// CHECKSTYLE:OFF
package com.jscape.inet.ssh.protocol.v2.marshaling.algorithms.zlib;

public class InfBlocks {

    private static final int MANY = 1440;

    // And'ing with mask[n] masks the lower n bits
    private static final int[] INFLATE_MASK = {
            0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000f,
            0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 0x000001ff,
            0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff, 0x00003fff,
            0x00007fff, 0x0000ffff
    };

    // Table for deflate from PKZIP's appnote.txt.
    // Order of the bit length code lengths
    static final int[] BORDER = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };

    private static final int Z_OK = 0;
    private static final int Z_STREAM_END = 1;
    private static final int Z_NEED_DICT = 2;
    private static final int Z_ERRNO = -1;
    private static final int Z_STREAM_ERROR = -2;
    private static final int Z_DATA_ERROR = -3;
    private static final int Z_MEM_ERROR = -4;
    private static final int Z_BUF_ERROR = -5;
    private static final int Z_VERSION_ERROR = -6;

    private static final int TYPE = 0;  // get type bits (3, including end bit)
    private static final int LENS = 1;  // get lengths for stored
    private static final int STORED = 2;// processing stored block
    private static final int TABLE = 3; // get table lengths
    private static final int BTREE = 4; // get bit lengths tree for a dynamic block
    private static final int DTREE = 5; // get length, distance trees for a dynamic block
    private static final int CODES = 6; // processing fixed or dynamic block
    private static final int DRY = 7;   // output remaining window bytes
    private static final int DONE = 8;  // finished last block, done
    private static final int BAD = 9;   // ot a data error--stuck here

    int mode;            // current inflate_block mode

    int left;            // if STORED, bytes left to copy

    int table;           // table lengths (14 bits)
    int index;           // index into blens (or border)
    int[] blens;         // bit lengths of codes
    int[] bb = new int[1]; // bit length tree depth
    int[] tb = new int[1]; // bit length decoding tree

    int[] bl = new int[1];
    int[] bd = new int[1];

    int[][] tl = new int[1][];
    int[][] td = new int[1][];
    int[] tli = new int[1]; // tl_index
    int[] tdi = new int[1]; // td_index

    private final InfCodes codes;      // if CODES, current state

    int last;            // true if this block is the last block

    // mode independent information
    int bitk;            // bits in bit buffer
    int bitb;            // bit buffer
    int[] hufts;         // single malloc for tree space
    byte[] window;       // sliding window
    int end;             // one byte after sliding window
    int read;            // window read pointer
    int write;           // window write pointer
    private boolean check;

    private final InfTree inftree = new InfTree();

    private final ZStream z;

    InfBlocks(ZStream z, int w) {
        this.z = z;
        this.codes = new InfCodes(this.z, this);
        hufts = new int[MANY * 3];
        window = new byte[w];
        end = w;
        this.check = (z.istate.wrap == 0) ? false : true;
        mode = TYPE;
        reset();
    }

    void reset() {
        if (mode == CODES) {
            codes.free(z);
        }
        mode = TYPE;
        bitk = 0;
        bitb = 0;
        read = write = 0;
        if (check) {
            z.adler.reset();
        }
    }

    int proc(int r) {
        int t;              // temporary storage
        int b;              // bit buffer
        int k;              // bits in bit buffer
        int p;              // input data pointer
        int n;              // bytes available there
        int q;              // output window write pointer
        int m;              // bytes to end of window or read pointer

        // copy input/output information to locals (UPDATE macro restores)
        {
            p = z.nextInIndex;
            n = z.availIn;
            b = bitb;
            k = bitk;
        }
        {
            q = write;
            m = q < read ? read - q - 1 : end - q;
        }

        // process input based on current state
        while (true) {
            switch (mode) {
                case TYPE:

                    while (k < (3)) {
                        if (n != 0) {
                            r = Z_OK;
                        } else {
                            bitb = b;
                            bitk = k;
                            z.availIn = n;
                            z.totalIn += p - z.nextInIndex;
                            z.nextInIndex = p;
                            write = q;
                            return inflate_flush(r);
                        }
                        ;
                        n--;
                        b |= (z.nextIn[p++] & 0xff) << k;
                        k += 8;
                    }
                    t = b & 7;
                    last = t & 1;

                    switch (t >>> 1) {
                        case 0:                         // stored
                        {
                            b >>>= (3);
                            k -= (3);
                        }
                        t = k & 7;                    // go to byte boundary

                        {
                            b >>>= (t);
                            k -= (t);
                        }
                        mode = LENS;                  // get length of stored block
                        break;
                        case 1:                         // fixed
                            InfTree.inflate_trees_fixed(bl, bd, tl, td, z);
                            codes.init(bl[0], bd[0], tl[0], 0, td[0], 0);

                        {
                            b >>>= (3);
                            k -= (3);
                        }

                        mode = CODES;
                        break;
                        case 2:                         // dynamic

                        {
                            b >>>= (3);
                            k -= (3);
                        }

                        mode = TABLE;
                        break;
                        case 3:                         // illegal

                        {
                            b >>>= (3);
                            k -= (3);
                        }
                        mode = BAD;
                        z.msg = "invalid block type";
                        r = Z_DATA_ERROR;

                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }
                    break;
                case LENS:

                    while (k < (32)) {
                        if (n != 0) {
                            r = Z_OK;
                        } else {
                            bitb = b;
                            bitk = k;
                            z.availIn = n;
                            z.totalIn += p - z.nextInIndex;
                            z.nextInIndex = p;
                            write = q;
                            return inflate_flush(r);
                        }
                        n--;
                        b |= (z.nextIn[p++] & 0xff) << k;
                        k += 8;
                    }

                    if ((((~b) >>> 16) & 0xffff) != (b & 0xffff)) {
                        mode = BAD;
                        z.msg = "invalid stored block lengths";
                        r = Z_DATA_ERROR;

                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }
                    left = (b & 0xffff);
                    b = k = 0;                       // dump bits
                    mode = left != 0 ? STORED : (last != 0 ? DRY : TYPE);
                    break;
                case STORED:
                    if (n == 0) {
                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }

                    if (m == 0) {
                        if (q == end && read != 0) {
                            q = 0;
                            m = q < read ? read - q - 1 : end - q;
                        }
                        if (m == 0) {
                            write = q;
                            r = inflate_flush(r);
                            q = write;
                            m = q < read ? read - q - 1 : end - q;
                            if (q == end && read != 0) {
                                q = 0;
                                m = q < read ? read - q - 1 : end - q;
                            }
                            if (m == 0) {
                                bitb = b;
                                bitk = k;
                                z.availIn = n;
                                z.totalIn += p - z.nextInIndex;
                                z.nextInIndex = p;
                                write = q;
                                return inflate_flush(r);
                            }
                        }
                    }
                    r = Z_OK;

                    t = left;
                    if (t > n) t = n;
                    if (t > m) t = m;
                    System.arraycopy(z.nextIn, p, window, q, t);
                    p += t;
                    n -= t;
                    q += t;
                    m -= t;
                    if ((left -= t) != 0)
                        break;
                    mode = last != 0 ? DRY : TYPE;
                    break;
                case TABLE:

                    while (k < (14)) {
                        if (n != 0) {
                            r = Z_OK;
                        } else {
                            bitb = b;
                            bitk = k;
                            z.availIn = n;
                            z.totalIn += p - z.nextInIndex;
                            z.nextInIndex = p;
                            write = q;
                            return inflate_flush(r);
                        }
                        ;
                        n--;
                        b |= (z.nextIn[p++] & 0xff) << k;
                        k += 8;
                    }

                    table = t = (b & 0x3fff);
                    if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) {
                        mode = BAD;
                        z.msg = "too many length or distance symbols";
                        r = Z_DATA_ERROR;

                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }
                    t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
                    if (blens == null || blens.length < t) {
                        blens = new int[t];
                    } else {
                        for (int i = 0; i < t; i++) {
                            blens[i] = 0;
                        }
                    }

                {
                    b >>>= (14);
                    k -= (14);
                }

                index = 0;
                mode = BTREE;
                case BTREE:
                    while (index < 4 + (table >>> 10)) {
                        while (k < (3)) {
                            if (n != 0) {
                                r = Z_OK;
                            } else {
                                bitb = b;
                                bitk = k;
                                z.availIn = n;
                                z.totalIn += p - z.nextInIndex;
                                z.nextInIndex = p;
                                write = q;
                                return inflate_flush(r);
                            }
                            ;
                            n--;
                            b |= (z.nextIn[p++] & 0xff) << k;
                            k += 8;
                        }

                        blens[BORDER[index++]] = b & 7;

                        {
                            b >>>= (3);
                            k -= (3);
                        }
                    }

                    while (index < 19) {
                        blens[BORDER[index++]] = 0;
                    }

                    bb[0] = 7;
                    t = inftree.inflate_trees_bits(blens, bb, tb, hufts, z);
                    if (t != Z_OK) {
                        r = t;
                        if (r == Z_DATA_ERROR) {
                            blens = null;
                            mode = BAD;
                        }

                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }

                    index = 0;
                    mode = DTREE;
                case DTREE:
                    while (true) {
                        t = table;
                        if (!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))) {
                            break;
                        }

                        int[] h;
                        int i, j, c;

                        t = bb[0];

                        while (k < (t)) {
                            if (n != 0) {
                                r = Z_OK;
                            } else {
                                bitb = b;
                                bitk = k;
                                z.availIn = n;
                                z.totalIn += p - z.nextInIndex;
                                z.nextInIndex = p;
                                write = q;
                                return inflate_flush(r);
                            }
                            ;
                            n--;
                            b |= (z.nextIn[p++] & 0xff) << k;
                            k += 8;
                        }

                        if (tb[0] == -1) {
                            //System.err.println("null...");
                        }

                        t = hufts[(tb[0] + (b & INFLATE_MASK[t])) * 3 + 1];
                        c = hufts[(tb[0] + (b & INFLATE_MASK[t])) * 3 + 2];

                        if (c < 16) {
                            b >>>= (t);
                            k -= (t);
                            blens[index++] = c;
                        } else { // c == 16..18
                            i = c == 18 ? 7 : c - 14;
                            j = c == 18 ? 11 : 3;

                            while (k < (t + i)) {
                                if (n != 0) {
                                    r = Z_OK;
                                } else {
                                    bitb = b;
                                    bitk = k;
                                    z.availIn = n;
                                    z.totalIn += p - z.nextInIndex;
                                    z.nextInIndex = p;
                                    write = q;
                                    return inflate_flush(r);
                                }
                                ;
                                n--;
                                b |= (z.nextIn[p++] & 0xff) << k;
                                k += 8;
                            }

                            b >>>= (t);
                            k -= (t);

                            j += (b & INFLATE_MASK[i]);

                            b >>>= (i);
                            k -= (i);

                            i = index;
                            t = table;
                            if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
                                    (c == 16 && i < 1)) {
                                blens = null;
                                mode = BAD;
                                z.msg = "invalid bit length repeat";
                                r = Z_DATA_ERROR;

                                bitb = b;
                                bitk = k;
                                z.availIn = n;
                                z.totalIn += p - z.nextInIndex;
                                z.nextInIndex = p;
                                write = q;
                                return inflate_flush(r);
                            }

                            c = c == 16 ? blens[i - 1] : 0;
                            do {
                                blens[i++] = c;
                            }
                            while (--j != 0);
                            index = i;
                        }
                    }

                    tb[0] = -1;
                {
                    bl[0] = 9;         // must be <= 9 for lookahead assumptions
                    bd[0] = 6;         // must be <= 9 for lookahead assumptions
                    t = table;
                    t = inftree.inflate_trees_dynamic(257 + (t & 0x1f),
                                                      1 + ((t >> 5) & 0x1f),
                                                      blens, bl, bd, tli, tdi, hufts, z);

                    if (t != Z_OK) {
                        if (t == Z_DATA_ERROR) {
                            blens = null;
                            mode = BAD;
                        }
                        r = t;

                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }
                    codes.init(bl[0], bd[0], hufts, tli[0], hufts, tdi[0]);
                }
                mode = CODES;
                case CODES:
                    bitb = b;
                    bitk = k;
                    z.availIn = n;
                    z.totalIn += p - z.nextInIndex;
                    z.nextInIndex = p;
                    write = q;

                    if ((r = codes.proc(r)) != Z_STREAM_END) {
                        return inflate_flush(r);
                    }
                    r = Z_OK;
                    codes.free(z);

                    p = z.nextInIndex;
                    n = z.availIn;
                    b = bitb;
                    k = bitk;
                    q = write;
                    m = q < read ? read - q - 1 : end - q;

                    if (last == 0) {
                        mode = TYPE;
                        break;
                    }
                    mode = DRY;
                case DRY:
                    write = q;
                    r = inflate_flush(r);
                    q = write;
                    m = q < read ? read - q - 1 : end - q;
                    if (read != write) {
                        bitb = b;
                        bitk = k;
                        z.availIn = n;
                        z.totalIn += p - z.nextInIndex;
                        z.nextInIndex = p;
                        write = q;
                        return inflate_flush(r);
                    }
                    mode = DONE;
                case DONE:
                    r = Z_STREAM_END;

                    bitb = b;
                    bitk = k;
                    z.availIn = n;
                    z.totalIn += p - z.nextInIndex;
                    z.nextInIndex = p;
                    write = q;
                    return inflate_flush(r);
                case BAD:
                    r = Z_DATA_ERROR;

                    bitb = b;
                    bitk = k;
                    z.availIn = n;
                    z.totalIn += p - z.nextInIndex;
                    z.nextInIndex = p;
                    write = q;
                    return inflate_flush(r);

                default:
                    r = Z_STREAM_ERROR;

                    bitb = b;
                    bitk = k;
                    z.availIn = n;
                    z.totalIn += p - z.nextInIndex;
                    z.nextInIndex = p;
                    write = q;
                    return inflate_flush(r);
            }
        }
    }

    void free() {
        reset();
        window = null;
        hufts = null;
        //ZFREE(z, s);
    }

    void set_dictionary(byte[] d, int start, int n) {
        System.arraycopy(d, start, window, 0, n);
        read = write = n;
    }

    // Returns true if inflate is currently at the end of a block generated
    // by Z_SYNC_FLUSH or Z_FULL_FLUSH.
    int sync_point() {
        return mode == LENS ? 1 : 0;
    }

    // copy as much as possible from the sliding window to the output area
    int inflate_flush(int r) {
        int n;
        int p;
        int q;

        // local copies of source and destination pointers
        p = z.nextOutIndex;
        q = read;

        // compute number of bytes to copy as far as end of window
        n = (q <= write ? write : end) - q;
        if (n > z.availOut) {
            n = z.availOut;
        }
        if (n != 0 && r == Z_BUF_ERROR) {
            r = Z_OK;
        }

        // update counters
        z.availOut -= n;
        z.totalOut += n;

        // update check information
        if (check && n > 0) {
            z.adler.update(window, q, n);
        }

        // copy as far as end of window
        System.arraycopy(window, q, z.nextOut, p, n);
        p += n;
        q += n;

        // see if more to copy at beginning of window
        if (q == end) {
            // wrap pointers
            q = 0;
            if (write == end)
                write = 0;

            // compute bytes to copy
            n = write - q;
            if (n > z.availOut) {
                n = z.availOut;
            }
            if (n != 0 && r == Z_BUF_ERROR) {
                r = Z_OK;
            }

            // update counters
            z.availOut -= n;
            z.totalOut += n;

            // update check information
            if (check && n > 0) {
                z.adler.update(window, q, n);
            }

            // copy
            System.arraycopy(window, q, z.nextOut, p, n);
            p += n;
            q += n;
        }

        // update pointers
        z.nextOutIndex = p;
        read = q;

        // done
        return r;
    }
}
