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	/*
	* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.util.regex;

	import java.util.HashMap;
	import java.util.regex.Pattern.CharPredicate;
	import static java.util.regex.ASCII.*;

	/**
	* A utility class to print out the pattern node tree.
	*/

	class PrintPattern {

	private static HashMap<Pattern.Node, Integer> ids = new HashMap<>();

	private static void print(Pattern.Node node, String text, int depth) {
	if (!ids.containsKey(node))
	ids.put(node, ids.size());
	System.out.printf("%6d:%" + (depth==0? "": depth<<1) + "s<%s>",
	ids.get(node), "", text);
	if (ids.containsKey(node.next))
	System.out.printf(" (=>%d)", ids.get(node.next));
	System.out.printf("%n");
	}

	private static void print(String s, int depth) {
	System.out.printf(" %" + (depth==0?"":depth<<1) + "s<%s>%n",
	"", s);
	}

	private static String toStringCPS(int[] cps) {
	StringBuilder sb = new StringBuilder(cps.length);
	for (int cp : cps)
	sb.append(toStringCP(cp));
	return sb.toString();
	}

	private static String toStringCP(int cp) {
	return (isPrint(cp) ? "" + (char)cp
	: "\\u" + Integer.toString(cp, 16));
	}

	private static String toStringRange(int min, int max) {
	if (max == Pattern.MAX_REPS) {
	if (min == 0)
	return " * ";
	else if (min == 1)
	return " + ";
	return "{" + min + ", max}";
	}
	return "{" + min + ", " + max + "}";
	}

	private static String toStringCtype(int type) {
	return switch (type) {
	case UPPER -> "ASCII.UPPER";
	case LOWER -> "ASCII.LOWER";
	case DIGIT -> "ASCII.DIGIT";
	case SPACE -> "ASCII.SPACE";
	case PUNCT -> "ASCII.PUNCT";
	case CNTRL -> "ASCII.CNTRL";
	case BLANK -> "ASCII.BLANK";
	case UNDER -> "ASCII.UNDER";
	case ASCII -> "ASCII.ASCII";
	case ALPHA -> "ASCII.ALPHA";
	case ALNUM -> "ASCII.ALNUM";
	case GRAPH -> "ASCII.GRAPH";
	case WORD -> "ASCII.WORD";
	case XDIGIT -> "ASCII.XDIGIT";
	default -> "ASCII ?";
	};
	}

	private static String toString(Pattern.Node node) {
	String name = node.getClass().getName();
	return name.substring(name.lastIndexOf('$') + 1);
	}

	static HashMap<CharPredicate, String> pmap;
	static {
	pmap = new HashMap<>();
	pmap.put(Pattern.ALL(), "All");
	pmap.put(Pattern.DOT(), "Dot");
	pmap.put(Pattern.UNIXDOT(), "UnixDot");
	pmap.put(Pattern.VertWS(), "VertWS");
	pmap.put(Pattern.HorizWS(), "HorizWS");

	pmap.put(CharPredicates.ASCII_DIGIT(), "ASCII.DIGIT");
	pmap.put(CharPredicates.ASCII_WORD(), "ASCII.WORD");
	pmap.put(CharPredicates.ASCII_SPACE(), "ASCII.SPACE");
	}

	static void walk(Pattern.Node node, int depth) {
	depth++;
	while(node != null) {
	String name = toString(node);
	String str;
	if (node instanceof Pattern.Prolog) {
	print(node, name, depth);
	// print the loop here
	Pattern.Loop loop = ((Pattern.Prolog)node).loop;
	name = toString(loop);
	str = name + " " + toStringRange(loop.cmin, loop.cmax);
	print(loop, str, depth);
	walk(loop.body, depth);
	print("/" + name, depth);
	node = loop;
	} else if (node instanceof Pattern.Loop) {
	return; // stop here, body.next -> loop
	} else if (node instanceof Pattern.Curly c) {
	str = "Curly " + c.type + " " + toStringRange(c.cmin, c.cmax);
	print(node, str, depth);
	walk(c.atom, depth);
	print("/Curly", depth);
	} else if (node instanceof Pattern.GroupCurly gc) {
	str = "GroupCurly " + gc.groupIndex / 2 +
	", " + gc.type + " " + toStringRange(gc.cmin, gc.cmax);
	print(node, str, depth);
	walk(gc.atom, depth);
	print("/GroupCurly", depth);
	} else if (node instanceof Pattern.GroupHead head) {
	Pattern.GroupTail tail = head.tail;
	print(head, "Group.head " + (tail.groupIndex / 2), depth);
	walk(head.next, depth);
	print(tail, "/Group.tail " + (tail.groupIndex / 2), depth);
	node = tail;
	} else if (node instanceof Pattern.GroupTail) {
	return; // stopper
	} else if (node instanceof Pattern.Ques) {
	print(node, "Ques " + ((Pattern.Ques)node).type, depth);
	walk(((Pattern.Ques)node).atom, depth);
	print("/Ques", depth);
	} else if (node instanceof Pattern.Branch b) {
	print(b, name, depth);
	int i = 0;
	while (true) {
	if (b.atoms[i] != null) {
	walk(b.atoms[i], depth);
	} else {
	print(" (accepted)", depth);
	}
	if (++i == b.size)
	break;
	print("-branch.separator-", depth);
	}
	node = b.conn;
	print(node, "/Branch", depth);
	} else if (node instanceof Pattern.BranchConn) {
	return;
	} else if (node instanceof Pattern.CharProperty) {
	str = pmap.get(((Pattern.CharProperty)node).predicate);
	if (str == null)
	str = toString(node);
	else
	str = "Single \"" + str + "\"";
	print(node, str, depth);
	} else if (node instanceof Pattern.SliceNode) {
	str = name + " \"" +
	toStringCPS(((Pattern.SliceNode)node).buffer) + "\"";
	print(node, str, depth);
	} else if (node instanceof Pattern.CharPropertyGreedy gcp) {
	String pstr = pmap.get(gcp.predicate);
	if (pstr == null)
	pstr = gcp.predicate.toString();
	else
	pstr = "Single \"" + pstr + "\"";
	str = name + " " + pstr;
	if (gcp.cmin == 0)
	str += "*";
	else if (gcp.cmin == 1)
	str += "+";
	else
	str += "{" + gcp.cmin + ",}";
	print(node, str, depth);
	} else if (node instanceof Pattern.BackRef) {
	str = "GroupBackRef " + ((Pattern.BackRef)node).groupIndex / 2;
	print(node, str, depth);
	} else if (node instanceof Pattern.LastNode) {
	print(node, "END", depth);
	} else if (node == Pattern.accept) {
	return;
	} else {
	print(node, name, depth);
	}
	node = node.next;
	}
	}

	public static void main(String[] args) {
	Pattern p = Pattern.compile(args[0]);
	System.out.println(" Pattern: " + p);
	walk(p.root, 0);
	}
	}

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