gradle-master/subprojects/core/src/main/java/org/gradle/execution/commandline/CommandLineTaskConfigurer.java
/*
 * Copyright 2012 the original author or authors.
 *
 * 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 org.gradle.execution.commandline;

import org.gradle.api.Task;
import org.gradle.api.internal.tasks.TaskOptionsGenerator;
import org.gradle.api.internal.tasks.TaskOptionsGenerator.TaskOptions;
import org.gradle.api.internal.tasks.options.OptionDescriptor;
import org.gradle.api.internal.tasks.options.OptionReader;
import org.gradle.cli.CommandLineArgumentException;
import org.gradle.cli.CommandLineParser;
import org.gradle.cli.ParsedCommandLine;
import org.gradle.cli.ParsedCommandLineOption;
import org.gradle.internal.service.scopes.Scopes;
import org.gradle.internal.service.scopes.ServiceScope;
import org.gradle.internal.typeconversion.TypeConversionException;

import java.util.Collection;
import java.util.List;

@ServiceScope(Scopes.Gradle.class)
public class CommandLineTaskConfigurer {
    private OptionReader optionReader;

    public CommandLineTaskConfigurer(OptionReader optionReader) {
        this.optionReader = optionReader;
    }

    public List<String> configureTasks(Collection<Task> tasks, List<String> arguments) {
        assert !tasks.isEmpty();
        if (arguments.isEmpty()) {
            return arguments;
        }
        return configureTasksNow(tasks, arguments);
    }

    private List<String> configureTasksNow(Collection<Task> tasks, List<String> arguments) {
        List<String> remainingArguments = null;
        for (Task task : tasks) {
            CommandLineParser parser = new CommandLineParser();
            TaskOptions taskOptions = TaskOptionsGenerator.generate(task, optionReader);
            List<OptionDescriptor> commandLineOptions = taskOptions.getAll();
            for (OptionDescriptor optionDescriptor : commandLineOptions) {
                String optionName = optionDescriptor.getName();
                org.gradle.cli.CommandLineOption option = parser.option(optionName);
                option.hasDescription(optionDescriptor.getDescription());
                option.hasArgument(optionDescriptor.getArgumentType());
            }
            taskOptions.addMutualExclusions(parser);

            ParsedCommandLine parsed;
            try {
                parsed = parser.parse(arguments);
            } catch (CommandLineArgumentException e) {
                //we expect that all options must be applicable for each task
                throw new TaskConfigurationException(task.getPath(), "Problem configuring task " + task.getPath() + " from command line.", e);
            }

            for (OptionDescriptor commandLineOptionDescriptor : commandLineOptions) {
                final String name = commandLineOptionDescriptor.getName();
                if (parsed.hasOption(name)) {
                    ParsedCommandLineOption o = parsed.option(name);
                    try {
                        commandLineOptionDescriptor.apply(task, o.getValues());
                    } catch (TypeConversionException ex) {
                        throw new TaskConfigurationException(task.getPath(),
                                String.format("Problem configuring option '%s' on task '%s' from command line.", name, task.getPath()), ex);
                    }
                }
            }
            assert remainingArguments == null || remainingArguments.equals(parsed.getExtraArguments())
                    : "we expect all options to be consumed by each task so remainingArguments should be the same for each task";
            remainingArguments = parsed.getExtraArguments();
        }
        return remainingArguments;
    }
}
