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

/*

Copyright (c) 2000,2001,2002,2003 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 InfCodes{

  static final private int[] inflate_mask = {

    0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000f,

    0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 0x000001ff,

    0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff, 0x00003fff,

    0x00007fff, 0x0000ffff

  };

  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;

  // waiting for "i:"=input,

  //             "o:"=output,

  //             "x:"=nothing

  static final private int START=0;  // x: set up for LEN

  static final private int LEN=1;    // i: get length/literal/eob next

  static final private int LENEXT=2; // i: getting length extra (have base)

  static final private int DIST=3;   // i: get distance next

  static final private int DISTEXT=4;// i: getting distance extra

  static final private int COPY=5;   // o: copying bytes in window, waiting for space

  static final private int LIT=6;    // o: got literal, waiting for output space

  static final private int WASH=7;   // o: got eob, possibly still output waiting

  static final private int END=8;    // x: got eob and all data flushed

  static final private int BADCODE=9;// x: got error

  int mode;      // current inflate_codes mode

  // mode dependent information

  int len;

  int[] tree; // pointer into tree

  int tree_index=0;

  int need;   // bits needed

  int lit;

  // if EXT or COPY, where and how much

  int get;              // bits to get for extra

  int dist;             // distance back to copy from

  byte lbits;           // ltree bits decoded per branch

  byte dbits;           // dtree bits decoder per branch

  int[] ltree;          // literal/length/eob tree

  int ltree_index;      // literal/length/eob tree

  int[] dtree;          // distance tree

  int dtree_index;      // distance tree

  private final ZStream z;

  private final InfBlocks s;

  InfCodes(ZStream z, InfBlocks s){

    this.z=z; 

    this.s=s; 

  }

  void init(int bl, int bd,

	   int[] tl, int tl_index,

	   int[] td, int td_index){

    mode=START;

    lbits=(byte)bl;

    dbits=(byte)bd;

    ltree=tl;

    ltree_index=tl_index;

    dtree = td;

    dtree_index=td_index;

    tree=null;

  }

  int proc(int r){ 

    int j;              // temporary storage

    int[] t;            // temporary pointer

    int tindex;         // temporary pointer

    int e;              // extra bits or operation

    int b=0;            // bit buffer

    int k=0;            // bits in bit buffer

    int p=0;            // input data pointer

    int n;              // bytes available there

    int q;              // output window write pointer

    int m;              // bytes to end of window or read pointer

    int f;              // pointer to copy strings from

    // copy input/output information to locals (UPDATE macro restores)

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

    q=s.write;m=q<s.read?s.read-q-1:s.end-q;

    // process input and output based on current state

    while (true){

      switch (mode){

	// waiting for "i:"=input, "o:"=output, "x:"=nothing

      case START:         // x: set up for LEN

	if (m >= 258 && n >= 10){

	  s.bitb=b;s.bitk=k;

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

	  s.write=q;

	  r = inflate_fast(lbits, dbits, 

			   ltree, ltree_index, 

			   dtree, dtree_index,

			   s, z);

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

	  q=s.write;m=q<s.read?s.read-q-1:s.end-q;

	  if (r != Z_OK){

	    mode = r == Z_STREAM_END ? WASH : BADCODE;

	    break;

	  }

	}

	need = lbits;

	tree = ltree;

	tree_index=ltree_index;

	mode = LEN;

      case LEN:           // i: get length/literal/eob next

	j = need;

	while(k<(j)){

	  if(n!=0)r=Z_OK;

	  else{

	    s.bitb=b;s.bitk=k;

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

	    s.write=q;

	    return s.inflate_flush(r);

	  }

	  n--;

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

	  k+=8;

	}

	tindex=(tree_index+(b&inflate_mask[j]))*3;

	b>>>=(tree[tindex+1]);

	k-=(tree[tindex+1]);

	e=tree[tindex];

	if(e == 0){               // literal

	  lit = tree[tindex+2];

	  mode = LIT;

	  break;

	}

	if((e & 16)!=0 ){          // length

	  get = e & 15;

	  len = tree[tindex+2];

	  mode = LENEXT;

	  break;

	}

	if ((e & 64) == 0){        // next table

	  need = e;

	  tree_index = tindex/3+tree[tindex+2];

	  break;

	}

	if ((e & 32)!=0){               // end of block

	  mode = WASH;

	  break;

	}

	mode = BADCODE;        // invalid code

	z.msg = "invalid literal/length code";

	r = Z_DATA_ERROR;

	s.bitb=b;s.bitk=k;

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

	s.write=q;

	return s.inflate_flush(r);

      case LENEXT:        // i: getting length extra (have base)

	j = get;

	while(k<(j)){

	  if(n!=0)r=Z_OK;

	  else{

	    s.bitb=b;s.bitk=k;

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

	    s.write=q;

	    return s.inflate_flush(r);

	  }

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

	  k+=8;

	}

	len += (b & inflate_mask[j]);

	b>>=j;

	k-=j;

	need = dbits;

	tree = dtree;

	tree_index=dtree_index;

	mode = DIST;

      case DIST:          // i: get distance next

	j = need;

	while(k<(j)){

	  if(n!=0)r=Z_OK;

	  else{

	    s.bitb=b;s.bitk=k;

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

	    s.write=q;

	    return s.inflate_flush(r);

	  }

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

	  k+=8;

	}

	tindex=(tree_index+(b & inflate_mask[j]))*3;

	b>>=tree[tindex+1];

	k-=tree[tindex+1];

	e = (tree[tindex]);

	if((e & 16)!=0){               // distance

	  get = e & 15;

	  dist = tree[tindex+2];

	  mode = DISTEXT;

	  break;

	}

	if ((e & 64) == 0){        // next table

	  need = e;

	  tree_index = tindex/3 + tree[tindex+2];

	  break;

	}

	mode = BADCODE;        // invalid code

	z.msg = "invalid distance code";

	r = Z_DATA_ERROR;

	s.bitb=b;s.bitk=k;

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

	s.write=q;

	return s.inflate_flush(r);

      case DISTEXT:       // i: getting distance extra

	j = get;

	while(k<(j)){

	  if(n!=0)r=Z_OK;

	  else{

	    s.bitb=b;s.bitk=k;

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

	    s.write=q;

	    return s.inflate_flush(r);

	  }

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

	  k+=8;

	}

	dist += (b & inflate_mask[j]);

	b>>=j;

	k-=j;

	mode = COPY;

      case COPY:          // o: copying bytes in window, waiting for space

        f = q - dist;

        while(f < 0){     // modulo window size-"while" instead

          f += s.end;     // of "if" handles invalid distances

	}

	while (len!=0){

	  if(m==0){

	    if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}

	    if(m==0){

	      s.write=q; r=s.inflate_flush(r);

	      q=s.write;m=q<s.read?s.read-q-1:s.end-q;

	      if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}

	      if(m==0){

		s.bitb=b;s.bitk=k;

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

		s.write=q;

		return s.inflate_flush(r);

	      }  

	    }

	  }

	  s.window[q++]=s.window[f++]; m--;

	  if (f == s.end)

            f = 0;

	  len--;

	}

	mode = START;

	break;

      case LIT:           // o: got literal, waiting for output space

	if(m==0){

	  if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}

	  if(m==0){

	    s.write=q; r=s.inflate_flush(r);

	    q=s.write;m=q<s.read?s.read-q-1:s.end-q;

	    if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}

	    if(m==0){

	      s.bitb=b;s.bitk=k;

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

	      s.write=q;

	      return s.inflate_flush(r);

	    }

	  }

	}

	r=Z_OK;

	s.window[q++]=(byte)lit; m--;

	mode = START;

	break;

      case WASH:           // o: got eob, possibly more output

	if (k > 7){        // return unused byte, if any

	  k -= 8;

	  n++;

	  p--;             // can always return one

	}

	s.write=q; r=s.inflate_flush(r);

	q=s.write;m=q<s.read?s.read-q-1:s.end-q;

	if (s.read != s.write){

	  s.bitb=b;s.bitk=k;

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

	  s.write=q;

	  return s.inflate_flush(r);

	}

	mode = END;

      case END:

	r = Z_STREAM_END;

	s.bitb=b;s.bitk=k;

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

	s.write=q;

	return s.inflate_flush(r);

      case BADCODE:       // x: got error

	r = Z_DATA_ERROR;

	s.bitb=b;s.bitk=k;

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

	s.write=q;

	return s.inflate_flush(r);

      default:

	r = Z_STREAM_ERROR;

	s.bitb=b;s.bitk=k;

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

	s.write=q;

	return s.inflate_flush(r);

      }

    }

  }

  void free(ZStream z){

    //  ZFREE(z, c);

  }

  // Called with number of bytes left to write in window at least 258

  // (the maximum string length) and number of input bytes available

  // at least ten.  The ten bytes are six bytes for the longest length/

  // distance pair plus four bytes for overloading the bit buffer.

  int inflate_fast(int bl, int bd, 

		   int[] tl, int tl_index,

		   int[] td, int td_index,

		   InfBlocks s, ZStream z){

    int t;                // temporary pointer

    int[] tp;             // temporary pointer

    int tp_index;         // temporary pointer

    int e;                // extra bits or operation

    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

    int ml;               // mask for literal/length tree

    int md;               // mask for distance tree

    int c;                // bytes to copy

    int d;                // distance back to copy from

    int r;                // copy source pointer

    int tp_index_t_3;     // (tp_index+t)*3

    // load input, output, bit values

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

    q=s.write;m=q<s.read?s.read-q-1:s.end-q;

    // initialize masks

    ml = inflate_mask[bl];

    md = inflate_mask[bd];

    // do until not enough input or output space for fast loop

    do {                          // assume called with m >= 258 && n >= 10

      // get literal/length code

      while(k<(20)){              // max bits for literal/length code

	n--;

	b|=(z.next_in[p++]&0xff)<<k;k+=8;

      }

      t= b&ml;

      tp=tl; 

      tp_index=tl_index;

      tp_index_t_3=(tp_index+t)*3;

      if ((e = tp[tp_index_t_3]) == 0){

	b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);

	s.window[q++] = (byte)tp[tp_index_t_3+2];

	m--;

	continue;

      }

      do {

	b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);

	if((e&16)!=0){

	  e &= 15;

	  c = tp[tp_index_t_3+2] + ((int)b & inflate_mask[e]);

	  b>>=e; k-=e;

	  // decode distance base of block to copy

	  while(k<(15)){           // max bits for distance code

	    n--;

	    b|=(z.next_in[p++]&0xff)<<k;k+=8;

	  }

	  t= b&md;

	  tp=td;

	  tp_index=td_index;

          tp_index_t_3=(tp_index+t)*3;

	  e = tp[tp_index_t_3];

	  do {

	    b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);

	    if((e&16)!=0){

	      // get extra bits to add to distance base

	      e &= 15;

	      while(k<(e)){         // get extra bits (up to 13)

		n--;

		b|=(z.next_in[p++]&0xff)<<k;k+=8;

	      }

	      d = tp[tp_index_t_3+2] + (b&inflate_mask[e]);

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

	      // do the copy

	      m -= c;

	      if (q >= d){                // offset before dest

		//  just copy

		r=q-d;

		if(q-r>0 && 2>(q-r)){           

		  s.window[q++]=s.window[r++]; // minimum count is three,

		  s.window[q++]=s.window[r++]; // so unroll loop a little

		  c-=2;

		}

		else{

		  System.arraycopy(s.window, r, s.window, q, 2);

		  q+=2; r+=2; c-=2;

		}

	      }

	      else{                  // else offset after destination

                r=q-d;

                do{

                  r+=s.end;          // force pointer in window

                }while(r<0);         // covers invalid distances

		e=s.end-r;

		if(c>e){             // if source crosses,

		  c-=e;              // wrapped copy

		  if(q-r>0 && e>(q-r)){           

		    do{s.window[q++] = s.window[r++];}

		    while(--e!=0);

		  }

		  else{

		    System.arraycopy(s.window, r, s.window, q, e);

		    q+=e; r+=e; e=0;

		  }

		  r = 0;                  // copy rest from start of window

		}

	      }

	      // copy all or what's left

	      if(q-r>0 && c>(q-r)){           

		do{s.window[q++] = s.window[r++];}

		while(--c!=0);

	      }

	      else{

		System.arraycopy(s.window, r, s.window, q, c);

		q+=c; r+=c; c=0;

	      }

	      break;

	    }

	    else if((e&64)==0){

	      t+=tp[tp_index_t_3+2];

	      t+=(b&inflate_mask[e]);

	      tp_index_t_3=(tp_index+t)*3;

	      e=tp[tp_index_t_3];

	    }

	    else{

	      z.msg = "invalid distance code";

	      c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;

	      s.bitb=b;s.bitk=k;

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

	      s.write=q;

	      return Z_DATA_ERROR;

	    }

	  }

	  while(true);

	  break;

	}

	if((e&64)==0){

	  t+=tp[tp_index_t_3+2];

	  t+=(b&inflate_mask[e]);

	  tp_index_t_3=(tp_index+t)*3;

	  if((e=tp[tp_index_t_3])==0){

	    b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);

	    s.window[q++]=(byte)tp[tp_index_t_3+2];

	    m--;

	    break;

	  }

	}

	else if((e&32)!=0){

	  c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;

	  s.bitb=b;s.bitk=k;

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

	  s.write=q;

	  return Z_STREAM_END;

	}

	else{

	  z.msg="invalid literal/length code";

	  c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;

	  s.bitb=b;s.bitk=k;

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

	  s.write=q;

	  return Z_DATA_ERROR;

	}

      } 

      while(true);

    } 

    while(m>=258 && n>= 10);

    // not enough input or output--restore pointers and return

    c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;

    s.bitb=b;s.bitk=k;

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

    s.write=q;

    return Z_OK;

  }

}