//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
//=============================================================================//

#ifndef AI_GRENADE_H
#define AI_GRENADE_H
#ifdef _WIN32
#pragma once
#endif

// I wish I didn't have to #include all this, but I don't really have a choice.
// I guess something similar to CAI_BehaviorHost's backbridges could be tried.
#include "cbase.h"
#include "ai_basenpc.h"
#include "npcevent.h"
#include "grenade_frag.h"
#include "basegrenade_shared.h"
#include "ai_squad.h"
#include "GlobalStrings.h"

#define COMBINE_AE_GREN_TOSS		( 7 )

#define COMBINE_GRENADE_THROW_SPEED 650
#define COMBINE_GRENADE_TIMER		3.5
#define COMBINE_GRENADE_FLUSH_TIME	3.0		// Don't try to flush an enemy who has been out of sight for longer than this.
#define COMBINE_GRENADE_FLUSH_DIST	256.0	// Don't try to flush an enemy who has moved farther than this distance from the last place I saw him.

#define	COMBINE_MIN_GRENADE_CLEAR_DIST	250

#define	DEFINE_AIGRENADE_DATADESC() \
	DEFINE_KEYFIELD( m_iNumGrenades, FIELD_INTEGER, "NumGrenades" ),	\
	DEFINE_FIELD( m_flNextGrenadeCheck, FIELD_TIME ),	\
	DEFINE_FIELD( m_hForcedGrenadeTarget, FIELD_EHANDLE ),	\
	DEFINE_FIELD( m_flNextAltFireTime, FIELD_TIME ),	\
	DEFINE_FIELD( m_vecAltFireTarget, FIELD_VECTOR ),	\
	DEFINE_FIELD( m_vecTossVelocity, FIELD_VECTOR ),	\
	DEFINE_INPUTFUNC( FIELD_STRING,	"ThrowGrenadeAtTarget",	InputThrowGrenadeAtTarget ),	\
	DEFINE_INPUTFUNC( FIELD_INTEGER,	"SetGrenades",	InputSetGrenades ),	\
	DEFINE_INPUTFUNC( FIELD_INTEGER,	"AddGrenades",	InputAddGrenades ),	\
	DEFINE_OUTPUT(m_OnThrowGrenade, "OnThrowGrenade"),	\
	DEFINE_OUTPUT(m_OnOutOfGrenades, "OnOutOfGrenades"),  \

// Use extern float GetCurrentGravity( void );
#define SMGGrenadeArc(shootpos, targetpos) \
	Vector vecShootPos = shootpos; \
	Vector vecThrow = (targetpos - vecShootPos); \
	float time = vecThrow.Length() / 600.0; \
	vecThrow = vecThrow * (1.0 / time); \
	vecThrow.z += (GetCurrentGravity() * 0.5) * time * 0.5; \
	Vector vecFace = vecShootPos + (vecThrow * 0.5); \
	AddFacingTarget(vecFace, 1.0, 0.5); \

// Mask used for Combine ball hull traces.
// This used MASK_SHOT before, but this has been changed to MASK_SHOT_HULL.
// This fixes the existing problem of soldiers trying to fire energy balls through grates,
// but it's also important to prevent soldiers from blowing themselves up with their newfound SMG grenades.
#define MASK_COMBINE_BALL_LOS MASK_SHOT_HULL

extern int COMBINE_AE_BEGIN_ALTFIRE;
extern int COMBINE_AE_ALTFIRE;

//-----------------------------------------------------------------------------
// Other classes can use this and access some CAI_GrenadeUser functions.
//-----------------------------------------------------------------------------
class CAI_GrenadeUserSink
{
public:
	CAI_GrenadeUserSink() { }

	virtual bool			UsingOnThrowGrenade() { return false; }
};

//-----------------------------------------------------------------------------
//
// Template class for NPCs using grenades or weapon alt-fire stuff.
// You'll still have to use DEFINE_AIGRENADE_DATADESC() in your derived class's datadesc.
// 
// I wanted to have these functions defined in a CPP file, but template class definitions must be in the header.
// Please excuse the bloat below the class definition.
//
//-----------------------------------------------------------------------------
template <class BASE_NPC>
class CAI_GrenadeUser : public BASE_NPC, public CAI_GrenadeUserSink
{
	DECLARE_CLASS_NOFRIEND( CAI_GrenadeUser, BASE_NPC );
public:
	CAI_GrenadeUser() : CAI_GrenadeUserSink() { }

	void AddGrenades( int inc, CBaseEntity *pLastGrenade = NULL )
	{
		m_iNumGrenades += inc;
		if (m_iNumGrenades <= 0)
			m_OnOutOfGrenades.Set( pLastGrenade, pLastGrenade, this );
	}

	virtual bool	IsAltFireCapable() { return false; }
	virtual bool	IsGrenadeCapable() { return true; }
	inline bool		HasGrenades() { return m_iNumGrenades > 0; }

	void InputSetGrenades( inputdata_t &inputdata ) { AddGrenades( inputdata.value.Int() - m_iNumGrenades ); }
	void InputAddGrenades( inputdata_t &inputdata ) { AddGrenades( inputdata.value.Int() ); }
	void InputThrowGrenadeAtTarget( inputdata_t &inputdata );

	virtual void DelayGrenadeCheck( float delay ) { m_flNextGrenadeCheck = gpGlobals->curtime + delay; }

	void 			HandleAnimEvent( animevent_t *pEvent );

	// Soldiers use "lefthand", cops use "LHand", and citizens use "anim_attachment_LH"
	virtual const char*		GetGrenadeAttachment() { return "anim_attachment_LH"; }

	void			ClearAttackConditions( void );

	Vector			GetAltFireTarget() { return m_vecAltFireTarget; }
	virtual bool	CanAltFireEnemy( bool bUseFreeKnowledge );
	void			DelayAltFireAttack( float flDelay );
	void			DelaySquadAltFireAttack( float flDelay );

	virtual bool	CanGrenadeEnemy( bool bUseFreeKnowledge = true );
	bool			CanThrowGrenade( const Vector &vecTarget );
	bool			CheckCanThrowGrenade( const Vector &vecTarget );

	// For OnThrowGrenade + point_entity_replace, see grenade_frag.cpp
	bool			UsingOnThrowGrenade() { return m_OnThrowGrenade.NumberOfElements() > 0; }

protected:

	void			StartTask_FaceAltFireTarget( const Task_t *pTask );
	void			StartTask_GetPathToForced( const Task_t *pTask );
	void			StartTask_DeferSquad( const Task_t *pTask );

	void			RunTask_FaceAltFireTarget( const Task_t *pTask );
	void			RunTask_GetPathToForced( const Task_t *pTask );
	void			RunTask_FaceTossDir( const Task_t *pTask );

protected: // We can't have any private saved variables because only derived classes use the datadescs

	int m_iNumGrenades;
	float m_flNextGrenadeCheck;
	EHANDLE m_hForcedGrenadeTarget;

	float			m_flNextAltFireTime;
	Vector			m_vecAltFireTarget;
	Vector			m_vecTossVelocity;

	COutputEHANDLE	m_OnThrowGrenade;
	COutputEHANDLE	m_OnOutOfGrenades;
};

//------------------------------------------------------------------------------
// Purpose: Handle animation events
//------------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::HandleAnimEvent( animevent_t *pEvent )
{
	if ( pEvent->event == COMBINE_AE_BEGIN_ALTFIRE )
	{
		EmitSound( "Weapon_CombineGuard.Special1" );
		//SpeakIfAllowed( TLK_CMB_THROWGRENADE, "altfire:1" );
		return;
	}
	if ( pEvent->event == COMBINE_AE_ALTFIRE )
	{
		animevent_t fakeEvent;

		fakeEvent.pSource = this;
		fakeEvent.event = EVENT_WEAPON_AR2_ALTFIRE;
		GetActiveWeapon()->Operator_HandleAnimEvent( &fakeEvent, this );

		// Stop other squad members from combine balling for a while.
		DelaySquadAltFireAttack( 10.0f );

		AddGrenades(-1);

		return;
	}

	if ( pEvent->event == COMBINE_AE_GREN_TOSS )
	{
		Vector vecSpin;
		vecSpin.x = random->RandomFloat( -1000.0, 1000.0 );
		vecSpin.y = random->RandomFloat( -1000.0, 1000.0 );
		vecSpin.z = random->RandomFloat( -1000.0, 1000.0 );

		Vector vecStart;
		GetAttachment( GetGrenadeAttachment(), vecStart );

		if( m_NPCState == NPC_STATE_SCRIPT )
		{
			// Use a fixed velocity for grenades thrown in scripted state.
			// Grenades thrown from a script do not count against grenades remaining for the AI to use.
			Vector forward, up, vecThrow;

			GetVectors( &forward, NULL, &up );
			vecThrow = forward * 750 + up * 175;

			// This code is used by player allies now, so it's only "combine spawned" if the thrower isn't allied with the player.
			CBaseEntity *pGrenade = Fraggrenade_Create( vecStart, vec3_angle, vecThrow, vecSpin, this, COMBINE_GRENADE_TIMER, !IsPlayerAlly() );
			m_OnThrowGrenade.Set(pGrenade, pGrenade, this);
		}
		else
		{
			// Use the Velocity that AI gave us.
			CBaseEntity *pGrenade = Fraggrenade_Create( vecStart, vec3_angle, m_vecTossVelocity, vecSpin, this, COMBINE_GRENADE_TIMER, !IsPlayerAlly() );
			m_OnThrowGrenade.Set(pGrenade, pGrenade, this);
			AddGrenades(-1, pGrenade);
		}

		// wait six seconds before even looking again to see if a grenade can be thrown.
		m_flNextGrenadeCheck = gpGlobals->curtime + 6;
		return;
	}

	BaseClass::HandleAnimEvent( pEvent );
}

//-----------------------------------------------------------------------------
// Purpose: Force the combine soldier to throw a grenade at the target
//			If I'm a combine elite, fire my combine ball at the target instead.
// Input  : &inputdata - 
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::InputThrowGrenadeAtTarget( inputdata_t &inputdata )
{
	// Ignore if we're inside a scripted sequence
	if ( m_NPCState == NPC_STATE_SCRIPT && m_hCine )
		return;

	CBaseEntity *pEntity = gEntList.FindEntityByName( NULL, inputdata.value.String(), this, inputdata.pActivator, inputdata.pCaller );
	if ( !pEntity )
	{
		DevMsg("%s (%s) received ThrowGrenadeAtTarget input, but couldn't find target entity '%s'\n", GetClassname(), GetDebugName(), inputdata.value.String() );
		return;
	}

	m_hForcedGrenadeTarget = pEntity;
	m_flNextGrenadeCheck = 0;

	ClearSchedule( "Told to throw grenade via input" );
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
template <class BASE_NPC>
bool CAI_GrenadeUser<BASE_NPC>::CanAltFireEnemy( bool bUseFreeKnowledge )
{
	if (!HasGrenades())
		return false;

	if (!IsAltFireCapable())
		return false;

	if (!GetActiveWeapon())
		return false;

	if (IsCrouching())
		return false;

	if ( gpGlobals->curtime < m_flNextAltFireTime || gpGlobals->curtime < m_flNextGrenadeCheck )
		return false;

	if( !GetEnemy() )
		return false;

	if (!EntIsClass(GetActiveWeapon(), gm_isz_class_AR2) && !EntIsClass(GetActiveWeapon(), gm_isz_class_SMG1))
		return false;

	CBaseEntity *pEnemy = GetEnemy();

	Vector vecTarget;

	// Determine what point we're shooting at
	if( bUseFreeKnowledge )
	{
		vecTarget = GetEnemies()->LastKnownPosition( pEnemy ) + (pEnemy->GetViewOffset()*0.75);// approximates the chest
	}
	else
	{
		vecTarget = GetEnemies()->LastSeenPosition( pEnemy ) + (pEnemy->GetViewOffset()*0.75);// approximates the chest
	}

	// Trace a hull about the size of the combine ball (don't shoot through grates!)
	trace_t tr;

	Vector mins( -12, -12, -12 );
	Vector maxs( 12, 12, 12 );

	Vector vShootPosition = EyePosition();

	if ( GetActiveWeapon() )
	{
		GetActiveWeapon()->GetAttachment( "muzzle", vShootPosition );
	}

	// Trace a hull about the size of the combine ball.
	UTIL_TraceHull( vShootPosition, vecTarget, mins, maxs, MASK_COMBINE_BALL_LOS, this, COLLISION_GROUP_NONE, &tr );

	float flLength = (vShootPosition - vecTarget).Length();

	flLength *= tr.fraction;

	// If the ball can travel at least 65% of the distance to the player then let the NPC shoot it.
	// (unless it hit the world)
	if( tr.fraction >= 0.65 && (!tr.m_pEnt || !tr.m_pEnt->IsWorld()) && flLength > 128.0f )
	{
		// Target is valid
		m_vecAltFireTarget = vecTarget;
		return true;
	}


	// Check again later
	m_vecAltFireTarget = vec3_origin;
	m_flNextGrenadeCheck = gpGlobals->curtime + 1.0f;
	return false;
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::DelayAltFireAttack( float flDelay )
{
	float flNextAltFire = gpGlobals->curtime + flDelay;

	if( flNextAltFire > m_flNextAltFireTime )
	{
		// Don't let this delay order preempt a previous request to wait longer.
		m_flNextAltFireTime = flNextAltFire;
	}
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::DelaySquadAltFireAttack( float flDelay )
{
	// Make sure to delay my own alt-fire attack.
	DelayAltFireAttack( flDelay );

	AISquadIter_t iter;
	CAI_BaseNPC *pSquadmate = m_pSquad ? m_pSquad->GetFirstMember( &iter ) : NULL;
	while ( pSquadmate )
	{
		CAI_GrenadeUser *pUser = dynamic_cast<CAI_GrenadeUser*>(pSquadmate);
		if( pUser && pUser->IsAltFireCapable() )
		{
			pUser->DelayAltFireAttack( flDelay );
		}

		pSquadmate = m_pSquad->GetNextMember( &iter );
	}
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
template <class BASE_NPC>
bool CAI_GrenadeUser<BASE_NPC>::CanGrenadeEnemy( bool bUseFreeKnowledge )
{
	CBaseEntity *pEnemy = GetEnemy();

	Assert( pEnemy != NULL );

	if( pEnemy )
	{
		// I'm not allowed to throw grenades during dustoff
		if ( IsCurSchedule(SCHED_DROPSHIP_DUSTOFF) )
			return false;

		if( bUseFreeKnowledge )
		{
			// throw to where we think they are.
			return CanThrowGrenade( GetEnemies()->LastKnownPosition( pEnemy ) );
		}
		else
		{
			// hafta throw to where we last saw them.
			return CanThrowGrenade( GetEnemies()->LastSeenPosition( pEnemy ) );
		}
	}

	return false;
}

//-----------------------------------------------------------------------------
// Purpose: Return true if the combine has grenades, hasn't checked lately, and
//			can throw a grenade at the target point.
// Input  : &vecTarget - 
// Output : Returns true on success, false on failure.
//-----------------------------------------------------------------------------
template <class BASE_NPC>
bool CAI_GrenadeUser<BASE_NPC>::CanThrowGrenade( const Vector &vecTarget )
{
	if( m_iNumGrenades < 1 )
	{
		// Out of grenades!
		return false;
	}

	if (!IsGrenadeCapable())
	{
		// Must be capable of throwing grenades
		return false;
	}

	if ( gpGlobals->curtime < m_flNextGrenadeCheck )
	{
		// Not allowed to throw another grenade right now.
		return false;
	}

	float flDist;
	flDist = ( vecTarget - GetAbsOrigin() ).Length();

	if( flDist > 1024 || flDist < 128 )
	{
		// Too close or too far!
		m_flNextGrenadeCheck = gpGlobals->curtime + 1; // one full second.
		return false;
	}

	// -----------------------
	// If moving, don't check.
	// -----------------------
	if ( m_flGroundSpeed != 0 )
		return false;

	// ---------------------------------------------------------------------
	// Are any of my squad members near the intended grenade impact area?
	// ---------------------------------------------------------------------
	if ( m_pSquad )
	{
		if (m_pSquad->SquadMemberInRange( vecTarget, COMBINE_MIN_GRENADE_CLEAR_DIST ))
		{
			// crap, I might blow my own guy up. Don't throw a grenade and don't check again for a while.
			m_flNextGrenadeCheck = gpGlobals->curtime + 1; // one full second.

			// Tell my squad members to clear out so I can get a grenade in
			// Mapbase uses a new context here that gets all nondescript allies away since this code is shared between Combine and non-Combine now.
			CSoundEnt::InsertSound( SOUND_MOVE_AWAY | SOUND_CONTEXT_OWNER_ALLIES, vecTarget, COMBINE_MIN_GRENADE_CLEAR_DIST, 0.1, this );
			return false;
		}
	}

	return CheckCanThrowGrenade( vecTarget );
}

//-----------------------------------------------------------------------------
// Purpose: Returns true if the combine can throw a grenade at the specified target point
// Input  : &vecTarget - 
// Output : Returns true on success, false on failure.
//-----------------------------------------------------------------------------
template <class BASE_NPC>
bool CAI_GrenadeUser<BASE_NPC>::CheckCanThrowGrenade( const Vector &vecTarget )
{
	//NDebugOverlay::Line( EyePosition(), vecTarget, 0, 255, 0, false, 5 );

	// ---------------------------------------------------------------------
	// Check that throw is legal and clear
	// ---------------------------------------------------------------------
	// FIXME: this is only valid for hand grenades, not RPG's
	Vector vecToss;
	Vector vecMins = -Vector(4,4,4);
	Vector vecMaxs = Vector(4,4,4);
	if( FInViewCone( vecTarget ) && CBaseEntity::FVisible( vecTarget ) )
	{
		vecToss = VecCheckThrow( this, EyePosition(), vecTarget, COMBINE_GRENADE_THROW_SPEED, 1.0, &vecMins, &vecMaxs );
	}
	else
	{
		// Have to try a high toss. Do I have enough room?
		trace_t tr;
		AI_TraceLine( EyePosition(), EyePosition() + Vector( 0, 0, 64 ), MASK_SHOT, this, COLLISION_GROUP_NONE, &tr );
		if( tr.fraction != 1.0 )
		{
			return false;
		}

		vecToss = VecCheckToss( this, EyePosition(), vecTarget, -1, 1.0, true, &vecMins, &vecMaxs );
	}

	if ( vecToss != vec3_origin )
	{
		m_vecTossVelocity = vecToss;

		// don't check again for a while.
		m_flNextGrenadeCheck = gpGlobals->curtime + 1; // 1/3 second.
		return true;
	}
	else
	{
		// don't check again for a while.
		m_flNextGrenadeCheck = gpGlobals->curtime + 1; // one full second.
		return false;
	}
}

//-----------------------------------------------------------------------------
// Purpose: This was copied from soldier code for general AI grenades.
//			
//			"Soldiers use CAN_RANGE_ATTACK2 to indicate whether they can throw
//			a grenade. Because they check only every half-second or so, this
//			condition must persist until it is updated again by the code
//			that determines whether a grenade can be thrown, so prevent the 
//			base class from clearing it out. (sjb)"
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::ClearAttackConditions()
{
	bool fCanRangeAttack2 = IsGrenadeCapable() && HasCondition( COND_CAN_RANGE_ATTACK2 );

	// Call the base class.
	BaseClass::ClearAttackConditions();

	if( fCanRangeAttack2 )
	{
		// We don't allow the base class to clear this condition because we
		// don't sense for it every frame.
		SetCondition( COND_CAN_RANGE_ATTACK2 );
	}
}

//-----------------------------------------------------------------------------
// Purpose: Task helpers
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::StartTask_FaceAltFireTarget( const Task_t *pTask )
{
	SetIdealActivity( (Activity)(int)pTask->flTaskData );
	GetMotor()->SetIdealYawToTargetAndUpdate( m_vecAltFireTarget, AI_KEEP_YAW_SPEED );
}

template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::StartTask_GetPathToForced( const Task_t *pTask )
{
	if ( !m_hForcedGrenadeTarget )
	{
		TaskFail(FAIL_NO_ENEMY);
		return;
	}

	float flMaxRange = 2000;
	float flMinRange = 0;

	Vector vecEnemy = m_hForcedGrenadeTarget->GetAbsOrigin();
	Vector vecEnemyEye = vecEnemy + m_hForcedGrenadeTarget->GetViewOffset();

	Vector posLos;
	bool found = false;

	if ( GetTacticalServices()->FindLateralLos( vecEnemyEye, &posLos ) )
	{
		float dist = ( posLos - vecEnemyEye ).Length();
		if ( dist < flMaxRange && dist > flMinRange )
			found = true;
	}

	if ( !found && GetTacticalServices()->FindLos( vecEnemy, vecEnemyEye, flMinRange, flMaxRange, 1.0, &posLos ) )
	{
		found = true;
	}

	if ( !found )
	{
		TaskFail( FAIL_NO_SHOOT );
	}
	else
	{
		// else drop into run task to offer an interrupt
		m_vInterruptSavePosition = posLos;
	}
}

template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::StartTask_DeferSquad( const Task_t *pTask )
{
	if ( m_pSquad )
	{
		// iterate my squad and stop everyone from throwing grenades for a little while.
		AISquadIter_t iter;

		CAI_BaseNPC *pSquadmate = m_pSquad ? m_pSquad->GetFirstMember( &iter ) : NULL;
		while ( pSquadmate )
		{
			pSquadmate->DelayGrenadeCheck(5);

			pSquadmate = m_pSquad->GetNextMember( &iter );
		}
	}

	TaskComplete();
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::RunTask_FaceAltFireTarget( const Task_t *pTask )
{
	GetMotor()->SetIdealYawToTargetAndUpdate( m_vecAltFireTarget, AI_KEEP_YAW_SPEED );

	// New Mapbase thing that fixes forced alt-fires not changing weapon yaw/pitch
	SetAim( m_vecAltFireTarget - Weapon_ShootPosition() );

	if (IsActivityFinished())
	{
		TaskComplete();
	}
}

template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::RunTask_GetPathToForced( const Task_t *pTask )
{
	if ( !m_hForcedGrenadeTarget )
	{
		TaskFail(FAIL_NO_ENEMY);
		return;
	}

	if ( GetTaskInterrupt() > 0 )
	{
		ClearTaskInterrupt();

		Vector vecEnemy = m_hForcedGrenadeTarget->GetAbsOrigin();
		AI_NavGoal_t goal( m_vInterruptSavePosition, ACT_RUN, AIN_HULL_TOLERANCE );

		GetNavigator()->SetGoal( goal, AIN_CLEAR_TARGET );
		GetNavigator()->SetArrivalDirection( vecEnemy - goal.dest );
	}
	else
	{
		TaskInterrupt();
	}
}

template <class BASE_NPC>
void CAI_GrenadeUser<BASE_NPC>::RunTask_FaceTossDir( const Task_t *pTask )
{
	// project a point along the toss vector and turn to face that point.
	GetMotor()->SetIdealYawToTargetAndUpdate( GetLocalOrigin() + m_vecTossVelocity * 64, AI_KEEP_YAW_SPEED );

	if ( FacingIdeal() )
	{
		TaskComplete( true );
	}
}

#endif