/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * <BR><BR>
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * <BR><BR>
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * <BR><BR>
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * <BR><BR>
 *
 * This program 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 for more details.
 *
 * <BR><BR>
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *########################################################################
 */

package org.greenstone.gatherer.util;


// Don't even think about adding import java.awt.* here!
// The functions in this class should not use any graphical classes. Put your function somewhere else buster!
import java.io.*;
import java.net.*;
import java.util.*;
// Don't even think about adding import javax.swing.* here!
// The functions in this class should not use any graphical classes. Put your function somewhere else buster!
import org.greenstone.gatherer.Dictionary;
// Don't even think about adding import org.greenstone.gatherer.Gatherer in here!
// The functions in this class should be independent of the Gatherer class. Put your function somewhere else buster!


/** To provide a library of common methods, in a static context, for use in the Gatherer.
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.3b
 */
public class Utility
{
    /** Definition of an important directory name, in this case the file the collection configuration is expect to be in. */
    static final public String CONFIG_FILE = "etc" + File.separator + "collect.cfg";
    static final public String CONFIG_GS3_FILE = "etc" + File.separator + "collectionConfig.xml";
    static final public String COLLECT_CFG = "collect.cfg";
    static final public String COLLECT_BAK = "collect.bak";
    static final public String COLLECTION_CONFIG_XML = "collectionConfig.xml";
    static final public String COLLECTION_CONFIG_BAK = "collectionConfig.bak";
    static final public String GS3MODE_ARGUMENT = "-gs3mode";
    static final public String BUILD_CFG = "build.cfg";
    static final public String BUILD_CONFIG_XML = "buildConfig.xml";

    /** The default name of the perl executable under unix. */
    static final public String PERL_EXECUTABLE_UNIX = "perl";
    /** The default name of the perl executable under windows. */
    static final public String PERL_EXECUTABLE_WINDOWS = "Perl.exe";


    /**
     * Delete a file or directory
     * @param file The <strong>File</strong> you want to delete.
     * @return A <i>boolean</i> which is <i>true</i> if the file specified was successfully deleted, <i>false</i> otherwise.
     */
    static public boolean delete(File file)
    {
	// Nothing to do if it doesn't exist
	if (!file.exists()) {
	    return true;
	}

	return deleteInternal(file);
    }


    /** Convenience function. */
    static public boolean delete(String filename)
    {
	return delete(new File(filename));
    }


    /** In Java you have to make sure a directory is empty before you delete it, so recursively delete. */
    static private boolean deleteInternal(File file)
    {
	// If file is a directory, we have to recursively delete its contents first
	if (file.isDirectory()) {
	    File files[] = file.listFiles();
	    for (int i = 0; i < files.length; i++) {
		if (deleteInternal(files[i]) == false) {
		    System.err.println("Error: Could not delete folder " + file);
		    return false;
		}
	    }
	}

	// Delete file
	if (file.delete() == false) {
	    System.err.println("Error: Could not delete file " + file);
	    return false;
	}

	return true;
    }


    /** Convert a long, detailing the length of a file in bytes, into a nice human readable string using b, kb, Mb and Gb. */
    static final public String BYTE_SUFFIX = " b";
    static final public long GIGABYTE = 1024000000l;
    static final public String GIGABYTE_SUFFIX = " Gb";
    static final public long KILOBYTE =       1024l;
    static final public String KILOBYTE_SUFFIX = " kb";
    static final public long MEGABYTE =    1024000l;
    static final public String MEGABYTE_SUFFIX = " Mb";
    static final public String formatFileLength(long length) {
	StringBuffer result = new StringBuffer("");
	float number = 0f;
	String suffix = null;
	// Determine the floating point number and the suffix (radix) used.
	if(length >= GIGABYTE) {
	    number = (float) length / (float) GIGABYTE;
	    suffix = GIGABYTE_SUFFIX;
	}
	else if(length >= MEGABYTE) {
	    number = (float) length / (float) MEGABYTE;
	    suffix = MEGABYTE_SUFFIX;
	}
	else if(length >= KILOBYTE) {
	    number = (float) length / (float) KILOBYTE;
	    suffix = KILOBYTE_SUFFIX;
	}
	else {
	    // Don't need to do anything fancy if the file is smaller than a kilobyte
	    return length + BYTE_SUFFIX;
	}
	// Create the formatted string remembering to round the number to 2.d.p. To do this copy everything in the number string from the start to the first occurance of '.' then copy two more digits. Finally search for and print anything that appears after (and including) the optional 'E' delimter.
	String number_str = Float.toString(number);
	char number_char[] = number_str.toCharArray();
	int pos = 0;
	// Print the characters up to the '.'
	while(number_char != null && pos < number_char.length && number_char[pos] != '.') {
	    result.append(number_char[pos]);
	    pos++;
	}
	if(pos < number_char.length) {
	    // Print the '.' and at most two characters after it
	    result.append(number_char[pos]);
	    pos++;
	    for(int i = 0; i < 2 && pos < number_char.length; i++, pos++) {
		result.append(number_char[pos]);
	    }
	    // Search through the remaining string for 'E'
	    while(pos < number_char.length && number_char[pos] != 'E') {
		pos++;
	    }
	    // If we still have string then we found an E. Copy the remaining string.
	    while(pos < number_char.length) {
		result.append(number_char[pos]);
		pos++;
	    }
	}
	// Add suffix
	result.append(suffix);
	// Done
	return result.toString();
    }

    /** This method formats a given string, using HTML markup, so its width does not exceed the given width and its appearance if justified.
     * @param text The <strong>String</strong> requiring formatting.
     * @param width The maximum width per line as an <i>int</i>.
     * @return A <strong>String</strong> formatted so as to have no line longer than the specified width.
     * TODO Currently HTML formatting tags are simply removed from the text, as the effects of spreading HTML tags over a break are undetermined. To solve this we need to associate tags with a certain text token so if it gets broken on to the next line the tags go with it, or if the tags cover a sequence of words that are broken we need to close then reopen the tags. However all this is a major task and well beyond anything I have time to 'muck-round' on.
     */
    static public String formatHTMLWidth(String text, int width) {
	if(text == null) {
	    return "Error";
	}
	HTMLStringTokenizer html = new HTMLStringTokenizer(text);
	int current_width = 0;
	int threshold = width / 2;
	Stack lines = new Stack();
	String line = "";
	while(html.hasMoreTokens()) {
	    String token = html.nextToken();
	    while(token != null) {
		if(html.isTag()) {
		    // Insert smart HTML tag code here.
		    token = null;
		}
		else {
		    // If the token is bigger than two thirds width, before we've even started break it down.
		    if(current_width + 1 + token.length() > width && token.length() > threshold) {
			if(width == current_width) {
			    lines.push(line);
			    line = token;
			    current_width = token.length();
			}
			else {
			    String prefix = token.substring(0, width - 1 - current_width);
			    token = token.substring(prefix.length());
			    if(current_width == 0) {
				line = line + prefix;
			    }
			    else {
				line = line + " " + prefix;
			    }
			    lines.push(line);
			    line = "";
			    current_width = 0;
			}
		    }
		    // If adding the next token would push us over the maximum line width.
		    else if(current_width + 1 + token.length() > width) {
			lines.push(line);
			line = token;
			current_width = token.length();
			token = null;
		    }
		    // Otherwise we should be able to just add the token, give or take.
		    else {
			if(current_width == 0) {
			    line = line + token;
			    current_width = token.length();
			}
			else {
			    // Special case for standard punctuation which may exist after a tag like so:
			    // My name is <scratchy>Slim Shady</scratchy>.   <-- Annoying punctuation.
			    if(token.equals(".") || token.equals(",") || token.equals("!") || token.equals("?")) {
				line = line + token;
				current_width = current_width + 1;
			    }
			    else {
				line = line + " " + token;
				current_width = current_width + 1 + token.length();
			    }
			}
			token = null;
		    }
		}
	    }
	}
	String result = line;
	while(!lines.empty()) {
	    result = (String)lines.pop() + "<BR>" + result;
	}
	// Replace ' ' with "&nbsp;"
	boolean tag = false;
	int pos = 0;
	while(pos < result.length()) {
	    if(result.charAt(pos) == '<') {
		tag = true;
	    }
	    else if(result.charAt(pos) == '>') {
		tag = false;
	    }
	    else if(result.charAt(pos) == ' ' && !tag) {
		String prefix = result.substring(0, pos);
		String suffix = result.substring(pos + 1);
		result = prefix + "&nbsp;" + suffix;
	    }
	    pos++;
	}
	result = "<HTML>" + result + "</HTML>";
	return result;
    }


    static public String getDateString() {
	Calendar current = Calendar.getInstance();
	String day_name = null;
	switch(current.get(Calendar.DAY_OF_WEEK)) {
	case Calendar.MONDAY: day_name = "Dates.Mon"; break;
	case Calendar.TUESDAY: day_name = "Dates.Tue"; break;
	case Calendar.WEDNESDAY: day_name = "Dates.Wed"; break;
	case Calendar.THURSDAY: day_name = "Dates.Thu"; break;
	case Calendar.FRIDAY: day_name = "Dates.Fri"; break;
	case Calendar.SATURDAY: day_name = "Dates.Sat"; break;
	case Calendar.SUNDAY: day_name = "Dates.Sun"; break;
	default: day_name = "";
	}
	String month_name = null;
	switch(current.get(Calendar.MONTH)) {
	case Calendar.JANUARY: month_name = "Dates.Jan"; break;
	case Calendar.FEBRUARY: month_name = "Dates.Feb"; break;
	case Calendar.MARCH: month_name = "Dates.Mar"; break;
	case Calendar.APRIL: month_name = "Dates.Apr"; break;
	case Calendar.MAY: month_name = "Dates.May"; break;
	case Calendar.JUNE: month_name = "Dates.Jun"; break;
	case Calendar.JULY: month_name = "Dates.Jul"; break;
	case Calendar.AUGUST: month_name = "Dates.Aug"; break;
	case Calendar.SEPTEMBER: month_name = "Dates.Sep"; break;
	case Calendar.OCTOBER: month_name = "Dates.Oct"; break;
	case Calendar.NOVEMBER: month_name = "Dates.Nov"; break;
	case Calendar.DECEMBER: month_name = "Dates.Dec"; break;
	default: month_name = "";
	}
	int day = current.get(Calendar.DAY_OF_MONTH);
	int hour = current.get(Calendar.HOUR_OF_DAY);
	int minute = current.get(Calendar.MINUTE);
	int second = current.get(Calendar.SECOND);
	int year = current.get(Calendar.YEAR);

	return Dictionary.get(day_name) + " " + Dictionary.get(month_name) + " " + day + " " + year + " " + Utility.pad(String.valueOf(hour), 2, '0', true) + ":" + Utility.pad(String.valueOf(minute), 2, '0', true) + ":" + Utility.pad(String.valueOf(second), 2, '0', true);
    }


    /** Determine this machines name.
     * @return The name as a <strong>String</strong>.
     */
    static public String getMachineName() {
	try {
	    return InetAddress.getLocalHost().getHostName();
	}
	catch(UnknownHostException ex) {
	}
	return "Unknown Machine";
    }


    static public String getSitesDir(String gsdl3_path) {
	return gsdl3_path + "sites" + File.separator;

    }


    /** Method to determine if the host system is MacOS based.
     * @return a boolean which is true if the platform is MacOS, false otherwise
     */
    public static boolean isMac() {
	Properties props = System.getProperties();
	String os_name = props.getProperty("os.name","");
	if(os_name.startsWith("Mac OS")) {
	    return true;
	}
	return false;
    }

   
    /** Method to determine if the host system is Microsoft Windows based.
     * @return A <i>boolean</i> which is <i>true</i> if the platform is Windows, <i>false</i> otherwise.
     */
    public static boolean isWindows() {
	Properties props = System.getProperties();
	String os_name = props.getProperty("os.name","");
	if(os_name.startsWith("Windows")) {
	    return true;
	}
	return false;
    }

    public static boolean isWindows9x() {
	Properties props = System.getProperties();
	String os_name = props.getProperty("os.name","");
	if(os_name.startsWith("Windows") && os_name.indexOf("9") != -1) {
	    return true;
	}
	return false;
    }
    /** Takes a string and a desired length and pads out the string to the length by adding spaces to the left.
     * @param str The target <strong>String</strong> that needs to be padded.
     * @param length The desired length of the string as an <i>int</i>.
     * @return A <strong>String</strong> made from appending space characters with the string until it has a length equal to length.
     */
    static private String pad(String str_raw, int length, char fill, boolean end) {
	StringBuffer str = new StringBuffer(str_raw);
	while(str.length() < length) {
	    if(end) {
		str.insert(0, fill);
	    }
	    else {
		str.append(fill);
	    }
	}
	return str.toString();
    }


    /** Builds the cache dir by appending the user path and 'cache'.
     * @return a File representing the path to the private file cache within the current collection.
     */
    public static File getCacheDir() {
	return new File(getGLIUserFolder(), StaticStrings.CACHE_FOLDER);
    }

   /** Method which constructs the log directory given a certain collection.
     * @param col_dir The location of the collection directory as a <strong>String</strong>.
     * @return The location of the given collections log directory, also as a <strong>String</strong>.
     */
    public static String getLogDir(String col_dir) {
	if(col_dir != null) {
	    return col_dir + LOG_DIR;
	}
	else {
	    return getGLIUserFolder().getAbsolutePath() + File.separator + LOG_DIR;
	}
    }

    static final private String APPLICATION_DATA_FOLDER = "Application Data";
    static final private String UNIX_GLI_CONFIG_FOLDER = ".gli";
    static final private String USER_HOME_PROPERTY = "user.home";
    static final private String WIN_GLI_CONFIG_FOLDER = "Greenstone" + File.separator + "GLI";
     /** Definition of an important directory name, in this case the log directory for the collection. */
    static final public String LOG_DIR = "log" + File.separator;

    static public File getGLIUserFolder()
    {
	if (Utility.isWindows()) {
	    return new File(System.getProperty(USER_HOME_PROPERTY) + File.separator + APPLICATION_DATA_FOLDER + File.separator + WIN_GLI_CONFIG_FOLDER + File.separator);
	}
	else {
	    return new File(System.getProperty(USER_HOME_PROPERTY) + File.separator + UNIX_GLI_CONFIG_FOLDER + File.separator);
	}
    }

  static private HashMap plugin_map = null;
  
  static private void setUpPluginNameMap() {
    plugin_map = new HashMap();
    plugin_map.put("GAPlug", "GreenstoneXMLPlugin");
    plugin_map.put("RecPlug", "DirectoryPlugin");
    plugin_map.put("ArcPlug","ArchivesInfPlugin");
    plugin_map.put("TEXTPlug","TextPlugin");
    plugin_map.put("XMLPlug","ReadXMLFile");
    plugin_map.put("EMAILPlug","EmailPlugin");
    plugin_map.put("SRCPlug","SourceCodePlugin");
    plugin_map.put("NULPlug","NulPlugin");
    plugin_map.put("W3ImgPlug","HTMLImagePlugin");
    plugin_map.put("PagedImgPlug","PagedImagePlugin");
    plugin_map.put("METSPlug", "GreenstoneMETSPlugin");
    plugin_map.put("DBPlug", "DatabasePlugin");
    plugin_map.put("PPTPlug", "PowerPointPlugin");
    plugin_map.put("PSPlug", "PostScriptPlugin");
  }

  static public String ensureNewPluginName(String plugin) {
    if (plugin.endsWith("Plugin")) return plugin;
    if (plugin_map == null) {
      setUpPluginNameMap();
    }
    String new_name = (String)plugin_map.get(plugin);
    if (new_name != null) return new_name;
    new_name = plugin.replaceAll("Plug", "Plugin");
    return new_name;
  }

    
    /** Write out a property line--a (property, value) pair--to the gsdl(3)site.cfg file.
     * If the file already contains the line as-is, it is not re-written.	
     * If the file doesn't contain the line, it is appended.
     * If the file contained a different value for the property, the line is corrected
     * and the file is written out.
     * Not using the Properties class, as we want to keep the file's contents in the 
     * same order and preserve all the comments in as they're meant to help the user.
     */
    public static void updatePropertyConfigFile(String filename, String propertyName, String propertyValue) {
	File propFile = new File(filename);
	if(!propFile.exists()) {
		System.err.println("*** Unable to update property " + propertyName + " in file " 
				+ filename + "to\n" + propertyValue + ". File does not exist.\n");
		return;
	}	
	BufferedReader fin = null;
	BufferedWriter fout = null;
	StringBuffer contents = new StringBuffer();
	String insertLine = propertyName+"\t"+propertyValue+"\n"; // new line after every propertyLine
	boolean found = false;
	try {
	    fin = new BufferedReader(new FileReader(filename));
	    String line = "";
	    while((line = fin.readLine()) != null) {
		if(line.startsWith(propertyName)) { // won't match comment
		    found = true;
		    if(line.equals(insertLine)) { // file is already correct, nothing to do
			fin.close();
			fin = null;
			break;
		    } else {
			contents.append(insertLine);
		    }

		} else { // any other line
		    contents.append(line);		    
		    contents.append("\n"); // ensures the required new line at end of file
		}
	    }

	    if(fin != null) { // need to write something out to the file
		fin.close();
		fin = null;

		// if collecthome wasn't already specified in the file, append it
		if(!found) { 
		    fout = new BufferedWriter(new FileWriter(filename, true)); // append mode
		    fout.write(insertLine, 0, insertLine.length());
		} else {
		    
		    fout = new BufferedWriter(new FileWriter(filename)); // hopefully this will overwrite
		    fout.write(contents.toString(), 0, contents.length());
		}

		fout.close();
		fout = null;
	    } // else the file is fine
	} catch(IOException e) {
	    System.err.println("*** Could not update file: " + filename); 
	    System.err.println("with the " + propertyName + " property set to " + propertyValue);
	    System.err.println("Exception occurred: " + e.getMessage());
	} finally {
	    try {
		if(fin != null) {
		    fin.close();
		    fin = null;
		}
		if(fout != null) {
		    fout.close();
		    fout = null;
		}
	    } catch(IOException ioe) {
		fin = null;
		fout = null;
	    }
	    
	}
	
    }
   
}