/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.shell.help.def;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeSet;
import org.jnode.shell.Command;
import org.jnode.shell.CommandInfo;
import org.jnode.shell.Shell;
import org.jnode.shell.ShellUtils;
import org.jnode.shell.help.Help;
import org.jnode.shell.help.HelpException;
import org.jnode.shell.help.HelpFactory;
import org.jnode.shell.syntax.ArgumentBundle;
import org.jnode.shell.syntax.FlagArgument;
import org.jnode.shell.syntax.OptionSyntax;
import org.jnode.shell.syntax.SyntaxBundle;
import org.jnode.shell.syntax.SyntaxManager;
/**
* @author qades
* @author Fabien DUMINY (fduminy@jnode.org)
* @author crawley@jnode.org
*/
public class DefaultHelpFactory extends HelpFactory {
public static final String RESOURCE_NAME = "messages.properties";
private static final int NOMINAL_WIDTH = 75;
/* start with 80 spaces ... */
private static String spaces =
" ";
/**
* Create a new instance
*/
public DefaultHelpFactory() {
}
@Override
public Help getHelp(String alias, CommandInfo cmdInfo) throws HelpException {
SyntaxBundle syntaxes = null;
ArgumentBundle bundle = null;
try {
final Shell shell = ShellUtils.getShellManager().getCurrentShell();
final SyntaxManager syntaxManager = shell.getSyntaxManager();
Command cmd = cmdInfo.createCommandInstance();
if (cmd != null) {
bundle = cmd.getArgumentBundle();
syntaxes = syntaxManager.getSyntaxBundle(alias);
if (syntaxes == null) {
syntaxes = new SyntaxBundle(alias, bundle.createDefaultSyntax());
}
}
} catch (Exception ex) {
throw new HelpException(ex.getMessage(), ex);
}
if (syntaxes != null && bundle != null) {
return new NewSyntaxHelp(syntaxes, bundle);
} else {
return null;
}
}
@Override
public void help(SyntaxBundle syntaxes, ArgumentBundle bundle, PrintWriter out) {
usage(syntaxes, bundle, out);
if (bundle.getDescription() != null) {
out.println("\n" + HelpFactory.getLocalizedHelp("help.description") + ":");
format(out, new Cell[]{new Cell(4, NOMINAL_WIDTH - 4)},
new String[]{bundle.getDescription()});
}
Map<String, TreeSet<String>> flagMap = buildFlagMap(syntaxes);
boolean first = true;
for (org.jnode.shell.syntax.Argument<?> arg : bundle) {
if (arg instanceof FlagArgument) {
if (first) {
out.println("\n" + HelpFactory.getLocalizedHelp("help.options") + ":");
first = false;
}
describeOption((FlagArgument) arg, flagMap.get(arg.getLabel()), out);
}
}
first = true;
for (org.jnode.shell.syntax.Argument<?> arg : bundle) {
if (!(arg instanceof FlagArgument)) {
if (first) {
out.println("\n" + HelpFactory.getLocalizedHelp("help.parameters") + ":");
first = false;
}
describeArgument(arg, out);
}
}
}
private Map<String, TreeSet<String>> buildFlagMap(SyntaxBundle syntaxes) {
HashMap<String, TreeSet<String>> res = new HashMap<String, TreeSet<String>>();
for (org.jnode.shell.syntax.Syntax syntax : syntaxes.getSyntaxes()) {
buildFlagMap(syntax, res);
}
return res;
}
private void buildFlagMap(org.jnode.shell.syntax.Syntax syntax,
HashMap<String, TreeSet<String>> res) {
if (syntax instanceof OptionSyntax) {
OptionSyntax os = (OptionSyntax) syntax;
String key = os.getArgName();
TreeSet<String> options = res.get(key);
if (options == null) {
options = new TreeSet<String>();
res.put(key, options);
}
String shortOptName = os.getShortOptName();
if (shortOptName != null) {
options.add(shortOptName);
}
String longOptName = os.getLongOptName();
if (longOptName != null) {
options.add(longOptName);
}
} else {
for (org.jnode.shell.syntax.Syntax child : syntax.getChildren()) {
buildFlagMap(child, res);
}
}
}
@Override
public void usage(SyntaxBundle syntaxBundle, ArgumentBundle bundle, PrintWriter out) {
String command = syntaxBundle.getAlias();
String usageText = HelpFactory.getLocalizedHelp("help.usage") + ":";
int usageLength = usageText.length();
int commandLength = command.length();
Cell[] cells =
new Cell[]{new Cell(0, usageLength), new Cell(1, commandLength),
new Cell(1, NOMINAL_WIDTH - 2 - usageLength - commandLength)};
String[] texts = new String[]{usageText, command, null};
String[] texts2 = new String[]{"", "", null};
org.jnode.shell.syntax.Syntax[] syntaxes = syntaxBundle.getSyntaxes();
if (syntaxes.length > 0) {
for (int i = 0; i < syntaxes.length; i++) {
if (i == 1) {
texts[0] = getSpaces(usageLength);
}
texts[2] = syntaxes[i].format(bundle);
format(out, cells, texts);
texts2[2] = syntaxes[i].getDescription();
format(out, cells, texts2);
}
} else {
texts[2] = "";
format(out, cells, texts);
}
}
@Override
public void describeArgument(org.jnode.shell.syntax.Argument<?> arg, PrintWriter out) {
String description = "(" + arg.getTypeDescription() + ") " + arg.getDescription();
format(out, new Cell[]{new Cell(4, 16), new Cell(2, NOMINAL_WIDTH - 22)},
new String[]{"<" + arg.getLabel() + ">", description});
}
@Override
public void describeOption(FlagArgument arg, TreeSet<String> flagTokens, PrintWriter out) {
StringBuilder sb = new StringBuilder();
for (String flagToken : flagTokens) {
if (sb.length() > 0) {
sb.append(" | ");
}
sb.append(flagToken);
}
format(out, new Cell[]{new Cell(4, 16), new Cell(2, NOMINAL_WIDTH - 22)},
new String[]{sb.toString(), arg.getDescription()});
}
protected void format(PrintWriter out, Cell[] cells, String[] texts) {
if (cells.length != texts.length) {
throw new IllegalArgumentException("Number of cells and texts must match");
}
// The text remaining to be formatted for each column.
String[] remains = new String[texts.length];
// The total count of characters remaining
int remainsCount = 0;
// Initialize 'remains' and 'remainsCount' for the first iteration
for (int i = 0; i < texts.length; i++) {
remains[i] = (texts[i] == null) ? "" : texts[i].trim();
remainsCount += remains[i].length();
}
StringBuilder result = new StringBuilder();
// Repeat while there is still text to output.
while (remainsCount > 0) {
// Each iteration uses 'fit' to get up to 'cell.width' characters from each column
// and then uses 'stamp' to append to them to the buffer with the leading margin
// and trailing padding as required.
remainsCount = 0;
for (int i = 0; i < cells.length; i++) {
String field = cells[i].fit(remains[i]);
remains[i] = remains[i].substring(field.length());
remainsCount += remains[i].length();
result.append(cells[i].stamp(field.trim()));
}
result.append('\n');
}
out.print(result.toString());
}
/**
* Get a String consisting of 'count' spaces.
*
* @param count the number of spaces
* @return the string
*/
private static String getSpaces(int count) {
// The following assumes that 1) StringBuilder.append is efficient if you
// preallocate the StringBuilder, 2) StringBuilder.toString() does no character
// copying, and 3) String.substring(...) also does no character copying.
int len = spaces.length();
if (count > len) {
StringBuilder sb = new StringBuilder(count);
for (int i = 0; i < count; i++) {
sb.append(' ');
}
spaces = sb.toString();
return spaces;
} else if (count == len) {
return spaces;
} else {
return spaces.substring(0, count);
}
}
/**
* A Cell is a template for formatting text for help messages. (It is 'protected' so that
* the unit test can declare a subclass ...)
*/
protected static class Cell {
final String field;
final int margin;
final int width;
/**
* Construct a Cell with a leading margin and a text width.
*
* @param margin the number of leading spaces for the Cell
* @param width the width of the text part of the Cell
*/
protected Cell(int margin, int width) {
this.margin = margin;
this.width = width;
// for performance, we pre-build the field mask
this.field = getSpaces(margin + width);
}
/**
* Heuristically, split of a head substring of 'text' to fit within this Cell's width. We try
* to split at a space character, but if this will make the text too ragged, we simply chop.
*/
protected String fit(String text) {
if (width >= text.length()) {
return text;
}
String hardFit = text.substring(0, width);
if (hardFit.endsWith(" ")) {
return hardFit;
}
int lastSpace = hardFit.lastIndexOf(' ');
if (lastSpace > 3 * width / 4) {
return hardFit.substring(0, lastSpace);
} else {
return hardFit;
}
}
/**
* Stamp out a line with leading and trailing spaces to fill the Cell.
*/
protected String stamp(String text) {
if (text.length() > field.length())
throw new IllegalArgumentException("Text length exceeds field width");
return field.substring(0, margin) + text + field.substring(0, width - text.length());
}
}
}