#include "quakedef.h"
#include "protocol.h"

static void QW_TranslateEffects(entity_state_t *s, int qweffects)
{
	s->effects = 0;
	s->internaleffects = 0;
	if (qweffects & QW_EF_BRIGHTFIELD)
		s->effects |= EF_BRIGHTFIELD;
	if (qweffects & QW_EF_MUZZLEFLASH)
		s->effects |= EF_MUZZLEFLASH;
	if (qweffects & QW_EF_FLAG1)
	{
		// mimic FTEQW's interpretation of EF_FLAG1 as EF_NODRAW on non-player entities
		if (s->number > cl.maxclients)
			s->effects |= EF_NODRAW;
		else
			s->internaleffects |= INTEF_FLAG1QW;
	}
	if (qweffects & QW_EF_FLAG2)
	{
		// mimic FTEQW's interpretation of EF_FLAG2 as EF_ADDITIVE on non-player entities
		if (s->number > cl.maxclients)
			s->effects |= EF_ADDITIVE;
		else
			s->internaleffects |= INTEF_FLAG2QW;
	}
	if (qweffects & QW_EF_RED)
	{
		if (qweffects & QW_EF_BLUE)
			s->effects |= EF_RED | EF_BLUE;
		else
			s->effects |= EF_RED;
	}
	else if (qweffects & QW_EF_BLUE)
		s->effects |= EF_BLUE;
	else if (qweffects & QW_EF_BRIGHTLIGHT)
		s->effects |= EF_BRIGHTLIGHT;
	else if (qweffects & QW_EF_DIMLIGHT)
		s->effects |= EF_DIMLIGHT;
}

extern cvar_t cl_rollangle;
extern cvar_t cl_rollspeed;

void EntityStateQW_ReadPlayerUpdate(void)
{
	int slot = MSG_ReadByte(&cl_message);
	int enumber = slot + 1;
	int weaponframe;
	int msec;
	int playerflags;
	int bits;
	entity_state_t *s;
	// look up the entity
	entity_t *ent = cl.entities + enumber;
	vec3_t viewangles;
	vec3_t velocity;

	// slide the current state into the previous
	ent->state_previous = ent->state_current;

	// read the update
	s = &ent->state_current;
	*s = defaultstate;
	s->active = ACTIVE_NETWORK;
	s->number = enumber;
	s->colormap = enumber;
	playerflags = MSG_ReadShort(&cl_message);
	MSG_ReadVector(&cl_message, s->origin, cls.protocol);
	s->frame = MSG_ReadByte(&cl_message);

	VectorClear(viewangles);
	VectorClear(velocity);

	if (playerflags & QW_PF_MSEC)
	{
		// time difference between last update this player sent to the server,
		// and last input we sent to the server (this packet is in response to
		// our input, so msec is how long ago the last update of this player
		// entity occurred, compared to our input being received)
		msec = MSG_ReadByte(&cl_message);
	}
	else
		msec = 0;
	if (playerflags & QW_PF_COMMAND)
	{
		bits = MSG_ReadByte(&cl_message);
		if (bits & QW_CM_ANGLE1)
			viewangles[0] = MSG_ReadAngle16i(&cl_message); // cmd->angles[0]
		if (bits & QW_CM_ANGLE2)
			viewangles[1] = MSG_ReadAngle16i(&cl_message); // cmd->angles[1]
		if (bits & QW_CM_ANGLE3)
			viewangles[2] = MSG_ReadAngle16i(&cl_message); // cmd->angles[2]
		if (bits & QW_CM_FORWARD)
			MSG_ReadShort(&cl_message); // cmd->forwardmove
		if (bits & QW_CM_SIDE)
			MSG_ReadShort(&cl_message); // cmd->sidemove
		if (bits & QW_CM_UP)
			MSG_ReadShort(&cl_message); // cmd->upmove
		if (bits & QW_CM_BUTTONS)
			(void) MSG_ReadByte(&cl_message); // cmd->buttons
		if (bits & QW_CM_IMPULSE)
			(void) MSG_ReadByte(&cl_message); // cmd->impulse
		(void) MSG_ReadByte(&cl_message); // cmd->msec
	}
	if (playerflags & QW_PF_VELOCITY1)
		velocity[0] = MSG_ReadShort(&cl_message);
	if (playerflags & QW_PF_VELOCITY2)
		velocity[1] = MSG_ReadShort(&cl_message);
	if (playerflags & QW_PF_VELOCITY3)
		velocity[2] = MSG_ReadShort(&cl_message);
	if (playerflags & QW_PF_MODEL)
		s->modelindex = MSG_ReadByte(&cl_message);
	else
		s->modelindex = cl.qw_modelindex_player;
	if (playerflags & QW_PF_SKINNUM)
		s->skin = MSG_ReadByte(&cl_message);
	if (playerflags & QW_PF_EFFECTS)
		QW_TranslateEffects(s, MSG_ReadByte(&cl_message));
	if (playerflags & QW_PF_WEAPONFRAME)
		weaponframe = MSG_ReadByte(&cl_message);
	else
		weaponframe = 0;

	if (enumber == cl.playerentity)
	{
		// if this is an update on our player, update the angles
		VectorCopy(cl.viewangles, viewangles);
	}

	// calculate the entity angles from the viewangles
	s->angles[0] = viewangles[0] * -0.0333;
	s->angles[1] = viewangles[1];
	s->angles[2] = 0;
	s->angles[2] = Com_CalcRoll(s->angles, velocity, cl_rollangle.value, cl_rollspeed.value)*4;

	// if this is an update on our player, update interpolation state
	if (enumber == cl.playerentity)
	{
		VectorCopy (cl.mpunchangle[0], cl.mpunchangle[1]);
		VectorCopy (cl.mpunchvector[0], cl.mpunchvector[1]);
		VectorCopy (cl.mvelocity[0], cl.mvelocity[1]);
		cl.mviewzoom[1] = cl.mviewzoom[0];

		cl.idealpitch = 0;
		cl.mpunchangle[0][0] = 0;
		cl.mpunchangle[0][1] = 0;
		cl.mpunchangle[0][2] = 0;
		cl.mpunchvector[0][0] = 0;
		cl.mpunchvector[0][1] = 0;
		cl.mpunchvector[0][2] = 0;
		cl.mvelocity[0][0] = 0;
		cl.mvelocity[0][1] = 0;
		cl.mvelocity[0][2] = 0;
		cl.mviewzoom[0] = 1;

		VectorCopy(velocity, cl.mvelocity[0]);
		cl.stats[STAT_WEAPONFRAME] = weaponframe;
		if (playerflags & QW_PF_GIB)
			cl.stats[STAT_VIEWHEIGHT] = 8;
		else if (playerflags & QW_PF_DEAD)
			cl.stats[STAT_VIEWHEIGHT] = -16;
		else
			cl.stats[STAT_VIEWHEIGHT] = 22;
	}

	// set the cl.entities_active flag
	cl.entities_active[enumber] = (s->active == ACTIVE_NETWORK);
	// set the update time
	s->time = cl.mtime[0] - msec * 0.001; // qw has no clock
	// check if we need to update the lerp stuff
	if (s->active == ACTIVE_NETWORK)
		CL_MoveLerpEntityStates(&cl.entities[enumber]);
}

static void EntityStateQW_ReadEntityUpdate(entity_state_t *s, int bits)
{
	int qweffects = 0;
	s->active = ACTIVE_NETWORK;
	s->number = bits & 511;
	bits &= ~511;
	if (bits & QW_U_MOREBITS)
		bits |= MSG_ReadByte(&cl_message);

	// store the QW_U_SOLID bit here?

	if (bits & QW_U_MODEL)
		s->modelindex = MSG_ReadByte(&cl_message);
	if (bits & QW_U_FRAME)
		s->frame = MSG_ReadByte(&cl_message);
	if (bits & QW_U_COLORMAP)
		s->colormap = MSG_ReadByte(&cl_message);
	if (bits & QW_U_SKIN)
		s->skin = MSG_ReadByte(&cl_message);
	if (bits & QW_U_EFFECTS)
		QW_TranslateEffects(s, qweffects = MSG_ReadByte(&cl_message));
	if (bits & QW_U_ORIGIN1)
		s->origin[0] = MSG_ReadCoord13i(&cl_message);
	if (bits & QW_U_ANGLE1)
		s->angles[0] = MSG_ReadAngle8i(&cl_message);
	if (bits & QW_U_ORIGIN2)
		s->origin[1] = MSG_ReadCoord13i(&cl_message);
	if (bits & QW_U_ANGLE2)
		s->angles[1] = MSG_ReadAngle8i(&cl_message);
	if (bits & QW_U_ORIGIN3)
		s->origin[2] = MSG_ReadCoord13i(&cl_message);
	if (bits & QW_U_ANGLE3)
		s->angles[2] = MSG_ReadAngle8i(&cl_message);

	if (developer_networkentities.integer >= 2)
	{
		Con_Printf("ReadFields e%i", s->number);
		if (bits & QW_U_MODEL)
			Con_Printf(" U_MODEL %i", s->modelindex);
		if (bits & QW_U_FRAME)
			Con_Printf(" U_FRAME %i", s->frame);
		if (bits & QW_U_COLORMAP)
			Con_Printf(" U_COLORMAP %i", s->colormap);
		if (bits & QW_U_SKIN)
			Con_Printf(" U_SKIN %i", s->skin);
		if (bits & QW_U_EFFECTS)
			Con_Printf(" U_EFFECTS %i", qweffects);
		if (bits & QW_U_ORIGIN1)
			Con_Printf(" U_ORIGIN1 %f", s->origin[0]);
		if (bits & QW_U_ANGLE1)
			Con_Printf(" U_ANGLE1 %f", s->angles[0]);
		if (bits & QW_U_ORIGIN2)
			Con_Printf(" U_ORIGIN2 %f", s->origin[1]);
		if (bits & QW_U_ANGLE2)
			Con_Printf(" U_ANGLE2 %f", s->angles[1]);
		if (bits & QW_U_ORIGIN3)
			Con_Printf(" U_ORIGIN3 %f", s->origin[2]);
		if (bits & QW_U_ANGLE3)
			Con_Printf(" U_ANGLE3 %f", s->angles[2]);
		if (bits & QW_U_SOLID)
			Con_Printf(" U_SOLID");
		Con_Print("\n");
	}
}

entityframeqw_database_t *EntityFrameQW_AllocDatabase(mempool_t *pool)
{
	entityframeqw_database_t *d;
	d = (entityframeqw_database_t *)Mem_Alloc(pool, sizeof(*d));
	return d;
}

void EntityFrameQW_FreeDatabase(entityframeqw_database_t *d)
{
	Mem_Free(d);
}

void EntityFrameQW_CL_ReadFrame(qbool delta)
{
	qbool invalid = false;
	int number, oldsnapindex, newsnapindex, oldindex, newindex, oldnum, newnum;
	entity_t *ent;
	entityframeqw_database_t *d;
	entityframeqw_snapshot_t *oldsnap, *newsnap;

	if (!cl.entitydatabaseqw)
		cl.entitydatabaseqw = EntityFrameQW_AllocDatabase(cls.levelmempool);
	d = cl.entitydatabaseqw;

	// there is no cls.netcon in demos, so this reading code can't access
	// cls.netcon-> at all...  so cls.qw_incoming_sequence and
	// cls.qw_outgoing_sequence are updated every time the corresponding
	// cls.netcon->qw. variables are updated
	// read the number of this frame to echo back in next input packet
	cl.qw_validsequence = cls.qw_incoming_sequence;
	newsnapindex = cl.qw_validsequence & QW_UPDATE_MASK;
	newsnap = d->snapshot + newsnapindex;
	memset(newsnap, 0, sizeof(*newsnap));
	oldsnap = NULL;
	if (delta)
	{
		number = MSG_ReadByte(&cl_message);
		oldsnapindex = cl.qw_deltasequence[newsnapindex];
		if ((number & QW_UPDATE_MASK) != (oldsnapindex & QW_UPDATE_MASK))
			Con_DPrintf("WARNING: from mismatch\n");
		if (oldsnapindex != -1)
		{
			if (cls.qw_outgoing_sequence - oldsnapindex >= QW_UPDATE_BACKUP-1)
			{
				Con_DPrintf("delta update too old\n");
				newsnap->invalid = invalid = true; // too old
				delta = false;
			}
			oldsnap = d->snapshot + (oldsnapindex & QW_UPDATE_MASK);
		}
		else
			delta = false;
	}

	// if we can't decode this frame properly, report that to the server
	if (invalid)
		cl.qw_validsequence = 0;

	// read entity numbers until we find a 0x0000
	// (which would be an empty update on world entity, but is actually a terminator)
	newsnap->num_entities = 0;
	oldindex = 0;
	for (;;)
	{
		int word = (unsigned short)MSG_ReadShort(&cl_message);
		if (cl_message.badread)
			return; // just return, the main parser will print an error
		newnum = word == 0 ? 512 : (word & 511);
		oldnum = delta ? (oldindex >= oldsnap->num_entities ? 9999 : oldsnap->entities[oldindex].number) : 9999;

		// copy unmodified oldsnap entities
		while (newnum > oldnum) // delta only
		{
			if (developer_networkentities.integer >= 2)
				Con_Printf("copy %i\n", oldnum);
			// copy one of the old entities
			if (newsnap->num_entities >= QW_MAX_PACKET_ENTITIES)
				Host_Error("EntityFrameQW_CL_ReadFrame: newsnap->num_entities == MAX_PACKETENTITIES");
			newsnap->entities[newsnap->num_entities] = oldsnap->entities[oldindex++];
			newsnap->num_entities++;
			oldnum = oldindex >= oldsnap->num_entities ? 9999 : oldsnap->entities[oldindex].number;
		}

		if (word == 0)
			break;

		if (developer_networkentities.integer >= 2)
		{
			if (word & QW_U_REMOVE)
				Con_Printf("remove %i\n", newnum);
			else if (newnum == oldnum)
				Con_Printf("delta %i\n", newnum);
			else
				Con_Printf("baseline %i\n", newnum);
		}

		if (word & QW_U_REMOVE)
		{
			if (newnum != oldnum && !delta && !invalid)
			{
				cl.qw_validsequence = 0;
				Con_Printf(CON_WARN "WARNING: U_REMOVE %i on full update\n", newnum);
			}
		}
		else
		{
			if (newsnap->num_entities >= QW_MAX_PACKET_ENTITIES)
				Host_Error("EntityFrameQW_CL_ReadFrame: newsnap->num_entities == MAX_PACKETENTITIES");
			newsnap->entities[newsnap->num_entities] = (newnum == oldnum) ? oldsnap->entities[oldindex] : cl.entities[newnum].state_baseline;
			EntityStateQW_ReadEntityUpdate(newsnap->entities + newsnap->num_entities, word);
			newsnap->num_entities++;
		}

		if (newnum == oldnum)
			oldindex++;
	}

	// expand cl.num_entities to include every entity we've seen this game
	newnum = newsnap->num_entities ? newsnap->entities[newsnap->num_entities - 1].number : 1;
	if (cl.num_entities <= newnum)
	{
		cl.num_entities = newnum + 1;
		if (cl.max_entities < newnum + 1)
			CL_ExpandEntities(newnum);
	}

	// now update the non-player entities from the snapshot states
	number = cl.maxclients + 1;
	for (newindex = 0;;newindex++)
	{
		newnum = newindex >= newsnap->num_entities ? cl.num_entities : newsnap->entities[newindex].number;
		// kill any missing entities
		for (;number < newnum;number++)
		{
			if (cl.entities_active[number])
			{
				cl.entities_active[number] = false;
				cl.entities[number].state_current.active = ACTIVE_NOT;
			}
		}
		if (number >= cl.num_entities)
			break;
		// update the entity
		ent = &cl.entities[number];
		ent->state_previous = ent->state_current;
		ent->state_current = newsnap->entities[newindex];
		ent->state_current.time = cl.mtime[0];
		CL_MoveLerpEntityStates(ent);
		// the entity lives again...
		cl.entities_active[number] = true;
		number++;
	}
}