Dépôt officiel du code source de l'ERP OpenConcerto

/*

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

 *

 * Copyright 2011 OpenConcerto, by ILM Informatique. All rights reserved.

 *

 * The contents of this file are subject to the terms of the GNU General Public License Version 3

 * only ("GPL"). You may not use this file except in compliance with the License. You can obtain a

 * copy of the License at http://www.gnu.org/licenses/gpl-3.0.html See the License for the specific

 * language governing permissions and limitations under the License.

 *

 * When distributing the software, include this License Header Notice in each file.

 */

 package org.openconcerto.erp.core.sales.pos.model;

import org.openconcerto.erp.core.sales.pos.POSConfiguration;

import org.openconcerto.erp.core.sales.pos.model.RegisterLog.EventType;

import org.openconcerto.erp.core.sales.pos.model.RegisterLogEntry.ReceiptEntry;

import org.openconcerto.erp.core.sales.pos.model.RegisterState.Status;

import org.openconcerto.utils.CompareUtils;

import org.openconcerto.utils.FileUtils;

import org.openconcerto.utils.MessageDigestUtils;

import org.openconcerto.utils.StringUtils;

import org.openconcerto.utils.cc.ExnTransformer;

import org.openconcerto.utils.checks.ValidState;

import java.io.BufferedInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.RandomAccessFile;

import java.nio.file.DirectoryStream;

import java.nio.file.FileVisitResult;

import java.nio.file.Files;

import java.nio.file.LinkOption;

import java.nio.file.Path;

import java.nio.file.SimpleFileVisitor;

import java.nio.file.StandardCopyOption;

import java.nio.file.attribute.BasicFileAttributes;

import java.security.DigestInputStream;

import java.security.DigestOutputStream;

import java.sql.SQLException;

import java.text.ParseException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Calendar;

import java.util.Collections;

import java.util.Comparator;

import java.util.Date;

import java.util.List;

import java.util.SortedSet;

import java.util.TreeSet;

import java.util.logging.Level;

import java.util.regex.Pattern;

import org.jdom2.Document;

import org.jdom2.Element;

import org.jdom2.JDOMException;

import org.jdom2.input.SAXBuilder;

import org.jdom2.output.Format;

import org.jdom2.output.XMLOutputter;

/**

 * <pre>

lockFile

2017

  12

    18/current or if not there previous

       log.xml

       log.xml.hash

       0218121700001.xml

       0218121700001.xml.hash

 * </pre>

 */

public class RegisterFiles {

    private static final String REGISTER_DIRNAME = "register";

    public static final String STRUCT_VERSION_2013 = "v20131206";

    public static final String STRUCT_VERSION = "v20171220";

    private static final String LOG_FILENAME = "log.xml";

    static final String HASH_SUFFIX = ".hash";

    private static final String LOG_HASH_FILENAME = LOG_FILENAME + HASH_SUFFIX;

    static private final Comparator<Path> FILENAME_COMPARATOR = new Comparator<Path>() {

        @Override

        public int compare(Path p1, Path p2) {

            return p1.getFileName().toString().compareTo(p2.getFileName().toString());

        }

    };

    static private final Comparator<Path> PATH_COMPARATOR = new Comparator<Path>() {

        @Override

        public int compare(Path p1, Path p2) {

            return p1.toString().compareTo(p2.toString());

        }

    };

    static private final Path getGreatestSubDir(final Path dir) throws IOException {

        Path res = null;

        if (dir != null && Files.exists(dir, LinkOption.NOFOLLOW_LINKS)) {

            try (final DirectoryStream<Path> subdirs = Files.newDirectoryStream(dir, FileUtils.DIR_PATH_FILTER)) {

                for (final Path subdir : subdirs) {

                    if (res == null || FILENAME_COMPARATOR.compare(subdir, res) > 0) {

                        res = subdir;

                    }

                }

            }

        }

        return res;

    }

    static private final ValidState canReadFile(final Path f, final String missingString, final String missingPermString) throws IOException {

        if (!Files.isRegularFile(f))

            return ValidState.createCached(false, missingString);

        if (!Files.isReadable(f))

            return ValidState.createCached(false, missingPermString);

        return ValidState.getTrueInstance();

    }

    static public final byte[] save(final Document doc, final Path f) throws IOException {

        final XMLOutputter out = new XMLOutputter(Format.getPrettyFormat());

        final byte[] res;

        try (final DigestOutputStream digestStream = new DigestOutputStream(Files.newOutputStream(f), MessageDigestUtils.getSHA256())) {

            out.output(doc, digestStream);

            res = digestStream.getMessageDigest().digest();

        }

        Files.write(f.resolveSibling(f.getFileName() + HASH_SUFFIX), MessageDigestUtils.asHex(res).getBytes(StringUtils.UTF8));

        return res;

    }

    static public final class HashMode {

        static public final HashMode NOT_REQUIRED = new HashMode(false, null);

        static public final HashMode REQUIRED = new HashMode(true, null);

        static public final HashMode equalTo(final String hashRequired) {

            return new HashMode(true, hashRequired);

        }

        private final boolean hashFileRequired;

        private final String hashRequired;

        private HashMode(boolean hashFileRequired, String hashRequired) {

            super();

            this.hashFileRequired = hashFileRequired;

            this.hashRequired = hashRequired;

        }

    }

    static public final Document parse(final Path f) throws IOException, JDOMException {

        return parse(f, HashMode.REQUIRED);

    }

    static public final Document parse(final Path f, final HashMode hashMode) throws IOException, JDOMException {

        final byte[] hash;

        final Path logHashFile = f.resolveSibling(f.getFileName() + HASH_SUFFIX);

        if (Files.isRegularFile(logHashFile)) {

            final String hashString = Files.readAllLines(logHashFile, StringUtils.UTF8).get(0);

            if (hashMode.hashRequired != null && !hashString.equals(hashMode.hashRequired))

                throw new IllegalStateException("Required hash doesn't match recorded hash");

            hash = MessageDigestUtils.fromHex(hashString);

            assert hash != null;

        } else if (hashMode.hashFileRequired) {

            throw new IllegalStateException("Missing required hash file for " + f);

        } else {

            hash = null;

        }

        final Document doc;

        try (final InputStream ins = new BufferedInputStream(Files.newInputStream(f, LinkOption.NOFOLLOW_LINKS));

                final DigestInputStream dIns = new DigestInputStream(ins, MessageDigestUtils.getSHA256())) {

            doc = new SAXBuilder().build(dIns);

            if (hash != null && !Arrays.equals(hash, dIns.getMessageDigest().digest()))

                throw new IOException("File hash doesn't match recorded hash for " + f);

        }

        return doc;

    }

    static private final Pattern DIGITS_PATTERN = Pattern.compile("[0-9]+");

    static public final List<RegisterFiles> scan(final Path rootDir) throws IOException {

        final Path registersDir = rootDir.resolve(REGISTER_DIRNAME);

        if (!Files.exists(registersDir))

            return Collections.emptyList();

        final List<RegisterFiles> res = new ArrayList<>();

        try (final DirectoryStream<Path> stream = Files.newDirectoryStream(registersDir, new DirectoryStream.Filter<Path>() {

            @Override

            public boolean accept(Path entry) throws IOException {

                return DIGITS_PATTERN.matcher(entry.getFileName().toString()).matches();

            }

        })) {

            for (final Path registerDir : stream) {

                if (Files.isDirectory(registerDir.resolve(STRUCT_VERSION))) {

                    res.add(new RegisterFiles(rootDir, true, Integer.parseInt(registerDir.getFileName().toString())));

                }

            }

        }

        return res;

    }

    // under that year/month/day

    private final Path rootDir;

    private final boolean useHardLinks;

    private final int posID;

    private final ThreadLocal<Boolean> hasLock = new ThreadLocal<Boolean>() {

        protected Boolean initialValue() {

            return Boolean.FALSE;

        };

    };

    public RegisterFiles(final Path rootDir, final boolean useHardLinks, final int caisse) {

        super();

        this.rootDir = rootDir.resolve(REGISTER_DIRNAME).resolve(Integer.toString(caisse));

        this.useHardLinks = useHardLinks;

        this.posID = caisse;

    }

    private final Path getRootDir() {

        return this.rootDir;

    }

    public final Path getVersionDir() {

        return this.getRootDir().resolve(STRUCT_VERSION);

    }

    public final Path getDayDir(final Calendar day, final boolean create) {

        return ReceiptCode.getDayDir(getVersionDir().toFile(), day, create).toPath();

    }

    public final Path getReceiptFile(final ReceiptCode code) throws IOException {

        final Path dayDirToUse = getDayDirToUse(getDayDir(code.getDay(), false));

        return dayDirToUse == null ? null : dayDirToUse.resolve(code.getFileName());

    }

    public final int getPosID() {

        return this.posID;

    }

    public <T, Exn extends Exception> T doWithLock(final ExnTransformer<RegisterFiles, T, Exn> transf) throws IOException, Exn {

        if (this.hasLock.get())

            throw new IllegalStateException("Already locked");

        this.hasLock.set(Boolean.TRUE);

        try {

            return FileUtils.doWithLock(this.getRootDir().resolve("lockFile").toFile(), new ExnTransformer<RandomAccessFile, T, Exn>() {

                @Override

                public T transformChecked(RandomAccessFile input) throws Exn {

                    return transf.transformChecked(RegisterFiles.this);

                }

            });

        } finally {

            this.hasLock.set(Boolean.FALSE);

        }

    }

    public final RegisterLog getLastLog() throws IOException, JDOMException {

        final Path lastLogFile = this.findLastLogFile();

        if (lastLogFile == null)

            return null;

        return new RegisterLog(lastLogFile).parse();

    }

    public final Path findLastLogFile() throws IOException {

        final Path versionDir = this.getVersionDir();

        // first quick search

        final Path yearDir = getGreatestSubDir(versionDir);

        final Path monthDir = getGreatestSubDir(yearDir);

        if (monthDir != null) {

            final SortedSet<Path> sortedDays = new TreeSet<>(Collections.reverseOrder(FILENAME_COMPARATOR));

            try (final DirectoryStream<Path> dayDirs = Files.newDirectoryStream(monthDir, FileUtils.DIR_PATH_FILTER)) {

                for (final Path dayDir : dayDirs) {

                    sortedDays.add(dayDir);

                }

            }

            Path logToUse = getLogToUse(sortedDays);

            if (logToUse != null)

                return logToUse;

            // then walk the whole tree before giving up

            logToUse = getLogToUse(getSortedDays(false));

            if (logToUse != null)

                return logToUse;

        }

        return null;

    }

    private SortedSet<Path> getSortedDays(final boolean chronological) throws IOException {

        final Path versionDir = this.getVersionDir();

        final SortedSet<Path> sortedPaths = new TreeSet<>(chronological ? PATH_COMPARATOR : Collections.reverseOrder(PATH_COMPARATOR));

        if (Files.exists(versionDir)) {

            Files.walkFileTree(versionDir, new SimpleFileVisitor<Path>() {

                @Override

                public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {

                    final Path dateDir = versionDir.relativize(dir);

                    if (dateDir.getNameCount() == 3) {

                        sortedPaths.add(dir);

                        return FileVisitResult.SKIP_SUBTREE;

                    } else {

                        return FileVisitResult.CONTINUE;

                    }

                }

            });

        }

        return sortedPaths;

    }

    private Path getLogToUse(final SortedSet<Path> sortedDays) throws IOException {

        for (final Path dayDir : sortedDays) {

            final Path dayDirToUse = getDayDirToUse(dayDir);

            if (dayDirToUse != null)

                return dayDirToUse.resolve(LOG_FILENAME);

        }

        return null;

    }

    public final List<Path> findLogFiles() throws IOException {

        final List<Path> res = new ArrayList<>();

        for (final Path dayDir : getSortedDays(true)) {

            final Path dayDirToUse = getDayDirToUse(dayDir);

            if (dayDirToUse != null)

                res.add(dayDirToUse.resolve(LOG_FILENAME));

        }

        return res;

    }

    private final Path getDayDirToUse(final Path dayDir) throws IOException {

        for (final Path subdir : new Path[] { dayDir.resolve("current"), dayDir.resolve("previous") }) {

            if (Files.exists(subdir)) {

                final ValidState validity = getDayDirValidity(subdir);

                if (validity.isValid())

                    return subdir;

                else

                    throw new IOException("Invalid " + subdir + " : " + validity.getValidationText());

            }

        }

        return null;

    }

    private final ValidState getDayDirValidity(final Path dayDir) throws IOException {

        if (!Files.isDirectory(dayDir))

            return ValidState.createCached(false, "Not a directory");

        final ValidState canReadLog = canReadFile(dayDir.resolve(LOG_FILENAME), "Missing log file", "Unreadable log file");

        if (!canReadLog.isValid())

            return canReadLog;

        final ValidState canReadLogHash = canReadFile(dayDir.resolve(LOG_HASH_FILENAME), "Missing log hash file", "Unreadable log hash file");

        if (!canReadLogHash.isValid())

            return canReadLogHash;

        return ValidState.getTrueInstance();

    }

    public final RegisterLog open(final int userID, final DBState dbState) throws IOException {

        if (!this.hasLock.get())

            throw new IllegalStateException("Not locked");

        return createOpen(userID, null, dbState).transformChecked(this);

    }

    public final RegisterLog open(final int userID, final RegisterDB registerDB) throws IOException {

        return this.doWithLock(createOpen(userID, registerDB, null));

    }

    static private final ExnTransformer<RegisterFiles, RegisterLog, IOException> createOpen(final int userID, final RegisterDB registerDB, final DBState passedDBState) throws IOException {

        // TODO use UpdateDir like save() and close()

        return new ExnTransformer<RegisterFiles, RegisterLog, IOException>() {

            @Override

            public RegisterLog transformChecked(RegisterFiles input) throws IOException {

                POSConfiguration.getLogger().log(Level.FINE, "Begin opening of FS state for register {0}", input.getPosID());

                POSConfiguration.checkRegisterID(input.getPosID(), registerDB.getPosID());

                final RegisterLog lastLog = input.checkStatus(true);

                final String lastLocalHash;

                if (lastLog == null) {

                    lastLocalHash = null;

                } else {

                    try {

                        lastLocalHash = lastLog.getLastReceiptHash();

                    } catch (ParseException e) {

                        throw new IOException("Couldn't parse last receipt of log", e);

                    }

                }

                final DBState dbState;

                if (passedDBState == null) {

                    try {

                        dbState = registerDB.open(lastLocalHash, userID);

                    } catch (SQLException e) {

                        throw new IOException("Couldn't open the register in the DB", e);

                    }

                } else {

                    dbState = passedDBState;

                }

                if (dbState.getRegisterState().getStatus() != Status.OPEN)

                    throw new IllegalArgumentException("DB not open : " + dbState);

                final Calendar cal = dbState.getLastEntry().getDate("DATE");

                // e.g. 2017/12/21/

                final Path dayDir = input.getDayDir(cal, true);

                // e.g. 2017/12/21/current/

                final Path dayDirToUse = input.getDayDirToUse(dayDir);

                if (dayDirToUse != null)

                    throw new IllegalStateException(cal.getTime() + " already open");

                final Path stagingDir = dayDir.resolve("staging");

                final Path currentDir = stagingDir.resolveSibling("current");

                final Path prevDir = stagingDir.resolveSibling("previous");

                FileUtils.rm_R(stagingDir);

                FileUtils.rm_R(currentDir);

                FileUtils.rm_R(prevDir);

                Files.createDirectory(stagingDir);

                final Element rootElem = new Element("registerLog");

                rootElem.addContent(new RegisterLogEntry.RegisterEntry(EventType.REGISTER_OPENING, cal.getTime(), userID, input.getPosID(), lastLocalHash).toXML());

                save(new Document(rootElem), stagingDir.resolve(LOG_FILENAME));

                Files.move(stagingDir, currentDir, StandardCopyOption.ATOMIC_MOVE);

                POSConfiguration.getLogger().log(Level.INFO, "Finished opening of FS state for register {0}", registerDB);

                // TODO parse and validate before moving into place

                try {

                    return new RegisterLog(currentDir.resolve(LOG_FILENAME)).parse();

                } catch (JDOMException e) {

                    throw new IOException("Couldn't parse new log");

                }

            }

        };

    }

    private abstract class UpdateDir<I, T> extends ExnTransformer<RegisterFiles, T, IOException> {

        private final String logMsg;

        public UpdateDir(final String logMsg) {

            this.logMsg = logMsg;

        }

        @Override

        public T transformChecked(RegisterFiles input) throws IOException {

            POSConfiguration.getLogger().log(Level.FINE, "Begin " + this.logMsg + " for register {0}", input.getPosID());

            final RegisterLog lastLog = checkStatus(needsClosed());

            // e.g. 2017/12/21/current/

            final Path toUse = lastLog.getLogFile().getParent();

            final Path stagingDir = toUse.resolveSibling("staging");

            final Path currentDir = stagingDir.resolveSibling("current");

            final Path prevDir = stagingDir.resolveSibling("previous");

            FileUtils.rm_R(stagingDir);

            FileUtils.copyDirectory(toUse, stagingDir, input.useHardLinks, StandardCopyOption.COPY_ATTRIBUTES);

            final I intermediateRes = updateDir(stagingDir, lastLog);

            if (Files.exists(currentDir)) {

                FileUtils.rm_R(prevDir);

                Files.move(currentDir, prevDir, StandardCopyOption.ATOMIC_MOVE);

            }

            assert !Files.exists(currentDir);

            Files.move(stagingDir, currentDir, StandardCopyOption.ATOMIC_MOVE);

            POSConfiguration.getLogger().log(Level.INFO, "Finished " + this.logMsg + " for register {0}", input.getPosID());

            assert Files.isDirectory(currentDir);

            try {

                FileUtils.rm_R(prevDir);

            } catch (Exception e) {

                // OK to leave behind some small files

                e.printStackTrace();

            }

            return createResult(currentDir, intermediateRes);

        }

        protected abstract boolean needsClosed();

        protected abstract I updateDir(final Path stagingDir, final RegisterLog lastLog) throws IOException;

        protected abstract T createResult(final Path currentDir, final I intermediateRes) throws IOException;

    }

    private final RegisterLog checkStatus(final boolean needsClosed) throws IOException {

        final RegisterLog lastLog;

        try {

            lastLog = getLastLog();

            final boolean closed = lastLog == null || lastLog.getLastRegisterEvent().getType() != EventType.REGISTER_OPENING;

            if (closed != needsClosed)

                throw new IllegalStateException(needsClosed ? "Not closed" : "Not open");

        } catch (JDOMException | ParseException e) {

            throw new IOException(e);

        }

        return lastLog;

    }

    public final RegisterLog close(final int userID) throws IOException {

        return this.doWithLock(new UpdateDir<Object, RegisterLog>("closure of FS state") {

            @Override

            protected boolean needsClosed() {

                return false;

            }

            @Override

            protected Object updateDir(final Path stagingDir, final RegisterLog lastLog) throws IOException {

                final String lastHash;

                try {

                    lastHash = lastLog.getLastReceiptHash();

                } catch (ParseException e) {

                    throw new IOException("Couldn't find last receipt hash", e);

                }

                // TODO verify that receipts' files match the log's content

                final Document doc = lastLog.getDocument().clone();

                doc.getRootElement().addContent(new RegisterLogEntry.RegisterEntry(EventType.REGISTER_CLOSURE, new Date(), userID, getPosID(), lastHash).toXML());

                save(doc, stagingDir.resolve(LOG_FILENAME));

                return null;

            }

            @Override

            protected RegisterLog createResult(final Path currentDir, final Object intermediateRes) throws IOException {

                // TODO parse and validate before moving into place

                try {

                    return new RegisterLog(currentDir.resolve(LOG_FILENAME)).parse();

                } catch (JDOMException e) {

                    throw new IOException("Couldn't parse new log");

                }

            }

        });

    }

    public final String save(final Ticket t) throws IOException, SQLException {

        return this.doWithLock(new UpdateDir<String, String>("saving receipt") {

            @Override

            protected boolean needsClosed() {

                return false;

            }

            @Override

            protected String updateDir(final Path stagingDir, final RegisterLog lastLog) throws IOException {

                try {

                    final ReceiptEntry lastReceipt = lastLog.getLastReceiptCreationEvent();

                    final int expectedIndex;

                    final String expectedHash = lastLog.getLastReceiptHash();

                    if (lastReceipt == null) {

                        expectedIndex = 1;

                    } else {

                        expectedIndex = lastReceipt.getCode().getDayIndex() + 1;

                    }

                    if (t.getReceiptCode().getDayIndex() != expectedIndex)

                        throw new IllegalStateException("Non consecutive number");

                    if (!CompareUtils.equals(expectedHash, t.getPreviousHash()))

                        throw new IllegalStateException("Previous hash mismatch, expected " + expectedHash + " but previous of receipt was " + t.getPreviousHash());

                } catch (ParseException e) {

                    throw new IOException("Couldn't parse last receipt of log", e);

                }

                // save receipt

                final String fileHash = MessageDigestUtils.asHex(t.saveToFile(stagingDir.resolve(t.getReceiptCode().getFileName())));

                // update log

                final Document doc = lastLog.getDocument().clone();

                doc.getRootElement().addContent(new RegisterLogEntry.ReceiptEntry(t.getCreationDate(), t.getReceiptCode(), fileHash).toXML());

                save(doc, stagingDir.resolve(LOG_FILENAME));

                return fileHash;

            }

            @Override

            protected String createResult(final Path currentDir, final String intermediateRes) {

                return intermediateRes;

            }

        });

    }

}