/* -*-mode:java; c-basic-offset:2; -*- */

/*

Copyright (c) 2011 ymnk, JCraft,Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice,

     this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright 

     notice, this list of conditions and the following disclaimer in 

     the documentation and/or other materials provided with the distribution.

  3. The names of the authors may not be used to endorse or promote products

     derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,

INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,

INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,

INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,

OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * This program is based on zlib-1.1.3, so all credit should go authors

 * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)

 * and contributors of zlib.

 */

package org.apidesign.bck2brwsr.emul.zip;

import org.apidesign.bck2brwsr.emul.lang.System;

final class InfBlocks{

  static final private int MANY=1440;

  // And'ing with mask[n] masks the lower n bits

  static final private 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.

  static final int[] border = { // Order of the bit length code lengths

    16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15

  };

  static final private int Z_OK=0;

  static final private int Z_STREAM_END=1;

  static final private int Z_NEED_DICT=2;

  static final private int Z_ERRNO=-1;

  static final private int Z_STREAM_ERROR=-2;

  static final private int Z_DATA_ERROR=-3;

  static final private int Z_MEM_ERROR=-4;

  static final private int Z_BUF_ERROR=-5;

  static final private int Z_VERSION_ERROR=-6;

  static final private int TYPE=0;  // get type bits (3, including end bit)

  static final private int LENS=1;  // get lengths for stored

  static final private int STORED=2;// processing stored block

  static final private int TABLE=3; // get table lengths

  static final private int BTREE=4; // get bit lengths tree for a dynamic block

  static final private int DTREE=5; // get length, distance trees for a dynamic block

  static final private int CODES=6; // processing fixed or dynamic block

  static final private int DRY=7;   // output remaining window bytes

  static final private int DONE=8;  // finished last block, done

  static final private 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==BTREE || mode==DTREE){

    }

    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.next_in_index;n=z.avail_in;b=bitb;k=bitk;}

    {q=write;m=(int)(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.avail_in=n;

	    z.total_in+=p-z.next_in_index;z.next_in_index=p;

	    write=q;

	    return inflate_flush(r);

	  };

	  n--;

	  b|=(z.next_in[p++]&0xff)<<k;

	  k+=8;

	}

	t = (int)(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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n;

	    z.total_in+=p-z.next_in_index;z.next_in_index=p;

	    write=q;

	    return inflate_flush(r);

	  };

	  n--;

	  b|=(z.next_in[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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;

	  write=q;

	  return inflate_flush(r);

	}

	if(m==0){

	  if(q==end&&read!=0){

	    q=0; m=(int)(q<read?read-q-1:end-q);

	  }

	  if(m==0){

	    write=q; 

	    r=inflate_flush(r);

	    q=write;m=(int)(q<read?read-q-1:end-q);

	    if(q==end&&read!=0){

	      q=0; m=(int)(q<read?read-q-1:end-q);

	    }

	    if(m==0){

	      bitb=b; bitk=k; 

	      z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.next_in, 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.avail_in=n;

	    z.total_in+=p-z.next_in_index;z.next_in_index=p;

	    write=q;

	    return inflate_flush(r);

	  };

	  n--;

	  b|=(z.next_in[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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n;

	      z.total_in+=p-z.next_in_index;z.next_in_index=p;

	      write=q;

	      return inflate_flush(r);

	    };

	    n--;

	    b|=(z.next_in[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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n;

	      z.total_in+=p-z.next_in_index;z.next_in_index=p;

	      write=q;

	      return inflate_flush(r);

	    };

	    n--;

	    b|=(z.next_in[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.avail_in=n;

		z.total_in+=p-z.next_in_index;z.next_in_index=p;

		write=q;

		return inflate_flush(r);

	      };

	      n--;

	      b|=(z.next_in[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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.avail_in=n; z.total_in+=p-z.next_in_index;z.next_in_index=p;

	write=q;

	if ((r = codes.proc(r)) != Z_STREAM_END){

	  return inflate_flush(r);

	}

	r = Z_OK;

	codes.free(z);

	p=z.next_in_index; n=z.avail_in;b=bitb;k=bitk;

	q=write;m=(int)(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=(int)(q<read?read-q-1:end-q);

	if (read != write){

	  bitb=b; bitk=k; 

	  z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;

	  write=q;

	  return inflate_flush(r);

	}

	mode = DONE;

      case DONE:

	r = Z_STREAM_END;

	bitb=b; bitk=k; 

	z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;

	write=q;

	return inflate_flush(r);

      case BAD:

	r = Z_DATA_ERROR;

	bitb=b; bitk=k; 

	z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;

	write=q;

	return inflate_flush(r);

      default:

	r = Z_STREAM_ERROR;

	bitb=b; bitk=k; 

	z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=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.next_out_index;

    q = read;

    // compute number of bytes to copy as far as end of window

    n = (int)((q <= write ? write : end) - q);

    if(n > z.avail_out) n = z.avail_out;

    if(n!=0 && r == Z_BUF_ERROR) r = Z_OK;

    // update counters

    z.avail_out -= n;

    z.total_out += 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.next_out, 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.avail_out) n = z.avail_out;

      if (n!=0 && r == Z_BUF_ERROR) r = Z_OK;

      // update counters

      z.avail_out -= n;

      z.total_out += n;

      // update check information

      if(check && n>0){

	z.adler.update(window, q, n);

      }

      // copy

      System.arraycopy(window, q, z.next_out, p, n);

      p += n;

      q += n;

    }

    // update pointers

    z.next_out_index = p;

    read = q;

    // done

    return r;

  }

}