gradle-master/subprojects/platform-base/src/main/java/org/gradle/language/base/internal/plugins/CleanRule.java
/*
 * Copyright 2014 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.language.base.internal.plugins;

import org.apache.commons.lang.StringUtils;
import org.gradle.api.Rule;
import org.gradle.api.Task;
import org.gradle.api.tasks.Delete;
import org.gradle.api.tasks.TaskContainer;

public class CleanRule implements Rule {

    public static final String CLEAN = "clean";

    private final TaskContainer tasks;

    public CleanRule(TaskContainer tasks) {
        this.tasks = tasks;
    }

    @Override
    public String getDescription() {
        return "Pattern: " + CLEAN + "<TaskName>: Cleans the output files of a task.";
    }

    @Override
    public String toString() {
        return "Rule: " + getDescription();
    }

    @Override
    public void apply(String taskName) {
        if (!taskName.startsWith(CLEAN) || taskName.equals(CLEAN)) {
            return;
        }
        String targetTaskName = taskName.substring(CLEAN.length());
        if (Character.isLowerCase(targetTaskName.charAt(0))) {
            return;
        }

        Task task = tasks.findByName(StringUtils.uncapitalize(targetTaskName));
        if (task == null) {
            return;
        }

        Delete clean = tasks.create(taskName, Delete.class);
        clean.delete(task.getOutputs().getFiles());
    }
}
