/*
 * 
 * Copyright 2001-2004 The Ant-Contrib project
 *
 *  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 net.sf.antcontrib.cpptasks;
import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.Vector;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.taskdefs.LogStreamHandler;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.types.Environment;
/**
 * Some utilities used by the CC and Link tasks.
 * 
 * @author Adam Murdoch
 */
public class CUtil {
    /**
     * A class that splits a white-space, comma-separated list into a String
     * array. Used for task attributes.
     */
    public static final class StringArrayBuilder {
        private String[] _value;
        public StringArrayBuilder(String value) {
            // Split the defines up
            StringTokenizer tokens = new StringTokenizer(value, ", ");
            Vector vallist = new Vector();
            while (tokens.hasMoreTokens()) {
                String val = tokens.nextToken().trim();
                if (val.length() == 0) {
                    continue;
                }
                vallist.addElement(val);
            }
            _value = new String[vallist.size()];
            vallist.copyInto(_value);
        }
        public String[] getValue() {
            return _value;
        }
    }
    /**
     * Adds the elements of the array to the given vector
     */
    public static void addAll(Vector dest, Object[] src) {
        if (src == null) {
            return;
        }
        for (int i = 0; i < src.length; i++) {
            dest.addElement(src[i]);
        }
    }
    /**
     * Checks a array of names for non existent or non directory entries and
     * nulls them out.
     * 
     * @return Count of non-null elements
     */
    public static int checkDirectoryArray(String[] names) {
        int count = 0;
        for (int i = 0; i < names.length; i++) {
            if (names[i] != null) {
                File dir = new File(names[i]);
                if (dir.exists() && dir.isDirectory()) {
                    count++;
                } else {
                    names[i] = null;
                }
            }
        }
        return count;
    }
    /**
     * Extracts the basename of a file, removing the extension, if present
     */
    public static String getBasename(File file) {
        String path = file.getPath();
        // Remove the extension
        String basename = file.getName();
        int pos = basename.lastIndexOf('.');
        if (pos != -1) {
            basename = basename.substring(0, pos);
        }
        return basename;
    }
    /**
     * Gets the parent directory for the executable file name using the current
     * directory and system executable path
     * 
     * @param exeName
     *            Name of executable such as "cl.exe"
     * @return parent directory or null if not located
     */
    public static File getExecutableLocation(String exeName) {
        //
        //   must add current working directory to the
        //      from of the path from the "path" environment variable
        File currentDir = new File(System.getProperty("user.dir"));
        if (new File(currentDir, exeName).exists()) {
            return currentDir;
        }
        File[] envPath = CUtil.getPathFromEnvironment("PATH",
                File.pathSeparator);
        for (int i = 0; i < envPath.length; i++) {
            if (new File(envPath[i], exeName).exists()) {
                return envPath[i];
            }
        }
        return null;
    }
    /**
     * Extracts the parent of a file
     */
    public static String getParentPath(String path) {
        int pos = path.lastIndexOf(File.separator);
        if (pos <= 0) {
            return null;
        }
        return path.substring(0, pos);
    }
    /**
     * Returns an array of File for each existing directory in the specified
     * environment variable
     * 
     * @param envVariable
     *            environment variable name such as "LIB" or "INCLUDE"
     * @param delim
     *            delimitor used to separate parts of the path, typically ";"
     *            or ":"
     * @return array of File's for each part that is an existing directory
     */
    public static File[] getPathFromEnvironment(String envVariable, String delim) {
        // OS/4000 does not support the env command.
        if (System.getProperty("os.name").equals("OS/400"))
            return new File[]{};
        Vector osEnv = Execute.getProcEnvironment();
        String match = envVariable.concat("=");
        for (Enumeration e = osEnv.elements(); e.hasMoreElements();) {
            String entry = ((String) e.nextElement()).trim();
            if (entry.length() > match.length()) {
                String entryFrag = entry.substring(0, match.length());
                if (entryFrag.equalsIgnoreCase(match)) {
                    String path = entry.substring(match.length());
                    return parsePath(path, delim);
                }
            }
        }
        File[] noPath = new File[0];
        return noPath;
    }
    /**
     * Returns a relative path for the targetFile relative to the base
     * directory.
     * 
     * @param canonicalBase
     *            base directory as returned by File.getCanonicalPath()
     * @param targetFile
     *            target file
     * @return relative path of target file. Returns targetFile if there were
     *         no commonalities between the base and the target
     * 
     * @author Curt Arnold
     */
    public static String getRelativePath(String base, File targetFile) {
        try {
            //
            //   remove trailing file separator
            //
            String canonicalBase = base;
            if (base.charAt(base.length() - 1) == File.separatorChar) {
                canonicalBase = base.substring(0, base.length() - 1);
            }
            //
            //   get canonical name of target and remove trailing separator
            //
            String canonicalTarget;
            if (System.getProperty("os.name").equals("OS/400"))
                canonicalTarget = targetFile.getPath();
            else
                canonicalTarget = targetFile.getCanonicalPath();
            if (canonicalTarget.charAt(canonicalTarget.length() - 1) == File.separatorChar) {
                canonicalTarget = canonicalTarget.substring(0, canonicalTarget
                        .length() - 1);
            }
            if (canonicalTarget.equals(canonicalBase)) {
                return ".";
            }
            //
            //  see if the prefixes are the same
            //
            if (canonicalBase.substring(0, 2).equals("\\\\")) {
                //
                //  UNC file name, if target file doesn't also start with same
                //      server name, don't go there
                int endPrefix = canonicalBase.indexOf('\\', 2);
                String prefix1 = canonicalBase.substring(0, endPrefix);
                String prefix2 = canonicalTarget.substring(0, endPrefix);
                if (!prefix1.equals(prefix2)) {
                    return canonicalTarget;
                }
            } else {
                if (canonicalBase.substring(1, 3).equals(":\\")) {
                    int endPrefix = 2;
                    String prefix1 = canonicalBase.substring(0, endPrefix);
                    String prefix2 = canonicalTarget.substring(0, endPrefix);
                    if (!prefix1.equals(prefix2)) {
                        return canonicalTarget;
                    }
                } else {
                    if (canonicalBase.charAt(0) == '/') {
                        if (canonicalTarget.charAt(0) != '/') {
                            return canonicalTarget;
                        }
                    }
                }
            }
            char separator = File.separatorChar;
            int lastSeparator = -1;
            int minLength = canonicalBase.length();
            if (canonicalTarget.length() < minLength) {
                minLength = canonicalTarget.length();
            }
            int firstDifference = minLength + 1;
            //
            //  walk to the shorter of the two paths
            //      finding the last separator they have in common
            for (int i = 0; i < minLength; i++) {
                if (canonicalTarget.charAt(i) == canonicalBase.charAt(i)) {
                    if (canonicalTarget.charAt(i) == separator) {
                        lastSeparator = i;
                    }
                } else {
                    firstDifference = lastSeparator + 1;
                    break;
                }
            }
            StringBuffer relativePath = new StringBuffer(50);
            //
            //   walk from the first difference to the end of the base
            //      adding "../" for each separator encountered
            //
            if (canonicalBase.length() > firstDifference) {
                relativePath.append("..");
                for (int i = firstDifference; i < canonicalBase.length(); i++) {
                    if (canonicalBase.charAt(i) == separator) {
                        relativePath.append(separator);
                        relativePath.append("..");
                    }
                }
            }
            if (canonicalTarget.length() > firstDifference) {
                //
                //    append the rest of the target
                //
                //
                if (relativePath.length() > 0) {
                    relativePath.append(separator);
                }
                relativePath.append(canonicalTarget.substring(firstDifference));
            }
            return relativePath.toString();
        } catch (IOException ex) {
        }
        return targetFile.toString();
    }
    public static boolean isActive(Project p, String ifCond, String unlessCond)
            throws BuildException {
        if (ifCond != null) {
            String ifValue = p.getProperty(ifCond);
            if (ifValue == null) {
                return false;
            } else {
                if (ifValue.equals("false") || ifValue.equals("no")) {
                    throw new BuildException("if condition \"" + ifCond
                            + "\" has suspicious value \"" + ifValue);
                }
            }
        }
        if (unlessCond != null) {
            String unlessValue = p.getProperty(unlessCond);
            if (unlessValue != null) {
                if (unlessValue.equals("false") || unlessValue.equals("no")) {
                    throw new BuildException("unless condition \"" + unlessCond
                            + "\" has suspicious value \"" + unlessValue);
                }
                return false;
            }
        }
        return true;
    }
    /**
     * Parse a string containing directories into an File[]
     * 
     * @param path
     *            path string, for example ".;c:\something\include"
     * @param delim
     *            delimiter, typically ; or :
     */
    public static File[] parsePath(String path, String delim) {
        Vector libpaths = new Vector();
        int delimPos = 0;
        for (int startPos = 0; startPos < path.length(); startPos = delimPos
                + delim.length()) {
            delimPos = path.indexOf(delim, startPos);
            if (delimPos < 0) {
                delimPos = path.length();
            }
            //
            //   don't add an entry for zero-length paths
            //
            if (delimPos > startPos) {
                String dirName = path.substring(startPos, delimPos);
                File dir = new File(dirName);
                if (dir.exists() && dir.isDirectory()) {
                    libpaths.addElement(dir);
                }
            }
        }
        File[] paths = new File[libpaths.size()];
        libpaths.copyInto(paths);
        return paths;
    }
    /**
     * This method is exposed so test classes can overload and test the
     * arguments without actually spawning the compiler
     */
    public static int runCommand(CCTask task, File workingDir,
            String[] cmdline, boolean newEnvironment, Environment env)
            throws BuildException {
        try {
            task.log(Commandline.toString(cmdline), Project.MSG_VERBOSE);
            Execute exe = new Execute(new LogStreamHandler(task,
                    Project.MSG_INFO, Project.MSG_ERR));
            if (System.getProperty("os.name").equals("OS/390"))
                exe.setVMLauncher(false);
            exe.setAntRun(task.getProject());
            exe.setCommandline(cmdline);
            exe.setWorkingDirectory(workingDir);
            if (env != null) {
                String[] environment = env.getVariables();
                if (environment != null) {
                    for (int i = 0; i < environment.length; i++) {
                        task.log("Setting environment variable: "
                                + environment[i], Project.MSG_VERBOSE);
                    }
                }
                exe.setEnvironment(environment);
            }
            exe.setNewenvironment(newEnvironment);
            return exe.execute();
        } catch (java.io.IOException exc) {
            throw new BuildException("Could not launch " + cmdline[0] + ": "
                    + exc, task.getLocation());
        }
    }
    /**
     * Compares the contents of 2 arrays for equaliy.
     */
    public static boolean sameList(Object[] a, Object[] b) {
        if (a == null || b == null || a.length != b.length) {
            return false;
        }
        for (int i = 0; i < a.length; i++) {
            if (!a[i].equals(b[i])) {
                return false;
            }
        }
        return true;
    }
    /**
     * Compares the contents of an array and a Vector for equality.
     */
    public static boolean sameList(Vector v, Object[] a) {
        if (v == null || a == null || v.size() != a.length) {
            return false;
        }
        for (int i = 0; i < a.length; i++) {
            Object o = a[i];
            if (!o.equals(v.elementAt(i))) {
                return false;
            }
        }
        return true;
    }
    /**
     * Compares the contents of an array and a Vector for set equality. Assumes
     * input array and vector are sets (i.e. no duplicate entries)
     */
    public static boolean sameSet(Object[] a, Vector b) {
        if (a == null || b == null || a.length != b.size()) {
            return false;
        }
        if (a.length == 0) {
            return true;
        }
        // Convert the array into a set
        Hashtable t = new Hashtable();
        for (int i = 0; i < a.length; i++) {
            t.put(a[i], a[i]);
        }
        for (int i = 0; i < b.size(); i++) {
            Object o = b.elementAt(i);
            if (t.remove(o) == null) {
                return false;
            }
        }
        return (t.size() == 0);
    }
    /**
     * Converts a vector to a string array.
     */
    public static String[] toArray(Vector src) {
        String[] retval = new String[src.size()];
        src.copyInto(retval);
        return retval;
    }
    /**
     * Replaces any embedded quotes in the string so that the value can be
     * placed in an attribute in an XML file
     * 
     * @param attrValue
     *            value to be expressed
     * @return equivalent attribute literal
     *  
     */
    public static String xmlAttribEncode(String attrValue) {
        int quotePos = attrValue.indexOf('\"');
        if (quotePos < 0) {
            return attrValue;
        }
        int startPos = 0;
        StringBuffer buf = new StringBuffer(attrValue.length() + 20);
        while (quotePos >= 0) {
            buf.append(attrValue.substring(startPos, quotePos));
            buf.append("&quot;");
            startPos = quotePos + 1;
            quotePos = attrValue.indexOf('\"', startPos);
        }
        buf.append(attrValue.substring(startPos));
        return buf.toString();
    }
}
