/***
*
*	Copyright (c) 1996-2002, Valve LLC. All rights reserved.
*	
*	This product contains software technology licensed from Id 
*	Software, Inc. ("Id Technology").  Id Technology (c) 1996 Id Software, Inc. 
*	All Rights Reserved.
*
*   This source code contains proprietary and confidential information of
*   Valve LLC and its suppliers.  Access to this code is restricted to
*   persons who have executed a written SDK license with Valve.  Any access,
*   use or distribution of this code by or to any unlicensed person is illegal.
*
****/
//=========================================================
// leech - basic little swimming monster
//=========================================================
//
// UNDONE:
// DONE:Steering force model for attack
// DONE:Attack animation control / damage
// DONE:Establish range of up/down motion and steer around vertical obstacles
// DONE:Re-evaluate height periodically
// DONE:Fall (MOVETYPE_TOSS) and play different anim if out of water
// Test in complex room (c2a3?)
// DONE:Sounds? - Kelly will fix
// Blood cloud? Hurt effect?
// Group behavior?
// DONE:Save/restore
// Flop animation - just bind to ACT_TWITCH
// Fix fatal push into wall case
//
// Try this on a bird
// Try this on a model with hulls/tracehull?
//

#include	"float.h"
#include	"extdll.h"
#include	"util.h"
#include	"cbase.h"
#include	"monsters.h"

// Animation events
#define LEECH_AE_ATTACK		1
#define LEECH_AE_FLOP		2

// Movement constants

#define		LEECH_ACCELERATE		10
#define		LEECH_CHECK_DIST		45
#define		LEECH_SWIM_SPEED		50
#define		LEECH_SWIM_ACCEL		80
#define		LEECH_SWIM_DECEL		10
#define		LEECH_TURN_RATE			90
#define		LEECH_SIZEX				10
#define		LEECH_FRAMETIME			0.1

#define DEBUG_BEAMS		0

#if DEBUG_BEAMS
#include "effects.h"
#endif

class CLeech : public CBaseMonster
{
public:
	void Spawn( void );
	void Precache( void );

	void EXPORT SwimThink( void );
	void EXPORT DeadThink( void );
	void Touch( CBaseEntity *pOther )
	{
		if ( pOther->IsPlayer() )
		{
			// If the client is pushing me, give me some base velocity
			if ( gpGlobals->trace_ent && gpGlobals->trace_ent == edict() )
			{
				pev->basevelocity = pOther->pev->velocity;
				pev->flags |= FL_BASEVELOCITY;
			}
		}
	}

	void SetObjectCollisionBox( void )
	{
		pev->absmin = pev->origin + Vector(-8,-8,0);
		pev->absmax = pev->origin + Vector(8,8,2);
	}

	void AttackSound( void );
	void AlertSound( void );
	void UpdateMotion( void );
	float ObstacleDistance( CBaseEntity *pTarget );
	void MakeVectors( void );
	void RecalculateWaterlevel( void );
	void SwitchLeechState( void );
	
	// Base entity functions
	void HandleAnimEvent( MonsterEvent_t *pEvent );
	int	BloodColor( void ) { return DONT_BLEED; }
	void Killed( entvars_t *pevAttacker, int iGib );
	void Activate( void );
	int TakeDamage( entvars_t *pevInflictor, entvars_t *pevAttacker, float flDamage, int bitsDamageType );
	int	Classify( void ) { return CLASS_INSECT; }
	int IRelationship( CBaseEntity *pTarget );

	virtual int		Save( CSave &save );
	virtual int		Restore( CRestore &restore );
	static	TYPEDESCRIPTION m_SaveData[];

	static const char *pAttackSounds[];
	static const char *pAlertSounds[];

private:
	// UNDONE: Remove unused boid vars, do group behavior
	float	m_flTurning;// is this boid turning?
	BOOL	m_fPathBlocked;// TRUE if there is an obstacle ahead
	float	m_flAccelerate;
	float	m_obstacle;
	float	m_top;
	float	m_bottom;
	float	m_height;
	float	m_waterTime;
	float	m_sideTime;		// Timer to randomly check clearance on sides
	float	m_zTime;
	float	m_stateTime;
	float	m_attackSoundTime;

#if DEBUG_BEAMS
	CBeam	*m_pb;
	CBeam	*m_pt;
#endif
};

LINK_ENTITY_TO_CLASS( monster_leech, CLeech )

TYPEDESCRIPTION	CLeech::m_SaveData[] =
{
	DEFINE_FIELD( CLeech, m_flTurning, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_fPathBlocked, FIELD_BOOLEAN ),
	DEFINE_FIELD( CLeech, m_flAccelerate, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_obstacle, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_top, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_bottom, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_height, FIELD_FLOAT ),
	DEFINE_FIELD( CLeech, m_waterTime, FIELD_TIME ),
	DEFINE_FIELD( CLeech, m_sideTime, FIELD_TIME ),
	DEFINE_FIELD( CLeech, m_zTime, FIELD_TIME ),
	DEFINE_FIELD( CLeech, m_stateTime, FIELD_TIME ),
	DEFINE_FIELD( CLeech, m_attackSoundTime, FIELD_TIME ),
};

IMPLEMENT_SAVERESTORE( CLeech, CBaseMonster )

const char *CLeech::pAttackSounds[] =
{
	"leech/leech_bite1.wav",
	"leech/leech_bite2.wav",
	"leech/leech_bite3.wav",
};

const char *CLeech::pAlertSounds[] =
{
	"leech/leech_alert1.wav",
	"leech/leech_alert2.wav",
};

void CLeech::Spawn( void )
{
	Precache();
	SET_MODEL(ENT(pev), "models/leech.mdl");
	// Just for fun
	//	SET_MODEL(ENT(pev), "models/icky.mdl");
	
	//UTIL_SetSize( pev, g_vecZero, g_vecZero );
	UTIL_SetSize( pev, Vector(-1,-1,0), Vector(1,1,2));
	// Don't push the minz down too much or the water check will fail because this entity is really point-sized
	pev->solid			= SOLID_SLIDEBOX;
	pev->movetype		= MOVETYPE_FLY;
	SetBits(pev->flags, FL_SWIM);
	pev->health			= gSkillData.leechHealth;

	m_flFieldOfView		= -0.5;	// 180 degree FOV
	m_flDistLook		= 750;
	MonsterInit();
	SetThink( &CLeech::SwimThink );
	SetUse( NULL );
	SetTouch( NULL );
	pev->view_ofs = g_vecZero;

	m_flTurning = 0;
	m_fPathBlocked = FALSE;
	SetActivity( ACT_SWIM );
	SetState( MONSTERSTATE_IDLE );
	m_stateTime = gpGlobals->time + RANDOM_FLOAT( 1, 5 );
}

void CLeech::Activate( void )
{
	RecalculateWaterlevel();
}

void CLeech::RecalculateWaterlevel( void )
{
	// Calculate boundaries
	Vector vecTest = pev->origin - Vector(0,0,400);

	TraceResult tr;

	UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);
	if ( tr.flFraction != 1.0 )
		m_bottom = tr.vecEndPos.z + 1;
	else
		m_bottom = vecTest.z;

	m_top = UTIL_WaterLevel( pev->origin, pev->origin.z, pev->origin.z + 400 ) - 1;

	// Chop off 20% of the outside range
	float newBottom = m_bottom * 0.8 + m_top * 0.2;
	m_top = m_bottom * 0.2 + m_top * 0.8;
	m_bottom = newBottom;
	m_height = RANDOM_FLOAT( m_bottom, m_top );
	m_waterTime = gpGlobals->time + RANDOM_FLOAT( 5, 7 );
}

void CLeech::SwitchLeechState( void )
{
	m_stateTime = gpGlobals->time + RANDOM_FLOAT( 3, 6 );
	if ( m_MonsterState == MONSTERSTATE_COMBAT )
	{
		m_hEnemy = NULL;
		SetState( MONSTERSTATE_IDLE );
		// We may be up against the player, so redo the side checks
		m_sideTime = 0;
	}
	else
	{
		Look( m_flDistLook );
		CBaseEntity *pEnemy = BestVisibleEnemy();
		if ( pEnemy && pEnemy->pev->waterlevel != 0 )
		{
			m_hEnemy = pEnemy;
			SetState( MONSTERSTATE_COMBAT );
			m_stateTime = gpGlobals->time + RANDOM_FLOAT( 18, 25 );
			AlertSound();
		}
	}
}

int CLeech::IRelationship( CBaseEntity *pTarget )
{
	if ( pTarget->IsPlayer() )
		return R_DL;
	return CBaseMonster::IRelationship( pTarget );
}

void CLeech::AttackSound( void )
{
	if ( gpGlobals->time > m_attackSoundTime )
	{
		EMIT_SOUND_DYN ( ENT(pev), CHAN_VOICE, pAttackSounds[ RANDOM_LONG(0,ARRAYSIZE(pAttackSounds)-1) ], 1.0, ATTN_NORM, 0, PITCH_NORM );
		m_attackSoundTime = gpGlobals->time + 0.5;
	}
}

void CLeech::AlertSound( void )
{
	EMIT_SOUND_DYN ( ENT(pev), CHAN_VOICE, pAlertSounds[ RANDOM_LONG(0,ARRAYSIZE(pAlertSounds)-1) ], 1.0, ATTN_NORM * 0.5, 0, PITCH_NORM );
}

void CLeech::Precache( void )
{
	int i;

	//PRECACHE_MODEL("models/icky.mdl");
	PRECACHE_MODEL("models/leech.mdl");

	for ( i = 0; i < ARRAYSIZE( pAttackSounds ); i++ )
		PRECACHE_SOUND((char *)pAttackSounds[i]);
	for ( i = 0; i < ARRAYSIZE( pAlertSounds ); i++ )
		PRECACHE_SOUND((char *)pAlertSounds[i]);
}

int CLeech::TakeDamage( entvars_t *pevInflictor, entvars_t *pevAttacker, float flDamage, int bitsDamageType )
{
	pev->velocity = g_vecZero;

	// Nudge the leech away from the damage
	if ( pevInflictor )
	{
		pev->velocity = (pev->origin - pevInflictor->origin).Normalize() * 25;
	}

	return CBaseMonster::TakeDamage( pevInflictor, pevAttacker, flDamage, bitsDamageType );
}

void CLeech::HandleAnimEvent( MonsterEvent_t *pEvent )
{
	switch( pEvent->event )
	{
	case LEECH_AE_ATTACK:
		AttackSound();
		CBaseEntity *pEnemy;

		pEnemy = m_hEnemy;
		if ( pEnemy != NULL )
		{
			Vector dir, face;

			UTIL_MakeVectorsPrivate( pev->angles, face, NULL, NULL );
			face.z = 0;
			dir = (pEnemy->pev->origin - pev->origin);
			dir.z = 0;
			dir = dir.Normalize();
			face = face.Normalize();

			if ( DotProduct(dir, face) > 0.9 )		// Only take damage if the leech is facing the prey
				pEnemy->TakeDamage( pev, pev, gSkillData.leechDmgBite, DMG_SLASH );
		}
		m_stateTime -= 2;
		break;
	case LEECH_AE_FLOP:
		// Play flop sound
		break;
	default:
		CBaseMonster::HandleAnimEvent( pEvent );
		break;
	}
}

void CLeech::MakeVectors( void )
{
	Vector tmp = pev->angles;
	tmp.x = -tmp.x;
	UTIL_MakeVectors ( tmp );
}

//
// ObstacleDistance - returns normalized distance to obstacle
//
float CLeech::ObstacleDistance( CBaseEntity *pTarget )
{
	TraceResult		tr;
	Vector			vecTest;

	// use VELOCITY, not angles, not all boids point the direction they are flying
	//Vector vecDir = UTIL_VecToAngles( pev->velocity );
	MakeVectors();

	// check for obstacle ahead
	vecTest = pev->origin + gpGlobals->v_forward * LEECH_CHECK_DIST;
	UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);

	if ( tr.fStartSolid )
	{
		pev->speed = -LEECH_SWIM_SPEED * 0.5;
//		ALERT( at_console, "Stuck from (%f %f %f) to (%f %f %f)\n", pev->oldorigin.x, pev->oldorigin.y, pev->oldorigin.z, pev->origin.x, pev->origin.y, pev->origin.z );
//		UTIL_SetOrigin( pev, pev->oldorigin );
	}

	if ( tr.flFraction != 1.0 )
	{
		if ( (pTarget == NULL || tr.pHit != pTarget->edict()) )
		{
			return tr.flFraction;
		}
		else
		{
			if ( fabs(m_height - pev->origin.z) > 10 )
				return tr.flFraction;
		}
	}

	if ( m_sideTime < gpGlobals->time )
	{
		// extra wide checks
		vecTest = pev->origin + gpGlobals->v_right * LEECH_SIZEX * 2 + gpGlobals->v_forward * LEECH_CHECK_DIST;
		UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);
		if (tr.flFraction != 1.0)
			return tr.flFraction;

		vecTest = pev->origin - gpGlobals->v_right * LEECH_SIZEX * 2 + gpGlobals->v_forward * LEECH_CHECK_DIST;
		UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);
		if (tr.flFraction != 1.0)
			return tr.flFraction;

		// Didn't hit either side, so stop testing for another 0.5 - 1 seconds
		m_sideTime = gpGlobals->time + RANDOM_FLOAT(0.5,1);
	}
	return 1.0;
}

void CLeech::DeadThink( void )
{
	if ( m_fSequenceFinished )
	{
		if ( m_Activity == ACT_DIEFORWARD )
		{
			SetThink( NULL );
			StopAnimation();
			return;
		}
		else if ( pev->flags & FL_ONGROUND )
		{
			pev->solid = SOLID_NOT;
			SetActivity(ACT_DIEFORWARD);
		}
	}
	StudioFrameAdvance();
	pev->nextthink = gpGlobals->time + 0.1;

	// Apply damage velocity, but keep out of the walls
	if ( pev->velocity.x != 0 || pev->velocity.y != 0 )
	{
		TraceResult tr;

		// Look 0.5 seconds ahead
		UTIL_TraceLine(pev->origin, pev->origin + pev->velocity * 0.5, missile, edict(), &tr);
		if (tr.flFraction != 1.0)
		{
			pev->velocity.x = 0;
			pev->velocity.y = 0;
		}
	}
}

void CLeech::UpdateMotion( void )
{
	float flapspeed = (pev->speed - m_flAccelerate) / LEECH_ACCELERATE;
	m_flAccelerate = m_flAccelerate * 0.8 + pev->speed * 0.2;

	if (flapspeed < 0) 
		flapspeed = -flapspeed;
	flapspeed += 1.0;
	if (flapspeed < 0.5) 
		flapspeed = 0.5;
	if (flapspeed > 1.9) 
		flapspeed = 1.9;

	pev->framerate = flapspeed;

	if ( !m_fPathBlocked )
		pev->avelocity.y = pev->ideal_yaw;
	else
		pev->avelocity.y = pev->ideal_yaw * m_obstacle;

	if ( pev->avelocity.y > 150 )
		m_IdealActivity = ACT_TURN_LEFT;
	else if ( pev->avelocity.y < -150 )
		m_IdealActivity = ACT_TURN_RIGHT;
	else
		m_IdealActivity = ACT_SWIM;

	// lean
	float targetPitch, delta;
	delta = m_height - pev->origin.z;

	if ( delta < -10 )
		targetPitch = -30;
	else if ( delta > 10 )
		targetPitch = 30;
	else
		targetPitch = 0;

	pev->angles.x = UTIL_Approach( targetPitch, pev->angles.x, 60 * LEECH_FRAMETIME );

	// bank
	pev->avelocity.z = - (pev->angles.z + (pev->avelocity.y * 0.25));

	if ( m_MonsterState == MONSTERSTATE_COMBAT && HasConditions( bits_COND_CAN_MELEE_ATTACK1 ) )
		m_IdealActivity = ACT_MELEE_ATTACK1;

	// Out of water check
	if ( !pev->waterlevel )
	{
		pev->movetype = MOVETYPE_TOSS;
		m_IdealActivity = ACT_TWITCH;
		pev->velocity = g_vecZero;

		// Animation will intersect the floor if either of these is non-zero
		pev->angles.z = 0;
		pev->angles.x = 0;

		if ( pev->framerate < 1.0 )
			pev->framerate = 1.0;
	}
	else if ( pev->movetype == MOVETYPE_TOSS )
	{
		pev->movetype = MOVETYPE_FLY;
		pev->flags &= ~FL_ONGROUND;
		RecalculateWaterlevel();
		m_waterTime = gpGlobals->time + 2;	// Recalc again soon, water may be rising
	}

	if ( m_Activity != m_IdealActivity )
	{
		SetActivity ( m_IdealActivity );
	}
	float flInterval = StudioFrameAdvance();
	DispatchAnimEvents ( flInterval );
#if DEBUG_BEAMS
	if ( !m_pb )
		m_pb = CBeam::BeamCreate( "sprites/laserbeam.spr", 5 );
	if ( !m_pt )
		m_pt = CBeam::BeamCreate( "sprites/laserbeam.spr", 5 );
	m_pb->PointsInit( pev->origin, pev->origin + gpGlobals->v_forward * LEECH_CHECK_DIST );
	m_pt->PointsInit( pev->origin, pev->origin - gpGlobals->v_right * (pev->avelocity.y*0.25) );
	if ( m_fPathBlocked )
	{
		float color = m_obstacle * 30;
		if ( m_obstacle == 1.0 )
			color = 0;
		if ( color > 255 )
			color = 255;
		m_pb->SetColor( 255, (int)color, (int)color );
	}
	else
		m_pb->SetColor( 255, 255, 0 );
	m_pt->SetColor( 0, 0, 255 );
#endif
}

void CLeech::SwimThink( void )
{
	TraceResult		tr;
	float			flLeftSide;
	float			flRightSide;
	float			targetSpeed;
	float			targetYaw = 0;
	CBaseEntity		*pTarget;

	if ( FNullEnt( FIND_CLIENT_IN_PVS( edict() ) ) )
	{
		pev->nextthink = gpGlobals->time + RANDOM_FLOAT(1,1.5);
		pev->velocity = g_vecZero;
		return;
	}
	else
		pev->nextthink = gpGlobals->time + 0.1;

	targetSpeed = LEECH_SWIM_SPEED;

	if ( m_waterTime < gpGlobals->time )
		RecalculateWaterlevel();

	if ( m_stateTime < gpGlobals->time )
		SwitchLeechState();

	ClearConditions( bits_COND_CAN_MELEE_ATTACK1 );
	switch( m_MonsterState )
	{
	case MONSTERSTATE_COMBAT:
		pTarget = m_hEnemy;
		if ( !pTarget )
			SwitchLeechState();
		else
		{
			// Chase the enemy's eyes
			m_height = pTarget->pev->origin.z + pTarget->pev->view_ofs.z - 5;
			// Clip to viable water area
			if ( m_height < m_bottom )
				m_height = m_bottom;
			else if ( m_height > m_top )
				m_height = m_top;
			Vector location = pTarget->pev->origin - pev->origin;
			location.z += (pTarget->pev->view_ofs.z);
			if ( location.Length() < 40 )
				SetConditions( bits_COND_CAN_MELEE_ATTACK1 );
			// Turn towards target ent
			targetYaw = UTIL_VecToYaw( location );

			targetYaw = UTIL_AngleDiff( targetYaw, UTIL_AngleMod( pev->angles.y ) );

			if ( targetYaw < (-LEECH_TURN_RATE*0.75) )
				targetYaw = (-LEECH_TURN_RATE*0.75);
			else if ( targetYaw > (LEECH_TURN_RATE*0.75) )
				targetYaw = (LEECH_TURN_RATE*0.75);
			else
				targetSpeed *= 2;
		}
		break;
	default:
		if ( m_zTime < gpGlobals->time )
		{
			float newHeight = RANDOM_FLOAT( m_bottom, m_top );
			m_height = 0.5 * m_height + 0.5 * newHeight;
			m_zTime = gpGlobals->time + RANDOM_FLOAT( 1, 4 );
		}
		if ( RANDOM_LONG( 0, 100 ) < 10 )
			targetYaw = RANDOM_LONG( -30, 30 );
		pTarget = NULL;

		// oldorigin test
		if ( (pev->origin - pev->oldorigin).Length() < 1 )
		{
			// If leech didn't move, there must be something blocking it, so try to turn
			m_sideTime = 0;
		}
		break;
	}

	m_obstacle = ObstacleDistance( pTarget );
	pev->oldorigin = pev->origin;
	if ( m_obstacle < 0.1 )
		m_obstacle = 0.1;

	// is the way ahead clear?
	if ( m_obstacle == 1.0 )
	{
		// if the leech is turning, stop the trend.
		if ( m_flTurning != 0 )
		{
			m_flTurning = 0;
		}

		m_fPathBlocked = FALSE;
		pev->speed = UTIL_Approach( targetSpeed, pev->speed, LEECH_SWIM_ACCEL * LEECH_FRAMETIME );
		pev->velocity = gpGlobals->v_forward * pev->speed;

	}
	else
	{
		m_obstacle = 1.0 / m_obstacle;
		// IF we get this far in the function, the leader's path is blocked!
		m_fPathBlocked = TRUE;

		if ( m_flTurning == 0 )// something in the way and leech is not already turning to avoid
		{
			Vector vecTest;
			// measure clearance on left and right to pick the best dir to turn
			vecTest = pev->origin + (gpGlobals->v_right * LEECH_SIZEX) + (gpGlobals->v_forward * LEECH_CHECK_DIST);
			UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);
			flRightSide = tr.flFraction;

			vecTest = pev->origin + (gpGlobals->v_right * -LEECH_SIZEX) + (gpGlobals->v_forward * LEECH_CHECK_DIST);
			UTIL_TraceLine(pev->origin, vecTest, missile, edict(), &tr);
			flLeftSide = tr.flFraction;

			// turn left, right or random depending on clearance ratio
			float delta = (flRightSide - flLeftSide);
			if ( delta > 0.1 || (delta > -0.1 && RANDOM_LONG(0,100)<50) )
				m_flTurning = -LEECH_TURN_RATE;
			else
				m_flTurning = LEECH_TURN_RATE;
		}
		pev->speed = UTIL_Approach( -(LEECH_SWIM_SPEED*0.5), pev->speed, LEECH_SWIM_DECEL * LEECH_FRAMETIME * m_obstacle );
		pev->velocity = gpGlobals->v_forward * pev->speed;
	}
	pev->ideal_yaw = m_flTurning + targetYaw;
	UpdateMotion();
}

void CLeech::Killed(entvars_t *pevAttacker, int iGib)
{
	Vector			vecSplatDir;
	TraceResult		tr;

	//ALERT(at_aiconsole, "Leech: killed\n");
	// tell owner ( if any ) that we're dead.This is mostly for MonsterMaker functionality.
	CBaseEntity *pOwner = CBaseEntity::Instance(pev->owner);
	if (pOwner)
		pOwner->DeathNotice(pev);

	// When we hit the ground, play the "death_end" activity
	if ( pev->waterlevel )
	{
		pev->angles.z = 0;
		pev->angles.x = 0;
		pev->origin.z += 1;
		pev->avelocity = g_vecZero;
		if ( RANDOM_LONG( 0, 99 ) < 70 )
			pev->avelocity.y = RANDOM_LONG( -720, 720 );

		pev->gravity = 0.02;
		ClearBits(pev->flags, FL_ONGROUND);
		SetActivity( ACT_DIESIMPLE );
	}
	else
		SetActivity( ACT_DIEFORWARD );
	
	pev->movetype = MOVETYPE_TOSS;
	pev->takedamage = DAMAGE_NO;
	SetThink( &CLeech::DeadThink );
}