/*

 * 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.nio.fs;

import java.nio.file.*;

import java.nio.file.attribute.*;

import java.util.*;

import java.util.concurrent.TimeUnit;

import java.io.IOException;

import static sun.nio.fs.UnixNativeDispatcher.*;

class UnixFileAttributeViews {

    static class Basic extends AbstractBasicFileAttributeView {

        protected final UnixPath file;

        protected final boolean followLinks;

        Basic(UnixPath file, boolean followLinks) {

            this.file = file;

            this.followLinks = followLinks;

        }

        @Override

        public BasicFileAttributes readAttributes() throws IOException {

            file.checkRead();

            try {

                 UnixFileAttributes attrs =

                     UnixFileAttributes.get(file, followLinks);

                 return attrs.asBasicFileAttributes();

            } catch (UnixException x) {

                x.rethrowAsIOException(file);

                return null;    // keep compiler happy

            }

        }

        @Override

        public void setTimes(FileTime lastModifiedTime,

                             FileTime lastAccessTime,

                             FileTime createTime) throws IOException

        {

            // null => don't change

            if (lastModifiedTime == null && lastAccessTime == null) {

                // no effect

                return;

            }

            // permission check

            file.checkWrite();

            boolean haveFd = false;

            boolean useFutimes = false;

            boolean useLutimes = false;

            int fd = -1;

            try {

                if (!followLinks) {

                    useLutimes = lutimesSupported() &&

                        UnixFileAttributes.get(file, false).isSymbolicLink();

                }

                if (!useLutimes) {

                    fd = file.openForAttributeAccess(followLinks);

                    if (fd != -1) {

                        haveFd = true;

                    }

                }

            } catch (UnixException x) {

                if (!(x.errno() == UnixConstants.ENXIO ||

                     (x.errno() == UnixConstants.ELOOP && useLutimes))) {

                    x.rethrowAsIOException(file);

                }

            }

            try {

                // assert followLinks || !UnixFileAttributes.get(fd).isSymbolicLink();

                // if not changing both attributes then need existing attributes

                if (lastModifiedTime == null || lastAccessTime == null) {

                    try {

                        UnixFileAttributes attrs = haveFd ?

                            UnixFileAttributes.get(fd) :

                            UnixFileAttributes.get(file, followLinks);

                        if (lastModifiedTime == null)

                            lastModifiedTime = attrs.lastModifiedTime();

                        if (lastAccessTime == null)

                            lastAccessTime = attrs.lastAccessTime();

                    } catch (UnixException x) {

                        x.rethrowAsIOException(file);

                    }

                }

                boolean retry = false;

                try {

                        futimes(fd, accessValue, modValue);

                    } else if (useLutimes) {

                        lutimes(file, accessValue, modValue);

                    } else {

                        utimes(file, accessValue, modValue);

                    }

                } catch (UnixException x) {

                    // if futimes/utimes fails with EINVAL and one/both of the times is

                    // negative then we adjust the value to the epoch and retry.

                    if (x.errno() == UnixConstants.EINVAL &&

                        (modValue < 0L || accessValue < 0L)) {

                        retry = true;

                    } else {

                        x.rethrowAsIOException(file);

                    }

                }

                if (retry) {

                    if (modValue < 0L) modValue = 0L;

                    if (accessValue < 0L) accessValue= 0L;

                    try {

                            futimes(fd, accessValue, modValue);

                        } else if (useLutimes) {

                            lutimes(file, accessValue, modValue);

                        } else {

                            utimes(file, accessValue, modValue);

                        }

                    } catch (UnixException x) {

                        x.rethrowAsIOException(file);

                    }

                }

            } finally {

                close(fd);

            }

        }

    }

    private static class Posix extends Basic implements PosixFileAttributeView {

        private static final String PERMISSIONS_NAME = "permissions";

        private static final String OWNER_NAME = "owner";

        private static final String GROUP_NAME = "group";

        // the names of the posix attributes (includes basic)

        static final Set<String> posixAttributeNames =

            Util.newSet(basicAttributeNames, PERMISSIONS_NAME, OWNER_NAME, GROUP_NAME);

        Posix(UnixPath file, boolean followLinks) {

            super(file, followLinks);

        }

        final void checkReadExtended() {

            SecurityManager sm = System.getSecurityManager();

            if (sm != null) {

                file.checkRead();

                sm.checkPermission(new RuntimePermission("accessUserInformation"));

            }

        }

        final void checkWriteExtended() {

            SecurityManager sm = System.getSecurityManager();

            if (sm != null) {

                file.checkWrite();

                sm.checkPermission(new RuntimePermission("accessUserInformation"));

            }

        }

        @Override

        public String name() {

            return "posix";

        }

        @Override

        @SuppressWarnings("unchecked")

        public void setAttribute(String attribute, Object value)

            throws IOException

        {

            if (attribute.equals(PERMISSIONS_NAME)) {

                setPermissions((Set<PosixFilePermission>)value);

                return;

            }

            if (attribute.equals(OWNER_NAME)) {

                setOwner((UserPrincipal)value);

                return;

            }

            if (attribute.equals(GROUP_NAME)) {

                setGroup((GroupPrincipal)value);

                return;

            }

            super.setAttribute(attribute, value);

        }

        /**

         * Invoked by readAttributes or sub-classes to add all matching posix

         * attributes to the builder

         */

        final void addRequestedPosixAttributes(PosixFileAttributes attrs,

                                               AttributesBuilder builder)

        {

            addRequestedBasicAttributes(attrs, builder);

            if (builder.match(PERMISSIONS_NAME))

                builder.add(PERMISSIONS_NAME, attrs.permissions());

            if (builder.match(OWNER_NAME))

                 builder.add(OWNER_NAME, attrs.owner());

            if (builder.match(GROUP_NAME))

                builder.add(GROUP_NAME, attrs.group());

        }

        @Override

        public Map<String,Object> readAttributes(String[] requested)

            throws IOException

        {

            AttributesBuilder builder =

                AttributesBuilder.create(posixAttributeNames, requested);

            PosixFileAttributes attrs = readAttributes();

            addRequestedPosixAttributes(attrs, builder);

            return builder.unmodifiableMap();

        }

        @Override

        public UnixFileAttributes readAttributes() throws IOException {

            checkReadExtended();

            try {

                 return UnixFileAttributes.get(file, followLinks);

            } catch (UnixException x) {

                x.rethrowAsIOException(file);

                return null;    // keep compiler happy

            }

        }

        // chmod

        final void setMode(int mode) throws IOException {

            checkWriteExtended();

            try {

                if (followLinks) {

                    chmod(file, mode);

                } else {

                    int fd = file.openForAttributeAccess(false);

                    try {

                        fchmod(fd, mode);

                    } finally {

                        close(fd);

                    }

                }

            } catch (UnixException x) {

                x.rethrowAsIOException(file);

            }

        }

        // chown

        final void setOwners(int uid, int gid) throws IOException {

            checkWriteExtended();

            try {

                if (followLinks) {

                    chown(file, uid, gid);

                } else {

                    lchown(file, uid, gid);

                }

            } catch (UnixException x) {

                x.rethrowAsIOException(file);

            }

        }

        @Override

        public void setPermissions(Set<PosixFilePermission> perms)

            throws IOException

        {

            setMode(UnixFileModeAttribute.toUnixMode(perms));

        }

        @Override

        public void setOwner(UserPrincipal owner)

            throws IOException

        {

            if (owner == null)

                throw new NullPointerException("'owner' is null");

            if (!(owner instanceof UnixUserPrincipals.User))

                throw new ProviderMismatchException();

            if (owner instanceof UnixUserPrincipals.Group)

                throw new IOException("'owner' parameter can't be a group");

            int uid = ((UnixUserPrincipals.User)owner).uid();

            setOwners(uid, -1);

        }

        @Override

        public UserPrincipal getOwner() throws IOException {

            return readAttributes().owner();

        }

        @Override

        public void setGroup(GroupPrincipal group)

            throws IOException

        {

            if (group == null)

                throw new NullPointerException("'owner' is null");

            if (!(group instanceof UnixUserPrincipals.Group))

                throw new ProviderMismatchException();

            int gid = ((UnixUserPrincipals.Group)group).gid();

            setOwners(-1, gid);

        }

    }

    private static class Unix extends Posix {

        private static final String MODE_NAME = "mode";

        private static final String INO_NAME = "ino";

        private static final String DEV_NAME = "dev";

        private static final String RDEV_NAME = "rdev";

        private static final String NLINK_NAME = "nlink";

        private static final String UID_NAME = "uid";

        private static final String GID_NAME = "gid";

        private static final String CTIME_NAME = "ctime";

        // the names of the unix attributes (including posix)

        static final Set<String> unixAttributeNames =

            Util.newSet(posixAttributeNames,

                        MODE_NAME, INO_NAME, DEV_NAME, RDEV_NAME,

                        NLINK_NAME, UID_NAME, GID_NAME, CTIME_NAME);

        Unix(UnixPath file, boolean followLinks) {

            super(file, followLinks);

        }

        @Override

        public String name() {

            return "unix";

        }

        @Override

        public void setAttribute(String attribute, Object value)

            throws IOException

        {

            if (attribute.equals(MODE_NAME)) {

                setMode((Integer)value);

                return;

            }

            if (attribute.equals(UID_NAME)) {

                setOwners((Integer)value, -1);

                return;

            }

            if (attribute.equals(GID_NAME)) {

                setOwners(-1, (Integer)value);

                return;

            }

            super.setAttribute(attribute, value);

        }

        @Override

        public Map<String,Object> readAttributes(String[] requested)

            throws IOException

        {

            AttributesBuilder builder =

                AttributesBuilder.create(unixAttributeNames, requested);

            UnixFileAttributes attrs = readAttributes();

            addRequestedPosixAttributes(attrs, builder);

            if (builder.match(MODE_NAME))

                builder.add(MODE_NAME, attrs.mode());

            if (builder.match(INO_NAME))

                builder.add(INO_NAME, attrs.ino());

            if (builder.match(DEV_NAME))

                builder.add(DEV_NAME, attrs.dev());

            if (builder.match(RDEV_NAME))

                builder.add(RDEV_NAME, attrs.rdev());

            if (builder.match(NLINK_NAME))

                builder.add(NLINK_NAME, attrs.nlink());

            if (builder.match(UID_NAME))

                builder.add(UID_NAME, attrs.uid());

            if (builder.match(GID_NAME))

                builder.add(GID_NAME, attrs.gid());

            if (builder.match(CTIME_NAME))

                builder.add(CTIME_NAME, attrs.ctime());

            return builder.unmodifiableMap();

        }

    }

    static Basic createBasicView(UnixPath file, boolean followLinks) {

        return new Basic(file, followLinks);

    }

    static Posix createPosixView(UnixPath file, boolean followLinks) {

        return new Posix(file, followLinks);

    }

    static Unix createUnixView(UnixPath file, boolean followLinks) {

        return new Unix(file, followLinks);

    }

    static FileOwnerAttributeViewImpl createOwnerView(UnixPath file, boolean followLinks) {

        return new FileOwnerAttributeViewImpl(createPosixView(file, followLinks));

    }

}