/*
	War of the worlds, simulates a planet being at war with another
	planet by firing APC Warheads at them.
 
	Usage: [-i <sec>] <obj1_num> <obj2_num>

 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <math.h>
#include "../include/swserv-plugins.h"


/*
 *	Object Reference:
 *
 *	Relates each fighter to a reference object. This is used to
 *	check when a fighter has been destroyed (when it has become
 *	garbage) and to respawn it. It also can be used to check if the
 *	reference object has been destroyed (when it has become garbage)
 *	and to no longer respawn a fighter.
 */
typedef struct {

	int		obj_num,	/* The object doing the firing */
			tar_obj_num;	/* The victim object */

} ObjRef;

typedef struct {

	ObjRef		**objref_list;
	int		nobjrefs;

	time_t		next_update,		/* In seconds */
			update_int;
} Core;
#define CORE(p)		((Core *)(p))


static void WOWUpdate(SWServContext *ctx);


#define WEAPON_OPM_NAME				"APC Warhead"

#define WEAPON_DEF_DAMAGE_HULL			100.0
#define WEAPON_DEF_DAMAGE_SHIELDS		100.0

#define WOW_DEF_UPDATE_INVERVAL		(1 * 60)	/* In seconds */

#define USAGE_MESG	"\
Usage: [-i <sec>] <obj1_num> <tar_obj1_num> [obj2_num] [tar_obj2_num] ..."


#define ATOI(s)         (((s) != NULL) ? atoi(s) : 0)
#define ATOL(s)         (((s) != NULL) ? atol(s) : 0)
#define ATOF(s)         (((s) != NULL) ? atof(s) : 0.0f)
#define STRDUP(s)       (((s) != NULL) ? strdup(s) : NULL)

#define MAX(a,b)        (((a) > (b)) ? (a) : (b))
#define MIN(a,b)        (((a) < (b)) ? (a) : (b))
#define CLIP(a,l,h)     (MIN(MAX((a),(l)),(h)))
#define STRLEN(s)       (((s) != NULL) ? strlen(s) : 0)
#define STRISEMPTY(s)   (((s) != NULL) ? (*(s) == '\0') : TRUE)

#ifndef PI
# define PI		3.141592654
#endif


/*
 *	Fires an APC from the object to the target object.
 */
static void WOWUpdate(SWServContext *ctx)
{
	Core *core = CORE(SWServGetData(ctx));
	int	i, obj_num, tar_obj_num, wep_obj_num,
		wep_opm_num = SWServOPMGetByName(ctx, WEAPON_OPM_NAME);
	xsw_object_struct *obj, *tar_obj, *wep_obj;
	ObjRef *objref;
	if(wep_opm_num < 0)
	{
	    char *s = (char *)malloc(STRLEN(WEAPON_OPM_NAME) + 80);
	    sprintf(
		s,
		"OPM `%s' not defined.\n",
		WEAPON_OPM_NAME
	    );
	    SWServPrintError(ctx, s);
	    free(s);
	    return;
	}

	/* Iterate through the object references list */
	for(i = 0; i < core->nobjrefs; i++)
	{
	    objref = core->objref_list[i];
	    if(objref == NULL)
		continue;

	    obj_num = objref->obj_num;
	    obj = SWServObjectGetPointer(ctx, obj_num);

	    tar_obj_num = objref->tar_obj_num;
	    tar_obj = SWServObjectGetPointer(ctx, tar_obj_num);

	    if((obj == NULL) || (tar_obj == NULL))
	    {
		/* Th objects no longer exists, so delete this object
		 * reference
		 */
		free(objref);
		core->objref_list[i] = NULL;
		continue;
	    }

	    /* Create a new weapon */
	    wep_obj_num = SWServObjectCreate(
		ctx, SW_OBJ_TYPE_WEAPON
	    );
	    wep_obj = SWServObjectGetPointer(ctx, wep_obj_num);
	    if(wep_obj != NULL)
	    {
		float heading = (0.5 * PI) - atan2(
		    tar_obj->y - obj->y, tar_obj->x - obj->x
		);
		while(heading > (2 * PI))
		    heading -= (2 * PI);
		while(heading < (0 * PI))
		    heading += (2 * PI);

		SWServOPMModelObject(ctx, wep_opm_num, wep_obj_num);
		SWServWeaponSetFlags(
		    ctx, wep_obj_num, SW_WEP_FLAG_DESTROYABLE
		);
		SWServWeaponSetFlags(
		    ctx, wep_obj_num, SW_WEP_FLAG_SHOCKWAVE_HIT
		);
		wep_obj->owner = obj_num;
		wep_obj->sect_x = obj->sect_x;
		wep_obj->sect_y = obj->sect_y;
		wep_obj->sect_z = obj->sect_z;
		wep_obj->x = obj->x;
		wep_obj->y = obj->y;
		wep_obj->z = obj->z;
		wep_obj->heading = (float)heading;
		wep_obj->hp_max = WEAPON_DEF_DAMAGE_HULL;
		wep_obj->hp = WEAPON_DEF_DAMAGE_HULL;
		wep_obj->power_max = WEAPON_DEF_DAMAGE_SHIELDS;
		wep_obj->power = WEAPON_DEF_DAMAGE_SHIELDS;
		wep_obj->birth_time = SWServCurrentTimeMS(ctx);
/*
		strncpy(wep_obj->name, WEAPON_OPM_NAME, sizeof(obj->name));
		wep_obj->name[sizeof(wep_obj->name) - 1] = '\0';
 */
		strncpy(wep_obj->empire, obj->empire, sizeof(obj->empire));
 		wep_obj->empire[sizeof(wep_obj->empire) - 1] = '\0';
		SWServObjectSyncConnections(ctx, wep_obj_num, 1);
	    }
	}
}


/*
 *	SWServ Plugin destroy notify.
 */
SWPLUGIN_DESTROY_NOTIFY_FUNCRTN SWPLUGIN_DESTROY_NOTIFY_FUNC(
	int reason,
	int destroyed_obj_num,
	int destroyer_obj_num,
	int destroyer_obj_owner_num,
	SWServContext *ctx
)
{
	Core *core = CORE(SWServGetData(ctx));
	int i;
	ObjRef *objref;

	if(core == NULL)  
	    return;

	/* Iterate through the object references list */
	for(i = 0; i < core->nobjrefs; i++)
	{
	    objref = core->objref_list[i];
	    if(objref == NULL)
		continue;

	    /* This object destroyed? */
	    if(objref->obj_num == destroyed_obj_num)
	    {
		objref->obj_num = -1;
		break;
	    }
 
	    /* Target destroyed? */
	    if(objref->tar_obj_num == destroyed_obj_num)
	    {
		objref->tar_obj_num = -1;
		break;
	    }
	}
}


/*
 *	SWServ Plugin initialize.
 */
SWPLUGIN_INIT_FUNCRTN SWPLUGIN_INIT_FUNC(
	int argc, char **argv,
	int con_num,
	SWServContext *ctx
)
{
	int i;
	const char *arg;
	Core *core = CORE(calloc(1, sizeof(Core)));

	if(core == NULL)
	    return(1);

	core->objref_list = NULL;
	core->nobjrefs = 0;
	core->update_int = WOW_DEF_UPDATE_INVERVAL;
	core->next_update = SWServCurrentTimeSeconds(ctx);
	SWServSetData(ctx, core);

	for(i = 0; i < argc; i++)
	{
	    arg = argv[i];
	    if(arg == NULL)
		continue;

	    if(!strcasecmp(arg, "--help") ||
	       !strcasecmp(arg, "-help") ||
	       !strcasecmp(arg, "--h") ||
	       !strcasecmp(arg, "-h")   
	    )
	    {
		if(con_num > -1)
		    SWServConNotify(
			ctx, con_num, USAGE_MESG
		    );
		else
		    SWServPrint(
			ctx, USAGE_MESG "\n"
		    );
		free(core);
	        return(1);
	    }
	    else if(!strcasecmp(arg, "--interval") ||
		    !strcasecmp(arg, "-interval") ||
		    !strcasecmp(arg, "--int") ||
		    !strcasecmp(arg, "-int") ||
		    !strcasecmp(arg, "-i")
	    )
	    {
		/* In seconds */
		i++;
		if(i < argc)
		    core->update_int = MAX(atol(argv[i]), 0l);
	    }
	    else
	    {
		/* All else assume object number pair */
		int n;
		const int obj_num = ATOI(
		    (*arg == '#') ? (arg + 1) : arg
		);
		ObjRef *objref = (ObjRef *)calloc(
		    1, sizeof(ObjRef)
		);
		objref->obj_num = obj_num;
		objref->tar_obj_num = -1;

		n = core->nobjrefs;
		core->nobjrefs = n + 1;
		core->objref_list = (ObjRef **)realloc(
		    core->objref_list,
		    core->nobjrefs * sizeof(ObjRef *)
		);
		core->objref_list[n] = objref;

		i++;
		if(i < argc)
		{
		    arg = argv[i];
		    objref->tar_obj_num = ATOI(   
			(*arg == '#') ? (arg + 1) : arg
		    );
		}
	    }
	}

	/* No reference objects spcified? */
	if(core->nobjrefs <= 0)
	{
	    if(con_num > -1)
		SWServConNotify(
		    ctx, con_num, USAGE_MESG
		);
	    else
		SWServPrintError(
		    ctx, USAGE_MESG "\n"
		);
	    free(core);
	    return(1);
	}

	return(0);
}

/*
 *	SWServ Plugin manage.
 */
SWPLUGIN_MANAGE_FUNCRTN SWPLUGIN_MANAGE_FUNC(
	SWServContext *ctx
)
{
	Core *core = CORE(SWServGetData(ctx));   
	const time_t t = SWServCurrentTimeSeconds(ctx);

	if(core == NULL)
	    return(1);

	/* Time to update? */
	if(core->next_update <= t)
	{
	    WOWUpdate(ctx);
	    core->next_update = t + core->update_int;
	}

	return(0);
}

/*
 *	SWServ Plugin shutdown.
 */
SWPLUGIN_SHUTDOWN_FUNCRTN SWPLUGIN_SHUTDOWN_FUNC(
	SWServContext *ctx
)
{
	Core *core = CORE(SWServGetData(ctx));
	int i;
	ObjRef *objref;

	if(core == NULL)
	    return;

	for(i = 0; i < core->nobjrefs; i++)
	{
	    objref = core->objref_list[i];
	    if(objref == NULL)
		continue;

	    free(objref);
	}
	free(core->objref_list);
	free(core);
	SWServSetData(ctx, NULL);
}