/*

 * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.font;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.net.InetAddress;

import java.net.UnknownHostException;

import java.nio.charset.Charset;

import java.nio.charset.StandardCharsets;

import java.nio.file.Files;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Locale;

import java.util.Properties;

import java.util.Scanner;

import sun.awt.FcFontManager;

import sun.awt.FontConfiguration;

import sun.awt.FontDescriptor;

import sun.awt.SunToolkit;

import sun.font.CompositeFontDescriptor;

import sun.font.FontConfigManager.FontConfigInfo;

import sun.font.FontConfigManager.FcCompFont;

import sun.font.FontConfigManager.FontConfigFont;

import sun.util.logging.PlatformLogger;

public class FcFontConfiguration extends FontConfiguration {

    /** Version of the cache file format understood by this code.

     * Its part of the file name so that we can rev this at

     * any time, even in a minor JDK update.

     * It is stored as the value of the "version" property.

     * This is distinct from the version of "libfontconfig" that generated

     * the cached results, and which is the "fcversion" property in the file.

     * {@code FontConfiguration.getVersion()} also returns a version string,

     * and has meant the version of the fontconfiguration.properties file

     * that was read. Since this class doesn't use such files, then what

     * that really means is whether the methods on this class return

     * values that are compatible with the classes that do directly read

     * from such files. It is a compatible subset of version "1".

     */

    private static final String fileVersion = "1";

    private String fcInfoFileName = null;

    private FcCompFont[] fcCompFonts = null;

    public FcFontConfiguration(SunFontManager fm) {

        super(fm);

        init();

    }

    /* This isn't called but is needed to satisfy super-class contract. */

    public FcFontConfiguration(SunFontManager fm,

                               boolean preferLocaleFonts,

                               boolean preferPropFonts) {

        super(fm, preferLocaleFonts, preferPropFonts);

        init();

    }

    @Override

    public synchronized boolean init() {

        if (fcCompFonts != null) {

            return true;

        }

        setFontConfiguration();

        readFcInfo();

        FcFontManager fm = (FcFontManager) fontManager;

        FontConfigManager fcm = fm.getFontConfigManager();

        if (fcCompFonts == null) {

            fcCompFonts = fcm.loadFontConfig();

            if (fcCompFonts != null) {

                try {

                    writeFcInfo();

                } catch (Exception e) {

                    if (FontUtilities.debugFonts()) {

                        warning("Exception writing fcInfo " + e);

                    }

                }

            } else if (FontUtilities.debugFonts()) {

                warning("Failed to get info from libfontconfig");

            }

        } else {

            fcm.populateFontConfig(fcCompFonts);

        }

        if (fcCompFonts == null) {

            return false; // couldn't load fontconfig.

        }

        // NB already in a privileged block from SGE

        String javaHome = System.getProperty("java.home");

        if (javaHome == null) {

            throw new Error("java.home property not set");

        }

        String javaLib = javaHome + File.separator + "lib";

        getInstalledFallbackFonts(javaLib);

        return true;

    }

    @Override

    public String getFallbackFamilyName(String fontName,

                                        String defaultFallback) {

        // maintain compatibility with old font.properties files, which either

        // had aliases for TimesRoman & Co. or defined mappings for them.

        String compatibilityName = getCompatibilityFamilyName(fontName);

        if (compatibilityName != null) {

            return compatibilityName;

        }

        return defaultFallback;

    }

    @Override

    protected String

        getFaceNameFromComponentFontName(String componentFontName) {

        return null;

    }

    @Override

    protected String

        getFileNameFromComponentFontName(String componentFontName) {

        return null;

    }

    @Override

    public String getFileNameFromPlatformName(String platformName) {

        /* Platform name is the file name, but rather than returning

         * the arg, return null*/

        return null;

    }

    @Override

    protected Charset getDefaultFontCharset(String fontName) {

        return Charset.forName("ISO8859_1");

    }

    @Override

    protected String getEncoding(String awtFontName,

                                 String characterSubsetName) {

        return "default";

    }

    @Override

    protected void initReorderMap() {

        reorderMap = new HashMap<>();

    }

    @Override

    protected FontDescriptor[] buildFontDescriptors(int fontIndex, int styleIndex) {

        CompositeFontDescriptor[] cfi = get2DCompositeFontInfo();

        int idx = fontIndex * NUM_STYLES + styleIndex;

        String[] componentFaceNames = cfi[idx].getComponentFaceNames();

        FontDescriptor[] ret = new FontDescriptor[componentFaceNames.length];

        for (int i = 0; i < componentFaceNames.length; i++) {

            ret[i] = new FontDescriptor(componentFaceNames[i], StandardCharsets.ISO_8859_1.newEncoder(), new int[0]);

        }

        return ret;

    }

    @Override

    public int getNumberCoreFonts() {

        return 1;

    }

    @Override

    public String[] getPlatformFontNames() {

        HashSet<String> nameSet = new HashSet<String>();

        FcFontManager fm = (FcFontManager) fontManager;

        FontConfigManager fcm = fm.getFontConfigManager();

        FcCompFont[] fcCompFonts = fcm.loadFontConfig();

        for (int i=0; i<fcCompFonts.length; i++) {

            for (int j=0; j<fcCompFonts[i].allFonts.length; j++) {

                nameSet.add(fcCompFonts[i].allFonts[j].fontFile);

            }

        }

        return nameSet.toArray(new String[0]);

    }

    @Override

    public String getExtraFontPath() {

        return null;

    }

    @Override

    public boolean needToSearchForFile(String fileName) {

        return false;

    }

    private FontConfigFont[] getFcFontList(FcCompFont[] fcFonts,

                                           String fontname, int style) {

        if (fontname.equals("dialog")) {

            fontname = "sansserif";

        } else if (fontname.equals("dialoginput")) {

            fontname = "monospaced";

        }

        for (int i=0; i<fcFonts.length; i++) {

            if (fontname.equals(fcFonts[i].jdkName) &&

                style == fcFonts[i].style) {

                return fcFonts[i].allFonts;

            }

        }

        return fcFonts[0].allFonts;

    }

    @Override

    public CompositeFontDescriptor[] get2DCompositeFontInfo() {

        FcFontManager fm = (FcFontManager) fontManager;

        FontConfigManager fcm = fm.getFontConfigManager();

        FcCompFont[] fcCompFonts = fcm.loadFontConfig();

        CompositeFontDescriptor[] result =

                new CompositeFontDescriptor[NUM_FONTS * NUM_STYLES];

        for (int fontIndex = 0; fontIndex < NUM_FONTS; fontIndex++) {

            String fontName = publicFontNames[fontIndex];

            for (int styleIndex = 0; styleIndex < NUM_STYLES; styleIndex++) {

                String faceName = fontName + "." + styleNames[styleIndex];

                FontConfigFont[] fcFonts =

                    getFcFontList(fcCompFonts,

                                  fontNames[fontIndex], styleIndex);

                int numFonts = fcFonts.length;

                // fall back fonts listed in the lib/fonts/fallback directory

                if (installedFallbackFontFiles != null) {

                    numFonts += installedFallbackFontFiles.length;

                }

                String[] fileNames = new String[numFonts];

                String[] faceNames = new String[numFonts];

                int index;

                for (index = 0; index < fcFonts.length; index++) {

                    fileNames[index] = fcFonts[index].fontFile;

                    faceNames[index] = fcFonts[index].fullName;

                }

                if (installedFallbackFontFiles != null) {

                    System.arraycopy(installedFallbackFontFiles, 0,

                                     fileNames, fcFonts.length,

                                     installedFallbackFontFiles.length);

                }

                result[fontIndex * NUM_STYLES + styleIndex]

                        = new CompositeFontDescriptor(

                            faceName,

                            1,

                            faceNames,

                            fileNames,

                            null, null);

            }

        }

        return result;

    }

    /**

     * Gets the OS version string from a Linux release-specific file.

     */

    private String getVersionString(File f) {

        try (Scanner sc  = new Scanner(f)) {

            return sc.findInLine("(\\d)+((\\.)(\\d)+)*");

        } catch (Exception e) {

        }

        return null;

    }

    /**

     * Sets the OS name and version from environment information.

     */

    @Override

    protected void setOsNameAndVersion() {

        super.setOsNameAndVersion();

        if (!osName.equals("Linux")) {

            return;

        }

        try {

            File f;

            if ((f = new File("/etc/lsb-release")).canRead()) {

                    /* Ubuntu and (perhaps others) use only lsb-release.

                     * Syntax and encoding is compatible with java properties.

                     * For Ubuntu the ID is "Ubuntu".

                     */

                    Properties props = new Properties();

                    props.load(new FileInputStream(f));

                    osName = props.getProperty("DISTRIB_ID");

                    osVersion =  props.getProperty("DISTRIB_RELEASE");

            } else if ((f = new File("/etc/redhat-release")).canRead()) {

                osName = "RedHat";

                osVersion = getVersionString(f);

            } else if ((f = new File("/etc/SuSE-release")).canRead()) {

                osName = "SuSE";

                osVersion = getVersionString(f);

            } else if ((f = new File("/etc/turbolinux-release")).canRead()) {

                osName = "Turbo";

                osVersion = getVersionString(f);

            } else if ((f = new File("/etc/fedora-release")).canRead()) {

                osName = "Fedora";

                osVersion = getVersionString(f);

            }

        } catch (Exception e) {

            if (FontUtilities.debugFonts()) {

                warning("Exception identifying Linux distro.");

            }

        }

    }

    private File getFcInfoFile() {

        if (fcInfoFileName == null) {

            // NB need security permissions to get true IP address, and

            // we should have those as the whole initialisation is in a

            // doPrivileged block. But in this case no exception is thrown,

            // and it returns the loop back address, and so we end up with

            // "localhost"

            String hostname;

            try {

                hostname = InetAddress.getLocalHost().getHostName();

            } catch (UnknownHostException e) {

                hostname = "localhost";

            }

            String userDir = System.getProperty("user.home");

            String version = System.getProperty("java.version");

            String fs = File.separator;

            String dir = userDir+fs+".java"+fs+"fonts"+fs+version;

            Locale locale = SunToolkit.getStartupLocale();

            String lang = locale.getLanguage();

            String country = locale.getCountry();

            String name = "fcinfo-"+fileVersion+"-"+hostname+"-"+

                osName+"-"+osVersion+"-"+lang+"-"+country+".properties";

            fcInfoFileName = dir+fs+name;

        }

        return new File(fcInfoFileName);

    }

    private void writeFcInfo() {

        Properties props = new Properties();

        props.setProperty("version", fileVersion);

        FcFontManager fm = (FcFontManager) fontManager;

        FontConfigManager fcm = fm.getFontConfigManager();

        FontConfigInfo fcInfo = fcm.getFontConfigInfo();

        props.setProperty("fcversion", Integer.toString(fcInfo.fcVersion));

        if (fcInfo.cacheDirs != null) {

            for (int i=0;i<fcInfo.cacheDirs.length;i++) {

                if (fcInfo.cacheDirs[i] != null) {

                   props.setProperty("cachedir."+i,  fcInfo.cacheDirs[i]);

                }

            }

        }

        for (int i=0; i<fcCompFonts.length; i++) {

            FcCompFont fci = fcCompFonts[i];

            String styleKey = fci.jdkName+"."+fci.style;

            props.setProperty(styleKey+".length",

                              Integer.toString(fci.allFonts.length));

            for (int j=0; j<fci.allFonts.length; j++) {

                props.setProperty(styleKey+"."+j+".file",

                                  fci.allFonts[j].fontFile);

                if (fci.allFonts[j].fullName != null) {

                    props.setProperty(styleKey+"."+j+".fullName",

                                      fci.allFonts[j].fullName);

                }

            }

        }

        try {

            /* This writes into a temp file then renames when done.

             * Since the rename is an atomic action within the same

             * directory no client will ever see a partially written file.

             */

            File fcInfoFile = getFcInfoFile();

            File dir = fcInfoFile.getParentFile();

            dir.mkdirs();

            File tempFile = Files.createTempFile(dir.toPath(), "fcinfo", null).toFile();

            FileOutputStream fos = new FileOutputStream(tempFile);

            props.store(fos,

                      "JDK Font Configuration Generated File: *Do Not Edit*");

            fos.close();

            boolean renamed = tempFile.renameTo(fcInfoFile);

            if (!renamed && FontUtilities.debugFonts()) {

                System.out.println("rename failed");

                warning("Failed renaming file to "+ getFcInfoFile());

            }

        } catch (Exception e) {

            if (FontUtilities.debugFonts()) {

                warning("IOException writing to "+ getFcInfoFile());

            }

        }

    }

    /* We want to be able to use this cache instead of invoking

     * fontconfig except when we can detect the system cache has changed.

     * But there doesn't seem to be a way to find the location of

     * the system cache.

     */

    private void readFcInfo() {

        File fcFile = getFcInfoFile();

        if (!fcFile.exists()) {

            if (FontUtilities.debugFonts()) {

                warning("fontconfig info file " + fcFile.toString() + " does not exist");

            }

            return;

        }

        Properties props = new Properties();

        try (FileInputStream fis = new FileInputStream(fcFile)) {

            props.load(fis);

        } catch (IOException e) {

            if (FontUtilities.debugFonts()) {

                warning("IOException (" + e.getCause() + ") reading from " + fcFile.toString());

            }

            return;

        }

        String version = (String)props.get("version");

        if (version == null || !version.equals(fileVersion)) {

            if (FontUtilities.debugFonts()) {

                warning("fontconfig info file version mismatch (found: " + version +

                    ", expected: " + fileVersion + ")");

            }

            return;

        }

        // If there's a new, different fontconfig installed on the

        // system, we invalidate our fontconfig file.

        String fcVersionStr = (String)props.get("fcversion");

        if (fcVersionStr != null) {

            int fcVersion;

            try {

                fcVersion = Integer.parseInt(fcVersionStr);

                if (fcVersion != 0 &&

                    fcVersion != FontConfigManager.getFontConfigVersion()) {

                    if (FontUtilities.debugFonts()) {

                        warning("new, different fontconfig detected");

                    }

                    return;

                }

            } catch (Exception e) {

                if (FontUtilities.debugFonts()) {

                    warning("Exception parsing version " + fcVersionStr);

                }

                return;

            }

        }

        // If we can locate the fontconfig cache dirs, then compare the

        // time stamp of those with our properties file. If we are out

        // of date then re-generate.

        long lastModified = fcFile.lastModified();

        int cacheDirIndex = 0;

        while (cacheDirIndex<4) { // should never be more than 2 anyway.

            String dir = (String)props.get("cachedir."+cacheDirIndex);

            if (dir == null) {

                break;

            }

            File dirFile = new File(dir);

            if (dirFile.exists() && dirFile.lastModified() > lastModified) {

                if (FontUtilities.debugFonts()) {

                    warning("out of date cache directories detected");

                }

                return;

            }

            cacheDirIndex++;

        }

        String[] names = { "sansserif", "serif", "monospaced" };

        String[] fcnames = { "sans", "serif", "monospace" };

        int namesLen = names.length;

        int numStyles = 4;

        FcCompFont[] fci = new FcCompFont[namesLen*numStyles];

        try {

            for (int i=0; i<namesLen; i++) {

                for (int s=0; s<numStyles; s++) {

                    int index = i*numStyles+s;

                    fci[index] = new FcCompFont();

                    String key = names[i]+"."+s;

                    fci[index].jdkName = names[i];

                    fci[index].fcFamily = fcnames[i];

                    fci[index].style = s;

                    String lenStr = (String)props.get(key+".length");

                    int nfonts = Integer.parseInt(lenStr);

                    if (nfonts <= 0) {

                        if (FontUtilities.debugFonts()) {

                            warning("bad non-positive .length entry in fontconfig file " + fcFile.toString());

                        }

                        return; // bad file

                    }

                    fci[index].allFonts = new FontConfigFont[nfonts];