--- /dev/null
+package org.argeo.api.cli;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.List;
+import java.util.function.Function;
+
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.Options;
+
+/** A special command that can describe {@link DescribedCommand}. */
+public class HelpCommand implements DescribedCommand<String> {
+ /**
+ * System property forcing the root command to this value (typically the name of
+ * a script).
+ */
+ public final static String ROOT_COMMAND_PROPERTY = "org.argeo.api.cli.rootCommand";
+
+ final static String HELP = "help";
+ final static Option HELP_OPTION = Option.builder().longOpt(HELP).desc("print this help").build();
+
+ private CommandsCli commandsCli;
+ private CommandsCli parentCommandsCli;
+
+ // Help formatting
+ private static int helpWidth = 80;
+ private static int helpLeftPad = 4;
+ private static int helpDescPad = 20;
+
+ public HelpCommand(CommandsCli parentCommandsCli, CommandsCli commandsCli) {
+ super();
+ this.parentCommandsCli = parentCommandsCli;
+ this.commandsCli = commandsCli;
+ }
+
+ @Override
+ public String apply(List<String> args) {
+ StringWriter out = new StringWriter();
+
+ if (args.size() == 0) {// overview
+ printHelp(commandsCli, out);
+ } else {
+ String cmd = args.get(0);
+ Function<List<String>, ?> function = commandsCli.getCommand(cmd);
+ if (function == null)
+ return "Command " + cmd + " not found.";
+ Options options;
+ String examples;
+ DescribedCommand<?> command = null;
+ if (function instanceof DescribedCommand) {
+ command = (DescribedCommand<?>) function;
+ options = command.getOptions();
+ examples = command.getExamples();
+ } else {
+ options = new Options();
+ examples = null;
+ }
+ String description = getShortDescription(function);
+ String commandCall = getCommandUsage(cmd, command);
+ HelpFormatter formatter = new HelpFormatter();
+ formatter.printHelp(new PrintWriter(out), helpWidth, commandCall, description, options, helpLeftPad,
+ helpDescPad, examples, false);
+ }
+ return out.toString();
+ }
+
+ private static String getShortDescription(Function<List<String>, ?> function) {
+ if (function instanceof DescribedCommand) {
+ return ((DescribedCommand<?>) function).getDescription();
+ } else {
+ return function.toString();
+ }
+ }
+
+ public String getCommandUsage(String cmd, DescribedCommand<?> command) {
+ String commandCall = getCommandCall(commandsCli) + " " + cmd;
+ assert command != null;
+ if (command != null && command.getUsage() != null) {
+ commandCall = commandCall + " " + command.getUsage();
+ }
+ return commandCall;
+ }
+
+ @Override
+ public String getDescription() {
+ return "Shows this help or describes a command";
+ }
+
+ @Override
+ public String getUsage() {
+ return "[command]";
+ }
+
+ public CommandsCli getParentCommandsCli() {
+ return parentCommandsCli;
+ }
+
+ protected String getCommandCall(CommandsCli commandsCli) {
+ HelpCommand hc = commandsCli.getHelpCommand();
+ if (hc.getParentCommandsCli() != null) {
+ return getCommandCall(hc.getParentCommandsCli()) + " " + commandsCli.getCommandName();
+ } else {
+ String rootCommand = System.getProperty(ROOT_COMMAND_PROPERTY);
+ if (rootCommand != null)
+ return rootCommand;
+ return commandsCli.getCommandName();
+ }
+ }
+
+ public static void printHelp(DescribedCommand<?> command, StringWriter out) {
+ String usage = "java " + command.getClass().getName()
+ + (command.getUsage() != null ? " " + command.getUsage() : "");
+ HelpFormatter formatter = new HelpFormatter();
+ Options options = command.getOptions();
+ options.addOption(HelpCommand.HELP_OPTION);
+ formatter.printHelp(new PrintWriter(out), helpWidth, usage, command.getDescription(), options, helpLeftPad,
+ helpDescPad, command.getExamples(), false);
+
+ }
+
+ public static void printHelp(CommandsCli commandsCli, String commandName, StringWriter out) {
+ if (commandName == null) {
+ printHelp(commandsCli, out);
+ return;
+ }
+ DescribedCommand<?> command = (DescribedCommand<?>) commandsCli.getCommand(commandName);
+ String usage = commandsCli.getHelpCommand().getCommandUsage(commandName, command);
+ HelpFormatter formatter = new HelpFormatter();
+ Options options = command.getOptions();
+ options.addOption(HelpCommand.HELP_OPTION);
+ formatter.printHelp(new PrintWriter(out), helpWidth, usage, command.getDescription(), options, helpLeftPad,
+ helpDescPad, command.getExamples(), false);
+
+ }
+
+ public static void printHelp(CommandsCli commandsCli, StringWriter out) {
+ out.append(commandsCli.getDescription()).append('\n');
+ String leftPad = spaces(helpLeftPad);
+ for (String cmd : commandsCli.getSubCommands()) {
+ Function<List<String>, ?> function = commandsCli.getCommand(cmd);
+ assert function != null;
+ out.append(leftPad);
+ out.append(cmd);
+ // TODO deal with long commands
+ out.append(spaces(helpDescPad - cmd.length()));
+ out.append(getShortDescription(function));
+ out.append('\n');
+ }
+ }
+
+ private static String spaces(int count) {
+ // Java 11
+ // return " ".repeat(count);
+ if (count <= 0)
+ return "";
+ else {
+ StringBuilder sb = new StringBuilder(count);
+ for (int i = 0; i < count; i++)
+ sb.append(' ');
+ return sb.toString();
+ }
+ }
+}
projects / lgpl / argeo-commons.git / blobdiff