//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: Base class for many flying NPCs
//
// $NoKeywords: $
//=============================================================================//

#include "cbase.h"
#include "ai_basenpc_flyer.h"
#include "ai_route.h"
#include "ai_navigator.h"
#include "ai_motor.h"

// memdbgon must be the last include file in a .cpp file!!!
#include "tier0/memdbgon.h"

BEGIN_DATADESC( CAI_BaseFlyingBot )

	DEFINE_FIELD( m_vCurrentVelocity,			FIELD_VECTOR),
	DEFINE_FIELD( m_vCurrentAngularVelocity, FIELD_VECTOR ),
	DEFINE_FIELD( m_vCurrentBanking,			FIELD_VECTOR),
	DEFINE_FIELD( m_vNoiseMod,				FIELD_VECTOR),
	DEFINE_FIELD( m_fHeadYaw,					FIELD_FLOAT),
	DEFINE_FIELD( m_vLastPatrolDir,			FIELD_VECTOR),

END_DATADESC()


//------------------------------------------------------------------------------
// Purpose : Override to return correct velocity
// Input   :
// Output  :
//------------------------------------------------------------------------------
void CAI_BaseFlyingBot::GetVelocity(Vector *vVelocity, AngularImpulse *vAngVelocity)
{
	if (vVelocity != NULL)
	{
		VectorCopy(m_vCurrentVelocity,*vVelocity);
	}
	if (vAngVelocity != NULL)
	{
		QAngle tmp = GetLocalAngularVelocity();
		QAngleToAngularImpulse( tmp, *vAngVelocity );
	}
}

//-----------------------------------------------------------------------------
// Purpose: Turn head yaw into facing direction
// Input  :
// Output :
//-----------------------------------------------------------------------------
QAngle CAI_BaseFlyingBot::BodyAngles()
{
	return QAngle(0,m_fHeadYaw,0);
}

//-----------------------------------------------------------------------------
// Purpose:
// Input  :
// Output :
//-----------------------------------------------------------------------------
void CAI_BaseFlyingBot::TurnHeadToTarget(float flInterval, const Vector &MoveTarget )
{
	float flDestYaw = VecToYaw( MoveTarget - GetLocalOrigin() );
	
	float newYaw = AI_ClampYaw( GetHeadTurnRate() * 10.0f, m_fHeadYaw, flDestYaw, gpGlobals->curtime - GetLastThink() );
		
	if ( newYaw != m_fHeadYaw )
	{
		m_fHeadYaw = newYaw;
	}

	// Set us to face that way
	SetBoneController( 0, m_fHeadYaw );
}

//------------------------------------------------------------------------------
// Purpose :
// Input   :
// Output  :
//------------------------------------------------------------------------------
float CAI_BaseFlyingBot::MinGroundDist(void)
{
	return 0;
}

//------------------------------------------------------------------------------
// Purpose :
// Input   :
// Output  :
//------------------------------------------------------------------------------
Vector CAI_BaseFlyingBot::VelocityToAvoidObstacles(float flInterval)
{
	// --------------------------------
	//  Avoid banging into stuff
	// --------------------------------
	trace_t tr;
	Vector vTravelDir = m_vCurrentVelocity*flInterval;
	Vector endPos = GetAbsOrigin() + vTravelDir;
	AI_TraceEntity( this, GetAbsOrigin(), endPos, MASK_NPCSOLID|CONTENTS_WATER, &tr );
	if (tr.fraction != 1.0)
	{	
		// Bounce off in normal 
		Vector vBounce = tr.plane.normal * 0.5 * m_vCurrentVelocity.Length();
		return (vBounce);
	}
	
	// --------------------------------
	// Try to remain above the ground.
	// --------------------------------
	float flMinGroundDist = MinGroundDist();
	AI_TraceLine(GetAbsOrigin(), GetAbsOrigin() + Vector(0, 0, -flMinGroundDist), 
		MASK_NPCSOLID_BRUSHONLY|CONTENTS_WATER, this, COLLISION_GROUP_NONE, &tr);
	if (tr.fraction < 1)
	{
		// Clamp veloctiy
		if (tr.fraction < 0.1)
		{
			tr.fraction = 0.1;
		}

		return Vector(0, 0, 50/tr.fraction);
	}
	return vec3_origin;
}

//------------------------------------------------------------------------------
// Purpose :
// Input   :
// Output  :
//------------------------------------------------------------------------------
void CAI_BaseFlyingBot::StartTask( const Task_t *pTask )
{
	switch (pTask->iTask)
	{	
		// Skip as done via bone controller
		case TASK_FACE_ENEMY:
		{
			TaskComplete();
			break;
		}
		// Activity is just idle (have no run)
		case TASK_RUN_PATH:
		{
			GetNavigator()->SetMovementActivity(ACT_IDLE);
			TaskComplete();
			break;
		}
		// Don't check for run/walk activity
		case TASK_SCRIPT_RUN_TO_TARGET:
		case TASK_SCRIPT_WALK_TO_TARGET:
		{
			if (GetTarget() == NULL)
			{
				TaskFail(FAIL_NO_TARGET);
			}
			else 
			{
				if (!GetNavigator()->SetGoal( GOALTYPE_TARGETENT ) )
				{
					TaskFail(FAIL_NO_ROUTE);
					GetNavigator()->ClearGoal();
				}
			}
			TaskComplete();
			break;
		}
		// Override to get more to get a directional path
		case TASK_GET_PATH_TO_RANDOM_NODE:  
		{
			if ( GetNavigator()->SetRandomGoal( pTask->flTaskData, m_vLastPatrolDir ) )
				TaskComplete();
			else
				TaskFail(FAIL_NO_REACHABLE_NODE);
			break;
		}
		default:
		{
			BaseClass::StartTask(pTask);
		}
	}
}

//------------------------------------------------------------------------------

void CAI_BaseFlyingBot::MoveToTarget(float flInterval, const Vector &MoveTarget)
{
	Assert(0);	// This must be overridden in the leaf classes
}

//------------------------------------------------------------------------------

AI_NavPathProgress_t CAI_BaseFlyingBot::ProgressFlyPath( 
	float flInterval,
	const CBaseEntity *pNewTarget, 
	unsigned collisionMask, 
	bool bNewTrySimplify, 
	float strictPointTolerance)
{
  	AI_ProgressFlyPathParams_t params( collisionMask, strictPointTolerance );

	params.SetCurrent( pNewTarget, bNewTrySimplify );

	AI_NavPathProgress_t progress = GetNavigator()->ProgressFlyPath( params );
	
	switch ( progress )
	{
		case AINPP_NO_CHANGE:
		case AINPP_ADVANCED:
		{
			MoveToTarget(flInterval, GetNavigator()->GetCurWaypointPos());
			break;
		}
		
		case AINPP_COMPLETE:
		{
			TaskMovementComplete();
			break;
		}
		
		case AINPP_BLOCKED: // function is not supposed to test blocking, just simple path progression
		default:
		{
			AssertMsg( 0, ( "Unexpected result" ) );
			break;
		}
	}

	return progress;
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pTarget - 
//			&chasePosition - 
//-----------------------------------------------------------------------------
void CAI_BaseFlyingBot::TranslateNavGoal( CBaseEntity *pTarget, Vector &chasePosition )
{
	Assert( pTarget != NULL );

	if ( pTarget == NULL )
	{
		chasePosition = vec3_origin;
		return;
	}

	// Chase their eyes
	chasePosition = pTarget->GetAbsOrigin() + pTarget->GetViewOffset();
}

//------------------------------------------------------------------------------
// Purpose :
// Input   :
// Output  :
//------------------------------------------------------------------------------
CAI_BaseFlyingBot::CAI_BaseFlyingBot()
{
#ifdef _DEBUG
	m_vCurrentVelocity.Init();
	m_vCurrentBanking.Init();
	m_vLastPatrolDir.Init();
#endif
}