package com.trilead.ssh2;

/**
 * A <code>SFTPv3FileAttributes</code> object represents detail information
 * about a file on the server. Not all fields may/must be present.
 *
 * @author Christian Plattner, plattner@trilead.com
 * @version $Id: SFTPv3FileAttributes.java,v 1.2 2008/04/01 12:38:09 cplattne Exp $
 */

public class SFTPv3FileAttributes {
    /**
     * The SIZE attribute. <code>NULL</code> if not present.
     */
    public Long size = null;

    /**
     * The UID attribute. <code>NULL</code> if not present.
     */
    public Integer uid = null;

    /**
     * The GID attribute. <code>NULL</code> if not present.
     */
    public Integer gid = null;

    /**
     * The POSIX permissions. <code>NULL</code> if not present.
     * <p>
     * Here is a list:
     * <p>
     * <pre>Note: these numbers are all OCTAL.
     *
     *  S_IFMT     0170000   bitmask for the file type bitfields
     *  S_IFSOCK   0140000   socket
     *  S_IFLNK    0120000   symbolic link
     *  S_IFREG    0100000   regular file
     *  S_IFBLK    0060000   block device
     *  S_IFDIR    0040000   directory
     *  S_IFCHR    0020000   character device
     *  S_IFIFO    0010000   fifo
     *  S_ISUID    0004000   set UID bit
     *  S_ISGID    0002000   set GID bit
     *  S_ISVTX    0001000   sticky bit
     *
     *  S_IRWXU    00700     mask for file owner permissions
     *  S_IRUSR    00400     owner has read permission
     *  S_IWUSR    00200     owner has write permission
     *  S_IXUSR    00100     owner has execute permission
     *  S_IRWXG    00070     mask for group permissions
     *  S_IRGRP    00040     group has read permission
     *  S_IWGRP    00020     group has write permission
     *  S_IXGRP    00010     group has execute permission
     *  S_IRWXO    00007     mask for permissions for others (not in group)
     *  S_IROTH    00004     others have read permission
     *  S_IWOTH    00002     others have write permisson
     *  S_IXOTH    00001     others have execute permission
     * </pre>
     */
    public Integer permissions = null;

    /**
     * The ATIME attribute. Represented as seconds from Jan 1, 1970 in UTC.
     * <code>NULL</code> if not present.
     */
    public Long atime = null;

    /**
     * The MTIME attribute. Represented as seconds from Jan 1, 1970 in UTC.
     * <code>NULL</code> if not present.
     */
    public Long mtime = null;

    /**
     * Checks if this entry is a directory.
     *
     * @return Returns true if permissions are available and they indicate
     *         that this entry represents a directory.
     */
    public boolean isDirectory() {
        if (permissions == null)
            return false;

        return ((permissions.intValue() & 0040000) != 0);
    }

    /**
     * Checks if this entry is a regular file.
     *
     * @return Returns true if permissions are available and they indicate
     *         that this entry represents a regular file.
     */
    public boolean isRegularFile() {
        if (permissions == null)
            return false;

        return ((permissions.intValue() & 0100000) != 0);
    }

    /**
     * Checks if this entry is a a symlink.
     *
     * @return Returns true if permissions are available and they indicate
     *         that this entry represents a symlink.
     */
    public boolean isSymlink() {
        if (permissions == null)
            return false;

        return ((permissions.intValue() & 0120000) != 0);
    }

    /**
     * Turn the POSIX permissions into a 7 digit octal representation.
     * Note: the returned value is first masked with <code>0177777</code>.
     *
     * @return <code>NULL</code> if permissions are not available.
     */
    public String getOctalPermissions() {
        if (permissions == null)
            return null;

        String res = Integer.toString(permissions.intValue() & 0177777, 8);
        StringBuffer sb = new StringBuffer();
        int leadingZeros = 7 - res.length();

        while (leadingZeros > 0) {
            sb.append('0');
            leadingZeros--;
        }

        sb.append(res);
        return sb.toString();
    }
}