/*******************************************************************************
 * Source of this file 'http://www.eclemma.org/jacoco/trunk/doc/examples/java/ReportGenerator.java'
 * We have modified it to make it compatible with Buck's usage.
 *
 * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Brock Janiczak - initial API and implementation
 *******************************************************************************/
package com.facebook.buck.java;

import org.jacoco.core.analysis.Analyzer;
import org.jacoco.core.analysis.CoverageBuilder;
import org.jacoco.core.analysis.IBundleCoverage;
import org.jacoco.core.tools.ExecFileLoader;
import org.jacoco.report.DirectorySourceFileLocator;
import org.jacoco.report.FileMultiReportOutput;
import org.jacoco.report.IReportVisitor;
import org.jacoco.report.ISourceFileLocator;
import org.jacoco.report.MultiSourceFileLocator;
import org.jacoco.report.csv.CSVFormatter;
import org.jacoco.report.html.HTMLFormatter;
import org.jacoco.report.xml.XMLFormatter;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * This example creates a HTML report for eclipse like projects based on a
 * single execution data store called jacoco.exec. The report contains no
 * grouping information.
 *
 * The class files under test must be compiled with debug information, otherwise
 * source highlighting will not work.
 */
public class ReportGenerator {

        private static final int TAB_WIDTH = 4;

        private final String title;

        private final File executionDataFile;
        private final ExecFileLoader execFileLoader;
        private final String classesPath;
        private final String sourcesPath;
        private final File reportDirectory;
        private final String reportFormat;

        /**
         * Create a new generator based for the given project.
         */
        public ReportGenerator() {
                String jacocoOutputDir = System.getProperty("jacoco.output.dir");
                this.title = "Code-Coverage Analysis";
                this.executionDataFile = new File(
                    jacocoOutputDir, System.getProperty("jacoco.exec.data.file"));
                this.execFileLoader = new ExecFileLoader();
                this.classesPath = System.getProperty("classes.dir");
                this.sourcesPath = System.getProperty("src.dir");
                this.reportDirectory = new File(jacocoOutputDir, "code-coverage");
                this.reportFormat = System.getProperty("jacoco.format", "html");
        }

        /**
         * Create the report.
         *
         * @throws IOException
         */
        public void create() throws IOException {

                // Read the jacoco.exec file. Multiple data files could be merged
                // at this point
                loadExecutionData();

                // Run the structure analyzer on a single class folder to build up
                // the coverage model. The process would be similar if your classes
                // were in a jar file. Typically you would create a bundle for each
                // class folder and each jar you want in your report. If you have
                // more than one bundle you will need to add a grouping node to your
                // report
                final IBundleCoverage bundleCoverage = analyzeStructure();

                createReport(bundleCoverage);

        }

        private void createReport(final IBundleCoverage bundleCoverage)
                        throws IOException {

                // Create a concrete report visitor based on some supplied
                // configuration. In this case we use the defaults
                IReportVisitor visitor;
                switch (reportFormat) {
                    case "csv":
                        reportDirectory.mkdirs();
                        CSVFormatter csvFormatter = new CSVFormatter();
                        visitor = csvFormatter.createVisitor(
                            new FileOutputStream(new File(reportDirectory, "coverage.csv")));
                        break;

                    case "html":
                        HTMLFormatter htmlFormatter = new HTMLFormatter();
                        visitor = htmlFormatter.createVisitor(
                            new FileMultiReportOutput(reportDirectory));
                        break;

                    case "xml":
                        reportDirectory.mkdirs();
                        XMLFormatter xmlFormatter = new XMLFormatter();
                        visitor = xmlFormatter.createVisitor(
                            new FileOutputStream(new File(reportDirectory, "coverage.xml")));
                        break;

                    default:
                        throw new RuntimeException("Unable to parse format: " + reportFormat);
                }

                // Initialize the report with all of the execution and session
                // information. At this point the report doesn't know about the
                // structure of the report being created
                visitor.visitInfo(execFileLoader.getSessionInfoStore().getInfos(),
                                execFileLoader.getExecutionDataStore().getContents());

                // Populate the report structure with the bundle coverage information.
                // Call visitGroup if you need groups in your report.
                visitor.visitBundle(bundleCoverage, createSourceFileLocator());

                // Signal end of structure information to allow report to write all
                // information out
                visitor.visitEnd();

        }

        private void loadExecutionData() throws IOException {
                executionDataFile.createNewFile();
                execFileLoader.load(executionDataFile);
        }

        private IBundleCoverage analyzeStructure() throws IOException {
                final CoverageBuilder coverageBuilder = new CoverageBuilder();
                final Analyzer analyzer = new Analyzer(
                    execFileLoader.getExecutionDataStore(), coverageBuilder);

                String[] jarsPath = classesPath.split(":");
                for (String jarPath : jarsPath) {
                        analyzer.analyzeAll(new File(jarPath));
                }

                return coverageBuilder.getBundle(title);
        }

        private ISourceFileLocator createSourceFileLocator() {
          final MultiSourceFileLocator result = new MultiSourceFileLocator(TAB_WIDTH);

          String[] sourceDirectoryPaths = sourcesPath.split(":");
          for (String sourceDirectoryPath : sourceDirectoryPaths) {
            File sourceDirectory = new File(sourceDirectoryPath);
            result.add(new DirectorySourceFileLocator(sourceDirectory, "utf-8", TAB_WIDTH));
          }

          return result;
        }

        /**
         * Starts the report generation process
         *
         * @param args
         *            Arguments to the application. This will be the location of the
         *            eclipse projects that will be used to generate reports for
         * @throws IOException
         */
        public static void main(final String[] args) throws IOException {
                final ReportGenerator generator = new ReportGenerator();
                generator.create();
        }

}