import java.math.BigInteger;
import java.util.Date;

import jcifs.SmbConstants;
import jcifs.smb.SID;

/**
 * Input stream for reading PAC data structures with proper alignment and byte ordering.
 * Handles little-endian byte order and data alignment requirements of PAC structures.
 */
public class PacDataInputStream {

    private final DataInputStream dis;
    private final int size;

    /**

        }

        @Test
        @DisplayName("Test write string with odd Unicode alignment")
        void testWriteStringUnicodeAlignment() {
            testBlock.setUseUnicode(true);
            byte[] buffer = new byte[100];
            String testString = "Test";

            // Test odd Unicode alignment - headerStart affects alignment
            int bytesWritten = testBlock.writeString(testString, buffer, 2);

        return buf;
    }

    /**
     * Aligns the buffer index to the specified boundary with a fill value.
     *
     * @param boundary the alignment boundary
     * @param value the fill value for padding
     * @return the number of bytes added for alignment
     */
    public int align(final int boundary, final byte value) {
        final int n = align(boundary);
        int i = n;
        while (i > 0) {

        return this.buf;
    }

    /**
     * Aligns the buffer index to the specified boundary with a fill value.
     *
     * @param boundary the alignment boundary
     * @param value the fill value for padding
     * @return the number of bytes added for alignment
     */
    public int align(final int boundary, final byte value) {
        final int n = align(boundary);
        int i = n;
        while (i > 0) {

        // Test alignment from position 1 to 4
        byte[] data = new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05 };
        PacDataInputStream pdis = createInputStream(data);
        pdis.readByte(); // position is 1
        pdis.align(4);
        assertEquals(1, pdis.available());
        assertEquals(0x05, pdis.readByte());

        // Test no alignment needed

        // Then
        // The writeBytesWireFormat writes the structure and calculates padding
        // Base structure: 24 bytes, then pad8 alignment, then token: 5 bytes
        // Total bytes written includes padding for 8-byte alignment
        int expectedBytesWritten = 35;
        assertEquals(expectedBytesWritten, bytesWritten);

        // Verify structure

    }

    String readString(final byte[] src, final int srcIndex, int len) {
        String str = null;
        try {
            if (useUnicode) {
                // should Unicode alignment be corrected for here?
                str = new String(src, srcIndex, len, UNI_ENCODING);
            } else {

                /* On NT without Unicode the fileNameLength

    }

    @Override
    public byte[] getName() {
        return CONTEXT_NAME_BYTES;
    }

    @Override
    public int size() {
        // Context header (16) + name length (4) + padding to 8-byte alignment + data (16)
        return 16 + 4 + 4 + STRUCTURE_SIZE;
    }

    @Override
    public int encode(byte[] dst, int dstIndex) {
        int start = dstIndex;

        // Write context header

     */
    public byte[] getFileId() {
        return Arrays.copyOf(fileId, 16);
    }

    @Override
    public int size() {
        // Context header (16) + name length (4) + padding to 8-byte alignment + data (16)
        return 16 + 4 + 4 + STRUCTURE_SIZE;
    }

    @Override
    public int encode(byte[] dst, int dstIndex) {
        int start = dstIndex;

        // Write context header

        writeInt2(0x80 | attributes, dst, dstIndex);
        dstIndex += 2;
        /* 6 zeros observed with NT */
        writeInt8(0L, dst, dstIndex);
        dstIndex += 6;

        /* Also observed 4 byte alignment but we stick
         * with the default for jCIFS which is 2 */

        return dstIndex - start;
    }

    @Override
    int readSetupWireFormat(final byte[] buffer, final int bufferIndex, final int len) {