package org.apache.maven.plugins.site.render;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import org.apache.maven.artifact.Artifact;
import org.apache.maven.doxia.site.decoration.DecorationModel;
import org.apache.maven.doxia.site.decoration.Menu;
import org.apache.maven.doxia.site.decoration.MenuItem;
import org.apache.maven.doxia.siterenderer.DocumentRenderer;
import org.apache.maven.doxia.siterenderer.Renderer;
import org.apache.maven.doxia.siterenderer.RendererException;
import org.apache.maven.doxia.siterenderer.RenderingContext;
import org.apache.maven.doxia.siterenderer.SiteRenderingContext;
import org.apache.maven.doxia.tools.SiteToolException;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.model.ReportPlugin;
import org.apache.maven.model.Reporting;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugin.descriptor.PluginDescriptor;
import org.apache.maven.plugins.annotations.Component;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.plugins.site.descriptor.AbstractSiteDescriptorMojo;
import org.apache.maven.reporting.MavenReport;
import org.apache.maven.reporting.exec.MavenReportExecution;
import org.apache.maven.reporting.exec.MavenReportExecutor;
import org.apache.maven.reporting.exec.MavenReportExecutorRequest;
import org.codehaus.plexus.util.ReaderFactory;
import org.codehaus.plexus.util.StringUtils;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import static org.apache.maven.shared.utils.logging.MessageUtils.buffer;

/**
 * Base class for site rendering mojos.
 *
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 *
 */
public abstract class AbstractSiteRenderingMojo extends AbstractSiteDescriptorMojo
{
    /**
     * Module type exclusion mappings
     * ex: <code>fml  -> **&#47;*-m1.fml</code>  (excludes fml files ending in '-m1.fml' recursively)
     * <p/>
     * The configuration looks like this:
     * <pre>
     *   &lt;moduleExcludes&gt;
     *     &lt;moduleType&gt;filename1.ext,**&#47;*sample.ext&lt;/moduleType&gt;
     *     &lt;!-- moduleType can be one of 'apt', 'fml' or 'xdoc'. --&gt;
     *     &lt;!-- The value is a comma separated list of           --&gt;
     *     &lt;!-- filenames or fileset patterns.                   --&gt;
     *     &lt;!-- Here's an example:                               --&gt;
     *     &lt;xdoc&gt;changes.xml,navigation.xml&lt;/xdoc&gt;
     *   &lt;/moduleExcludes&gt;
     * </pre>
     */
    @Parameter
    private Map<String, String> moduleExcludes;

    /**
     * The location of a Velocity template file to use. When used, skins and the default templates, CSS and images
     * are disabled. It is highly recommended that you package this as a skin instead.
     *
     * @since 2.0-beta-5
     */
    @Parameter( property = "templateFile" )
    private File templateFile;

    /**
     * Additional template properties for rendering the site. See
     * <a href="/doxia/doxia-sitetools/doxia-site-renderer/">Doxia Site Renderer</a>.
     */
    @Parameter
    private Map<String, Object> attributes;

    /**
     * Site renderer.
     */
    @Component
    protected Renderer siteRenderer;

    /**
     * Reports (Maven 2).
     */
    @Parameter( defaultValue = "${reports}", required = true, readonly = true )
    protected List<MavenReport> reports;

    /**
     * Alternative directory for xdoc source, useful for m1 to m2 migration
     *
     * @deprecated use the standard m2 directory layout
     */
    @Parameter( defaultValue = "${basedir}/xdocs" )
    private File xdocDirectory;

    /**
     * Directory containing generated documentation in source format (Doxia supported markup).
     * This is used to pick up other source docs that might have been generated at build time (by reports or any other
     * build time mean).
     * This directory is expected to have the same structure as <code>siteDirectory</code>
     * (ie. one directory per Doxia-source-supported markup types).
     *
     * todo should we deprecate in favour of reports directly using Doxia Sink API, without this Doxia source
     * intermediate step?
     */
    @Parameter( alias = "workingDirectory", defaultValue = "${project.build.directory}/generated-site" )
    protected File generatedSiteDirectory;

    /**
     * The current Maven session.
     */
    @Parameter( defaultValue = "${session}", readonly = true, required = true )
    protected MavenSession mavenSession;

    /**
     * replaces previous reportPlugins parameter, that was injected by Maven core from
     * reporting section: but this new configuration format has been abandoned.
     *
     * @since 3.7.1
     */
    @Parameter( defaultValue = "${project.reporting}", readonly = true )
    private Reporting reporting;

    /**
     * Whether to generate the summary page for project reports: project-info.html.
     *
     * @since 2.3
     */
    @Parameter( property = "generateProjectInfo", defaultValue = "true" )
    private boolean generateProjectInfo;

    /**
     * Specifies the input encoding.
     *
     * @since 2.3
     */
    @Parameter( property = "encoding", defaultValue = "${project.build.sourceEncoding}" )
    private String inputEncoding;

    /**
     * Specifies the output encoding.
     *
     * @since 2.3
     */
    @Parameter( property = "outputEncoding", defaultValue = "${project.reporting.outputEncoding}" )
    private String outputEncoding;

    @Component
    protected MavenReportExecutor mavenReportExecutor;

    /**
     * Gets the input files encoding.
     *
     * @return The input files encoding, never <code>null</code>.
     */
    protected String getInputEncoding()
    {
        return ( StringUtils.isEmpty( inputEncoding ) ) ? ReaderFactory.FILE_ENCODING : inputEncoding;
    }

    /**
     * Gets the effective reporting output files encoding.
     *
     * @return The effective reporting output file encoding, never <code>null</code>.
     */
    protected String getOutputEncoding()
    {
        return ( outputEncoding == null ) ? ReaderFactory.UTF_8 : outputEncoding;
    }

    /**
     * Whether to save Velocity processed Doxia content (<code>*.&lt;ext&gt;.vm</code>)
     * to <code>${generatedSiteDirectory}/processed</code>.
     *
     * @since 3.5
     */
    @Parameter
    private boolean saveProcessedContent;

    protected void checkInputEncoding()
    {
        if ( StringUtils.isEmpty( inputEncoding ) )
        {
            getLog().warn( "Input file encoding has not been set, using platform encoding "
                + ReaderFactory.FILE_ENCODING + ", i.e. build is platform dependent!" );
        }
    }

    protected List<MavenReportExecution> getReports()
        throws MojoExecutionException
    {
        MavenReportExecutorRequest mavenReportExecutorRequest = new MavenReportExecutorRequest();
        mavenReportExecutorRequest.setLocalRepository( localRepository );
        mavenReportExecutorRequest.setMavenSession( mavenSession );
        mavenReportExecutorRequest.setProject( project );
        mavenReportExecutorRequest.setReportPlugins( getReportingPlugins() );

        List<MavenReportExecution> allReports = mavenReportExecutor.buildMavenReports( mavenReportExecutorRequest );

        // filter out reports that can't be generated
        List<MavenReportExecution> reportExecutions = new ArrayList<>( allReports.size() );
        for ( MavenReportExecution exec : allReports )
        {
            if ( exec.canGenerateReport() )
            {
                reportExecutions.add( exec );
            }
        }
        return reportExecutions;
    }

    /**
     * Get the report plugins from reporting section, adding if necessary (i.e. not excluded)
     * default reports (i.e. maven-project-info-reports)
     *
     * @return the effective list of reports
     * @since 3.7.1
     */
    private ReportPlugin[] getReportingPlugins()
    {
        List<ReportPlugin> reportingPlugins = reporting.getPlugins();

        // MSITE-806: add default report plugin like done in maven-model-builder DefaultReportingConverter
        boolean hasMavenProjectInfoReportsPlugin = false;
        for ( ReportPlugin plugin : reportingPlugins )
        {
            if ( "org.apache.maven.plugins".equals( plugin.getGroupId() )
                && "maven-project-info-reports-plugin".equals( plugin.getArtifactId() ) )
            {
                hasMavenProjectInfoReportsPlugin = true;
                break;
            }
        }

        if ( !reporting.isExcludeDefaults() && !hasMavenProjectInfoReportsPlugin )
        {
            ReportPlugin mpir = new ReportPlugin();
            mpir.setArtifactId( "maven-project-info-reports-plugin" );
            reportingPlugins.add( mpir );
        }
        return reportingPlugins.toArray( new ReportPlugin[reportingPlugins.size()] );
    }

    protected SiteRenderingContext createSiteRenderingContext( Locale locale )
        throws MojoExecutionException, IOException, MojoFailureException
    {
        DecorationModel decorationModel = prepareDecorationModel( locale );
        if ( attributes == null )
        {
            attributes = new HashMap<>();
        }

        if ( attributes.get( "project" ) == null )
        {
            attributes.put( "project", project );
        }

        if ( attributes.get( "inputEncoding" ) == null )
        {
            attributes.put( "inputEncoding", getInputEncoding() );
        }

        if ( attributes.get( "outputEncoding" ) == null )
        {
            attributes.put( "outputEncoding", getOutputEncoding() );
        }

        // Put any of the properties in directly into the Velocity context
        for ( Map.Entry<Object, Object> entry : project.getProperties().entrySet() )
        {
            attributes.put( (String) entry.getKey(), entry.getValue() );
        }

        SiteRenderingContext context;
        if ( templateFile != null )
        {
            getLog().info( buffer().a( "Rendering content with " ).strong( templateFile
                + " template file" ).a( '.' ).toString() );

            if ( !templateFile.exists() )
            {
                throw new MojoFailureException( "Template file '" + templateFile + "' does not exist" );
            }
            context = siteRenderer.createContextForTemplate( templateFile, attributes, decorationModel,
                                                             project.getName(), locale );
        }
        else
        {
            try
            {
                Artifact skinArtifact =
                    siteTool.getSkinArtifactFromRepository( localRepository, repositories, decorationModel );

                getLog().info( buffer().a( "Rendering content with " ).strong( skinArtifact.getId()
                    + " skin" ).a( '.' ).toString() );

                context = siteRenderer.createContextForSkin( skinArtifact, attributes, decorationModel,
                                                             project.getName(), locale );
            }
            catch ( SiteToolException e )
            {
                throw new MojoExecutionException( "SiteToolException while preparing skin: " + e.getMessage(), e );
            }
            catch ( RendererException e )
            {
                throw new MojoExecutionException( "RendererException while preparing context for skin: "
                    + e.getMessage(), e );
            }
        }

        // Generate static site
        context.setRootDirectory( project.getBasedir() );
        if ( !locale.getLanguage().equals( Locale.getDefault().getLanguage() ) )
        {
            context.addSiteDirectory( new File( siteDirectory, locale.getLanguage() ) );
            context.addModuleDirectory( new File( xdocDirectory, locale.getLanguage() ), "xdoc" );
            context.addModuleDirectory( new File( xdocDirectory, locale.getLanguage() ), "fml" );
        }
        else
        {
            context.addSiteDirectory( siteDirectory );
            context.addModuleDirectory( xdocDirectory, "xdoc" );
            context.addModuleDirectory( xdocDirectory, "fml" );
        }

        if ( moduleExcludes != null )
        {
            context.setModuleExcludes( moduleExcludes );
        }

        if ( saveProcessedContent )
        {
            context.setProcessedContentOutput( new File( generatedSiteDirectory, "processed" ) );
        }

        return context;
    }

    /**
     * Go through the list of reports and process each one like this:
     * <ul>
     * <li>Add the report to a map of reports keyed by filename having the report itself as value
     * <li>If the report is not yet in the map of documents, add it together with a suitable renderer
     * </ul>
     *
     * @param reports A List of MavenReports
     * @param documents A Map of documents, keyed by filename
     * @param locale the Locale the reports are processed for.
     * @return A map with all reports keyed by filename having the report itself as value.
     * The map will be used to populate a menu.
     */
    protected Map<String, MavenReport> locateReports( List<MavenReportExecution> reports,
                                                      Map<String, DocumentRenderer> documents, Locale locale )
    {
        // copy Collection to prevent ConcurrentModificationException
        List<MavenReportExecution> filtered = new ArrayList<>( reports );

        Map<String, MavenReport> reportsByOutputName = new LinkedHashMap<>();
        for ( MavenReportExecution mavenReportExecution : filtered )
        {
            MavenReport report = mavenReportExecution.getMavenReport();

            String outputName = report.getOutputName() + ".html";

            // Always add the report to the menu, see MSITE-150
            reportsByOutputName.put( report.getOutputName(), report );

            if ( documents.containsKey( outputName ) )
            {
                String reportMojoInfo =
                    ( mavenReportExecution.getGoal() == null ) ? "" : ( " ("
                        + mavenReportExecution.getPlugin().getArtifactId() + ':'
                        + mavenReportExecution.getPlugin().getVersion() + ':' + mavenReportExecution.getGoal() + ')' );

                getLog().info( "Skipped \"" + report.getName( locale ) + "\" report" + reportMojoInfo + ", file \""
                                   + outputName + "\" already exists." );

                reports.remove( mavenReportExecution );
            }
            else
            {
                String reportMojoInfo = mavenReportExecution.getPlugin().getGroupId() + ':'
                    + mavenReportExecution.getPlugin().getArtifactId() + ':'
                    + mavenReportExecution.getPlugin().getVersion() + ':' + mavenReportExecution.getGoal();
                RenderingContext renderingContext = new RenderingContext( siteDirectory, outputName, reportMojoInfo );
                DocumentRenderer renderer =
                    new ReportDocumentRenderer( mavenReportExecution, renderingContext, getLog() );
                documents.put( outputName, renderer );
            }
        }
        return reportsByOutputName;
    }

    /**
     * Go through the collection of reports and put each report into a list for the appropriate category. The list is
     * put into a map keyed by the name of the category.
     *
     * @param reports A Collection of MavenReports
     * @return A map keyed category having the report itself as value
     */
    protected Map<String, List<MavenReport>> categoriseReports( Collection<MavenReport> reports )
    {
        Map<String, List<MavenReport>> categories = new LinkedHashMap<>();
        for ( MavenReport report : reports )
        {
            List<MavenReport> categoryReports = categories.get( report.getCategoryName() );
            if ( categoryReports == null )
            {
                categoryReports = new ArrayList<>();
                categories.put( report.getCategoryName(), categoryReports );
            }
            categoryReports.add( report );
        }
        return categories;
    }

    /**
     * Locate every document to be rendered for given locale:<ul>
     * <li>handwritten content, ie Doxia files,</li>
     * <li>reports,</li>
     * <li>"Project Information" and "Project Reports" category summaries.</li>
     * </ul>
     *
     * @param context the site context
     * @param reports the documents
     * @param locale the locale
     * @return the documents and their renderers
     * @throws IOException in case of file reading issue
     * @throws RendererException in case of Doxia rendering issue
     * @see CategorySummaryDocumentRenderer
     */
    protected Map<String, DocumentRenderer> locateDocuments( SiteRenderingContext context,
                                                             List<MavenReportExecution> reports, Locale locale )
        throws IOException, RendererException
    {
        Map<String, DocumentRenderer> documents = siteRenderer.locateDocumentFiles( context, true );

        Map<String, MavenReport> reportsByOutputName = locateReports( reports, documents, locale );

        // TODO: I want to get rid of categories eventually. There's no way to add your own in a fully i18n manner
        Map<String, List<MavenReport>> categories = categoriseReports( reportsByOutputName.values() );

        siteTool.populateReportsMenu( context.getDecoration(), locale, categories );
        populateReportItems( context.getDecoration(), locale, reportsByOutputName );

        if ( categories.containsKey( MavenReport.CATEGORY_PROJECT_INFORMATION ) && generateProjectInfo )
        {
            // add "Project Information" category summary document
            List<MavenReport> categoryReports = categories.get( MavenReport.CATEGORY_PROJECT_INFORMATION );

            RenderingContext renderingContext =
                new RenderingContext( siteDirectory, "project-info.html",
                                      getSitePluginInfo() + ":CategorySummaryDocumentRenderer" );
            String title = i18n.getString( "site-plugin", locale, "report.information.title" );
            String desc1 = i18n.getString( "site-plugin", locale, "report.information.description1" );
            String desc2 = i18n.getString( "site-plugin", locale, "report.information.description2" );
            DocumentRenderer renderer = new CategorySummaryDocumentRenderer( renderingContext, title, desc1, desc2,
                                                                             i18n, categoryReports, getLog() );

            if ( !documents.containsKey( renderer.getOutputName() ) )
            {
                documents.put( renderer.getOutputName(), renderer );
            }
            else
            {
                getLog().info( "Category summary '" + renderer.getOutputName() + "' skipped; already exists" );
            }
        }

        if ( categories.containsKey( MavenReport.CATEGORY_PROJECT_REPORTS ) )
        {
            // add "Project Reports" category summary document
            List<MavenReport> categoryReports = categories.get( MavenReport.CATEGORY_PROJECT_REPORTS );
            RenderingContext renderingContext =
                new RenderingContext( siteDirectory, "project-reports.html",
                                      getSitePluginInfo() + ":CategorySummaryDocumentRenderer" );
            String title = i18n.getString( "site-plugin", locale, "report.project.title" );
            String desc1 = i18n.getString( "site-plugin", locale, "report.project.description1" );
            String desc2 = i18n.getString( "site-plugin", locale, "report.project.description2" );
            DocumentRenderer renderer = new CategorySummaryDocumentRenderer( renderingContext, title, desc1, desc2,
                                                                             i18n, categoryReports, getLog() );

            if ( !documents.containsKey( renderer.getOutputName() ) )
            {
                documents.put( renderer.getOutputName(), renderer );
            }
            else
            {
                getLog().info( "Category summary '" + renderer.getOutputName() + "' skipped; already exists" );
            }
        }
        return documents;
    }

    private String getSitePluginInfo()
    {
        PluginDescriptor pluginDescriptor = (PluginDescriptor) getPluginContext().get( "pluginDescriptor" );
        return pluginDescriptor.getId();
    }
    protected void populateReportItems( DecorationModel decorationModel, Locale locale,
                                        Map<String, MavenReport> reportsByOutputName )
    {
        for ( Menu menu : decorationModel.getMenus() )
        {
            populateItemRefs( menu.getItems(), locale, reportsByOutputName );
        }
    }

    private void populateItemRefs( List<MenuItem> items, Locale locale, Map<String, MavenReport> reportsByOutputName )
    {
        for ( Iterator<MenuItem> i = items.iterator(); i.hasNext(); )
        {
            MenuItem item = i.next();

            if ( item.getRef() != null )
            {
                MavenReport report = reportsByOutputName.get( item.getRef() );

                if ( report != null )
                {
                    if ( item.getName() == null )
                    {
                        item.setName( report.getName( locale ) );
                    }

                    if ( item.getHref() == null || item.getHref().length() == 0 )
                    {
                        item.setHref( report.getOutputName() + ".html" );
                    }
                }
                else
                {
                    getLog().warn( "Unrecognised reference: '" + item.getRef() + "'" );
                    i.remove();
                }
            }

            populateItemRefs( item.getItems(), locale, reportsByOutputName );
        }
    }
}