/*
 * Copyright (c) 2008, 2014, 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.awt.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.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.FontManager;
import sun.font.FontConfigManager.FontConfigInfo;
import sun.font.FontConfigManager.FcCompFont;
import sun.font.FontConfigManager.FontConfigFont;
import sun.java2d.SunGraphicsEnvironment;
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. 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". /** 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].familyName;
                }

                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.
/**
     * 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.
/**
     * 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;
            String lang = SunToolkit.getStartupLocale().getLanguage();
            String name = "fcinfo-"+fileVersion+"-"+hostname+"-"+
                osName+"-"+osVersion+"-"+lang+".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+".family",
                                  fci.allFonts[j].familyName);
                props.setProperty(styleKey+"."+j+".file",
                                  fci.allFonts[j].fontFile);
            }
        }
        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()) {
            return;
        }
        Properties props = new Properties();
        FcFontManager fm = (FcFontManager) fontManager;
        FontConfigManager fcm = fm.getFontConfigManager();
        try {
            FileInputStream fis = new FileInputStream(fcFile);
            props.load(fis);
            fis.close();
        } catch (IOException e) {
            if (FontUtilities.debugFonts()) {
                warning("IOException reading from "+fcFile.toString());
            }
            return;
        }
        String version = (String)props.get("version");
        if (version == null || !version.equals(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()) {
                    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) {
                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) {
                        return; // bad file
                    }
                    fci[index].allFonts = new FontConfigFont[nfonts];
                    for (int f=0; f<nfonts; f++) {
                        fci[index].allFonts[f] = new FontConfigFont();
                        String fkey = key+"."+f+".family";
                        String family = (String)props.get(fkey);
                        fci[index].allFonts[f].familyName = family;
                        fkey = key+"."+f+".file";
                        String file = (String)props.get(fkey);
                        if (file == null) {
                            return; // bad file
                        }
                        fci[index].allFonts[f].fontFile = file;
                    }
                    fci[index].firstFont =  fci[index].allFonts[0];

                }
            }
            fcCompFonts = fci;
        } catch (Throwable t) {
            if (FontUtilities.debugFonts()) {
                warning(t.toString());
            }
        }
    }

    private static void warning(String msg) {
        PlatformLogger logger = PlatformLogger.getLogger("sun.awt.FontConfiguration");
        logger.warning(msg);
    }
}