/*
 * Copyright (c) 2003 The Visigoth Software Society. All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above
copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software
itself,
 *    if and wherever such third-party acknowledgements normally
appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names
of the
 *    project contributors may be used to endorse or promote products
derived
 *    from this software without prior written permission. For written
 *    permission, please contact visigo...@visigoths.org.
 *
 * 5. Products derived from this software may not be called
"FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software
Society.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */

package freemarker.core;

import java.io.IOException;

/**
 * A TemplateElement representing a block of plain text.
 *
 * @version $Id: TextBlock.java,v 1.17 2004/01/06 17:06:42 szegedia Exp $
 */
public final class TextBlock extends TemplateElement {
 private static final char[] EMPTY_CHAR_ARRAY = new char[0];
 static final TextBlock EMPTY_BLOCK = new TextBlock(EMPTY_CHAR_ARRAY, false);
 // We're using char[] instead of String for storing the text block because
 // Writer.write(String) involves copying the String contents to a char[]
 // using String.getChars(), and then calling Writer.write(char[]).By
 // using Writer.write(char[]) directly, we avoid array copying on each
 // write.
 private char[] text;
 private final boolean unparsed;

 public TextBlock(String text) {
 this(text, false);
 }

 public TextBlock(String text, boolean unparsed) {
 this(text.toCharArray(), unparsed);
 }

 private TextBlock(char[] text, boolean unparsed) {
 this.text = text;
 this.unparsed = unparsed;
 }

 /**
 * Simply outputs the text.
 */
 public void accept(Environment env) throws IOException {
 env.getOut().write(text);
 }

 public String getCanonicalForm() {
 String text = new String(this.text);
 if (unparsed) {
 return "<#noparse>" + text + "</#noparse>";
 }
 return text;
 }

 public String getDescription() {
 String s = new String(text).trim();
 if (s.length() == 0) {
 return "whitespace";
 }
 if (s.length() > 20) {
 s = s.substring(0, 20) + "...";
 s = s.replace('\n', ' ');
 s = s.replace('\r', ' ');
 }
 return "text block (" + s + ")";
 }

 TemplateElement postParseCleanup(boolean stripWhitespace) {
 if (text.length == 0)
 return this;
 int openingCharsToStrip = 0, trailingCharsToStrip = 0;
 boolean deliberateLeftTrim = deliberateLeftTrim();
 boolean deliberateRightTrim = deliberateRightTrim();
 if (!stripWhitespace || text.length == 0) {
 return this;
 }
 if (parent.parent == null && previousSibling() == null)
 return this;
 if (!deliberateLeftTrim) {
 trailingCharsToStrip = trailingCharsToStrip();
 }
 if (!deliberateRightTrim) {
 openingCharsToStrip = openingCharsToStrip();
 }
 if (openingCharsToStrip == 0 && trailingCharsToStrip == 0) {
 return this;
 }
 this.text = substring(text, openingCharsToStrip, text.length
 - trailingCharsToStrip);
 if (openingCharsToStrip > 0) {
 this.beginLine++;
 this.beginColumn = 1;
 }
 if (trailingCharsToStrip > 0) {
 this.endColumn = 0;
 }
 return this;
 }

 /**
 * Scans forward the nodes on the same line to see whether there is a
 * deliberate left trim in effect. Returns true if the left trim was
 * present.
 */
 private boolean deliberateLeftTrim() {
 boolean result = false;
 for (TemplateElement elem = this.nextTerminalNode(); elem != null
 && elem.beginLine == this.endLine; elem = elem
 .nextTerminalNode()) {
 if (elem instanceof TrimInstruction) {
 TrimInstruction ti = (TrimInstruction) elem;
 if (!ti.left && !ti.right) {
 result = true;
 }
 if (ti.left) {
 result = true;
 int lastNewLineIndex = lastNewLineIndex();
 if (lastNewLineIndex >= 0 || beginColumn == 1) {
 char[] firstPart = substring(text, 0,
 lastNewLineIndex + 1);
 char[] lastLine = substring(text, 1 + lastNewLineIndex);
 if (trim(lastLine).length == 0) {
 this.text = firstPart;
 this.endColumn = 0;
 } else {
 int i = 0;
 while (Character.isWhitespace(lastLine[i])) {
 i++;
 }
 char[] printablePart = substring(lastLine, i);
 this.text = concat(firstPart, printablePart);
 }
 }
 }
 }
 }
 if (result) {
 }
 return result;
 }

 /**
 * Checks for the presence of a t or rt directive on the same line. Returns
 * true if the right trim directive was present.
 */
 private boolean deliberateRightTrim() {
 boolean result = false;
 for (TemplateElement elem = this.prevTerminalNode(); elem != null
 && elem.endLine == this.beginLine; elem = elem
 .prevTerminalNode()) {
 if (elem instanceof TrimInstruction) {
 TrimInstruction ti = (TrimInstruction) elem;
 if (!ti.left && !ti.right) {
 result = true;
 }
 if (ti.right) {
 result = true;
 int firstLineIndex = firstNewLineIndex() + 1;
 if (firstLineIndex == 0) {
 return false;
 }
 if (text.length > firstLineIndex
 && text[firstLineIndex - 1] == '\r'
 && text[firstLineIndex] == '\n') {
 firstLineIndex++;
 }
 char[] trailingPart = substring(text, firstLineIndex);
 char[] openingPart = substring(text, 0, firstLineIndex);
 if (trim(openingPart).length == 0) {
 this.text = trailingPart;
 this.beginLine++;
 this.beginColumn = 1;
 } else {
 int lastNonWS = openingPart.length - 1;
 while (Character.isWhitespace(text[lastNonWS])) {
 lastNonWS--;
 }
 char[] printablePart = substring(text, 0, lastNonWS + 1);
 if (trim(trailingPart).length == 0) {
 // THIS BLOCK IS HEINOUS! THERE MUST BE A BETTER
 // WAY! REVISIT (JR)
 boolean trimTrailingPart = true;
 for (TemplateElement te = this.nextTerminalNode(); te != null
 && te.beginLine == this.endLine; te = te
 .nextTerminalNode()) {
 if (te.heedsOpeningWhitespace()) {
 trimTrailingPart = false;
 }
 if (te instanceof TrimInstruction
 && ((TrimInstruction) te).left) {
 trimTrailingPart = true;
 break;
 }
 }
 if (trimTrailingPart)
 trailingPart = EMPTY_CHAR_ARRAY;
 }
 this.text = concat(printablePart, trailingPart);
 }
 }
 }
 }
 return result;
 }

 /*
 * private String leftTrim(String s) { int i =0; while (i<s.length()) { if * (!Character.isWhitespace(s.charAt(i))) break; ++i; } return * s.substring(i); } */ private int firstNewLineIndex() { String content = new String(text); int newlineIndex1 = content.indexOf('\n'); int newlineIndex2 = content.indexOf('\r'); int result = newlineIndex1 >= 0 ? newlineIndex1 : newlineIndex2;
 if (newlineIndex1 >= 0 && newlineIndex2 >= 0) {
 result = Math.min(newlineIndex1, newlineIndex2);
 }
 return result;
 }

 private int lastNewLineIndex() {
 String content = new String(text);
 return Math.max(content.lastIndexOf('\r'), content.lastIndexOf('\n'));
 }

 /**
 * figures out how many opening whitespace characters to strip in the
 * post-parse cleanup phase.
 */
 private int openingCharsToStrip() {
 int newlineIndex = firstNewLineIndex();
 if (newlineIndex == -1 && beginColumn != 1) {
 return 0;
 }
 ++newlineIndex;
 if (text.length > newlineIndex) {
 if (newlineIndex > 0 && text[newlineIndex - 1] == '\r'
 && text[newlineIndex] == '\n') {
 ++newlineIndex;
 }
 }
 if (new String(text).substring(0, newlineIndex).trim().length() > 0) {
 return 0;
 }
 // We look at the preceding elements on the line to see if we should
 // strip the opening newline and any whitespace preceding it.
 for (TemplateElement elem = this.prevTerminalNode(); elem != null
 && elem.endLine == this.beginLine; elem = elem
 .prevTerminalNode()) {
 if (elem.heedsOpeningWhitespace()) {
 return 0;
 }
 }
 return newlineIndex;
 }

 /**
 * figures out how many trailing whitespace characters to strip in the
 * post-parse cleanup phase.
 */
 private int trailingCharsToStrip() {
 String content = new String(text);
 int lastNewlineIndex = lastNewLineIndex();
 if (lastNewlineIndex == -1 && beginColumn != 1) {
 return 0;
 }
 String substring = content.substring(lastNewlineIndex + 1);
 if (substring.trim().length() > 0) {
 return 0;
 }
 // We look at the elements afterward on the same line to see if we
 // should strip any whitespace after the last newline
 for (TemplateElement elem = this.nextTerminalNode(); elem != null
 && elem.beginLine == this.endLine; elem = elem
 .nextTerminalNode()) {
 if (elem.heedsTrailingWhitespace()) {
 return 0;
 }
 }
 return substring.length();
 }

 boolean heedsTrailingWhitespace() {
 if (isIgnorable()) {
 return false;
 }
 for (int i = 0; i < text.length; i++) { char c = text[i]; if (c == '\n' || c == '\r') { return false; } if (!Character.isWhitespace(c)) { return true; } } return true; } boolean heedsOpeningWhitespace() { if (isIgnorable()) { return false; } for (int i = text.length - 1; i >= 0; i--) {
 char c = text[i];
 if (c == '\n' || c == '\r') {
 return false;
 }
 if (!Character.isWhitespace(c)) {
 return true;
 }
 }
 return true;
 }

 boolean isIgnorable() {
 if (text == null || text.length == 0) {
 return true;
 }
 if (!isWhitespace()) {
 return false;
 }
 // trick here
 boolean atTopLevel = true;
 TemplateElement prevSibling = previousSibling();
 TemplateElement nextSibling = nextSibling();
 return ((prevSibling == null && atTopLevel) || nonOutputtingType(prevSibling))
 && ((nextSibling == null && atTopLevel) || nonOutputtingType(nextSibling));
 }

 private boolean nonOutputtingType(TemplateElement element) {
 return (element instanceof Macro || element instanceof Assignment
 || element instanceof AssignmentInstruction
 || element instanceof PropertySetting
 || element instanceof LibraryLoad || element instanceof Comment);
 }

 private static char[] substring(char[] c, int from, int to) {
 char[] c2 = new char[to - from];
 System.arraycopy(c, from, c2, 0, c2.length);
 return c2;
 }

 private static char[] substring(char[] c, int from) {
 return substring(c, from, c.length);
 }

 private static char[] trim(char[] c) {
 if (c.length == 0) {
 return c;
 }
 return new String(c).trim().toCharArray();
 }

 private static char[] concat(char[] c1, char[] c2) {
 char[] c = new char[c1.length + c2.length];
 System.arraycopy(c1, 0, c, 0, c1.length);
 System.arraycopy(c2, 0, c, c1.length, c2.length);
 return c;
 }

 boolean isWhitespace() {
 return text == null || trim(text).length == 0;
 }