#ifdef __plan9__
#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.h>
#else
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
typedef uint8_t u8int;
typedef uint32_t u32int;
#define nil NULL
typedef struct {
} Memimage;
typedef struct {
	u32int *base;
	u8int *bdata;
} Memdata;
static char *argv0;
#define fprint(x, arg...) fprintf(stderr, arg)
#define exits(s) exit(s == NULL ? 0 : 1)
#define sysfatal(s) \
	do { \
		fprintf(stderr, "error\n"); \
		exit(1); \
	} while(0)
#define ARGBEGIN \
	for(((argv0 = *argv)), argv++, argc--; \
		argv[0] && argv[0][0] == '-' && argv[0][1]; \
		argc--, argv++) { \
		char *_args, _argc, *_argt; \
		_args = &argv[0][1]; \
		if(_args[0] == '-' && _args[1] == 0) { \
			argc--; \
			argv++; \
			break; \
		} \
		_argc = 0; \
		while(*_args && (_argc = *_args++)) \
			switch(_argc)
#define ARGEND \
	} \
	;
#define EARGF(x) \
	(_argt = _args, _args = "", (*_argt ? _argt : argv[1] ? (argc--, *++argv) \
														  : ((x), abort(), (char *)0)))
#endif

static int hor = 44, ver = 26, bpp = 1;

#define xy2n(x, y) ((y & 7) + (x / 8 + y / 8 * hor) * bpp * 8)

static u8int *
readall(int f, int *isz)
{
	int bufsz, sz, n;
	u8int *s;

	bufsz = 1023;
	s = nil;
	for(sz = 0;; sz += n) {
		if(bufsz - sz < 1024) {
			bufsz *= 2;
			s = realloc(s, bufsz);
		}
		if((n = read(f, s + sz, bufsz - sz)) < 1)
			break;
	}
	if(n < 0 || sz < 1) {
		free(s);
		return nil;
	}
	*isz = sz;

	return s;
}

static int
getcoli(int x, int y, u8int *p)
{
	int ch1, ch2, r;

	r = xy2n(x, y);
	ch1 = (p[r + 0] >> (7 - (x & 7))) & 1;
	ch2 = bpp < 2 ? 0 : (p[r + 8] >> (7 - (x & 7))) & 1;

	return ch2 << 1 | ch1;
}

static int
writebmp(int w, int h, u32int *p)
{
	/* clang-format off */
	u8int hd[14+40+4*4] = {
		'B', 'M',
		0, 0, 0, 0, /* file size */
		0, 0,
		0, 0,
		14+40+4*4, 0, 0, 0, /* pixel data offset */
		40+4*4, 0, 0, 0, /* BITMAPINFOHEADER */
		w, w>>8, 0, 0, /* width */
		h, h>>8, 0, 0, /* height */
		1, 0, /* color planes */
		32, 0, /* bpp = rgba */
		3, 0, 0, 0, /* no compression */
		0, 0, 0, 0, /* dummy raw size */
		0, 0, 0, 0, /* dummy hor ppm */
		0, 0, 0, 0, /* dummy ver ppm */
		0, 0, 0, 0, /* dummy num of colors */
		0, 0, 0, 0, /* dummy important colors */
		0, 0, 0, 0xff,
		0, 0, 0xff, 0,
		0, 0xff, 0, 0,
		0xff, 0, 0, 0,
	};
	int sz;
	/* clang-format on */

	sz = 14 + 40 + 4 * 4 + 4 * w * h;
	hd[2] = sz;
	hd[3] = sz >> 8;
	hd[4] = sz >> 16;
	hd[5] = sz >> 24;

	write(1, hd, sizeof(hd));
	while(h-- >= 0)
		write(1, p + w * h, 4 * w);

	return 0;
}

static void
usage(void)
{
	fprint(2, "usage: %s [-1] [-2] [-w WIDTH]\n", argv0);
	exits("usage");
}

int
main(int argc, char **argv)
{
	int sz, esz, h, w, x, y;
	Memimage *m;
	Memdata d;
	u8int *p;
	u32int col[2][4] = {
		{0xffffffff, 0x000000ff, 0x000000ff, 0x000000ff},
		{0xffffff00, 0xffffffff, 0x72dec2ff, 0x666666ff},
	};

	ARGBEGIN
	{
	case '1':
		bpp = 1;
		break;
	case '2':
		bpp = 2;
		break;
	case 'w':
		hor = atoi(EARGF(usage()));
		break;
	default:
		usage();
	}
	ARGEND

	if((p = readall(0, &sz)) == nil)
		sysfatal("%r");

	ver = sz / (bpp * 8) / hor;
	esz = (hor * ver * (bpp * 8));
	w = hor * 8;
	h = ver * 8;
	if(sz != esz)
		fprint(2, "warning: size differs (%d vs %d), dimensions must be wrong\n", sz, esz);

	memset(&d, 0, sizeof(d));
	if((d.base = malloc(4 * w * h)) == nil)
		sysfatal("memory");
	d.bdata = (u8int *)d.base;

	for(y = 0; y < h; y++) {
		for(x = 0; x < w; x++)
			d.base[y * w + x] = col[bpp - 1][getcoli(x, y, p)];
	}

#ifdef __plan9__
	memimageinit();
	if((m = allocmemimaged(Rect(0, 0, w, h), RGBA32, &d)) == nil)
		sysfatal("%r");
	if(writememimage(1, m) != 0)
		sysfatal("%r");
#else
	(void)m;
	writebmp(w, h, d.base);
#endif

	exits(nil);
	return 0;
}