#include <u.h>
#include <libc.h>
#include <bio.h>
#include <flate.h>
#include <tiff.h>

static int
unZzero(Tiff * t, Biobuf *b, uchar *buf, int l)
{
	switch(t->bpp){
	case 16:
		return Btiffshorts(b, (short*)buf, l/2, t->order);
	case 32:
		return Btifflongs(b, (long*)buf, l/4, t->order);
	default:
		fprint(2, "l = %d\n", l);
		return Bread(b, buf, l);
	}
}

static int
unZccitt(Tiff *t, Biobuf *b, uchar *buf, int l)
{
	return tiffhuff(b, buf, l, lookifd(t, Tphotometric), lookifd(t, Twidth));
}

static int
unZpack(Tiff *, Biobuf *b, uchar* buf, int l)
{
	int c, n;

	for(n = 0; n != l; ){
		c = Bgetc(b);
		if(c < 128)
			Bread(b, buf+n, c+1);
		else if(c > 128){
			c = 256-c;
			memset(buf+n, Bgetc(b), c+1);
		} else
			continue;
		n += c+1;
	}
	return n;
}

#ifdef nosabe
static int
unZlzw(Tiff *, Biobuf *b, uchar *buf, int l)
{
	uchar block[8*1024], *p, *e;
	static int didinit;
	int c, s, r;

	if(!didinit++)
		inflateinit();
	s = iounit(Bfildes(b));
	if(s < 100 || s > sizeof block)
		s = sizeof block;
fprint(2, "s=%d\n", s);
	for(p = buf, e = p+l; e != p; p += r){
		c = Bread(b, block, s);
		if(c < 0)
			break;
		r = inflateblock(p, e-p, block, c);
		if(r < 0){
			fprint(2, "%d: %r\n", r);
			break;
		}
fprint(2, "buf=%011uld: p %011uld e %011uld  r=%d\n", (ulong)buf, (ulong)p, (ulong)e, r);
	}
	return p-buf;
}
#endif
typedef struct {
	uchar *a;
	long   offset;
	long l;
} A;

static int
dmemcpy(void *t, void *s, int n){
	A *a;

	a = t;
	fprint(2, "x %lx n=%d\n", a->offset, n);
	if(a->offset+n >= a->l)
		return -1;
	memcpy(a->a + a->offset, s, n);
	a->offset += n;
	return n;
}

extern int inflatelzw(void *wr, int (*w)(void*, void*, int), void *getr, int (*get)(void*));
static int
unZlzw(Tiff *, Biobuf *b, uchar *buf, int l)
{
	A a;

	a.a = buf;
	a.offset = 0;
	a.l = l;
	return inflatelzw(&a, dmemcpy, b, (int (*)(void*))Bgetc);
}

int
unbad(Tiff*, Biobuf*, uchar*, int)
{
	return -1;
}

typedef struct {
	Ztype z;
	int (*f)(Tiff*, Biobuf*, uchar*, int);
	char *s;
} Ztab;

Ztab tab[] = {
	{Zzero,		unZzero,	"none"		},
	{Zccitt,		unZccitt,	"ccitt",		},
	{Zgroup3,	unZccitt,	"group3",	},
	{Zgroup4,	unZccitt,	"group4",	},
	{Zlzw,		unZlzw,		"lzw",		},
	{Zjpeg,		unbad,		"jpg",		},
	{Zpack,		unZpack,	"packbits",	},
	{0, 		unbad,		"unknown",	}
};

char*
tiffzstr(ushort ztype)
{
	Ztab *z, *e;
	for(z = tab, e = tab+nelem(tab); z < e; z++)
		if(z->z == ztype)
			return z->s;
	return 0;
}

int
tiffunz(Tiff *t, ushort ztype, Biobuf* b, int l)
{
	Ztab *z, *e;

	for(z = tab, e = tab+nelem(tab)-1; z < e; z++)
		if(z->z == ztype)
			break;
	return z->f(t, b, t->rawimge, l);
}