/*
 * Copyright 2015 Goldman Sachs.
 *
 * 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.gs.collections.codegenerator.maven;

import java.net.URL;
import java.net.URLClassLoader;
import java.util.Arrays;
import java.util.List;

import com.gs.collections.codegenerator.GsCollectionsCodeGenerator;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.project.MavenProject;

/**
 * @goal generate
 * @phase generate-sources
 * @requiresDependencyResolution compile
 */
public class GenerateMojo extends AbstractMojo
{
    /**
     * Skips code generation if true.
     *
     * @parameter expression="${skipCodeGen}"
     */
    private boolean skipCodeGen;

    /**
     * @parameter expression="${project.build.directory}/generated-sources"
     * @required
     */
    private String templateDirectory;

    /**
     * The Maven project to act upon.
     *
     * @parameter expression="${project}"
     * @required
     */
    private MavenProject project;

    public void execute() throws MojoExecutionException, MojoFailureException
    {
        if (this.skipCodeGen)
        {
            this.getLog().info("Skipping code generation in " + this.project.getArtifactId());
        }
        else
        {
            this.getLog().info("Generating sources to " + this.project.getArtifactId());
        }

        List<URL> urls = Arrays.asList(((URLClassLoader) GenerateMojo.class.getClassLoader()).getURLs());

        final boolean[] error = new boolean[1];
        GsCollectionsCodeGenerator.ErrorListener errorListener = new GsCollectionsCodeGenerator.ErrorListener()
        {
            public void error(String string)
            {
                GenerateMojo.this.getLog().error(string);
                error[0] = true;
            }
        };
        GsCollectionsCodeGenerator gsCollectionsCodeGenerator =
                new GsCollectionsCodeGenerator(this.templateDirectory, this.project.getBasedir(), urls, errorListener);
        if (!this.skipCodeGen)
        {
            int numFilesWritten = gsCollectionsCodeGenerator.generateFiles();
            this.getLog().info("Generated " + numFilesWritten + " files");
        }
        if (error[0])
        {
            throw new MojoExecutionException("Error(s) during code generation.");
        }

        if (gsCollectionsCodeGenerator.isTest())
        {
            this.project.addTestCompileSourceRoot(GsCollectionsCodeGenerator.GENERATED_TEST_SOURCES_LOCATION);
        }
        else
        {
            this.project.addCompileSourceRoot(GsCollectionsCodeGenerator.GENERATED_SOURCES_LOCATION);
        }
    }
}