// worldio.cpp: loading & saving of maps and savegames

#include "cube.h"

void
backup(char *name, char *backupname)
{
	remove(backupname);
	rename(name, backupname);
};

string cgzname, bakname, pcfname, mcfname;

void
setnames(char *name)
{
	string pakname, mapname;
	char *slash = strpbrk(name, "/\\");
	if (slash) {
		strn0cpy(pakname, name, slash - name + 1);
		strcpy_s(mapname, slash + 1);
	} else {
		strcpy_s(pakname, "base");
		strcpy_s(mapname, name);
	};
	sprintf_s(cgzname)("packages/%s/%s.cgz", pakname, mapname);
	sprintf_s(bakname)(
	    "packages/%s/%s_%d.BAK", pakname, mapname, lastmillis);
	sprintf_s(pcfname)("packages/%s/package.cfg", pakname);
	sprintf_s(mcfname)("packages/%s/%s.cfg", pakname, mapname);

	path(cgzname);
	path(bakname);
};

// the optimize routines below are here to reduce the detrimental effects of
// messy mapping by setting certain properties (vdeltas and textures) to
// neighbouring values wherever there is no visible difference. This allows the
// mipmapper to generate more efficient mips. the reason it is done on save is
// to reduce the amount spend in the mipmapper (as that is done in realtime).

inline bool
nhf(sqr *s)
{
	return s->type != FHF && s->type != CHF;
};

void
voptimize() // reset vdeltas on non-hf cubes
{
	loop(x, ssize) loop(y, ssize)
	{
		sqr *s = S(x, y);
		if (x && y) {
			if (nhf(s) && nhf(S(x - 1, y)) &&
			    nhf(S(x - 1, y - 1)) && nhf(S(x, y - 1)))
				s->vdelta = 0;
		} else
			s->vdelta = 0;
	};
};

void
topt(sqr *s, bool &wf, bool &uf, int &wt, int &ut)
{
	sqr *o[4];
	o[0] = SWS(s, 0, -1, ssize);
	o[1] = SWS(s, 0, 1, ssize);
	o[2] = SWS(s, 1, 0, ssize);
	o[3] = SWS(s, -1, 0, ssize);
	wf = true;
	uf = true;
	if (SOLID(s)) {
		loopi(4) if (!SOLID(o[i]))
		{
			wf = false;
			wt = s->wtex;
			ut = s->utex;
			return;
		};
	} else {
		loopi(4) if (!SOLID(o[i]))
		{
			if (o[i]->floor < s->floor) {
				wt = s->wtex;
				wf = false;
			};
			if (o[i]->ceil > s->ceil) {
				ut = s->utex;
				uf = false;
			};
		};
	};
};

void
toptimize() // FIXME: only does 2x2, make atleast for 4x4 also
{
	bool wf[4], uf[4];
	sqr *s[4];
	for (int x = 2; x < ssize - 4; x += 2)
		for (int y = 2; y < ssize - 4; y += 2) {
			s[0] = S(x, y);
			int wt = s[0]->wtex, ut = s[0]->utex;
			topt(s[0], wf[0], uf[0], wt, ut);
			topt(s[1] = SWS(s[0], 0, 1, ssize), wf[1], uf[1], wt,
			    ut);
			topt(s[2] = SWS(s[0], 1, 1, ssize), wf[2], uf[2], wt,
			    ut);
			topt(s[3] = SWS(s[0], 1, 0, ssize), wf[3], uf[3], wt,
			    ut);
			loopi(4)
			{
				if (wf[i])
					s[i]->wtex = wt;
				if (uf[i])
					s[i]->utex = ut;
			};
		};
};

// these two are used by getmap/sendmap.. transfers compressed maps directly

void
writemap(char *mname, int msize, uchar *mdata)
{
	setnames(mname);
	backup(cgzname, bakname);
	FILE *f = fopen(cgzname, "wb");
	if (!f) {
		conoutf("could not write map to %s", cgzname);
		return;
	};
	fwrite(mdata, 1, msize, f);
	fclose(f);
	conoutf("wrote map %s as file %s", mname, cgzname);
}

uchar *
readmap(char *mname, int *msize)
{
	setnames(mname);
	uchar *mdata = (uchar *)loadfile(cgzname, msize);
	if (!mdata) {
		conoutf("could not read map %s", cgzname);
		return NULL;
	};
	return mdata;
}

// save map as .cgz file. uses 2 layers of compression: first does simple
// run-length encoding and leaves out data for certain kinds of cubes, then zlib
// removes the last bits of redundancy. Both passes contribute greatly to the
// miniscule map sizes.

void
save_world(char *mname)
{
	resettagareas(); // wouldn't be able to reproduce tagged areas otherwise
	voptimize();
	toptimize();
	if (!*mname)
		mname = getclientmap();
	setnames(mname);
	backup(cgzname, bakname);
	gzFile f = gzopen(cgzname, "wb9");
	if (!f) {
		conoutf("could not write map to %s", cgzname);
		return;
	};
	hdr.version = MAPVERSION;
	hdr.numents = 0;
	loopv(ents) if (ents[i].type != NOTUSED) hdr.numents++;
	header tmp = hdr;
	endianswap(&tmp.version, sizeof(int), 4);
	endianswap(&tmp.waterlevel, sizeof(int), 16);
	gzwrite(f, &tmp, sizeof(header));
	loopv(ents)
	{
		if (ents[i].type != NOTUSED) {
			entity tmp = ents[i];
			endianswap(&tmp, sizeof(short), 4);
			gzwrite(f, &tmp, sizeof(persistent_entity));
		};
	};
	sqr *t = NULL;
	int sc = 0;
#define spurge                                                                 \
	while (sc) {                                                           \
		gzputc(f, 255);                                                \
		if (sc > 255) {                                                \
			gzputc(f, 255);                                        \
			sc -= 255;                                             \
		} else {                                                       \
			gzputc(f, sc);                                         \
			sc = 0;                                                \
		}                                                              \
	};
	loopk(cubicsize)
	{
		sqr *s = &world[k];
#define c(f) (s->f == t->f)
		// 4 types of blocks, to compress a bit:
		// 255 (2): same as previous block + count
		// 254 (3): same as previous, except light // deprecated
		// SOLID (5)
		// anything else (9)

		if (SOLID(s)) {
			if (t && c(type) && c(wtex) && c(vdelta)) {
				sc++;
			} else {
				spurge;
				gzputc(f, s->type);
				gzputc(f, s->wtex);
				gzputc(f, s->vdelta);
			};
		} else {
			if (t && c(type) && c(floor) && c(ceil) && c(ctex) &&
			    c(ftex) && c(utex) && c(wtex) && c(vdelta) &&
			    c(tag)) {
				sc++;
			} else {
				spurge;
				gzputc(f, s->type);
				gzputc(f, s->floor);
				gzputc(f, s->ceil);
				gzputc(f, s->wtex);
				gzputc(f, s->ftex);
				gzputc(f, s->ctex);
				gzputc(f, s->vdelta);
				gzputc(f, s->utex);
				gzputc(f, s->tag);
			};
		};
		t = s;
	};
	spurge;
	gzclose(f);
	conoutf("wrote map file %s", cgzname);
	settagareas();
};

void
load_world(char *mname) // still supports all map formats that have existed
                        // since the earliest cube betas!
{
	stopifrecording();
	cleardlights();
	pruneundos();
	setnames(mname);
	gzFile f = gzopen(cgzname, "rb9");
	if (!f) {
		conoutf("could not read map %s", cgzname);
		return;
	};
	gzread(f, &hdr, sizeof(header) - sizeof(int) * 16);
	endianswap(&hdr.version, sizeof(int), 4);
	if (strncmp(hdr.head, "CUBE", 4) != 0)
		fatal("while reading map: header malformatted");
	if (hdr.version > MAPVERSION)
		fatal("this map requires a newer version of cube");
	if (sfactor < SMALLEST_FACTOR || sfactor > LARGEST_FACTOR)
		fatal("illegal map size");
	if (hdr.version >= 4) {
		gzread(f, &hdr.waterlevel, sizeof(int) * 16);
		endianswap(&hdr.waterlevel, sizeof(int), 16);
	} else {
		hdr.waterlevel = -100000;
	};
	ents.setsize(0);
	loopi(hdr.numents)
	{
		entity &e = ents.add();
		gzread(f, &e, sizeof(persistent_entity));
		endianswap(&e, sizeof(short), 4);
		e.spawned = false;
		if (e.type == LIGHT) {
			if (!e.attr2)
				e.attr2 = 255; // needed for MAPVERSION<=2
			if (e.attr1 > 32)
				e.attr1 = 32; // 12_03 and below
		};
	};
	free(world);
	setupworld(hdr.sfactor);
	char texuse[256];
	loopi(256) texuse[i] = 0;
	sqr *t = NULL;
	loopk(cubicsize)
	{
		sqr *s = &world[k];
		int type = gzgetc(f);
		switch (type) {
		case 255: {
			int n = gzgetc(f);
			for (int i = 0; i < n; i++, k++)
				memcpy(&world[k], t, sizeof(sqr));
			k--;
			break;
		};
		case 254: // only in MAPVERSION<=2
		{
			memcpy(s, t, sizeof(sqr));
			s->r = s->g = s->b = gzgetc(f);
			gzgetc(f);
			break;
		};
		case SOLID: {
			s->type = SOLID;
			s->wtex = gzgetc(f);
			s->vdelta = gzgetc(f);
			if (hdr.version <= 2) {
				gzgetc(f);
				gzgetc(f);
			};
			s->ftex = DEFAULT_FLOOR;
			s->ctex = DEFAULT_CEIL;
			s->utex = s->wtex;
			s->tag = 0;
			s->floor = 0;
			s->ceil = 16;
			break;
		};
		default: {
			if (type < 0 || type >= MAXTYPE) {
				sprintf_sd(t)("%d @ %d", type, k);
				fatal("while reading map: type out of range: ",
				    t);
			};
			s->type = type;
			s->floor = gzgetc(f);
			s->ceil = gzgetc(f);
			if (s->floor >= s->ceil)
				s->floor = s->ceil - 1; // for pre 12_13
			s->wtex = gzgetc(f);
			s->ftex = gzgetc(f);
			s->ctex = gzgetc(f);
			if (hdr.version <= 2) {
				gzgetc(f);
				gzgetc(f);
			};
			s->vdelta = gzgetc(f);
			s->utex = (hdr.version >= 2) ? gzgetc(f) : s->wtex;
			s->tag = (hdr.version >= 5) ? gzgetc(f) : 0;
			s->type = type;
		};
		};
		s->defer = 0;
		t = s;
		texuse[s->wtex] = 1;
		if (!SOLID(s))
			texuse[s->utex] = texuse[s->ftex] = texuse[s->ctex] = 1;
	};
	gzclose(f);
	calclight();
	settagareas();
	int xs, ys;
	loopi(256) if (texuse) lookuptexture(i, xs, ys);
	conoutf("read map %s (%d milliseconds)", cgzname,
	    SDL_GetTicks() - lastmillis);
	conoutf("%s", hdr.maptitle);
	startmap(mname);
	loopl(256)
	{
		sprintf_sd(aliasname)(
		    "level_trigger_%d", l); // can this be done smarter?
		if (identexists(aliasname))
			alias(aliasname, "");
	};
	execfile("data/default_map_settings.cfg");
	execfile(pcfname);
	execfile(mcfname);
};

COMMANDN(savemap, save_world, ARG_1STR);