/*
    * Copyright 2002-2007 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.argeo.osgi.boot.internal.springutil;
  
  /**
   * PathMatcher implementation for Ant-style path patterns.
   * Examples are provided below.
   *
   * <p>Part of this mapping code has been kindly borrowed from
   * <a href="http://ant.apache.org">Apache Ant</a>.
   *
   * <p>The mapping matches URLs using the following rules:<br>
   * <ul>
   * <li>? matches one character</li>
   * <li>* matches zero or more characters</li>
   * <li>** matches zero or more 'directories' in a path</li>
   * </ul>
   *
   * <p>Some examples:<br>
   * <ul>
   * <li><code>com/t?st.jsp</code> - matches <code>com/test.jsp</code> but also
   * <code>com/tast.jsp</code> or <code>com/txst.jsp</code></li>
   * <li><code>com/*.jsp</code> - matches all <code>.jsp</code> files in the
   * <code>com</code> directory</li>
   * <li><code>com/&#42;&#42;/test.jsp</code> - matches all <code>test.jsp</code>
   * files underneath the <code>com</code> path</li>
   * <li><code>org/springframework/&#42;&#42;/*.jsp</code> - matches all <code>.jsp</code>
   * files underneath the <code>org/springframework</code> path</li>
   * <li><code>org/&#42;&#42;/servlet/bla.jsp</code> - matches
   * <code>org/springframework/servlet/bla.jsp</code> but also
   * <code>org/springframework/testing/servlet/bla.jsp</code> and
   * <code>org/servlet/bla.jsp</code></li>
   * </ul>
   *
   * @author Alef Arendsen
   * @author Juergen Hoeller
   * @author Rob Harrop
   * @since 16.07.2003
   */
  public class AntPathMatcher implements PathMatcher {
  
  	/** Default path separator: "/" */
  	public static final String DEFAULT_PATH_SEPARATOR = "/";
  
  	private String pathSeparator = DEFAULT_PATH_SEPARATOR;
  
  
  	/**
  	 * Set the path separator to use for pattern parsing.
  	 * Default is "/", as in Ant.
  	 */
  	public void setPathSeparator(String pathSeparator) {
  		this.pathSeparator = (pathSeparator != null ? pathSeparator : DEFAULT_PATH_SEPARATOR);
  	}
  
  
  	public boolean isPattern(String path) {
  		return (path.indexOf('*') != -1 || path.indexOf('?') != -1);
  	}
  
  	public boolean match(String pattern, String path) {
  		return doMatch(pattern, path, true);
  	}
  
  	public boolean matchStart(String pattern, String path) {
  		return doMatch(pattern, path, false);
  	}
  
  
  	/**
  	 * Actually match the given <code>path</code> against the given <code>pattern</code>.
  	 * @param pattern the pattern to match against
  	 * @param path the path String to test
  	 * @param fullMatch whether a full pattern match is required
  	 * (else a pattern match as far as the given base path goes is sufficient)
  	 * @return <code>true</code> if the supplied <code>path</code> matched,
  	 * <code>false</code> if it didn't
  	 */
  	protected boolean doMatch(String pattern, String path, boolean fullMatch) {
  		if (path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
  			return false;
  		}
  
  		String[] pattDirs = StringUtils.tokenizeToStringArray(pattern, this.pathSeparator);
  		String[] pathDirs = StringUtils.tokenizeToStringArray(path, this.pathSeparator);
 
 		int pattIdxStart = 0;
 		int pattIdxEnd = pattDirs.length - 1;
 		int pathIdxStart = 0;
 		int pathIdxEnd = pathDirs.length - 1;
 
 		// Match all elements up to the first **
 		while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
 			String patDir = pattDirs[pattIdxStart];
 			if ("**".equals(patDir)) {
 				break;
 			}
 			if (!matchStrings(patDir, pathDirs[pathIdxStart])) {
 				return false;
 			}
 			pattIdxStart++;
 			pathIdxStart++;
 		}
 
 		if (pathIdxStart > pathIdxEnd) {
 			// Path is exhausted, only match if rest of pattern is * or **'s
 			if (pattIdxStart > pattIdxEnd) {
 				return (pattern.endsWith(this.pathSeparator) ?
 						path.endsWith(this.pathSeparator) : !path.endsWith(this.pathSeparator));
 			}
 			if (!fullMatch) {
 				return true;
 			}
 			if (pattIdxStart == pattIdxEnd && pattDirs[pattIdxStart].equals("*") &&
 					path.endsWith(this.pathSeparator)) {
 				return true;
 			}
 			for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
 				if (!pattDirs[i].equals("**")) {
 					return false;
 				}
 			}
 			return true;
 		}
 		else if (pattIdxStart > pattIdxEnd) {
 			// String not exhausted, but pattern is. Failure.
 			return false;
 		}
 		else if (!fullMatch && "**".equals(pattDirs[pattIdxStart])) {
 			// Path start definitely matches due to "**" part in pattern.
 			return true;
 		}
 
 		// up to last '**'
 		while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
 			String patDir = pattDirs[pattIdxEnd];
 			if (patDir.equals("**")) {
 				break;
 			}
 			if (!matchStrings(patDir, pathDirs[pathIdxEnd])) {
 				return false;
 			}
 			pattIdxEnd--;
 			pathIdxEnd--;
 		}
 		if (pathIdxStart > pathIdxEnd) {
 			// String is exhausted
 			for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
 				if (!pattDirs[i].equals("**")) {
 					return false;
 				}
 			}
 			return true;
 		}
 
 		while (pattIdxStart != pattIdxEnd && pathIdxStart <= pathIdxEnd) {
 			int patIdxTmp = -1;
 			for (int i = pattIdxStart + 1; i <= pattIdxEnd; i++) {
 				if (pattDirs[i].equals("**")) {
 					patIdxTmp = i;
 					break;
 				}
 			}
 			if (patIdxTmp == pattIdxStart + 1) {
 				// '**/**' situation, so skip one
 				pattIdxStart++;
 				continue;
 			}
 			// Find the pattern between padIdxStart & padIdxTmp in str between
 			// strIdxStart & strIdxEnd
 			int patLength = (patIdxTmp - pattIdxStart - 1);
 			int strLength = (pathIdxEnd - pathIdxStart + 1);
 			int foundIdx = -1;
 
 			strLoop:
 			    for (int i = 0; i <= strLength - patLength; i++) {
 				    for (int j = 0; j < patLength; j++) {
 					    String subPat = (String) pattDirs[pattIdxStart + j + 1];
 					    String subStr = (String) pathDirs[pathIdxStart + i + j];
 					    if (!matchStrings(subPat, subStr)) {
 						    continue strLoop;
 					    }
 				    }
 				    foundIdx = pathIdxStart + i;
 				    break;
 			    }
 
 			if (foundIdx == -1) {
 				return false;
 			}
 
 			pattIdxStart = patIdxTmp;
 			pathIdxStart = foundIdx + patLength;
 		}
 
 		for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
 			if (!pattDirs[i].equals("**")) {
 				return false;
 			}
 		}
 
 		return true;
 	}
 
 	/**
 	 * Tests whether or not a string matches against a pattern.
 	 * The pattern may contain two special characters:<br>
 	 * '*' means zero or more characters<br>
 	 * '?' means one and only one character
 	 * @param pattern pattern to match against.
 	 * Must not be <code>null</code>.
 	 * @param str string which must be matched against the pattern.
 	 * Must not be <code>null</code>.
 	 * @return <code>true</code> if the string matches against the
 	 * pattern, or <code>false</code> otherwise.
 	 */
 	private boolean matchStrings(String pattern, String str) {
 		char[] patArr = pattern.toCharArray();
 		char[] strArr = str.toCharArray();
 		int patIdxStart = 0;
 		int patIdxEnd = patArr.length - 1;
 		int strIdxStart = 0;
 		int strIdxEnd = strArr.length - 1;
 		char ch;
 
 		boolean containsStar = false;
 		for (int i = 0; i < patArr.length; i++) {
 			if (patArr[i] == '*') {
 				containsStar = true;
 				break;
 			}
 		}
 
 		if (!containsStar) {
 			// No '*'s, so we make a shortcut
 			if (patIdxEnd != strIdxEnd) {
 				return false; // Pattern and string do not have the same size
 			}
 			for (int i = 0; i <= patIdxEnd; i++) {
 				ch = patArr[i];
 				if (ch != '?') {
 					if (ch != strArr[i]) {
 						return false;// Character mismatch
 					}
 				}
 			}
 			return true; // String matches against pattern
 		}
 
 
 		if (patIdxEnd == 0) {
 			return true; // Pattern contains only '*', which matches anything
 		}
 
 		// Process characters before first star
 		while ((ch = patArr[patIdxStart]) != '*' && strIdxStart <= strIdxEnd) {
 			if (ch != '?') {
 				if (ch != strArr[strIdxStart]) {
 					return false;// Character mismatch
 				}
 			}
 			patIdxStart++;
 			strIdxStart++;
 		}
 		if (strIdxStart > strIdxEnd) {
 			// All characters in the string are used. Check if only '*'s are
 			// left in the pattern. If so, we succeeded. Otherwise failure.
 			for (int i = patIdxStart; i <= patIdxEnd; i++) {
 				if (patArr[i] != '*') {
 					return false;
 				}
 			}
 			return true;
 		}
 
 		// Process characters after last star
 		while ((ch = patArr[patIdxEnd]) != '*' && strIdxStart <= strIdxEnd) {
 			if (ch != '?') {
 				if (ch != strArr[strIdxEnd]) {
 					return false;// Character mismatch
 				}
 			}
 			patIdxEnd--;
 			strIdxEnd--;
 		}
 		if (strIdxStart > strIdxEnd) {
 			// All characters in the string are used. Check if only '*'s are
 			// left in the pattern. If so, we succeeded. Otherwise failure.
 			for (int i = patIdxStart; i <= patIdxEnd; i++) {
 				if (patArr[i] != '*') {
 					return false;
 				}
 			}
 			return true;
 		}
 
 		// process pattern between stars. padIdxStart and patIdxEnd point
 		// always to a '*'.
 		while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
 			int patIdxTmp = -1;
 			for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
 				if (patArr[i] == '*') {
 					patIdxTmp = i;
 					break;
 				}
 			}
 			if (patIdxTmp == patIdxStart + 1) {
 				// Two stars next to each other, skip the first one.
 				patIdxStart++;
 				continue;
 			}
 			// Find the pattern between padIdxStart & padIdxTmp in str between
 			// strIdxStart & strIdxEnd
 			int patLength = (patIdxTmp - patIdxStart - 1);
 			int strLength = (strIdxEnd - strIdxStart + 1);
 			int foundIdx = -1;
 			strLoop:
 			for (int i = 0; i <= strLength - patLength; i++) {
 				for (int j = 0; j < patLength; j++) {
 					ch = patArr[patIdxStart + j + 1];
 					if (ch != '?') {
 						if (ch != strArr[strIdxStart + i + j]) {
 							continue strLoop;
 						}
 					}
 				}
 
 				foundIdx = strIdxStart + i;
 				break;
 			}
 
 			if (foundIdx == -1) {
 				return false;
 			}
 
 			patIdxStart = patIdxTmp;
 			strIdxStart = foundIdx + patLength;
 		}
 
 		// All characters in the string are used. Check if only '*'s are left
 		// in the pattern. If so, we succeeded. Otherwise failure.
 		for (int i = patIdxStart; i <= patIdxEnd; i++) {
 			if (patArr[i] != '*') {
 				return false;
 			}
 		}
 
 		return true;
 	}
 
 	/**
 	 * Given a pattern and a full path, determine the pattern-mapped part.
 	 * <p>For example:
 	 * <ul>
 	 * <li>'<code>/docs/cvs/commit.html</code>' and '<code>/docs/cvs/commit.html</code> to ''</li>
 	 * <li>'<code>/docs/*</code>' and '<code>/docs/cvs/commit</code> to '<code>cvs/commit</code>'</li>
 	 * <li>'<code>/docs/cvs/*.html</code>' and '<code>/docs/cvs/commit.html</code> to '<code>commit.html</code>'</li>
 	 * <li>'<code>/docs/**</code>' and '<code>/docs/cvs/commit</code> to '<code>cvs/commit</code>'</li>
 	 * <li>'<code>/docs/**\/*.html</code>' and '<code>/docs/cvs/commit.html</code> to '<code>cvs/commit.html</code>'</li>
 	 * <li>'<code>/*.html</code>' and '<code>/docs/cvs/commit.html</code> to '<code>docs/cvs/commit.html</code>'</li>
 	 * <li>'<code>*.html</code>' and '<code>/docs/cvs/commit.html</code> to '<code>/docs/cvs/commit.html</code>'</li>
 	 * <li>'<code>*</code>' and '<code>/docs/cvs/commit.html</code> to '<code>/docs/cvs/commit.html</code>'</li>
 	 * </ul>
 	 * <p>Assumes that {@link #match} returns <code>true</code> for '<code>pattern</code>'
 	 * and '<code>path</code>', but does <strong>not</strong> enforce this.
 	 */
 	public String extractPathWithinPattern(String pattern, String path) {
 		String[] patternParts = StringUtils.tokenizeToStringArray(pattern, this.pathSeparator);
 		String[] pathParts = StringUtils.tokenizeToStringArray(path, this.pathSeparator);
 
 		StringBuffer buffer = new StringBuffer();
 
 		// Add any path parts that have a wildcarded pattern part.
 		int puts = 0;
 		for (int i = 0; i < patternParts.length; i++) {
 			String patternPart = patternParts[i];
 			if ((patternPart.indexOf('*') > -1 || patternPart.indexOf('?') > -1) && pathParts.length >= i + 1) {
 				if (puts > 0 || (i == 0 && !pattern.startsWith(this.pathSeparator))) {
 					buffer.append(this.pathSeparator);
 				}
 				buffer.append(pathParts[i]);
 				puts++;
 			}
 		}
 
 		// Append any trailing path parts.
 		for (int i = patternParts.length; i < pathParts.length; i++) {
 			if (puts > 0 || i > 0) {
 				buffer.append(this.pathSeparator);
 			}
 			buffer.append(pathParts[i]);
 		}
 
 		return buffer.toString();
 	}
 
 }