/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2015-2016 ForgeRock AS.
 */
package org.forgerock.opendj.maven.doc;

import static com.forgerock.opendj.ldap.CoreMessages.*;
import static org.forgerock.opendj.maven.doc.Utils.*;

import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.forgerock.opendj.ldap.schema.CoreSchemaSupportedLocales;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * Generate schema-related reference documentation sources.
 */
@Mojo(name = "generate-schema-ref")
public class GenerateSchemaDocMojo extends AbstractMojo {
    /** The locale for which to generate the documentation. */
    @Parameter(defaultValue = "en")
    private String locale;

    /** Output directory for source files. */
    @Parameter(defaultValue = "${project.build.directory}/docbkx-sources/shared")
    private File outputDirectory;

    /**
     * Writes schema reference documentation source files.
     * @throws MojoExecutionException   Not used.
     * @throws MojoFailureException     Failed to write a file.
     */
    @Override
    public void execute() throws MojoExecutionException, MojoFailureException {
        final Locale currentLocale = Locale.forLanguageTag(locale);
        final String localeReference = getLocalesAndSubTypesDocumentation(currentLocale);
        final File localeReferenceFile = new File(outputDirectory, "sec-locales-subtypes.xml");
        try {
            writeStringToFile(localeReference, localeReferenceFile);
        } catch (IOException e) {
            throw new MojoExecutionException("Failed to write " + localeReferenceFile.getPath());
        }
    }

    /**
     * Returns a DocBook XML Section element documenting supported locales and language subtypes.
     * @param currentLocale The locale for which to generate the documentation.
     * @return A DocBook XML Section element documenting supported locales and language subtypes.
     */
    private String getLocalesAndSubTypesDocumentation(final Locale currentLocale) {
        final Map<String, Object> map = new HashMap<>();
        map.put("year", new SimpleDateFormat("yyyy").format(new Date()));
        map.put("lang", currentLocale.toLanguageTag());
        map.put("title", DOC_LOCALE_SECTION_TITLE.get());
        map.put("info", DOC_LOCALE_SECTION_INFO.get());
        map.put("locales", getLocalesDocMap(currentLocale));
        map.put("subtypes", getSubTypesDocMap(currentLocale));
        return applyTemplate("sec-locales-subtypes.ftl", map);
    }

    private final Map<String, String> localeTagsToOids =
            CoreSchemaSupportedLocales.getJvmSupportedLocaleNamesToOids();

    /** Container for documentation regarding a locale. */
    private class LocaleDoc {
        String tag;
        String language;
        String oid;
    }

    /**
     * Returns a map of languages to Locale documentation containers.
     * @param currentLocale     The Locale of the resulting documentation.
     * @return A map of languages to Locale documentation containers.
     */
    private Map<String, LocaleDoc> getLanguagesToLocalesMap(final Locale currentLocale) {
        Map<String, LocaleDoc> locales = new TreeMap<>();
        for (String tag : localeTagsToOids.keySet()) {
            final Locale locale = Locale.forLanguageTag(tag);
            if (isNullOrEmpty(locale)) {
                continue;
            }
            final LocaleDoc localeDoc = new LocaleDoc();
            localeDoc.tag = tag;
            localeDoc.language = locale.getDisplayName(currentLocale);
            localeDoc.oid = localeTagsToOids.get(tag);
            if (!localeDoc.language.equals(localeDoc.tag)) {
                // No display language so must not be supported in current JVM
                locales.put(localeDoc.language, localeDoc);
            } else if (localeDoc.tag.equals("sh")) {
                localeDoc.language = DOC_LANGUAGE_SH.get().toString(currentLocale);
                locales.put(localeDoc.language, localeDoc);
            }
        }
        return locales;
    }

    /**
     * Returns a map of information for documenting supported locales.
     * @param currentLocale The locale for which to generate the information.
     * @return A map of information for documenting supported locales.
     */
    private Map<String, Object> getLocalesDocMap(final Locale currentLocale) {
        final Map<String, Object> result = new HashMap<>();
        result.put("title", DOC_SUPPORTED_LOCALES_TITLE.get());
        result.put("indexTerm", DOC_SUPPORTED_LOCALES_INDEXTERM.get());
        final Map<String, LocaleDoc> localesMap = getLanguagesToLocalesMap(currentLocale);
        final Set<String> sortedLanguages = localesMap.keySet();
        final List<Map<String, Object>> locales = new LinkedList<>();
        for (final String language : sortedLanguages) {
            final LocaleDoc locale = localesMap.get(language);
            final Map<String, Object> map = new HashMap<>();
            map.put("language", locale.language);
            map.put("tag", DOC_LOCALE_TAG.get(locale.tag));
            map.put("oid", DOC_LOCALE_OID.get(locale.oid));
            locales.add(map);
        }
        result.put("locales", locales);
        return result;
    }

    /**
     * Returns a map of information for documenting supported language subtypes.
     * @param currentLocale The locale for which to generate the information.
     * @return A map of information for documenting supported language subtypes.
     */
    private Map<String, Object> getSubTypesDocMap(final Locale currentLocale) {
        final Map<String, Object> result = new HashMap<>();
        result.put("title", DOC_SUPPORTED_SUBTYPES_TITLE.get());
        result.put("indexTerm", DOC_SUPPORTED_SUBTYPES_INDEXTERM.get());
        final List<Map<String, Object>> locales = new LinkedList<>();
        for (final String tag : localeTagsToOids.keySet()) {
            final Map<String, Object> map = new HashMap<>();
            int idx = tag.indexOf('-');
            if (idx == -1) {
                final Locale locale = Locale.forLanguageTag(tag);
                if (isNullOrEmpty(locale)) {
                    continue;
                }
                final String language = locale.getDisplayName(currentLocale);
                if (!language.equals(tag)) {
                    map.put("language", language);
                    map.put("tag", tag);
                } else if (tag.equals("sh")) {
                    map.put("language", DOC_LANGUAGE_SH.get().toString(currentLocale));
                    map.put("tag", tag);
                }
                if (!map.isEmpty()) {
                    locales.add(map);
                }
            }
        }
        result.put("locales", locales);
        return result;
    }

    private boolean isNullOrEmpty(final Locale locale) {
        return locale == null || locale.getLanguage().equals("");
    }
}