to create the string **/
public StringBuffer getBuffer() {
  return result;
  }

/** 
Uses reflection to get the contents of the object. Reflection
does not expand and print all the array values even if the
current style's {@link ToString.Style#expandArray expandArray}
is set to true. To print all array values, use the
<tt>append</tt> methods.
**/
public ToString reflect() 
  {
  try {
    reflectImpl(client, client.getClass());
    }
  catch (IllegalAccessException e) {
    result.append("Cannot convert to string using reflection");
    result.append(e.toString());
    }
  return this;
  }
  
void reflectImpl(Object obj, Class clazz) 
throws IllegalAccessException
  {
  if (dbg) System.out.println("reflectImpl("+clazz+")");
  
  Field[] fields = clazz.getDeclaredFields();
  
  if (dbg) System.out.println("got declared fields: " + Arrays.asList(fields));
  
  //need this call, otherwise getting the fields does not work
  Field.setAccessible(fields, true);
  
  for(int n = 0; n < fields.length; n++) 
    {
    //if (dbg) System.out.println("declaredField["+n+"]; '"+fields[n].getName()+"'="+fields[n].get(obj));   
    
    Field f = fields[n];
    int mod = f.getModifiers();

    if (dbg) System.out.println(f.getName() +" modifier="+mod);

    if (! style.reflectStatics && Modifier.isStatic(mod)) {
      if (dbg) System.out.println("reflectStatics = false, ignoring static field: " + f.getName());
      continue;
      }
    
    boolean defaultVis = ! (Modifier.isPublic(mod) 
        || Modifier.isProtected(mod) 
        || Modifier.isPrivate(mod));
          

    if (style.ignoredFieldNames.contains(f.getName().toLowerCase())) {
      if (dbg) System.out.println("ignoring: " + f.getName() + " [in ingorelist]");     
      continue;
      }

    if (style.reflectVisibleLevel==Style.VisibleLevel.PUBLIC)
      {
      if (Modifier.isPublic(mod)) { 
        append(f.getName(), f.get(obj));
        } 
      }
    else if (style.reflectVisibleLevel==Style.VisibleLevel.PROTECTED)
      {
      if (Modifier.isPublic(mod) || Modifier.isProtected(mod)) {
        append(f.getName(), f.get(obj));
        }     
      }
    else if (style.reflectVisibleLevel==Style.VisibleLevel.DEFAULT)
      {
      if (Modifier.isPublic(mod) || Modifier.isProtected(mod)
          || defaultVis) {
        append(f.getName(), f.get(obj));
        }     
      }     
    else if (style.reflectVisibleLevel==Style.VisibleLevel.PRIVATE)
      {
      if (Modifier.isPublic(mod) || Modifier.isProtected(mod)
          || Modifier.isPrivate(mod) || defaultVis) {
        append(f.getName(), f.get(obj));
        }     
      }
    else
      {
      System.out.println("ERROR in ToString().reflecImpl(), this should not happen, toString won't be accurate");
      }
      
    if (dbg) System.out.println("buf=>>"+result+"<<");
    } //~for 

  if (style.reflectSuperClass) {
    Class superclazz = clazz.getSuperclass();
    if (superclazz != null && superclazz != Object.class)
      reflectImpl(obj, superclazz);
    }
  
  } //reflectImpl


void doStart(StringBuffer buf)
  {
  buf.append(style.startString);

  Class clazz = client.getClass();
  String name = clazz.getName();
  
  if (style.className)
    {
    if (style.fullClassName) {
      buf.append(name);
      }
    else {
      int last = name.lastIndexOf(".");
      last = (last < 0) ? 0 : last + 1; //+1 to skip '.' itself
      buf.append( name.substring(last, name.length()) );
      }
    }
    
  if (style.idHashCode) {
    buf.append("@");
    buf.append(System.identityHashCode(client));
    } 

  buf.append(style.startContent);
  }

void doEnd(StringBuffer buf) {
  buf.append(style.endContent);
  buf.append(style.endString); 
  }

/** Renders the string **/
public String render() 
  {
  StringBuffer finalResult = new StringBuffer(result.length() + 128);
  doStart(finalResult);
  finalResult.append(result);
  doEnd(finalResult); 
  return finalResult.toString();
  }

/** 
Returns information about the current state of the ToString
object itself. To get the target object's string, use the
{@link render} method.
**/
public String toString() 
  {
  return getClass().getName() + "; using: " + style;
  }
  
/** Unit test **/
public static void main(String[] args)
  { 
  System.out.println("=== Test using reflection ===");
  
  Style style = null;
  
  style = new Style();
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.PUBLIC;
  style.reflectStatics = true;
  System.out.println("public fields [including statics]");
  System.out.println(new TestClass(style, true));
  System.out.println("");
    
  style = new Style(); 
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.PUBLIC;
  System.out.println("public fields only");
  System.out.println(new TestClass(style, true));
  System.out.println("");

  style = new Style(); 
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.PUBLIC;
  style.idHashCode = false;
  style.className = false;
  System.out.println("public fields only, no id ref or class name");
  System.out.println(new TestClass(style, true));
  System.out.println("");
  
  style = new Style();
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.PROTECTED;
  System.out.println("protected and higher");
  System.out.println(new TestClass(style, true));
  System.out.println("");
  
  style = new Style();
  style.ignoreFieldName("style");
  style.reflectStatics = true;
  style.reflectVisibleLevel = Style.VisibleLevel.DEFAULT;
  System.out.println("package and higher [including statics]");
  System.out.println(new TestClass(style, true));
  System.out.println("");

  style = new Style();
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.DEFAULT;
  style.expandArrays = true;
  System.out.println("package and higher fields, arrays EXPANDED");
  System.out.println(new TestClass(style, true));
  System.out.println("");
  
  style = new Style();
  style.ignoreFieldName("style");
  style.reflectVisibleLevel = Style.VisibleLevel.PRIVATE;
  System.out.println("private (all) fields");
  System.out.println(new TestClass(style, true));
  System.out.println("");
  
  style = new Style();  
  style.ignoreFieldName("style");
  System.out.println("default style output");
  System.out.println(new TestClass(style, true));
  System.out.println("");
  
  System.out.println("==== Test without reflection ====");
  style = new Style();  
  System.out.println(new TestClass(style, false));
  System.out.println("");
  
  System.out.println("With no field names");
  style = new Style();  
  style.fieldName = false;
  System.out.println(new TestClass(style, false));
  System.out.println("");
  
  style = new Style();  
  style.reflectVisibleLevel = Style.VisibleLevel.DEFAULT;
  style.expandArrays = true;
  System.out.println("Expanded arrays");
  System.out.println(new TestClass(style, false));
  System.out.println("");
  }

private static class TestClass 
{
private Style   style;
private boolean useReflection;

TestClass(Style style, boolean useReflection) { 
  this.style = style; 
  this.useReflection = useReflection;
  }

static int staticInt = 10;
public  static String staticString = "staticString";
      
public    String   pubString    = "publicString";
protected   String   protectedString = "protectedString";
      String   defString    = "defaultString";
      int[]    intArray   = new int[] { 1, 2, 3};
      double[] doubleArray  = new double[] {1.3, 2.6, 3.9};
      Object[] objectArray  = new Object[] { null, new Object() };
      List   someList   = new ArrayList();
private   String   privateString  = "privateStrng";       

public String toString() 
  {
  if (useReflection)
    return new ToString(this, style).reflect().render();
  else {
    return new ToString(this, style).
      append("intArray", intArray).
      append("doubleArray", doubleArray).
      append("pubString", pubString).render();
    }
  }
} //~TestClass


/** 
Drives the formatting behavior. Behavior different than 
the defaults can be achieved by instantiating a new object
and setting it's properties appropriately.
**/
public static class Style 
  { 
  private List ignoredFieldNames = new ArrayList();

  /**
  Case insensitive field names that will be ignored (for example a
  public field "foo" may be printed otherwise, but if added to this
  list, it would be ignored). Use this method to add as many
  field names as needed.
  **/
  public void ignoreFieldName(String name) {
    ignoredFieldNames.add(name.toLowerCase());
    }
  
  /**
   The start of the entire string. default to empty: <tt>""</tt> 
  **/
  public String startString =     "";

  /** 
  The end of the entire string. default to empty: <tt>""</tt> 
  **/
  public String endString =       ""        ;

  /** 
  The start of the string <b>after</b> the object classname and
  identity reference. default: <tt>[</tt> 
  **/
  public String startContent =    "["       ;

  /** 
  The end of the string <b>after</b> the object classname and
  identity reference. default: <tt>]</tt> 
  **/
  public String endContent =      "]";

  /** default: <tt>=</tt> **/
  public String fieldAndValSep =    "=";

  /** default: <tt>,</tt> **/
  public String fieldSep =      ", ";

  /** default: <tt>{</tt> **/
  public String startArray =      "{";

  /** default: <tt>}</tt> **/
  public String endArray =      "}";

  /** default: <tt>,</tt> **/
  public String arrayValSep =     ",";
  
  /** 
  Expand array values, default: <tt>false</tt>. <bNote:</b> 
  expansion only works when arrays are manually added using
  one of the <tt>append(..)</tt> methods, not when using
  reflection.
  **/
  public boolean expandArrays = false;
  
  /** Print the field name ? default: <tt>true</tt>. If 
  field names are <b>not</b> printed, then neither is
  the {@link #FieldAndValSep} - only the value of a field
  is printed.
  **/
  public boolean fieldName = true;

  /** Print the class name at all ? default: <tt>true</tt> **/
  public boolean className = true;
  
  /** print full class name ? default: <tt>false</tt> **/
  public boolean fullClassName = false;
    
  /** print indentity hash code for the object ? default: <tt>true</tt> **/
  public boolean idHashCode =   true;
    
  /** print field names when using reflection ? default: <tt>true</tt>**/
  public boolean reflectFieldName = true;

  /** 
  Prints the superclass's variables when using reflection ? default: <tt>false</tt>
  **/
  public boolean reflectSuperClass = false;

  /** 
  Reflects static variables. By default this is <tt>false</tt> 
  since statics are not part of the object's instance-state.
  **/
  public boolean reflectStatics = false;

  /** 
  Default access level when using reflection (fields with
  this or looser access will be printed). default: PRIVATE (EVERYTHING
  IS PRINTED)
  **/
  public VisibleLevel reflectVisibleLevel = VisibleLevel.PRIVATE;
  
  public static final class VisibleLevel 
    {
    private VisibleLevel() { }
    public static VisibleLevel PUBLIC = new VisibleLevel ();
    public static VisibleLevel PROTECTED = new VisibleLevel ();
    public static VisibleLevel DEFAULT = new VisibleLevel ();
    public static VisibleLevel PRIVATE = new VisibleLevel ();
    }     
  
  public Style() { }
  public String toString() {
    return new ToString(this).reflect().render();  
    }
    
  } //~class Style


//==appends===========================================

/** 
Appends an arbitrary string to the result. This can be
used as a prologue, epilogue etc. 
**/
public ToString append(Object str) 
  {
  result.append(str);
  return this;
  }
  
public ToString append(String fieldName, Object val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);

  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    } 
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, String val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);

  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    } 
  result.append(val);

  firstFieldDone = true;
  return this;
    }

//Primitive Types
public ToString append(String fieldName, long val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, int val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, short val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, byte val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, double val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, float val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, char val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, boolean val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  result.append(val);
  
  firstFieldDone = true;
  return this;
    }

//Array types
public ToString append(String fieldName, Object[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, long[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, int[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, short[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, byte[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, char[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }
  
public ToString append(String fieldName, double[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }
  
public ToString append(String fieldName, float[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

public ToString append(String fieldName, boolean[] val) 
  {
  if (firstFieldDone)
    result.append(style.fieldSep);
    
  if (style.fieldName) { 
    result.append(fieldName);
    result.append(style.fieldAndValSep); 
    }
  
  if (style.expandArrays) 
    {
    result.append(style.startArray);
    for (int n = 0; n < val.length; n++) 
      {
      if (n != 0) 
        result.append(style.arrayValSep);
      result.append(val[n]);
      }
    result.append(style.endArray);
    }
  else
    result.append(val);

  firstFieldDone = true;
  return this;
    }

//==end appends============================================ 

}          //~class ToString