/*
	This file is part of Warzone 2100.
	Copyright (C) 1999-2004  Eidos Interactive
	Copyright (C) 2005-2019  Warzone 2100 Project

	Warzone 2100 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.

	Warzone 2100 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 Warzone 2100; if not, write to the Free Software
	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
 * Event.c
 *
 * The event management system.
 */
#include "lib/framework/frame.h"

#include "event.h"
#include "script.h"

// array to store release functions
static VAL_CREATE_FUNC	*asCreateFuncs = nullptr;
static VAL_RELEASE_FUNC	*asReleaseFuncs = nullptr;
static UDWORD		numFuncs;

/** The list of currently active triggers */
ACTIVE_TRIGGER		*psTrigList = nullptr;

/** The list of callback triggers */
ACTIVE_TRIGGER		*psCallbackList = nullptr;

/** The new triggers added this loop */
static ACTIVE_TRIGGER	*psAddedTriggers = nullptr;

/** The trigger which is currently firing */
static ACTIVE_TRIGGER	*psFiringTrigger = nullptr;
static UDWORD		updateTime;

/** The currently allocated contexts */
SCRIPT_CONTEXT	*psContList = nullptr;

// The current event trace level
static SDWORD			eventTraceLevel = 3;

// print info on trigger
#ifdef DEBUG
#define DB_TRIGINF(psTrigger, level)\
	if (eventTraceLevel >= (level)) \
		eventPrintTriggerInfo(psTrigger)

// Print out all the info available about a trigger
static void eventPrintTriggerInfo(ACTIVE_TRIGGER *psTrigger)
{
	SCRIPT_CODE *psCode = psTrigger->psContext->psCode;
	const char	*pTrigLab, *pEventLab;

	// find the debug info for the trigger
	pTrigLab = eventGetTriggerID(psCode, psTrigger->trigger);
	// find the debug info for the event
	pEventLab = eventGetEventID(psCode, psTrigger->event);

	debug(LOG_WARNING, "trigger %s at %d -> %s", pTrigLab, psTrigger->testTime, pEventLab);
	if (psTrigger->offset != 0)
	{
		debug(LOG_WARNING, " %d", psTrigger->offset);
	}
}
#else
#define DB_TRIGINF(psTrigger, level)
#endif

// event tracing printf
#ifdef DEBUG
#define DB_TRACE(x, level) \
	if (eventTraceLevel >= (level)) \
		debug(LOG_SCRIPT, x)
#else
#define DB_TRACE(x,level)
#endif

// Initialise a trigger
static bool eventInitTrigger(ACTIVE_TRIGGER **ppsTrigger, SCRIPT_CONTEXT *psContext,
                             UDWORD event, SDWORD trigger, UDWORD currTime);

// Add a trigger to the list in order
static void eventAddTrigger(ACTIVE_TRIGGER *psTrigger);

// Free up a trigger
static void eventFreeTrigger(ACTIVE_TRIGGER *psTrigger);

// Remove triggers marked for deletion
static void eventPruneList(ACTIVE_TRIGGER **psList);
static void eventPruneLists(void)
{
	eventPruneList(&psTrigList);
	eventPruneList(&psCallbackList);
	eventPruneList(&psAddedTriggers);
}

//resets the event timer - updateTime
void eventTimeReset(UDWORD initTime)
{
	updateTime = initTime;
}

/* Initialise the event system */
bool eventInitialise()
{
	psTrigList = nullptr;
	psCallbackList = nullptr;
	psContList = nullptr;
	eventTraceLevel = 0;
	asCreateFuncs = nullptr;
	asReleaseFuncs = nullptr;
	numFuncs = 0;
	sstrcpy(last_called_script_event, "<none>");
	return true;
}

// reset the event system
void eventReset(void)
{
	SDWORD			count = 0;

	// Free any active triggers and their context's
	while (psTrigList)
	{
		ACTIVE_TRIGGER	*psCurr = psTrigList;

		psTrigList = psTrigList->psNext;
		if (!psCurr->psContext->release)
		{
			count += 1;
		}
		eventRemoveContext(psCurr->psContext);
		free(psCurr);
	}
	// Free any active callback triggers and their context's
	while (psCallbackList)
	{
		ACTIVE_TRIGGER	*psCurr = psCallbackList;

		psCallbackList = psCallbackList->psNext;
		if (!psCurr->psContext->release)
		{
			count += 1;
		}
		eventRemoveContext(psCurr->psContext);
		free(psCurr);
	}
	// Now free any contexts that are left
	while (psContList)
	{
		if (!psContList->release)
		{
			count += 1;
		}
		eventRemoveContext(psContList);
	}

	if (count > 0)
	{
		debug(LOG_SCRIPT, "%d contexts still allocated at reset", count);
	}
}

// Shutdown the event system
void eventShutDown(void)
{
	eventReset();

	if (asCreateFuncs)
	{
		free(asCreateFuncs);
		asCreateFuncs = nullptr;
	}
	if (asReleaseFuncs)
	{
		free(asReleaseFuncs);
		asReleaseFuncs = nullptr;
	}
}

// get the trigger id string
const char *eventGetTriggerID(SCRIPT_CODE *psCode, SDWORD trigger)
{
	const char	*pID, *pTrigType;
	static char	aIDNum[255];
	SDWORD			i;
	TRIGGER_TYPE	type;

	if ((trigger >= 0) && (trigger < psCode->numTriggers))
	{
		type = psCode->psTriggerData[trigger].type;
	}
	else
	{
		return "INACTIVE";
	}

	pTrigType = "UNKNOWN";
	switch (type)
	{
	case TR_INIT:
		pTrigType = "INIT";
		break;
	case TR_CODE:
		pTrigType = "CODE";
		break;
	case TR_WAIT:
		pTrigType = "WAIT";
		break;
	case TR_EVERY:
		pTrigType = "EVERY";
		break;
	case TR_PAUSE:
		pTrigType = "PAUSE";
		break;
	default:
		if (asScrCallbackTab)
		{
			pTrigType = asScrCallbackTab[type - TR_CALLBACKSTART].pIdent;
		}
		break;
	}

	if (psCode->psDebug == nullptr || type != TR_CODE)
	{
		snprintf(aIDNum, sizeof(aIDNum), "%d (%s)", trigger, pTrigType);
	}
	else
	{
		pID = "NOT FOUND";
		for (i = 0; i < psCode->debugEntries; i++)
		{
			if (psCode->psDebug[i].offset == psCode->pTriggerTab[trigger])
			{
				pID = psCode->psDebug[i].pLabel;
				break;
			}
		}
		snprintf(aIDNum, sizeof(aIDNum), "%s (%s)", pID, pTrigType);
	}

	return aIDNum;
}

// get the event id string
const char *eventGetEventID(SCRIPT_CODE *psCode, SDWORD event)
{
	const char	*pID;
	static char	aIDNum[255];
	SDWORD			i;

	// skip if not debugging scripts
	if (!debugPartEnabled(LOG_SCRIPT))
	{
		pID = "N/A";
		return pID;
	}

	if ((psCode->psDebug == nullptr) ||
	    (event < 0) || (event > psCode->numEvents))
	{
		snprintf(aIDNum, sizeof(aIDNum), "%d", event);

		return aIDNum;
	}

	pID = "NOT FOUND";
	for (i = 0; i < psCode->debugEntries; i++)
	{
		if (psCode->psDebug[i].offset == psCode->pEventTab[event])
		{
			pID = psCode->psDebug[i].pLabel;
			break;
		}
	}
	return pID;
}

// Initialise the create/release function array - specify the maximum value type
bool eventInitValueFuncs(SDWORD maxType)
{
	ASSERT(asReleaseFuncs == nullptr, "eventInitValueFuncs: array already initialised");
	asCreateFuncs = (VAL_CREATE_FUNC *)calloc(maxType, sizeof(*asCreateFuncs));
	asReleaseFuncs = (VAL_RELEASE_FUNC *)calloc(maxType, sizeof(*asReleaseFuncs));
	numFuncs = maxType;
	return true;
}

// Add a new value create function
bool eventAddValueCreate(INTERP_TYPE type, VAL_CREATE_FUNC create)
{
	if (type >= numFuncs)
	{
		ASSERT(false, "eventAddValueCreate: type out of range");
		return false;
	}
	asCreateFuncs[type] = create;
	return true;
}

// Add a new value release function
bool eventAddValueRelease(INTERP_TYPE type, VAL_RELEASE_FUNC release)
{
	if (type >= numFuncs)
	{
		ASSERT(false, "eventAddValueRelease: type out of range");
		return false;
	}
	asReleaseFuncs[type] = release;
	return true;
}

// Create a new context for a script
bool eventNewContext(SCRIPT_CODE *psCode, CONTEXT_RELEASE release,
                     SCRIPT_CONTEXT **ppsContext)
{
	SCRIPT_CONTEXT	*psContext;
	SDWORD		val, storeIndex, arrayNum, arraySize;
	UDWORD		i, j;
	INTERP_TYPE	type;
	VAL_CHUNK	*psNewChunk;

	ASSERT(psCode != nullptr, "eventNewContext: Invalid code pointer");

	// Get a new context
	psContext = (SCRIPT_CONTEXT *)calloc(1, sizeof(*psContext));

	// Initialise the context
	psContext->psCode = psCode;
	psContext->triggerCount = 0;
	psContext->release = release;
	psContext->psGlobals = nullptr;
	psContext->id = -1;		// only used by the save game
	val = psCode->numGlobals + psCode->arraySize - 1;
	arrayNum = psCode->numArrays - 1;
	arraySize = 1;
	if (psCode->numArrays > 0)
	{
		for (i = 0; i < psCode->psArrayInfo[arrayNum].dimensions; i++)
		{
			arraySize *= psCode->psArrayInfo[arrayNum].elements[i];
		}
	}

	//prepare local variables (initialize, store type)
	//-------------------------------
	psCode->ppsLocalVarVal = (INTERP_VAL **)malloc(sizeof(INTERP_VAL *) * psCode->numEvents);	//allocate space for array of local var arrays for each event

	//debug(LOG_SCRIPT,"allocated space for %d events", psCode->numEvents);

	for (i = 0; i < psCode->numEvents; i++)
	{
		if (psCode->numLocalVars[i] > 0)	//this event has any local vars declared
		{
			psCode->ppsLocalVarVal[i] = (INTERP_VAL *)malloc(sizeof(INTERP_VAL) * psCode->numLocalVars[i]);	//allocate space for local vars array (for the current event)

			//debug(LOG_SCRIPT,"Event %d has %d local variables", i, psCode->numLocalVars[i]);

			for (j = 0; j < psCode->numLocalVars[i]; j++)
			{
				type = psCode->ppsLocalVars[i][j];

				//debug(LOG_SCRIPT,"var %d's type: %d", i, type);

				/* initialize Strings, integers, floats etc
				   memset to 0, the only special case is strings */
				memset(&(psCode->ppsLocalVarVal[i][j]), 0, sizeof(INTERP_VAL));
				if (type == VAL_STRING)
				{
					psCode->ppsLocalVarVal[i][j].v.sval = (char *)malloc(MAXSTRLEN);
					strcpy(psCode->ppsLocalVarVal[i][j].v.sval, "\0");
				}

				//Initialize objects
				if (asCreateFuncs != nullptr && type < numFuncs && asCreateFuncs[type])
				{
					if (!asCreateFuncs[type](&(psCode->ppsLocalVarVal[i][j])))
					{
						debug(LOG_ERROR, "asCreateFuncs failed for local var");
						free(psContext);
						return false;
					}
				}

				psCode->ppsLocalVarVal[i][j].type = type; //store (copy) var type (data used during parsing -> data used during interpreting)

				//debug(LOG_SCRIPT, "i=%d, j=%d, value=%d",i,j,psCode->ppsLocalVarVal[i][j].v.ival);
			}
		}
		else	//this event has no local vars
		{
			psCode->ppsLocalVarVal[i] = nullptr;
		}
	}

	while (val >= 0)
	{
		psNewChunk = (VAL_CHUNK *)malloc(sizeof(VAL_CHUNK));

		// Set the value types
		storeIndex = val % CONTEXT_VALS;
		while (storeIndex >= 0)
		{
			if (val >= psCode->numGlobals)
			{
				type = psCode->psArrayInfo[arrayNum].type;
			}
			else
			{
				type = psCode->pGlobals[val];
			}

			// initialize Strings, integers etc
			// memset to 0
			memset(&(psNewChunk->asVals[storeIndex]), 0, sizeof(INTERP_VAL));
			if (type == VAL_STRING)
			{
				psNewChunk->asVals[storeIndex].v.sval = (char *)malloc(MAXSTRLEN);
				strcpy(psNewChunk->asVals[storeIndex].v.sval, "\0");
			}

			// set type
			psNewChunk->asVals[storeIndex].type = type;

			//initialize objects
			if (asCreateFuncs != nullptr && type < numFuncs && asCreateFuncs[type])
			{
				if (!asCreateFuncs[type](psNewChunk->asVals + storeIndex))
				{
					debug(LOG_FATAL, "Failed to run script value init");
					free(psNewChunk);
					free(psContext);
					return false;
				}
			}
			storeIndex -= 1;
			val -= 1;
			arraySize -= 1;
			if (arraySize <= 0)
			{
				// finished this array
				arrayNum -= 1;
				if (arrayNum >= 0)
				{
					// calculate the next array size
					arraySize = 1;
					for (i = 0; i < psCode->psArrayInfo[arrayNum].dimensions; i++)
					{
						arraySize *= psCode->psArrayInfo[arrayNum].elements[i];
					}
				}
			}
		}
		psNewChunk->psNext = psContext->psGlobals;
		psContext->psGlobals = psNewChunk;
	}
	psContext->psNext = psContList;
	psContList = psContext;

	*ppsContext = psContext;

	return true;
}

// Add a new object to the trigger system
// Time is the application time at which all the triggers are to be started
bool eventRunContext(SCRIPT_CONTEXT *psContext, UDWORD time)
{
	SDWORD			event;
	ACTIVE_TRIGGER	*psTrigger;
	TRIGGER_DATA	*psData;
	SCRIPT_CODE		*psCode;

	ASSERT(psContext != nullptr, "Invalid context pointer");

	// Now setup all the triggers
	psContext->triggerCount = 0;
	psCode = psContext->psCode;
	for (event = 0; event < psCode->numEvents; event++)
	{
		if (psCode->pEventLinks[event] >= 0)
		{
			// See if this is an init event
			psData = psCode->psTriggerData + psCode->pEventLinks[event];
			if (psData->type == TR_INIT)
			{
				if (!interpRunScript(psContext,	IRT_EVENT, event, 0))
				{
					return false;
				}
			}
			else
			{
				if (!eventInitTrigger(&psTrigger, psContext, event,
				                      psCode->pEventLinks[event], time))
				{
					return false;
				}
				eventAddTrigger(psTrigger);
				DB_TRACE(("added "), 2);
				DB_TRIGINF(psTrigger, 2);
			}
		}
	}
	return true;
}

// Remove an object from the event system
void eventRemoveContext(SCRIPT_CONTEXT *psContext)
{
	ACTIVE_TRIGGER *psCurr, *psPrev, *psNext;
	VAL_CHUNK		*psCChunk, *psNChunk;
	SCRIPT_CONTEXT	*psCCont, *psPCont = nullptr;
	SDWORD			i, chunkStart;
	INTERP_VAL		*psVal;

	// Get rid of all it's triggers
	while (psTrigList && psTrigList->psContext == psContext)
	{
		psNext = psTrigList->psNext;
		eventFreeTrigger(psTrigList);
		psTrigList = psNext;
	}

	for (psPrev = nullptr, psCurr = psTrigList; psCurr; psCurr = psNext)
	{
		psNext = psCurr->psNext;
		if (psCurr->psContext == psContext)
		{
			eventFreeTrigger(psCurr);
			if (psPrev)
			{
				psPrev->psNext = psNext;
			}
		}
		else
		{
			psPrev = psCurr;
		}
	}
	// Get rid of all it's callback triggers
	while (psCallbackList && psCallbackList->psContext == psContext)
	{
		psNext = psCallbackList->psNext;
		eventFreeTrigger(psCallbackList);
		psCallbackList = psNext;
	}

	for (psPrev = nullptr, psCurr = psCallbackList; psCurr; psCurr = psNext)
	{
		psNext = psCurr->psNext;
		if (psCurr->psContext == psContext)
		{
			eventFreeTrigger(psCurr);
			if (psPrev)
			{
				psPrev->psNext = psNext;
			}
		}
		else
		{
			psPrev = psCurr;
		}
	}

	// Call the release function for all the values
	if (asReleaseFuncs != nullptr)
	{
		psCChunk = psContext->psGlobals;
		chunkStart = 0;
		for (i = 0; i < psContext->psCode->numGlobals; i++)
		{
			if (i - chunkStart >= CONTEXT_VALS)
			{
				chunkStart += CONTEXT_VALS;
				psCChunk = psCChunk->psNext;
				ASSERT(psCChunk != nullptr,
				       "eventRemoveContext: not enough value chunks");
			}
			psVal = psCChunk->asVals + (i - chunkStart);
			if (psVal->type < numFuncs && asReleaseFuncs[psVal->type] != nullptr)
			{
				asReleaseFuncs[psVal->type](psVal);
			}
		}
	}

	// Free it's variables
	for (psCChunk = psContext->psGlobals; psCChunk; psCChunk = psNChunk)
	{
		psNChunk = psCChunk->psNext;
		// FIXME FIXME FIXME - this is commented away because it made loading
		// different savegames many times crash for inexplicable reasons. It
		// will probably leak memory, though!
		/*		for(i=0;i < CONTEXT_VALS ; i++)
				{
					if (psCChunk->asVals[i].type == VAL_STRING && psCChunk->asVals[i].v.sval)
					{
						free(psCChunk->asVals[i].v.sval);
						psCChunk->asVals[i].v.sval = NULL;
					}
				}*/
		free(psCChunk);
	}
	psContext->psGlobals = nullptr;

	// Remove it from the context list
	if (psContext == psContList)
	{
		psCCont = psContList;
		psContList = psContList->psNext;
		free(psCCont);
	}
	else
	{
		for (psCCont = psContList; psCCont && psCCont != psContext;
		     psCCont = psCCont->psNext)
		{
			psPCont = psCCont;
		}
		if (psCCont)
		{
			psPCont->psNext = psCCont->psNext;
			free(psContext);
		}
		else
		{
			ASSERT(false, "Context not found");
		}
	}
}

// Get the value pointer for a variable index
bool eventGetContextVal(SCRIPT_CONTEXT *psContext, UDWORD index, INTERP_VAL **ppsVal)
{
	VAL_CHUNK	*psChunk;

	// Find the chunk for the variable
	psChunk = psContext->psGlobals;
	while (psChunk && index >= CONTEXT_VALS)
	{
		index -= CONTEXT_VALS;
		psChunk = psChunk->psNext;
	}
	if (!psChunk)
	{
		ASSERT(false, "Variable not found");
		return false;
	}

	*ppsVal = psChunk->asVals + index;

	return true;
}

// Set a global variable value for a context
bool eventSetContextVar(SCRIPT_CONTEXT *psContext, UDWORD index, INTERP_VAL *data)
{
	INTERP_VAL *psVal;

	if (!eventGetContextVal(psContext, index, &psVal))
	{
		return false;
	}

	if (!interpCheckEquiv(psVal->type, data->type))
	{
		ASSERT(false, "Variable type mismatch (var type: %d, data type: %d)", psVal->type, data->type);
		return false;
	}

	// Store the data
	if (data->type == VAL_STRING)
	{
		ASSERT(data->v.sval != nullptr, "Ininitialized source string pointer");

		strcpy(psVal->v.sval, data->v.sval);
		free(data->v.sval);		//not needed anymore
		data->v.sval = nullptr;
	}
	else
	{
		memcpy(psVal, data, sizeof(INTERP_VAL));
	}

	return true;
}

// Add a trigger to the list in order
static void eventAddTrigger(ACTIVE_TRIGGER *psTrigger)
{
	UDWORD	testTime = psTrigger->testTime;

	if (psTrigger->type >= TR_CALLBACKSTART)
	{
		// Add this to the callback trigger list
		if (psCallbackList == nullptr)
		{
			psTrigger->psNext = nullptr;
			psCallbackList = psTrigger;
		}
		else if (psTrigger->type <= psCallbackList->type)
		{
			psTrigger->psNext = psCallbackList;
			psCallbackList = psTrigger;
		}
		else
		{
			ACTIVE_TRIGGER *psCurr, *psPrev = nullptr;

			for (psCurr = psCallbackList; psCurr && psCurr->type < psTrigger->type; psCurr = psCurr->psNext)
			{
				psPrev = psCurr;
			}
			psTrigger->psNext = psPrev->psNext;
			psPrev->psNext =  psTrigger;
		}
	}
	else if (psTrigList == nullptr)
	{
		psTrigger->psNext = nullptr;
		psTrigList = psTrigger;
	}
	else if (testTime <= psTrigList->testTime)
	{
		psTrigger->psNext = psTrigList;
		psTrigList = psTrigger;
	}
	else
	{
		ACTIVE_TRIGGER *psCurr, *psPrev = nullptr;

		for (psCurr = psTrigList; psCurr && psCurr->testTime < testTime; psCurr = psCurr->psNext)
		{
			psPrev = psCurr;
		}
		psTrigger->psNext = psPrev->psNext;
		psPrev->psNext =  psTrigger;
	}
}

// Initialise a trigger
static bool eventInitTrigger(ACTIVE_TRIGGER **ppsTrigger, SCRIPT_CONTEXT *psContext,
                             UDWORD event, SDWORD trigger, UDWORD currTime)
{
	ACTIVE_TRIGGER	*psNewTrig;
	TRIGGER_DATA	*psTrigData;
	UDWORD			testTime;

	ASSERT(event < psContext->psCode->numEvents, "Event out of range");
	ASSERT(trigger < psContext->psCode->numTriggers, "Trigger out of range");
	if (trigger == -1)
	{
		return false;
	}

	// Get a trigger object
	psNewTrig = (ACTIVE_TRIGGER *)malloc(sizeof(ACTIVE_TRIGGER));

	// Initialise the trigger
	psNewTrig->psContext = psContext;
	psContext->triggerCount += 1;
	psTrigData = psContext->psCode->psTriggerData + trigger;
	testTime = currTime + psTrigData->time;
	psNewTrig->testTime = testTime;
	psNewTrig->trigger = (SWORD)trigger;
	psNewTrig->type = (SWORD)psTrigData->type;
	psNewTrig->event = (UWORD)event;
	psNewTrig->offset = 0;
	psNewTrig->deactivated = false;

	*ppsTrigger = psNewTrig;

	return true;
}

// Load a trigger into the system from a save game
bool eventLoadTrigger(UDWORD time, SCRIPT_CONTEXT *psContext,
                      SDWORD type, SDWORD trigger, UDWORD event, UDWORD offset)
{
	ACTIVE_TRIGGER	*psNewTrig;

	ASSERT(event < psContext->psCode->numEvents, "Event out of range");
	ASSERT(trigger < psContext->psCode->numTriggers, "Trigger out of range");

	// Get a trigger object
	psNewTrig = (ACTIVE_TRIGGER *)malloc(sizeof(ACTIVE_TRIGGER));

	// Initialise the trigger
	psNewTrig->psContext = psContext;
	psContext->triggerCount += 1;
	psNewTrig->testTime = time;
	psNewTrig->trigger = (SWORD)trigger;
	psNewTrig->type = (SWORD)type;
	psNewTrig->event = (UWORD)event;
	psNewTrig->offset = (UWORD)offset;
	psNewTrig->deactivated = false;

	eventAddTrigger(psNewTrig);

	return true;
}

// add a TR_PAUSE trigger to the event system.
bool eventAddPauseTrigger(SCRIPT_CONTEXT *psContext, UDWORD event, UDWORD offset, UDWORD time)
{
	ACTIVE_TRIGGER	*psNewTrig;
	SDWORD			trigger;

	ASSERT(event < psContext->psCode->numEvents, "Event out of range");

	// Get a trigger object
	psNewTrig = (ACTIVE_TRIGGER *)malloc(sizeof(ACTIVE_TRIGGER));

	// figure out what type of trigger will go into the system when the pause
	// finishes
	switch (psFiringTrigger->type)
	{
	case TR_WAIT:
		// fired by a wait trigger, no trigger to replace it
		trigger = -1;
		break;
	case TR_PAUSE:
		// fired by a pause trigger, use the trigger stored with it
		trigger = psFiringTrigger->trigger;
		break;
	default:
		// just store the trigger that fired
		trigger = psFiringTrigger->trigger;
		break;
	}

	// Initialise the trigger
	psNewTrig->psContext = psContext;
	psContext->triggerCount += 1;
	psNewTrig->testTime = updateTime + time;
	psNewTrig->trigger = (SWORD)trigger;
	psNewTrig->type = TR_PAUSE;
	psNewTrig->event = (UWORD)event;
	psNewTrig->offset = (UWORD)offset;
	psNewTrig->deactivated = false;

	// store the new trigger
	psNewTrig->psNext = psAddedTriggers;
	psAddedTriggers = psNewTrig;

	// mark the trigger for deletion
	psFiringTrigger->deactivated = true;

	return true;
}

// Free up a trigger
static void eventFreeTrigger(ACTIVE_TRIGGER *psTrigger)
{
	if (psTrigger->psContext->release && psTrigger->psContext->triggerCount <= 1)
	{
		// Free the context as well
		eventRemoveContext(psTrigger->psContext);
	}
	free(psTrigger);
}

// Activate a callback trigger
void eventFireCallbackTrigger(TRIGGER_TYPE callback)
{
	ACTIVE_TRIGGER	*psPrev = nullptr, *psCurr, *psNext;
	TRIGGER_DATA	*psTrigDat;
	int32_t		fired;		// was BOOL (int) ** see warning about conversion

	if (interpProcessorActive())
	{
		ASSERT(false, "Script interpreter is already running");
		return;
	}

	//this can be called from eventProcessTriggers and so will wipe out all the current added ones
	//psAddedTriggers = NULL;
	for (psCurr = psCallbackList; psCurr && psCurr->type <= (int)callback; psCurr = psNext)
	{
		psNext = psCurr->psNext;
		if (psCurr->type == (int)callback)
		{
			// see if the callback should be fired
			fired = false;
			if (psCurr->type != TR_PAUSE)
			{
				ASSERT(psCurr->trigger >= 0 && psCurr->trigger < psCurr->psContext->psCode->numTriggers, "Invalid trigger number");
				psTrigDat = psCurr->psContext->psCode->psTriggerData + psCurr->trigger;
			}
			else
			{
				psTrigDat = nullptr;
			}
			if (psTrigDat && psTrigDat->code)
			{
				if (!interpRunScript(psCurr->psContext, IRT_TRIGGER, psCurr->trigger, 0))
				{
					ASSERT(false, "Trigger %s: code failed", eventGetTriggerID(psCurr->psContext->psCode, psCurr->trigger));
					psPrev = psCurr;
					continue;
				}
				if (!stackPopParams(1, VAL_BOOL, &fired))
				{
					ASSERT(false, "Trigger %s: code failed", eventGetTriggerID(psCurr->psContext->psCode, psCurr->trigger));
					psPrev = psCurr;
					continue;
				}
			}
			else
			{
				fired = true;
			}

			// run the event
			if (fired)
			{
				DB_TRIGINF(psCurr, 1);
				DB_TRACE(" fired", 1);

				// remove the trigger from the list
				if (psPrev == nullptr)
				{
					psCallbackList = psCallbackList->psNext;
				}
				else
				{
					psPrev->psNext = psNext;
				}

				psFiringTrigger = psCurr;
				if (!interpRunScript(psCurr->psContext, IRT_EVENT, psCurr->event, psCurr->offset)) // this could set psCurr->deactivated
				{
					ASSERT(false, "Event %s: code failed", eventGetEventID(psCurr->psContext->psCode, psCurr->event));
				}
				if (psCurr->deactivated)
				{
					// don't need to add the trigger again - just free it
					eventFreeTrigger(psCurr);
				}
				else
				{
					// make sure the trigger goes back into the system
					psCurr->psNext = psAddedTriggers;
					psAddedTriggers = psCurr;
				}
			}
			else
			{
				psPrev = psCurr;
			}
		}
		else
		{
			psPrev = psCurr;
		}
	}

	// Delete marked triggers now
	eventPruneLists();

	// Now add all the new triggers
	for (psCurr = psAddedTriggers; psCurr; psCurr = psNext)
	{
		psNext = psCurr->psNext;
		eventAddTrigger(psCurr);
	}
	//clear out after added them all
	psAddedTriggers = nullptr;
}

// Run a trigger
static bool eventFireTrigger(ACTIVE_TRIGGER *psTrigger)
{
	bool fired = false;
	INTERP_VAL		sResult;

	psFiringTrigger = psTrigger;

	// If this is a code trigger see if it fires
	if (psTrigger->type == TR_CODE)
	{
		// Run the trigger
		if (!interpRunScript(psTrigger->psContext,
		                     IRT_TRIGGER, psTrigger->trigger, 0))
		{
			ASSERT(false, "Trigger %s: code failed", eventGetTriggerID(psTrigger->psContext->psCode, psTrigger->trigger));
			return false;
		}
		// Get the result
		sResult.type = VAL_BOOL;
		if (!stackPopType(&sResult))
		{
			return false;
		}
		fired = sResult.v.bval;
	}
	else
	{
		fired = true;
	}

	// If it fired run the event
	if (fired)
	{
		DB_TRIGINF(psTrigger, 1);
		DB_TRACE(" fired", 1);
		if (!interpRunScript(psTrigger->psContext, IRT_EVENT, psTrigger->event, psTrigger->offset))
		{
			ASSERT(false, "Event %s: code failed", eventGetEventID(psTrigger->psContext->psCode, psTrigger->event));
			return false;
		}
	}
#ifdef DEBUG
	else
	{
		DB_TRIGINF(psTrigger, 3);
	}
#endif

	return true;
}


// Process all the currently active triggers
void eventProcessTriggers(UDWORD currTime)
{
	ACTIVE_TRIGGER	*psCurr, *psNext, *psNew;
	TRIGGER_DATA	*psData;

	// Process all the current triggers
	psAddedTriggers = nullptr;
	updateTime = currTime;
	while (psTrigList && psTrigList->testTime <= currTime)
	{
		psCurr = psTrigList;
		psTrigList = psTrigList->psNext;

		// Run the trigger
		if (eventFireTrigger(psCurr))	// This might mark the trigger for deletion
		{
			if (psCurr->deactivated || psCurr->type == TR_WAIT)
			{
				// remove the trigger
				eventFreeTrigger(psCurr);
			}
			else if (psCurr->type == TR_PAUSE)
			{
				// restarted a paused event - replace the old trigger
				if (psCurr->trigger != -1)
				{
					if (eventInitTrigger(&psNew, psCurr->psContext, psCurr->event, psCurr->trigger, updateTime))
					{
						psNew->psNext = psAddedTriggers;
						psAddedTriggers = psNew;
					}
				}

				// remove the TR_PAUSE trigger
				eventFreeTrigger(psCurr);
			}
			else
			{
				// Add the trigger again
				psData = psCurr->psContext->psCode->psTriggerData + psCurr->trigger;
				psCurr->testTime = currTime + psData->time;
				psCurr->psNext = psAddedTriggers;
				psAddedTriggers = psCurr;
			}
		}
	}

	// Delete marked triggers now
	eventPruneLists();

	// Now add all the new triggers
	for (psCurr = psAddedTriggers; psCurr; psCurr = psNext)
	{
		psNext = psCurr->psNext;
		eventAddTrigger(psCurr);
	}
	//clear out after added them all
	psAddedTriggers = nullptr;
}

// remove all marked triggers
static void eventPruneList(ACTIVE_TRIGGER **ppsList)
{
	ACTIVE_TRIGGER	**ppsCurr = ppsList, *psTemp;

	while (*ppsCurr)
	{
		if ((*ppsCurr)->deactivated)
		{
			psTemp = (*ppsCurr)->psNext;
			free(*ppsCurr);
			*ppsCurr = psTemp;
		}
		else
		{
			ppsCurr = &(*ppsCurr)->psNext;
		}
	}
}

// Mark a trigger for removal from a list
static void eventMarkTriggerInList(ACTIVE_TRIGGER **ppsList, SCRIPT_CONTEXT *psContext, SDWORD event, SDWORD *pTrigger)
{
	ACTIVE_TRIGGER	**ppsCurr;

	for (ppsCurr = ppsList;; ppsCurr = &(*ppsCurr)->psNext)
	{
		if (!(*ppsCurr))
		{
			return;
		}
		else if ((*ppsCurr)->event == event &&
		         (*ppsCurr)->psContext == psContext)
		{
			break;
		}
	}
	if ((*ppsCurr)->type == TR_PAUSE)
	{
		// pause trigger, don't remove it,
		// just note the type for when the pause finishes
		(*ppsCurr)->trigger = (SWORD) * pTrigger;
		*pTrigger = -1;
	}
	else
	{
		(*ppsCurr)->deactivated = true;
	}
}

// Change the trigger assigned to an event - to be called from script functions
bool eventSetTrigger(void)
{
	ACTIVE_TRIGGER	*psTrigger;
	UDWORD			event;
	SDWORD			trigger;
	SCRIPT_CONTEXT	*psContext;

	if (!stackPopParams(2, VAL_EVENT, &event, VAL_TRIGGER, &trigger))
	{
		return false;
	}

#ifdef REALLY_DEBUG_THIS
	DB_TRACE(("eventSetTrigger %s %s\n",
	          eventGetEventID(psFiringTrigger->psContext->psCode, event),
	          eventGetTriggerID(psFiringTrigger->psContext->psCode, trigger)), 2);
#endif

	// See if this is the event that is running
	psContext = psFiringTrigger->psContext;
	if (psFiringTrigger->event == event)
	{
		psFiringTrigger->deactivated = true;
	}
	else
	{
		// Mark the old trigger in the lists
		eventMarkTriggerInList(&psTrigList, psContext, event, &trigger);
		eventMarkTriggerInList(&psCallbackList, psContext, event, &trigger);
		eventMarkTriggerInList(&psAddedTriggers, psContext, event, &trigger);
	}

	// Create a new trigger if necessary
	if (trigger >= 0)
	{
		if (!eventInitTrigger(&psTrigger, psFiringTrigger->psContext,
		                      event, trigger, updateTime))
		{
			return false;
		}
		psTrigger->psNext = psAddedTriggers;
		psAddedTriggers = psTrigger;
	}

	return true;
}

// set the event tracing level - to be called from script functions
bool eventSetTraceLevel(void)
{
	SDWORD	level;

	if (!stackPopParams(1, VAL_INT, &level))
	{
		return false;
	}

	if (level < 0)
	{
		level = 0;
	}
	if (level > 3)
	{
		level = 3;
	}

	eventTraceLevel = level;

	return true;
}
