com.facebook.buck.support.cli.args.PluginBasedCommandHelpPrinter.java Source code

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Here is the source code for com.facebook.buck.support.cli.args.PluginBasedCommandHelpPrinter.java

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/*
 * Copyright 2018-present Facebook, Inc.
 *
 * 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 com.facebook.buck.support.cli.args;

import com.google.common.base.Functions;
import com.google.common.collect.ImmutableSortedMap;
import java.io.OutputStreamWriter;
import java.io.PrintStream;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import org.kohsuke.args4j.OptionHandlerFilter;

/** A helper class that encapsulate printing of usage tests for a given command */
public class PluginBasedCommandHelpPrinter {

    /**
     * Prints the text with usage information for the given command to the provided stream.
     *
     * <p>This method divides command options into multiple categories: global options (common to all
     * commands), common options for this command and options for every plugin-based subcommand.
     */
    public void printUsage(PluginBasedCommand command, PrintStream stream) {
        printShortDescription(command, stream);
        CmdLineParserWithPrintInformation parser = new CmdLineParserWithPrintInformation(command);
        ImmutableSortedMap<PluginBasedSubCommand, CmdLineParserWithPrintInformation> subCommands = command
                .getSubCommands().stream()
                .collect(ImmutableSortedMap.toImmutableSortedMap(
                        Comparator.comparing(PluginBasedSubCommand::getOptionValue), Functions.identity(),
                        CmdLineParserWithPrintInformation::new));

        int len = calculateTotalMaxLen(parser, subCommands.values());

        OutputStreamWriter writer = new OutputStreamWriter(stream);

        printGlobalOptionsUsage(stream, writer, parser, len);
        printCommonOptionsUsage(stream, writer, parser, len);

        for (Map.Entry<PluginBasedSubCommand, CmdLineParserWithPrintInformation> subCommand : subCommands
                .entrySet()) {
            printSubCommandUsage(stream, writer, subCommand.getKey(), subCommand.getValue(),
                    command.getTypeOptionName(), len);
        }

        stream.println();
    }

    private static void printShortDescription(PluginBasedCommand command, PrintStream stream) {
        stream.println("Description: ");
        stream.println("  " + command.getShortDescription());
        stream.println();
    }

    private int calculateTotalMaxLen(CmdLineParserWithPrintInformation parser,
            Collection<CmdLineParserWithPrintInformation> subCommandParsers) {
        int maxLen = parser.calculateMaxLen();
        for (CmdLineParserWithPrintInformation subCommandParser : subCommandParsers) {
            maxLen = Math.max(maxLen, subCommandParser.calculateMaxLen());
        }
        return maxLen;
    }

    private void printGlobalOptionsUsage(PrintStream stream, OutputStreamWriter writer,
            CmdLineParserWithPrintInformation parser, int len) {
        stream.println("Global options:");
        parser.printUsage(writer, GlobalCliOptions::isGlobalOption, len);
        stream.println();
    }

    private void printCommonOptionsUsage(PrintStream stream, OutputStreamWriter writer,
            CmdLineParserWithPrintInformation parser, int len) {
        stream.println("Common options:");
        parser.printUsage(writer, optionHandler -> !GlobalCliOptions.isGlobalOption(optionHandler), len);
        stream.println();
    }

    private void printSubCommandUsage(PrintStream stream, OutputStreamWriter writer, PluginBasedSubCommand cmd,
            CmdLineParserWithPrintInformation subCommandParser, String typeOptionName, int len) {
        String message = cmd.getShortDescription() != null ? " (" + cmd.getShortDescription() + ")" : "";
        stream.println("Options for " + typeOptionName + " " + cmd.getOptionValue() + message + ":");
        subCommandParser.printUsage(writer, OptionHandlerFilter.PUBLIC, len);
        stream.println();
    }
}