/*
 * RegExpDebug.java
 *
 * Copyright (C) 1997 Shugo Maeda
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.
 */

package JP.ac.osaka_u.ender.util.regex;

import java.io.*;

/**
 * A class to debug RegExp 
 */
class RegExpDebug {

    private RegExpDebug() {}

    /**
     * It is called automatically by the system the application is started.
     */
    public static void main(String args[]) {
	RegExp re = new RegExp();
	String pattern;

	DataInputStream in = new DataInputStream(System.in);
	try {
	    while (true) {
		System.out.println("Pattern ?");
		if ((pattern = in.readLine()) == null) break;
		re.setPattern(pattern);
		System.out.println("Parse \"" + re + "\":");
		System.out.println("dump tree...");
		System.out.println(re.treeString());
		System.out.println("dump NFA...");
		System.out.println(re.nfaString());
		System.out.println("dump DFA...");
		System.out.println(re.dfaString());
	    }
	} catch (IOException e) {
	    System.out.println(e);
	} catch (RegExpSyntaxException e) {
	    System.out.println(e);
	} catch (NFABuildException e) {
	    System.out.println(e);
	}
    }

    /*
     * Dumps DFA.
     */
    public static String dfaToString(RegExpDFA dfa) {
	String result = "";
	DSList l;
	int i, j;

	for (i = 0; i < dfa.count(); i++) {
	    result += "state " + i + (dfa.getDState(i).accepted() ? "A" : " ") + ": ";
	    for (l = dfa.getDState(i).next(); l != null; l = l.next()) {
		for (j = 0; j < dfa.count(); j++) {
		    if (dfa.getDState(j) == l.to()) break;
		}
		result += "(" + l.chars().toString() + " => " + j + ") ";
	    }
	    result += "... { ";
	    for (j = 0; j < dfa.getNfa().count(); j++) {
		if (dfa.getDState(i).nfaStateSet().get(j)) result += j + " ";
	    }
	    result += "} ";
	    result += "\n";
	}
	return result;
    }

    /*
     * Dumps NFA.
     */
    public static String nfaToString(RegExpNFA nfa) {
	String result = "";
	int i;
	NList nl;

	for (i = 0; nfa.getNList(i) != null || i == nfa.exit(); i++) {
	    if (nfa.getNList(i) != null) {
		result += "state " + i + ": ";
		for (nl = nfa.getNList(i); nl != null; nl = nl.next()) {
		    result += "(" + nl.chars().toString()
						   + " => " + nl.to() + ") ";
		}
		result += "\n";
	    } else if (i == nfa.exit()) {
		result += "state " + i + ": exit\n";
	    }
	}
	return result;
    }

    /*
     * Dumps the regular expression tree.
     */
    public static String treeToString(RTree tree) {
	String result;
	switch(tree.operation()) {
	case RTree.OP_CHAR:
	    result = tree.chars().toString();
	    break;
	case RTree.OP_LHEAD:
	    result = "LHEAD";
	    break;
	case RTree.OP_LTAIL:
	    result = "LTAIL";
	    break;
	case RTree.OP_CONCAT:
	    result = "(concat " + treeToString(tree.left()) + " " + 
		   treeToString(tree.right()) + ")";
	    break;
	case RTree.OP_UNION:
	    result = "(or " + treeToString(tree.left()) + " " + treeToString(tree.right()) + ")";
	    break;
	case RTree.OP_CLOSURE:
	    result = "(closure " + treeToString(tree.left()) + ")";
	    break;
	case RTree.OP_EMPTY:
	    result = "EMPTY";
	    break;
	default:
	    result = "This can't happen in <dumpTree>";
	}
	return result;
    }
}