/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2010-2014 QuakeSpasm developers
Copyright (C) 2019 Alison G. Watson

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "q_defs.h"

ddef_t *pr_globaldefs;

cvar_t nomonsters   = {"nomonsters",   "0", CVAR_NONE};
cvar_t gamecfg      = {"gamecfg",      "0", CVAR_NONE};
cvar_t scratch1     = {"scratch1",     "0", CVAR_NONE};
cvar_t scratch2     = {"scratch2",     "0", CVAR_NONE};
cvar_t scratch3     = {"scratch3",     "0", CVAR_NONE};
cvar_t scratch4     = {"scratch4",     "0", CVAR_NONE};
cvar_t savedgamecfg = {"savedgamecfg", "0", CVAR_ARCHIVE};
cvar_t saved1       = {"saved1",       "0", CVAR_ARCHIVE};
cvar_t saved2       = {"saved2",       "0", CVAR_ARCHIVE};
cvar_t saved3       = {"saved3",       "0", CVAR_ARCHIVE};
cvar_t saved4       = {"saved4",       "0", CVAR_ARCHIVE};

static void PR_LoadProgHeader(byte *prog_data)
{
	progs.version = ReadLittleLong(&prog_data[4 * 0]);
	progs.crc     = ReadLittleLong(&prog_data[4 * 1]);

	progs.ofs_statements = ReadLittleLong(&prog_data[4 * 2]);
	progs.numstatements  = ReadLittleLong(&prog_data[4 * 3]);

	progs.ofs_globaldefs = ReadLittleLong(&prog_data[4 * 4]);
	progs.numglobaldefs  = ReadLittleLong(&prog_data[4 * 5]);

	progs.ofs_fielddefs = ReadLittleLong(&prog_data[4 * 6]);
	progs.numfielddefs  = ReadLittleLong(&prog_data[4 * 7]);

	progs.ofs_functions = ReadLittleLong(&prog_data[4 * 8]);
	progs.numfunctions  = ReadLittleLong(&prog_data[4 * 9]);

	progs.ofs_strings = ReadLittleLong(&prog_data[4 * 10]);
	progs.numstrings  = ReadLittleLong(&prog_data[4 * 11]);

	progs.ofs_globals = ReadLittleLong(&prog_data[4 * 12]);
	progs.numglobals  = ReadLittleLong(&prog_data[4 * 13]);

	progs.entityfields = ReadLittleLong(&prog_data[4 * 14]);

	if(progs.version != PROG_VERSION)
		Host_Error("progs.dat has wrong version number (%" PRIi32 " should be %" PRIi32 ")", progs.version, PROG_VERSION);

	if(progs.crc != PROGHEADER_CRC)
		Host_Error("progs.dat system vars have been modified, progdefs.h is out of date");
}

/*
===============
PR_LoadProgs
===============
*/
void PR_LoadProgs(void)
{
	byte *prog_data;
	int32_t i;

	ED_Load();

	CRC_Init(&pr_crc);

	prog_data = COM_LoadHunkFile("progs.dat", NULL);
	if(!prog_data)
		Host_Error("PR_LoadProgs: couldn't load progs.dat");
	Con_DPrintf("Programs occupy %" PRIi32 "K.\n", com_filesize / 1024);

	for(i = 0; i < com_filesize; i++)
		CRC_ProcessByte(&pr_crc, prog_data[i]);

	PR_LoadProgHeader(prog_data);

	pr_functions = (dfunction_t *)&prog_data[progs.ofs_functions];
	pr_strings = (char const *)&prog_data[progs.ofs_strings];
	if(progs.ofs_strings + progs.numstrings >= com_filesize)
		Host_Error("progs.dat strings go past end of file\n");

	// initialize the strings
	pr_numknownstrings = 0;
	pr_maxknownstrings = 0;
	if(pr_knownstrings)
		Z_Free(pr_knownstrings);
	pr_knownstrings = NULL;
	PR_SetEngineString("");

	pr_globaldefs = (ddef_t *)&prog_data[progs.ofs_globaldefs];
	pr_fielddefs = (ddef_t *)&prog_data[progs.ofs_fielddefs];
	pr_statements = (dstatement_t *)&prog_data[progs.ofs_statements];

	pr_global_struct = (globalvars_t *)&prog_data[progs.ofs_globals];
	pr_globals = (float *)pr_global_struct;

	// byte swap the lumps
	for(i = 0; i < progs.numstatements; i++)
	{
		pr_statements[i].op = LittleShort(pr_statements[i].op);
		pr_statements[i].a  = LittleShort(pr_statements[i].a);
		pr_statements[i].b  = LittleShort(pr_statements[i].b);
		pr_statements[i].c  = LittleShort(pr_statements[i].c);
	}

	for(i = 0; i < progs.numfunctions; i++)
	{
		pr_functions[i].first_statement = LittleLong(pr_functions[i].first_statement);
		pr_functions[i].parm_start = LittleLong(pr_functions[i].parm_start);
		pr_functions[i].s_name = LittleLong(pr_functions[i].s_name);
		pr_functions[i].s_file = LittleLong(pr_functions[i].s_file);
		pr_functions[i].numparms = LittleLong(pr_functions[i].numparms);
		pr_functions[i].locals = LittleLong(pr_functions[i].locals);
	}

	for(i = 0; i < progs.numglobaldefs; i++)
	{
		pr_globaldefs[i].type = LittleShort(pr_globaldefs[i].type);
		pr_globaldefs[i].ofs = LittleShort(pr_globaldefs[i].ofs);
		pr_globaldefs[i].s_name = LittleLong(pr_globaldefs[i].s_name);
	}

	pr_alpha_supported = false; //johnfitz

	for(i = 0; i < progs.numfielddefs; i++)
	{
		pr_fielddefs[i].type = LittleShort(pr_fielddefs[i].type);
		if(pr_fielddefs[i].type & DEF_SAVEGLOBAL)
			Host_Error("PR_LoadProgs: pr_fielddefs[i].type & DEF_SAVEGLOBAL");
		pr_fielddefs[i].ofs = LittleShort(pr_fielddefs[i].ofs);
		pr_fielddefs[i].s_name = LittleLong(pr_fielddefs[i].s_name);

		//johnfitz -- detect alpha support
		if(!strcmp(pr_strings + pr_fielddefs[i].s_name, "alpha"))
			pr_alpha_supported = true;
		//johnfitz
	}

	for(i = 0; i < progs.numglobals; i++)
		((int32_t *)pr_globals)[i] = LittleLong(((int32_t *)pr_globals)[i]);

	pr_edict_size = progs.entityfields * 4 + sizeof(edict_t) - sizeof(entvars_t);
	// round off to next highest whole word address (esp for Alpha)
	// this ensures that pointers in the engine data area are always
	// properly aligned
	pr_edict_size += sizeof(void *) - 1;
	pr_edict_size &= ~(sizeof(void *) - 1);
}


/*
===============
PR_Init
===============
*/
void PR_Init(void)
{
	ED_Init();
	Cmd_AddCommand("profile", PR_Profile_f);
	Cvar_RegisterVariable(&nomonsters);
	Cvar_RegisterVariable(&gamecfg);
	Cvar_RegisterVariable(&scratch1);
	Cvar_RegisterVariable(&scratch2);
	Cvar_RegisterVariable(&scratch3);
	Cvar_RegisterVariable(&scratch4);
	Cvar_RegisterVariable(&savedgamecfg);
	Cvar_RegisterVariable(&saved1);
	Cvar_RegisterVariable(&saved2);
	Cvar_RegisterVariable(&saved3);
	Cvar_RegisterVariable(&saved4);
}