/*
===========================================================================
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/>.
===========================================================================
*/

//
// NPC_move.cpp
//

#include "g_headers.h"

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

extern	cvar_t		*d_altRoutes;

qboolean G_BoundsOverlap(const vec3_t mins1, const vec3_t maxs1, const vec3_t mins2, const vec3_t maxs2);
int NAV_Steer( gentity_t *self, vec3_t dir, float distance );
extern int GetTime ( int lastTime );

navInfo_t	frameNavInfo;
extern qboolean FlyingCreature( gentity_t *ent );
extern qboolean PM_InKnockDown( playerState_t *ps );

/*
-------------------------
NPC_ClearPathToGoal
-------------------------
*/

qboolean NPC_ClearPathToGoal( vec3_t dir, gentity_t *goal )
{
	trace_t	trace;

	//FIXME: What does do about area portals?  THIS IS BROKEN
	//if ( gi.inPVS( NPC->currentOrigin, goal->currentOrigin ) == qfalse )
	//	return qfalse;

	//Look ahead and see if we're clear to move to our goal position
	if ( NAV_CheckAhead( NPC, goal->currentOrigin, trace, ( NPC->clipmask & ~CONTENTS_BODY )|CONTENTS_BOTCLIP ) )
	{
		//VectorSubtract( goal->currentOrigin, NPC->currentOrigin, dir );
		return qtrue;
	}

	if (!FlyingCreature(NPC))
	{
		//See if we're too far above
		if ( fabs( NPC->currentOrigin[2] - goal->currentOrigin[2] ) > 48 )
			return qfalse;
	}

	//This is a work around
	float	radius = ( NPC->maxs[0] > NPC->maxs[1] ) ? NPC->maxs[0] : NPC->maxs[1];
	float	dist = Distance( NPC->currentOrigin, goal->currentOrigin );
	float	tFrac = 1.0f - ( radius / dist );

	if ( trace.fraction >= tFrac )
		return qtrue;

	//See if we're looking for a navgoal
	if ( goal->svFlags & SVF_NAVGOAL )
	{
		//Okay, didn't get all the way there, let's see if we got close enough:
		if ( NAV_HitNavGoal( trace.endpos, NPC->mins, NPC->maxs, goal->currentOrigin, NPCInfo->goalRadius, FlyingCreature( NPC ) ) )
		{
			//VectorSubtract(goal->currentOrigin, NPC->currentOrigin, dir);
			return qtrue;
		}
	}

	return qfalse;
}

/*
-------------------------
NPC_CheckCombatMove
-------------------------
*/

inline qboolean NPC_CheckCombatMove( void )
{
	//return NPCInfo->combatMove;
	if ( ( NPCInfo->goalEntity && NPC->enemy && NPCInfo->goalEntity == NPC->enemy ) || ( NPCInfo->combatMove ) )
	{
		return qtrue;
	}

	if ( NPCInfo->goalEntity && NPCInfo->watchTarget )
	{
		if ( NPCInfo->goalEntity != NPCInfo->watchTarget )
		{
			return qtrue;
		}
	}

	return qfalse;
}

/*
-------------------------
NPC_LadderMove
-------------------------
*/

static void NPC_LadderMove( vec3_t dir )
{
	//FIXME: this doesn't guarantee we're facing ladder
	//ALSO: Need to be able to get off at top
	//ALSO: Need to play an anim
	//ALSO: Need transitionary anims?
	
	if ( ( dir[2] > 0 ) || ( dir[2] < 0 && NPC->client->ps.groundEntityNum == ENTITYNUM_NONE ) )
	{
		//Set our movement direction
		ucmd.upmove = (dir[2] > 0) ? 127 : -127;

		//Don't move around on XY
		ucmd.forwardmove = ucmd.rightmove = 0;
	}
}

/*
-------------------------
NPC_GetMoveInformation
-------------------------
*/

inline qboolean NPC_GetMoveInformation( vec3_t dir, float *distance )
{
	//NOTENOTE: Use path stacks!

	//Make sure we have somewhere to go
	if ( NPCInfo->goalEntity == NULL )
		return qfalse;

	//Get our move info
	VectorSubtract( NPCInfo->goalEntity->currentOrigin, NPC->currentOrigin, dir );
	*distance = VectorNormalize( dir );
	
	VectorCopy( NPCInfo->goalEntity->currentOrigin, NPCInfo->blockedDest );

	return qtrue;
}

/*
-------------------------
NAV_GetLastMove
-------------------------
*/

void NAV_GetLastMove( navInfo_t &info )
{
	info = frameNavInfo;
}

/*
-------------------------
NPC_GetMoveDirection
-------------------------
*/

qboolean NPC_GetMoveDirection( vec3_t out, float *distance )
{
	vec3_t		angles;

	//Clear the struct
	memset( &frameNavInfo, 0, sizeof( frameNavInfo ) );

	//Get our movement, if any
	if ( NPC_GetMoveInformation( frameNavInfo.direction, &frameNavInfo.distance ) == qfalse )
		return qfalse;

	//Setup the return value
	*distance = frameNavInfo.distance;

	//For starters
	VectorCopy( frameNavInfo.direction, frameNavInfo.pathDirection );

	//If on a ladder, move appropriately
	if ( NPC->watertype & CONTENTS_LADDER )
	{
		NPC_LadderMove( frameNavInfo.direction );
		return qtrue;
	}

	//Attempt a straight move to goal
	if ( NPC_ClearPathToGoal( frameNavInfo.direction, NPCInfo->goalEntity ) == qfalse )
	{
		//See if we're just stuck
		if ( NAV_MoveToGoal( NPC, frameNavInfo ) == WAYPOINT_NONE )
		{
			//Can't reach goal, just face
			vectoangles( frameNavInfo.direction, angles );
			NPCInfo->desiredYaw	= AngleNormalize360( angles[YAW] );		
			VectorCopy( frameNavInfo.direction, out );
			*distance = frameNavInfo.distance;
			return qfalse;
		}

		frameNavInfo.flags |= NIF_MACRO_NAV;
	}

	//Avoid any collisions on the way
	if ( NAV_AvoidCollision( NPC, NPCInfo->goalEntity, frameNavInfo ) == qfalse )
	{
		//FIXME: Emit a warning, this is a worst case scenario
		//FIXME: if we have a clear path to our goal (exluding bodies), but then this
		//			check (against bodies only) fails, shouldn't we fall back 
		//			to macro navigation?  Like so:
		if ( !(frameNavInfo.flags&NIF_MACRO_NAV) )
		{//we had a clear path to goal and didn't try macro nav, but can't avoid collision so try macro nav here
			//See if we're just stuck
			if ( NAV_MoveToGoal( NPC, frameNavInfo ) == WAYPOINT_NONE )
			{
				//Can't reach goal, just face
				vectoangles( frameNavInfo.direction, angles );
				NPCInfo->desiredYaw	= AngleNormalize360( angles[YAW] );		
				VectorCopy( frameNavInfo.direction, out );
				*distance = frameNavInfo.distance;
				return qfalse;
			}

			frameNavInfo.flags |= NIF_MACRO_NAV;
		}
	}

	//Setup the return values
	VectorCopy( frameNavInfo.direction, out );
	*distance = frameNavInfo.distance;

	return qtrue;
}

/*
-------------------------
NPC_GetMoveDirectionAltRoute
-------------------------
*/
extern int	NAVNEW_MoveToGoal( gentity_t *self, navInfo_t &info );
extern qboolean NAVNEW_AvoidCollision( gentity_t *self, gentity_t *goal, navInfo_t &info, qboolean setBlockedInfo, int blockedMovesLimit );
qboolean NPC_GetMoveDirectionAltRoute( vec3_t out, float *distance, qboolean tryStraight )
{
	vec3_t		angles;

	NPCInfo->aiFlags &= ~NPCAI_BLOCKED;

	//Clear the struct
	memset( &frameNavInfo, 0, sizeof( frameNavInfo ) );

	//Get our movement, if any
	if ( NPC_GetMoveInformation( frameNavInfo.direction, &frameNavInfo.distance ) == qfalse )
		return qfalse;

	//Setup the return value
	*distance = frameNavInfo.distance;

	//For starters
	VectorCopy( frameNavInfo.direction, frameNavInfo.pathDirection );

	//If on a ladder, move appropriately
	if ( NPC->watertype & CONTENTS_LADDER )
	{
		NPC_LadderMove( frameNavInfo.direction );
		return qtrue;
	}

	//Attempt a straight move to goal
	if ( !tryStraight || NPC_ClearPathToGoal( frameNavInfo.direction, NPCInfo->goalEntity ) == qfalse )
	{//blocked
		//Can't get straight to goal, use macro nav
		if ( NAVNEW_MoveToGoal( NPC, frameNavInfo ) == WAYPOINT_NONE )
		{
			//Can't reach goal, just face
			vectoangles( frameNavInfo.direction, angles );
			NPCInfo->desiredYaw	= AngleNormalize360( angles[YAW] );		
			VectorCopy( frameNavInfo.direction, out );
			*distance = frameNavInfo.distance;
			return qfalse;
		}
		//else we are on our way
		frameNavInfo.flags |= NIF_MACRO_NAV;
	}
	else
	{//we have no architectural problems, see if there are ents inthe way and try to go around them
		//not blocked
		if ( d_altRoutes->integer )
		{//try macro nav
			navInfo_t	tempInfo;
			memcpy( &tempInfo, &frameNavInfo, sizeof( tempInfo ) );
			if ( NAVNEW_AvoidCollision( NPC, NPCInfo->goalEntity, tempInfo, qtrue, 5 ) == qfalse )
			{//revert to macro nav
				//Can't get straight to goal, dump tempInfo and use macro nav
				if ( NAVNEW_MoveToGoal( NPC, frameNavInfo ) == WAYPOINT_NONE )
				{
					//Can't reach goal, just face
					vectoangles( frameNavInfo.direction, angles );
					NPCInfo->desiredYaw	= AngleNormalize360( angles[YAW] );		
					VectorCopy( frameNavInfo.direction, out );
					*distance = frameNavInfo.distance;
					return qfalse;
				}
				//else we are on our way
				frameNavInfo.flags |= NIF_MACRO_NAV;
			}
			else
			{//otherwise, either clear or can avoid
				memcpy( &frameNavInfo, &tempInfo, sizeof( frameNavInfo ) );
			}
		}
		else
		{//OR: just give up
			if ( NAVNEW_AvoidCollision( NPC, NPCInfo->goalEntity, frameNavInfo, qtrue, 30 ) == qfalse )
			{//give up
				return qfalse;
			}
		}
	}

	//Setup the return values
	VectorCopy( frameNavInfo.direction, out );
	*distance = frameNavInfo.distance;

	return qtrue;
}

void G_UcmdMoveForDir( gentity_t *self, usercmd_t *cmd, vec3_t dir )
{
	vec3_t	forward, right;

	AngleVectors( self->currentAngles, forward, right, NULL );

	dir[2] = 0;
	VectorNormalize( dir );
	//NPCs cheat and store this directly because converting movement into a ucmd loses precision
	VectorCopy( dir, self->client->ps.moveDir );

	float fDot = DotProduct( forward, dir ) * 127.0f;
	float rDot = DotProduct( right, dir ) * 127.0f;
	//Must clamp this because DotProduct is not guaranteed to return a number within -1 to 1, and that would be bad when we're shoving this into a signed byte
	if ( fDot > 127.0f )
	{
		fDot = 127.0f;
	}
	if ( fDot < -127.0f )
	{
		fDot = -127.0f;
	}
	if ( rDot > 127.0f )
	{
		rDot = 127.0f;
	}
	if ( rDot < -127.0f )
	{
		rDot = -127.0f;
	}
	cmd->forwardmove = floor(fDot);
	cmd->rightmove = floor(rDot);

	/*
	vec3_t	wishvel;
	for ( int i = 0 ; i < 3 ; i++ ) 
	{
		wishvel[i] = forward[i]*cmd->forwardmove + right[i]*cmd->rightmove;
	}
	VectorNormalize( wishvel );
	if ( !VectorCompare( wishvel, dir ) )
	{
		Com_Printf( "PRECISION LOSS: %s != %s\n", vtos(wishvel), vtos(dir) );
	}
	*/
}

/*
-------------------------
NPC_MoveToGoal

  Now assumes goal is goalEntity, was no reason for it to be otherwise
-------------------------
*/
#if	AI_TIMERS
extern int navTime;
#endif//	AI_TIMERS
qboolean NPC_MoveToGoal( qboolean tryStraight ) 
{
#if	AI_TIMERS
	int	startTime = GetTime(0);
#endif//	AI_TIMERS
	//If taking full body pain, don't move
	if ( PM_InKnockDown( &NPC->client->ps ) || ( ( NPC->s.legsAnim >= BOTH_PAIN1 ) && ( NPC->s.legsAnim <= BOTH_PAIN19 ) ) )
	{
		return qtrue;
	}

	if( NPC->s.eFlags & EF_LOCKED_TO_WEAPON )
	{//If in an emplaced gun, never try to navigate!
		return qtrue;
	}

	float	distance;
	vec3_t	dir;

	//FIXME: if can't get to goal & goal is a target (enemy), try to find a waypoint that has line of sight to target, at least?
	//Get our movement direction
#if 1
	if ( NPC_GetMoveDirectionAltRoute( dir, &distance, tryStraight ) == qfalse )
#else
	if ( NPC_GetMoveDirection( dir, &distance ) == qfalse )
#endif
		return qfalse;

	NPCInfo->distToGoal		= distance;

	//Convert the move to angles
	vectoangles( dir, NPCInfo->lastPathAngles );

	//FIXME: still getting ping-ponging in certain cases... !!!  Nav/avoidance error?  WTF???!!!
	//If in combat move, then move directly towards our goal
	if ( NPC_CheckCombatMove() )
	{//keep current facing
		G_UcmdMoveForDir( NPC, &ucmd, dir );
	}
	else
	{//face our goal
		//FIXME: strafe instead of turn if change in dir is small and temporary
		NPCInfo->desiredPitch	= 0.0f;
		NPCInfo->desiredYaw		= AngleNormalize360( NPCInfo->lastPathAngles[YAW] );
		
		//Pitch towards the goal and also update if flying or swimming
		if ( NPCInfo->stats.moveType == MT_FLYSWIM )
		{
			NPCInfo->desiredPitch = AngleNormalize360( NPCInfo->lastPathAngles[PITCH] );
			
			if ( dir[2] )
			{
				float scale = (dir[2] * distance);
				if ( scale > 64 )
				{
					scale = 64;
				}
				else if ( scale < -64 )
				{
					scale = -64;
				}
				NPC->client->ps.velocity[2] = scale;
				//NPC->client->ps.velocity[2] = (dir[2] > 0) ? 64 : -64;
			}
		}

		//Set any final info
		ucmd.forwardmove = 127;
	}

#if	AI_TIMERS
	navTime += GetTime( startTime );
#endif//	AI_TIMERS
	return qtrue;
}

/*
-------------------------
void NPC_SlideMoveToGoal( void )

  Now assumes goal is goalEntity, if want to use tempGoal, you set that before calling the func
-------------------------
*/
qboolean NPC_SlideMoveToGoal( void )
{
	float	saveYaw = NPC->client->ps.viewangles[YAW];

	NPCInfo->combatMove = qtrue;
	
	qboolean ret = NPC_MoveToGoal( qtrue );

	NPCInfo->desiredYaw	= saveYaw;

	return ret;
}


/*
-------------------------
NPC_ApplyRoff
-------------------------
*/

void NPC_ApplyRoff(void)
{
	PlayerStateToEntityState( &NPC->client->ps, &NPC->s );
	VectorCopy ( NPC->currentOrigin, NPC->lastOrigin );

	// use the precise origin for linking
	gi.linkentity(NPC);
}