/*
===========================================================================
Copyright (C) 2000 - 2013, Raven Software, Inc.
Copyright (C) 2001 - 2013, Activision, Inc.
Copyright (C) 2013 - 2015, OpenJK contributors

This file is part of the OpenJK source code.

OpenJK is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

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, see <http://www.gnu.org/licenses/>.
===========================================================================
*/
#include "g_headers.h"

#include "b_local.h"
#include "g_nav.h"
#include "anims.h"
#include "g_navigator.h"

extern void CG_DrawAlert( vec3_t origin, float rating );
extern void G_AddVoiceEvent( gentity_t *self, int event, int speakDebounceTime );
extern void G_SoundOnEnt( gentity_t *ent, soundChannel_t channel, const char *soundPath );
extern void NPC_TempLookTarget( gentity_t *self, int lookEntNum, int minLookTime, int maxLookTime );
extern qboolean G_ExpandPointToBBox( vec3_t point, const vec3_t mins, const vec3_t maxs, int ignore, int clipmask );
extern void NPC_AimAdjust( int change );
extern qboolean FlyingCreature( gentity_t *ent );

extern	CNavigator	navigator;

#define	MAX_VIEW_DIST		1024
#define MAX_VIEW_SPEED		250
#define	MAX_LIGHT_INTENSITY 255
#define	MIN_LIGHT_THRESHOLD	0.1

#define	DISTANCE_SCALE		0.25f
#define	DISTANCE_THRESHOLD	0.075f
#define	SPEED_SCALE			0.25f
#define	FOV_SCALE			0.5f
#define	LIGHT_SCALE			0.25f

#define	REALIZE_THRESHOLD	0.6f
#define CAUTIOUS_THRESHOLD	( REALIZE_THRESHOLD * 0.75 )

qboolean NPC_CheckPlayerTeamStealth( void );

static qboolean enemyLOS;
static qboolean enemyCS;
static qboolean faceEnemy;
static qboolean AImove;
static qboolean shoot;
static float	enemyDist;

//Local state enums
enum
{
	LSTATE_NONE = 0,
	LSTATE_UNDERFIRE,
	LSTATE_INVESTIGATE,
};

void Grenadier_ClearTimers( gentity_t *ent )
{
	TIMER_Set( ent, "chatter", 0 );
	TIMER_Set( ent, "duck", 0 );
	TIMER_Set( ent, "stand", 0 );
	TIMER_Set( ent, "shuffleTime", 0 );
	TIMER_Set( ent, "sleepTime", 0 );
	TIMER_Set( ent, "enemyLastVisible", 0 );
	TIMER_Set( ent, "roamTime", 0 );
	TIMER_Set( ent, "hideTime", 0 );
	TIMER_Set( ent, "attackDelay", 0 );	//FIXME: Slant for difficulty levels
	TIMER_Set( ent, "stick", 0 );
	TIMER_Set( ent, "scoutTime", 0 );
	TIMER_Set( ent, "flee", 0 );
}

void NPC_Grenadier_PlayConfusionSound( gentity_t *self )
{//FIXME: make this a custom sound in sound set
	if ( self->health > 0 )
	{
		G_AddVoiceEvent( self, Q_irand(EV_CONFUSE1, EV_CONFUSE3), 2000 );
	}
	//reset him to be totally unaware again
	TIMER_Set( self, "enemyLastVisible", 0 );
	TIMER_Set( self, "flee", 0 );
	self->NPC->squadState = SQUAD_IDLE;
	self->NPC->tempBehavior = BS_DEFAULT;
	
	//self->NPC->behaviorState = BS_PATROL;
	G_ClearEnemy( self );//FIXME: or just self->enemy = NULL;?

	self->NPC->investigateCount = 0;
}


/*
-------------------------
NPC_ST_Pain
-------------------------
*/

void NPC_Grenadier_Pain( gentity_t *self, gentity_t *inflictor, gentity_t *other, vec3_t point, int damage, int mod ) 
{
	self->NPC->localState = LSTATE_UNDERFIRE;

	TIMER_Set( self, "duck", -1 );
	TIMER_Set( self, "stand", 2000 );

	NPC_Pain( self, inflictor, other, point, damage, mod );

	if ( !damage && self->health > 0 )
	{//FIXME: better way to know I was pushed
		G_AddVoiceEvent( self, Q_irand(EV_PUSHED1, EV_PUSHED3), 2000 );
	}
}

/*
-------------------------
ST_HoldPosition
-------------------------
*/

static void Grenadier_HoldPosition( void )
{
	NPC_FreeCombatPoint( NPCInfo->combatPoint, qtrue );
	NPCInfo->goalEntity = NULL;
	
	/*if ( TIMER_Done( NPC, "stand" ) )
	{//FIXME: what if can't shoot from this pos?
		TIMER_Set( NPC, "duck", Q_irand( 2000, 4000 ) );
	}
	*/
}

/*
-------------------------
ST_Move
-------------------------
*/

static qboolean Grenadier_Move( void )
{
	NPCInfo->combatMove = qtrue;//always move straight toward our goal

	qboolean	moved = NPC_MoveToGoal( qtrue );
	navInfo_t	info;
	
	//Get the move info
	NAV_GetLastMove( info );

	//FIXME: if we bump into another one of our guys and can't get around him, just stop!
	//If we hit our target, then stop and fire!
	if ( info.flags & NIF_COLLISION ) 
	{
		if ( info.blocker == NPC->enemy )
		{
			Grenadier_HoldPosition();
		}
	}

	//If our move failed, then reset
	if ( moved == qfalse )
	{//couldn't get to enemy
		if ( (NPCInfo->scriptFlags&SCF_CHASE_ENEMIES) && NPC->client->ps.weapon == WP_THERMAL && NPCInfo->goalEntity && NPCInfo->goalEntity == NPC->enemy )
		{//we were running after enemy
			//Try to find a combat point that can hit the enemy
			int cpFlags = (CP_CLEAR|CP_HAS_ROUTE);
			if ( NPCInfo->scriptFlags&SCF_USE_CP_NEAREST )
			{
				cpFlags &= ~(CP_FLANK|CP_APPROACH_ENEMY|CP_CLOSEST);
				cpFlags |= CP_NEAREST;
			}
			int cp = NPC_FindCombatPoint( NPC->currentOrigin, NPC->currentOrigin, NPC->currentOrigin, cpFlags, 32 );
			if ( cp == -1 && !(NPCInfo->scriptFlags&SCF_USE_CP_NEAREST) )
			{//okay, try one by the enemy
				cp = NPC_FindCombatPoint( NPC->currentOrigin, NPC->currentOrigin, NPC->enemy->currentOrigin, CP_CLEAR|CP_HAS_ROUTE|CP_HORZ_DIST_COLL, 32 );
			}
			//NOTE: there may be a perfectly valid one, just not one within CP_COLLECT_RADIUS of either me or him...
			if ( cp != -1 )
			{//found a combat point that has a clear shot to enemy
				NPC_SetCombatPoint( cp );
				NPC_SetMoveGoal( NPC, level.combatPoints[cp].origin, 8, qtrue, cp );
				return moved;
			}
		}
		//just hang here
		Grenadier_HoldPosition();
	}

	return moved;
}

/*
-------------------------
NPC_BSGrenadier_Patrol
-------------------------
*/

void NPC_BSGrenadier_Patrol( void )
{//FIXME: pick up on bodies of dead buddies?
	if ( NPCInfo->confusionTime < level.time )
	{
		//Look for any enemies
		if ( NPCInfo->scriptFlags&SCF_LOOK_FOR_ENEMIES )
		{
			if ( NPC_CheckPlayerTeamStealth() )
			{
				//NPCInfo->behaviorState = BS_HUNT_AND_KILL;//should be automatic now
				//NPC_AngerSound();
				NPC_UpdateAngles( qtrue, qtrue );
				return;
			}
		}

		if ( !(NPCInfo->scriptFlags&SCF_IGNORE_ALERTS) )
		{
			//Is there danger nearby
			int alertEvent = NPC_CheckAlertEvents( qtrue, qtrue, -1, qfalse, AEL_SUSPICIOUS );
			if ( NPC_CheckForDanger( alertEvent ) )
			{
				NPC_UpdateAngles( qtrue, qtrue );
				return;
			}
			else
			{//check for other alert events
				//There is an event to look at
				if ( alertEvent >= 0 && level.alertEvents[alertEvent].ID != NPCInfo->lastAlertID )
				{
					NPCInfo->lastAlertID = level.alertEvents[alertEvent].ID;
					if ( level.alertEvents[alertEvent].level == AEL_DISCOVERED )
					{
						if ( level.alertEvents[alertEvent].owner && 
							level.alertEvents[alertEvent].owner->client && 
							level.alertEvents[alertEvent].owner->health >= 0 &&
							level.alertEvents[alertEvent].owner->client->playerTeam == NPC->client->enemyTeam )
						{//an enemy
							G_SetEnemy( NPC, level.alertEvents[alertEvent].owner );
							//NPCInfo->enemyLastSeenTime = level.time;
							TIMER_Set( NPC, "attackDelay", Q_irand( 500, 2500 ) );
						}
					}
					else
					{//FIXME: get more suspicious over time?
						//Save the position for movement (if necessary)
						VectorCopy( level.alertEvents[alertEvent].position, NPCInfo->investigateGoal );
						NPCInfo->investigateDebounceTime = level.time + Q_irand( 500, 1000 );
						if ( level.alertEvents[alertEvent].level == AEL_SUSPICIOUS )
						{//suspicious looks longer
							NPCInfo->investigateDebounceTime += Q_irand( 500, 2500 );
						}
					}
				}
			}

			if ( NPCInfo->investigateDebounceTime > level.time )
			{//FIXME: walk over to it, maybe?  Not if not chase enemies
				//NOTE: stops walking or doing anything else below
				vec3_t	dir, angles;
				float	o_yaw, o_pitch;
				
				VectorSubtract( NPCInfo->investigateGoal, NPC->client->renderInfo.eyePoint, dir );
				vectoangles( dir, angles );
				
				o_yaw = NPCInfo->desiredYaw;
				o_pitch = NPCInfo->desiredPitch;
				NPCInfo->desiredYaw = angles[YAW];
				NPCInfo->desiredPitch = angles[PITCH];
				
				NPC_UpdateAngles( qtrue, qtrue );

				NPCInfo->desiredYaw = o_yaw;
				NPCInfo->desiredPitch = o_pitch;
				return;
			}
		}
	}

	//If we have somewhere to go, then do that
	if ( UpdateGoal() )
	{
		ucmd.buttons |= BUTTON_WALKING;
		NPC_MoveToGoal( qtrue );
	}

	NPC_UpdateAngles( qtrue, qtrue );
}

/*
-------------------------
NPC_BSGrenadier_Idle
-------------------------
*/
/*
void NPC_BSGrenadier_Idle( void )
{
	//FIXME: check for other alert events?

	//Is there danger nearby?
	if ( NPC_CheckForDanger( NPC_CheckAlertEvents( qtrue, qtrue, -1, qfalse, AEL_DANGER ) ) )
	{
		NPC_UpdateAngles( qtrue, qtrue );
		return;
	}

	TIMER_Set( NPC, "roamTime", 2000 + Q_irand( 1000, 2000 ) );

	NPC_UpdateAngles( qtrue, qtrue );
}
*/
/*
-------------------------
ST_CheckMoveState
-------------------------
*/

static void Grenadier_CheckMoveState( void )
{
	//See if we're a scout
	if ( !(NPCInfo->scriptFlags & SCF_CHASE_ENEMIES) )//behaviorState == BS_STAND_AND_SHOOT )
	{
		if ( NPCInfo->goalEntity == NPC->enemy )
		{
			AImove = qfalse;
			return;
		}
	}
	//See if we're running away
	else if ( NPCInfo->squadState == SQUAD_RETREAT )
	{
		if ( TIMER_Done( NPC, "flee" ) )
		{
			NPCInfo->squadState = SQUAD_IDLE;
		}
		else
		{
			faceEnemy = qfalse;
		}
	}
	/*
	else if ( NPCInfo->squadState == SQUAD_IDLE )
	{
		if ( !NPCInfo->goalEntity )
		{
			AImove = qfalse;
			return;
		}
		//Should keep moving toward player when we're out of range... right?
	}
	*/

	//See if we're moving towards a goal, not the enemy
	if ( ( NPCInfo->goalEntity != NPC->enemy ) && ( NPCInfo->goalEntity != NULL ) )
	{
		//Did we make it?
		if ( NAV_HitNavGoal( NPC->currentOrigin, NPC->mins, NPC->maxs, NPCInfo->goalEntity->currentOrigin, 16, FlyingCreature( NPC ) ) || 
			( NPCInfo->squadState == SQUAD_SCOUT && enemyLOS && enemyDist <= 10000 ) )
		{
			//int	newSquadState = SQUAD_STAND_AND_SHOOT;
			//we got where we wanted to go, set timers based on why we were running
			switch ( NPCInfo->squadState )
			{
			case SQUAD_RETREAT://was running away
				TIMER_Set( NPC, "duck", (NPC->max_health - NPC->health) * 100 );
				TIMER_Set( NPC, "hideTime", Q_irand( 3000, 7000 ) );
				//newSquadState = SQUAD_COVER;
				break;
			case SQUAD_TRANSITION://was heading for a combat point
				TIMER_Set( NPC, "hideTime", Q_irand( 2000, 4000 ) );
				break;
			case SQUAD_SCOUT://was running after player
				break;
			default:
				break;
			}
			NPC_ReachedGoal();
			//don't attack right away
			TIMER_Set( NPC, "attackDelay", Q_irand( 250, 500 ) );	//FIXME: Slant for difficulty levels
			//don't do something else just yet
			TIMER_Set( NPC, "roamTime", Q_irand( 1000, 4000 ) );
			//stop fleeing
			if ( NPCInfo->squadState == SQUAD_RETREAT )
			{
				TIMER_Set( NPC, "flee", -level.time );
				NPCInfo->squadState = SQUAD_IDLE;
			}
			return;
		}

		//keep going, hold of roamTimer until we get there
		TIMER_Set( NPC, "roamTime", Q_irand( 4000, 8000 ) );
	}

	if ( !NPCInfo->goalEntity )
	{
		if ( NPCInfo->scriptFlags & SCF_CHASE_ENEMIES )
		{
			NPCInfo->goalEntity = NPC->enemy;
		}
	}
}

/*
-------------------------
ST_CheckFireState
-------------------------
*/

static void Grenadier_CheckFireState( void )
{
	if ( enemyCS )
	{//if have a clear shot, always try
		return;
	}

	if ( NPCInfo->squadState == SQUAD_RETREAT || NPCInfo->squadState == SQUAD_TRANSITION || NPCInfo->squadState == SQUAD_SCOUT )
	{//runners never try to fire at the last pos
		return;
	}

	if ( !VectorCompare( NPC->client->ps.velocity, vec3_origin ) )
	{//if moving at all, don't do this
		return;
	}

	//continue to fire on their last position
	/*
	if ( !Q_irand( 0, 1 ) && NPCInfo->enemyLastSeenTime && level.time - NPCInfo->enemyLastSeenTime < 4000 )
	{
		//Fire on the last known position
		vec3_t	muzzle, dir, angles;

		CalcEntitySpot( NPC, SPOT_WEAPON, muzzle );
		VectorSubtract( NPCInfo->enemyLastSeenLocation, muzzle, dir );

		VectorNormalize( dir );

		vectoangles( dir, angles );

		NPCInfo->desiredYaw		= angles[YAW];
		NPCInfo->desiredPitch	= angles[PITCH];
		//FIXME: they always throw toward enemy, so this will be very odd...
		shoot = qtrue;
		faceEnemy = qfalse;

		return;
	}
	*/
}

qboolean Grenadier_EvaluateShot( int hit )
{
	if ( !NPC->enemy )
	{
		return qfalse;
	}

	if ( hit == NPC->enemy->s.number || (&g_entities[hit] != NULL && (g_entities[hit].svFlags&SVF_GLASS_BRUSH)) )
	{//can hit enemy or will hit glass, so shoot anyway
		return qtrue;
	}
	return qfalse;
}

/*
-------------------------
NPC_BSGrenadier_Attack
-------------------------
*/

void NPC_BSGrenadier_Attack( void )
{
	//Don't do anything if we're hurt
	if ( NPC->painDebounceTime > level.time )
	{
		NPC_UpdateAngles( qtrue, qtrue );
		return;
	}

	//NPC_CheckEnemy( qtrue, qfalse );
	//If we don't have an enemy, just idle
	if ( NPC_CheckEnemyExt() == qfalse )//!NPC->enemy )//
	{
		NPC->enemy = NULL;
		NPC_BSGrenadier_Patrol();//FIXME: or patrol?
		return;
	}

	if ( TIMER_Done( NPC, "flee" ) && NPC_CheckForDanger( NPC_CheckAlertEvents( qtrue, qtrue, -1, qfalse, AEL_DANGER ) ) )
	{//going to run
		NPC_UpdateAngles( qtrue, qtrue );
		return;
	}

	if ( !NPC->enemy )
	{//WTF?  somehow we lost our enemy?
		NPC_BSGrenadier_Patrol();//FIXME: or patrol?
		return;
	}

	enemyLOS = enemyCS = qfalse;
	AImove = qtrue;
	faceEnemy = qfalse;
	shoot = qfalse;
	enemyDist = DistanceSquared( NPC->enemy->currentOrigin, NPC->currentOrigin );

	//See if we should switch to melee attack
	if ( enemyDist < 16384 && (!NPC->enemy->client||NPC->enemy->client->ps.weapon != WP_SABER||!NPC->enemy->client->ps.saberActive) )//128
	{//enemy is close and not using saber
		if ( NPC->client->ps.weapon == WP_THERMAL )
		{//grenadier
			trace_t	trace;
			gi.trace ( &trace, NPC->currentOrigin, NPC->enemy->mins, NPC->enemy->maxs, NPC->enemy->currentOrigin, NPC->s.number, NPC->enemy->clipmask, G2_NOCOLLIDE, 0 );
			if ( !trace.allsolid && !trace.startsolid && (trace.fraction == 1.0 || trace.entityNum == NPC->enemy->s.number ) )
			{//I can get right to him
				//reset fire-timing variables
				NPC_ChangeWeapon( WP_MELEE );
				if ( !(NPCInfo->scriptFlags&SCF_CHASE_ENEMIES) )//NPCInfo->behaviorState == BS_STAND_AND_SHOOT )
				{//FIXME: should we be overriding scriptFlags?
					NPCInfo->scriptFlags |= SCF_CHASE_ENEMIES;//NPCInfo->behaviorState = BS_HUNT_AND_KILL;
				}
			}
		}
	}
	else if ( enemyDist > 65536 || (NPC->enemy->client && NPC->enemy->client->ps.weapon == WP_SABER && NPC->enemy->client->ps.saberActive) )//256
	{//enemy is far or using saber
		if ( NPC->client->ps.weapon == WP_MELEE && (NPC->client->ps.stats[STAT_WEAPONS]&(1<<WP_THERMAL)) )
		{//fisticuffs, make switch to thermal if have it
			//reset fire-timing variables
			NPC_ChangeWeapon( WP_THERMAL );
		}
	}

	//can we see our target?
	if ( NPC_ClearLOS( NPC->enemy ) )
	{
		NPCInfo->enemyLastSeenTime = level.time;
		enemyLOS = qtrue;

		if ( NPC->client->ps.weapon == WP_MELEE )
		{
			if ( enemyDist <= 4096 && InFOV( NPC->enemy->currentOrigin, NPC->currentOrigin, NPC->client->ps.viewangles, 90, 45 ) )//within 64 & infront
			{
				VectorCopy( NPC->enemy->currentOrigin, NPCInfo->enemyLastSeenLocation );
				enemyCS = qtrue;
			}
		}
		else if ( InFOV( NPC->enemy->currentOrigin, NPC->currentOrigin, NPC->client->ps.viewangles, 45, 90 ) )
		{//in front of me 
			//can we shoot our target?
			//FIXME: how accurate/necessary is this check?
			int hit = NPC_ShotEntity( NPC->enemy );
			gentity_t *hitEnt = &g_entities[hit];
			if ( hit == NPC->enemy->s.number 
				|| ( hitEnt && hitEnt->client && hitEnt->client->playerTeam == NPC->client->enemyTeam ) )
			{
				VectorCopy( NPC->enemy->currentOrigin, NPCInfo->enemyLastSeenLocation );
				float enemyHorzDist = DistanceHorizontalSquared( NPC->enemy->currentOrigin, NPC->currentOrigin );
				if ( enemyHorzDist < 1048576 )
				{//within 1024
					enemyCS = qtrue;
					NPC_AimAdjust( 2 );//adjust aim better longer we have clear shot at enemy
				}
				else
				{
					NPC_AimAdjust( 1 );//adjust aim better longer we can see enemy
				}
			}
		}
	}
	else
	{
		NPC_AimAdjust( -1 );//adjust aim worse longer we cannot see enemy
	}
	/*
	else if ( gi.inPVS( NPC->enemy->currentOrigin, NPC->currentOrigin ) )
	{
		NPCInfo->enemyLastSeenTime = level.time;
		faceEnemy = qtrue;
	}
	*/

	if ( enemyLOS )
	{//FIXME: no need to face enemy if we're moving to some other goal and he's too far away to shoot?
		faceEnemy = qtrue;
	}

	if ( enemyCS )
	{
		shoot = qtrue;
		if ( NPC->client->ps.weapon == WP_THERMAL )
		{//don't chase and throw
			AImove = qfalse;
		}
		else if ( NPC->client->ps.weapon == WP_MELEE && enemyDist < (NPC->maxs[0]+NPC->enemy->maxs[0]+16)*(NPC->maxs[0]+NPC->enemy->maxs[0]+16) )
		{//close enough
			AImove = qfalse;
		}
	}//this should make him chase enemy when out of range...?

	//Check for movement to take care of
	Grenadier_CheckMoveState();

	//See if we should override shooting decision with any special considerations
	Grenadier_CheckFireState();

	if ( AImove )
	{//move toward goal
		if ( NPCInfo->goalEntity )//&& ( NPCInfo->goalEntity != NPC->enemy || enemyDist > 10000 ) )//100 squared
		{
			AImove = Grenadier_Move();
		}
		else
		{
			AImove = qfalse;
		}
	}

	if ( !AImove )
	{
		if ( !TIMER_Done( NPC, "duck" ) )
		{
			ucmd.upmove = -127;
		}
		//FIXME: what about leaning?
	}
	else
	{//stop ducking!
		TIMER_Set( NPC, "duck", -1 );
	}

	if ( !faceEnemy )
	{//we want to face in the dir we're running
		if ( AImove )
		{//don't run away and shoot
			NPCInfo->desiredYaw = NPCInfo->lastPathAngles[YAW];
			NPCInfo->desiredPitch = 0;
			shoot = qfalse;
		}
		NPC_UpdateAngles( qtrue, qtrue );
	}
	else// if ( faceEnemy )
	{//face the enemy
		NPC_FaceEnemy();
	}

	if ( NPCInfo->scriptFlags&SCF_DONT_FIRE )
	{
		shoot = qfalse;
	}

	//FIXME: don't shoot right away!
	if ( shoot )
	{//try to shoot if it's time
		if ( TIMER_Done( NPC, "attackDelay" ) )
		{	
			if( !(NPCInfo->scriptFlags & SCF_FIRE_WEAPON) ) // we've already fired, no need to do it again here
			{
				WeaponThink( qtrue );
				TIMER_Set( NPC, "attackDelay", NPCInfo->shotTime-level.time );
			}
			
		}
	}
}

void NPC_BSGrenadier_Default( void )
{
	if( NPCInfo->scriptFlags & SCF_FIRE_WEAPON )
	{
		WeaponThink( qtrue );
	}

	if( !NPC->enemy )
	{//don't have an enemy, look for one
		NPC_BSGrenadier_Patrol();
	}
	else//if ( NPC->enemy )
	{//have an enemy
		NPC_BSGrenadier_Attack();
	}
}