/*

 * Copyright (c) 2008, 2009, 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.attribute.*;

import java.io.IOException;

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

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

class WindowsUserPrincipals {

    private WindowsUserPrincipals() { }

    static class User implements UserPrincipal {

        // String representation of SID

        private final String sidString;

        // SID type

        private final int sidType;

        // Account name (if available) or SID

        private final String accountName;

        User(String sidString, int sidType, String accountName) {

            this.sidString = sidString;

            this.sidType = sidType;

            this.accountName = accountName;

        }

        // package-private

        String sidString() {

            return sidString;

        }

        @Override

        public String getName() {

            return accountName;

        }

        @Override

        public String toString() {

            String type;

            switch (sidType) {

                case SidTypeUser : type = "User"; break;

                case SidTypeGroup : type = "Group"; break;

                case SidTypeDomain : type = "Domain"; break;

                case SidTypeAlias : type = "Alias"; break;

                case SidTypeWellKnownGroup : type = "Well-known group"; break;

                case SidTypeDeletedAccount : type = "Deleted"; break;

                case SidTypeInvalid : type = "Invalid"; break;

                case SidTypeComputer : type = "Computer"; break;

                default: type = "Unknown";

            }

            return accountName + " (" + type + ")";

        }

        @Override

        public boolean equals(Object obj) {

            if (obj == this)

                return true;

            if (!(obj instanceof WindowsUserPrincipals.User))

                return false;

            WindowsUserPrincipals.User other = (WindowsUserPrincipals.User)obj;

            return this.sidString.equals(other.sidString);

        }

        @Override

        public int hashCode() {

            return sidString.hashCode();

        }

    }

    static class Group extends User implements GroupPrincipal {

        Group(String sidString, int sidType, String accountName) {

            super(sidString, sidType, accountName);

        }

    }

    static UserPrincipal fromSid(long sidAddress) throws IOException {

        String sidString;

        try {

            sidString = ConvertSidToStringSid(sidAddress);

            if (sidString == null) {

                // pre-Windows XP system?

                throw new AssertionError();

            }

        } catch (WindowsException x) {

            throw new IOException("Unable to convert SID to String: " +

                x.errorString());

        }

        // lookup account; if not available then use the SID as the name

        Account account = null;

        String name;

        try {

            account = LookupAccountSid(sidAddress);

            name = account.domain() + "\\" + account.name();

        } catch (WindowsException x) {

            name = sidString;

        }

        int sidType = (account == null) ? SidTypeUnknown : account.use();

        if ((sidType == SidTypeGroup) ||

            (sidType == SidTypeWellKnownGroup) ||

            (sidType == SidTypeAlias)) // alias for local group

        {

            return new Group(sidString, sidType, name);

        } else {

            return new User(sidString, sidType, name);

        }

    }

    static UserPrincipal lookup(String name) throws IOException {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

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

        }

        // invoke LookupAccountName to get buffer size needed for SID

        int size = 0;

        try {

            size = LookupAccountName(name, 0L, 0);

        } catch (WindowsException x) {

            if (x.lastError() == ERROR_NONE_MAPPED)

                throw new UserPrincipalNotFoundException(name);

            throw new IOException(name + ": " + x.errorString());

        }

        assert size > 0;

        // allocate buffer and re-invoke LookupAccountName get SID

        NativeBuffer sidBuffer = NativeBuffers.getNativeBuffer(size);

        try {

            int newSize = LookupAccountName(name, sidBuffer.address(), size);

            if (newSize != size) {

                // can this happen?

                throw new AssertionError("SID change during lookup");

            }

            // return user principal

            return fromSid(sidBuffer.address());

        } catch (WindowsException x) {

            throw new IOException(name + ": " + x.errorString());

        } finally {

            sidBuffer.release();

        }

    }

}