X-Git-Url: https://git.argeo.org/?p=lgpl%2Fargeo-commons.git;a=blobdiff_plain;f=org.argeo.cms%2Fsrc%2Forg%2Fargeo%2Fapi%2Fcli%2FHelpCommand.java;fp=org.argeo.cms%2Fsrc%2Forg%2Fargeo%2Fapi%2Fcli%2FHelpCommand.java;h=cd51d76953b6e4f63b23914ad9edbac4313e45dd;hp=0000000000000000000000000000000000000000;hb=b95462873703848193e56fcbe997693630db6121;hpb=55d88fba80cec198a0f11ba7545e19878c51fc5e

diff --git a/org.argeo.cms/src/org/argeo/api/cli/HelpCommand.java b/org.argeo.cms/src/org/argeo/api/cli/HelpCommand.java
new file mode 100644
index 000000000..cd51d7695
--- /dev/null
+++ b/org.argeo.cms/src/org/argeo/api/cli/HelpCommand.java
@@ -0,0 +1,164 @@
+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();
+		}
+	}
+}