package tester;

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

//import org.apache.log4j.Logger;

/**
 * Copyright 2007, 2008 Viera K. Proulx
 * This program is distributed under the terms of the 
 * GNU Lesser General Public License (LGPL)
 */

/**
 * This class leverages the use of the Java reflection classes to pretty-print
 * the values of an arbitrary object. It includes the values of user-defined
 * fields, but does not extend to fields inherited from Java library
 * superclasses.
 * 
 * @author Viera K. Proulx
 * @since 3 March 2008, 11 November 2008, 23 January 2009
 * 
 */
public class Printer {
	//private static final Logger logger = Logger
	//		.getLogger(Printer.class);
	/** current indentation level for pretty-printing */
	private static String INDENT = "";

	/** object counter */
	private static int counter;

	/**
	 * a hashmap of the hashcodes for the objects that are being printed: if the
	 * same pair is compared again, the loop of printing stops and produces true
	 */
	private static HashMap<Integer, Integer> hashmap = 
		new HashMap<Integer, Integer>();

	/**
	 * Print the values of the given object
	 * 
	 * @param obj the object to display in the console
	 */
	public static void print(Object obj) {
		hashmap.clear();
		counter = 0;
		System.out.println(makeString(obj));
	}

	/**
	 * Produce a <code>String</code> representation of the values 
	 * of the given object
	 * 
	 * @param obj the object to represent
	 * @return a <code>String</code> representation of the values 
	 *         of the given object
	 */
	public static String produceString(Object obj) {
		hashmap.clear();
		counter = 0;
		return makeString(obj);
	}
	
	/**
	 * Produce a <code>String</code> representation of the values 
	 * of the given object
	 * 
	 * @param it the object that produces the iterator to be used traverse data
	 * @return a <code>String</code> representation of the values 
	 *         of the given object
	 */
	 public static <T> String produceIterableStrings(Iterable<T> it) {
		hashmap.clear();
		counter = 0;
		return makeIterableStrings(it.iterator());
	}

		/**
		 * Produce a String representation of the values of the given object
		 * of the type Traversal
		 * 
		 * @param tr the <CODE>{@link Traversal Traversal}</CODE> iterator 
		 *           to be used traverse data
		 * @return a <code>String</code> representation of the values 
		 *         of the given object
		 */
		 public static <T> String produceTraversalStrings(Traversal<T> tr) {
			hashmap.clear();
			counter = 0;
			return makeTraversalStrings(tr);
		}	 
	 
	/**
	 * Produce a <code>String</code> representation of the given object.
	 * <P>Show <code>String</code> 'as is'.</P>
	 * <P>For primitive datatypes and their wrapper classes show the primitive
	 * values.</P>
	 * <P>For all <code>Array</code>s traverse over all elements.</P>
	 * <P>For datatypes that implement <code>Iterable</code> interface traverse
	 * over all elements.</P>
	 * <P>For datatypes that implement <CODE>{@link Traversal Traversal}</CODE>
	 * interface traverse over all elements.</P>
	 * <P>For an instance of a declared class show all fields</P>
	 * 
	 * @param obj the given object
	 */
	private static String makeString(Object obj) {

		// if the object is null, we are done
		if (obj == null)
			return "null";

		// if the object is a String already - show it
		if (obj instanceof java.lang.String)
		  return " \"" + obj.toString() + "\"";

		// if the object is an instance of Random - show it
		if (obj instanceof java.util.Random)
		  return " new Random() ";

		// if the object is a Color object already - show it
		if (obj instanceof java.awt.Color)
		  return " \"" + obj.toString() + "\"";
		
		if (obj instanceof java.lang.Enum) {
      Enum e = (Enum) obj;
      return e.getDeclaringClass().getName().replace('$', '.') + "." + e.name();
    }

		Class<?> objClass = obj.getClass();

		// if the object is of primitive data type
		// or an instance of a wrapper class - use default toString method
		if (objClass.isPrimitive()
				|| Inspector.isWrapperClass(objClass.getName())) {
			return obj.toString();
		}

		// if the class where the object is defined defined its own toString
		// method, use the String it produces
		String s = hasDefinedToString(obj);
		if (!(s == null))
			s = s + "\n";
		else
			s = "\n";
		// System.out.println("returned from hasDefinedString");

		// check whether the object has been viewed before, if not,
		// enter a record for this object into the hashmap
		Integer i1 = obj.hashCode();
		Integer i1match = hashmap.get(i1);

		if (i1match != null) {
			// object has been displayed already - show class name and its id
			return obj.getClass().getName() + ":" + i1match;
		} else {
			counter = counter + 1;
			i1match = counter;
			hashmap.put(i1, counter);
		}

		/** handle the Canvas class in the draw teachpack */
		if (Inspector.isOurCanvas(obj.getClass().getName()))
		  return obj.toString();

		// if the object is an Array -
		// traverse over the data
		if (obj instanceof Object[]) {
			
			// show the length of the array
			int length = Array.getLength(obj);
			
			StringBuilder tmp = new StringBuilder("\n" + INDENT + 
					                                  " new Object[" + length + "](){");
			INDENT = INDENT + "  ";
			
			// keep track of the index for each element and show it
			int n = 0;			
			for (int i = 0; i < length; i++) {
				tmp = tmp.append("\n" + INDENT+ "[" + n + "] "        
						                   + makeString(((Object[]) obj)[i]) + ",");
				n = n + 1;
			}
			if (Array.getLength(obj) > 0) {
				tmp.deleteCharAt(tmp.length() - 1);
			}
			INDENT = INDENT.substring(0, INDENT.length() - 2);
			tmp = tmp.append("}");
			return tmp + "";
		}

		// for an instance of a declared class start with the class name
		String result = s + INDENT + " new " + objClass.getName() + ":"
				+ i1match + "(";
		// + ":" + counter + "(";
		INDENT = INDENT + "  ";
		String field;

		// if the object is Iterable and a part of Java Collections
		// traverse over the data generated by the iterator
		// Note: user-specified traversals of Iterable are handled separately
		// and are invoked by check..Iterable tests
		if ((obj instanceof Iterable) &&
				 obj.getClass().getName().startsWith("java.util")){
			result = result + "){"
					+ makeIterableStrings(((Iterable<?>) obj).iterator())
					+ "}";
		}
 
		// instance of a Map: show the class and the key-value bindings
		else if (obj instanceof Map) {
			result = result + "){" + makeMapStrings((AbstractMap<?, ?>) obj)
					+ "}";
		}

		/** instance of a class that may have several defined fields */
		else {
			Reflector r = new Reflector(obj);

			// TBD: print only the public fields for Java library classes
			/*
			 * if (objClass.getName().startsWith("java."))
			 * System.out.println("Java library class: " + objClass.getName());
			 */

			/** display all fields */
			for (Field f : r.sampleDeclaredFields) {
				try {
					f.setAccessible(true);

					if ((f.get(obj)) == null)
						field = "this." + f.getName() + " = null";
					else
						field = "this." + f.getName() + " = "
								+ makeString(f.get(obj));

					result = result + "\n" + INDENT + field;

				} catch (IllegalAccessException e) {
					System.out
							.println("makeString cannot access the field "
									+ f.getName() + " of the class "
									+ r.sampleClass.getName()
									+ "\n   message: " + e.getMessage());
				}
			}
			/** close parentheses and finish up */
			result = result + ")";
		}

		INDENT = INDENT.substring(0, INDENT.length() - 2);
		return result;
	}

	/**
	 * Produce a <code>String</code> that represents the data generated by the
	 * given iterator -- comma separated.
	 * 
	 * @param it the iterator for generating data
	 * @return the <code>String</code> that represents all generated data
	 */
	private static <T> String makeIterableStrings(Iterator<T> it) {
		StringBuilder result = new StringBuilder();

		/** keep track of the index for each element and show we are iterating */
		int n = 0;
		while (it.hasNext()) {
			result = result.append("\n" + INDENT + "Iterable[" + n + "] " 
			                       + makeString(it.next()) + ",");
			n = n + 1;		
		}
		
		/** remove the last comma - if any data is present */
		if (result.length() > 0) 
			result.deleteCharAt(result.length() - 1);
	  return result + "";
	}

	/**
	 * Produce a <code>String</code> that represents the data generated by the
	 * given <CODE>{@link Traversal Traversal}</CODE> -- comma separated.
	 * 
	 * @param it the <CODE>{@link Traversal Traversal}</CODE> iterator 
	 *           for generating data
	 * @return the <code>String</code> that represents all generated data
	 */
	private static <T> String makeTraversalStrings(Traversal<T> tr) {
		StringBuilder result = new StringBuilder();

		/** keep track of the index for each element and show we are iterating */
		int n = 0;
		while (!tr.isEmpty()) {
			result = result.append("\n" + INDENT + "Traversal[" + n + "] " 
			                         + makeString(tr.getFirst()) + ",");
			n = n + 1;
			tr = tr.getRest();
		}
		
		/** remove the last comma - if any data is present */
		if (result.length() > 0)
			result.deleteCharAt(result.length() - 1);
	  return result + "";
	}
	
	
	/**
	 * Produce a <code>String</code> representation of the entries in the given
	 * <code>Map</code>.
	 * 
	 * @param <K> the type of the keys in this <code>Map</code>
	 * @param <V> the type of the values in this <code>Map</code>
	 * @param hm the <code>Map</code> to represent as <code>String</code>
	 * @return a <code>String</code> representation of the key and values in
	 *         this <code>Map</code>
	 */
	private static <K, V> String makeMapStrings(Map<K, V> hm) {
		StringBuilder result = new StringBuilder();
		Set<Map.Entry<K, V>> data = new HashSet<Map.Entry<K, V>>(hm.entrySet());
		
		for (Map.Entry<K, V> entry : data) {
			result = result.append("\n" + INDENT + "(key: "
					+ makeString(entry.getKey()) + "\n" + INDENT
					+ " value: " + makeString(entry.getValue()) + "),");
		}
		
		/** remove the last comma - if any data is present */
		if (result.length() > 0)
			result.deleteCharAt(result.length() - 1);
	  return result + "";
	}

	/**
	 * Produce a String generated by this object's <code>toString</code> method
	 * when the method has been defined there.
	 * 
	 * @param o the object to be converted to <code>String</code>
	 * @return null if the <code>toString</code> method has not been redefined,
	 *         or the <code.String</code> generated by the <code>toString</code>
	 *         method
	 */
	private static String hasDefinedToString(Object o) {

		Method tsm = null;

		// *** traverse up the class inheritance chain
		Class<?> c = o.getClass();
		Class<?> cs = c.getSuperclass();

		while (c != null) {
			// *** find the toString method
			try {
				// *** get the method toString for this class
				tsm = c.getDeclaredMethod("toString", new Class[] {});
			}
			// *** if method not found, do nothing
			catch (NoSuchMethodException e) {
				// -- omitted diagnostics
				// -- System.out.println("NoSuchMethodException:" +
				// -- e.getMessage());
				// -- System.out.println("Class: " + c.getName() + "\n");
			}

			// *** if found, invoke the method and return
			if (tsm != null) {
				try {
					// *** toString method found - get the declaring class
					Class<?> defclass = tsm.getDeclaringClass();

					// omit toString method in the Object class or
					// AbstractCollection
					if (defclass.getName().equals("java.lang.Object")
							|| defclass.getName().equals(
									"java.util.AbstractCollection"))
						return "";
					else {
						// invoke the toString method and return the String it
						// produces
						tsm.setAccessible(true);
						return (String) tsm.invoke(o, new Object[] {});
					}
				}
				// *** catch errors in invoking the toString method
				catch (IllegalAccessException e) {
					// *** do nothing
					// this should never happen
					// -- omitted diagnostics
					System.out.println("IllegalAccessException:"
							+ e.getMessage());
					System.out
							.println("Incorrectly invoked toString method in the class:"
									+ o.getClass().getName() + "\n");
				} catch (InvocationTargetException e) {
					// *** do nothing
					// this should never happen
					// -- omitted diagnostics
					System.out.println("InvocationTargetException:"
							+ e.getMessage());
					System.out
							.println("Incorrectly invoked toString method in the class:"
									+ o.getClass().getName() + "\n");
				}
			}
			// *** look for toString defined in the super class-es
			else {
				c = cs;
				cs = c.getSuperclass();
			}
		}
		return "";
	}
	
	/**
	 * Combine the representation of the actual and expected line-by-line
	 * and indicate with "......" the location of the first difference.
	 * If the actual is too long, print the actual and expected values in 
	 * consecutive lines and label them as such
	 * 
	 * @param expected the <code>String</code> that represents the expected
	 *        value
	 * @param actual the <code>String</code> that represents the actual
	 *        value
	 * @return <code>String</code> that represents the actual and expected
	 *         side-by-side
	 */
	protected static String combineActualExpected(String actual, String expected){
		// pad the space between actual and expected with spaces or dots
	  String space = "                                        ";
	  String fill =  "........................................";
		
		// the resulting String
		StringBuilder combined = new StringBuilder("");
		
		// setup the parsing of the expected and actual values
		StringTokenizer actLine = new StringTokenizer(actual, "\n");
		StringTokenizer expLine = new StringTokenizer(expected, "\n");
		
		// prime the while loop below with the first lines to compare and align
		String actString = actLine.nextToken();
		String expString = expLine.nextToken();
		
		// print the values side-by-side while they are matching
		while((expString.equals(actString))){
			// combine the matching lines with space between them
			combined.append(combineSpaceFill(actString, expString, space));
			
			// if no more lines in the expected print the rest of the actual
			if (!expLine.hasMoreTokens())
				return finishActual(combined, actLine);
			
			// if no more lines in the actual print the rest of the expected
			if (!actLine.hasMoreTokens())
				return finishExpected(combined, expLine);
				
			// get next lines for both, actual and expected
			actString = actLine.nextToken();
			expString = expLine.nextToken();
		}
		
		// produce the first differing line
		combined.append(combineSpaceFill(actString, expString, fill));
		
		
		// print the remaining values side-by-side 
		// we get here only after a differing line has been printed
		while (expLine.hasMoreTokens() && actLine.hasMoreTokens()){
			// get next lines for both, actual and expected
			actString = actLine.nextToken();
			expString = expLine.nextToken();

			// we only print spaces between lines after the first mis-match
			combined.append(combineSpaceFill(actString, expString, space));
		}
		
		// if no more lines in the expected print the rest of the actual
		if (!expLine.hasMoreTokens())
			return finishActual(combined, actLine);
		
		// if no more lines in the actual print the rest of the expected
		if (!actLine.hasMoreTokens())
			return finishExpected(combined, expLine);
		
		return combined.toString();		
	}
	
	/**
	 * <p>Combine one line of 'actual' and 'expected' into one line.<p>
	 * <p>Pad in between with either blanks or dots (if not a match).</p>
	 * <p>If actual is longer than 38 characters, print them on two lines
	 * and label the lines accordingly.</p>
	 * 
	 * @param act the <code>String</code> that represents the actual value
	 * @param exp the <code>String</code> that represents the expected value
	 * @param spfill the <code>String</code> of the padding characters
	 * @return <code>String</code> with the actual and expected combined.
	 */
	private static String combineSpaceFill(String act, String exp, String spfill){
		// make it two lines -- with blank line before and after
    // if actual is longer than 38 characters
		if (act.length() > 38)
			return "\n--  actual  : " + act +  spfill.substring(0,10) + "\n" +
					   "\n--  expected: " + exp +"\n\n"; 
		else
			// make it into one line
			return act + 
					   spfill.substring(0, 40 - act.length()) + 
					   exp + "\n"; 
	}
	
	/**
	 * Add the rest of the 'actual' <code>String</code> to the combined lines 
	 * when there is nothing more of 'expected' to display
	 * @param combined the combined actual-expected lines collected so far
	 * @param actLine the remainder of the 'actual' <code>String
	 * @return the final <code>String with the combined display
	 */
	private static String finishActual(StringBuilder combined, 
			                               StringTokenizer actLine){
		while(actLine.hasMoreTokens())
			combined.append(actLine.nextToken() + "\n");
		return combined.toString();
	}
	
	/**
	 * Add the rest of the 'expected' <code>String</code> to the combined lines 
	 * when there is nothing more of 'actual' to display
	 * @param combined the combined actual-expected lines collected so far
	 * @param expLine the remainder of the 'expected' <code>String
	 * @return the final <code>String with the combined display
	 */
	private static String finishExpected(StringBuilder combined, 
			                                 StringTokenizer expLine){
		String space40 = "                                        ";
		while(expLine.hasMoreTokens())
			combined.append(space40 + expLine.nextToken() + "\n");
		return combined.toString();
	}
	
	/**
	 * A simple test for the combining of the expected and actual lines
	 * @param argv
	 */
	public static void main(String[] argv){

		String act = "hello\ngoodbye\nadieau\n";
		String expTrue = "hello\ngoodbye\nadieau\n";
		String expFalse1 = "hello\ngoodbyes\nadieau\n";
		String expFalse2 = "hello\ngoodbye\n";
		String expFalse3 = "hello\ngoodbyes\nadieau\nahoy\n";
		String longact = "abcdefghijklmnopqrtsuvwxyzabcdefghijklmnopqrtsuvwxyz";
		String longexp = "abcdefghijklmnopqrtsuvwxyzabcdefghijklmnopqrtsuvwxyz";
		String longexpbad = "abcdefghijklmnopqrtsuvwxyzabcdefghijklmnopqrtsuvwxyz1";

		System.out.println(Printer.combineActualExpected(act, expTrue));
		System.out.println(Printer.combineActualExpected(act, expFalse1));
		System.out.println(Printer.combineActualExpected(act, expFalse2));
		System.out.println(Printer.combineActualExpected(act, expFalse3));
		System.out.println(Printer.combineActualExpected(longact, longexp));
		System.out.println(Printer.combineActualExpected(longact, longexpbad));
	}
}