/***
*
*	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.
*
*   Use, distribution, and modification of this source code and/or resulting
*   object code is restricted to non-commercial enhancements to products from
*   Valve LLC.  All other use, distribution, or modification is prohibited
*   without written permission from Valve LLC.
*
****/
/*

===== combat.cpp ========================================================

  functions dealing with damage infliction & death

*/

#include "extdll.h"
#include "utils.h"
#include "cbase.h"
#include "client.h"
#include "monsters.h"
#include "soundent.h"
#include "decals.h"
#include "animation.h"
#include "baseweapon.h"
#include "basebrush.h"
#include "defaults.h"

extern DLL_GLOBAL Vector		g_vecAttackDir;

extern Vector VecBModelOrigin( entvars_t* pevBModel );

MULTIDAMAGE gMultiDamage;


/*
==============================================================================

MULTI-DAMAGE

Collects multiple small damages into a single damage

==============================================================================
*/

//
// ClearMultiDamage - resets the global multi damage accumulator
//
void ClearMultiDamage(void)
{
	gMultiDamage.pEntity = NULL;
	gMultiDamage.amount	= 0;
	gMultiDamage.type = 0;
}


//
// ApplyMultiDamage - inflicts contents of global multi damage register on gMultiDamage.pEntity
//
// GLOBALS USED:
//		gMultiDamage

void ApplyMultiDamage(entvars_t *pevInflictor, entvars_t *pevAttacker )
{
	Vector		vecSpot1;//where blood comes from
	Vector		vecDir;//direction blood should go
	TraceResult	tr;
	
	if ( !gMultiDamage.pEntity )
		return;

	gMultiDamage.pEntity->TakeDamage(pevInflictor, pevAttacker, gMultiDamage.amount, gMultiDamage.type );
}


// GLOBALS USED:
//		gMultiDamage

void AddMultiDamage( entvars_t *pevInflictor, CBaseEntity *pEntity, float flDamage, int bitsDamageType)
{
	if ( !pEntity )
		return;
	
	gMultiDamage.type |= bitsDamageType;

	if ( pEntity != gMultiDamage.pEntity )
	{
		ApplyMultiDamage(pevInflictor,pevInflictor); // UNDONE: wrong attacker!
		gMultiDamage.pEntity	= pEntity;
		gMultiDamage.amount		= 0;
	}

	gMultiDamage.amount += flDamage;
}

void DecalGunshot( TraceResult *pTrace, int iBulletType )
{
	// Is the entity valid
	if ( !UTIL_IsValidEntity( pTrace->pHit ) )
		return;

	if ( VARS(pTrace->pHit)->solid == SOLID_BSP || VARS(pTrace->pHit)->movetype == MOVETYPE_PUSHSTEP )
	{
		CBaseEntity *pEntity = NULL;
		// Decal the wall with a gunshot
		if ( !FNullEnt(pTrace->pHit) )
			pEntity = CBaseEntity::Instance(pTrace->pHit);

		switch( iBulletType )
		{
		case BULLET_9MM:
		case BULLET_MP5:
		case BULLET_BUCKSHOT:
		case BULLET_357:
		default:
			// smoke and decal
			UTIL_GunshotDecalTrace( pTrace, DamageDecal( pEntity, DMG_BULLET ) );
			break;
		case BULLET_12MM:
			// smoke and decal
			UTIL_GunshotDecalTrace( pTrace, DamageDecal( pEntity, DMG_BULLET ) );
			break;
		case BULLET_CROWBAR:
			// wall decal
			UTIL_DecalTrace( pTrace, DamageDecal( pEntity, DMG_CLUB ) );
			break;
		}
	}
}

//
// EjectBrass - tosses a brass shell from passed origin at passed velocity
//
void EjectBrass ( const Vector &vecOrigin, const Vector &vecVelocity, float rotation, int model, int soundtype )
{
	// FIX: when the player shoots, their gun isn't in the same position as it is on the model other players see.

	MESSAGE_BEGIN( MSG_PVS, gmsg.TempEntity, vecOrigin );
		WRITE_BYTE( TE_MODEL);
		WRITE_COORD( vecOrigin.x);
		WRITE_COORD( vecOrigin.y);
		WRITE_COORD( vecOrigin.z);
		WRITE_COORD( vecVelocity.x);
		WRITE_COORD( vecVelocity.y);
		WRITE_COORD( vecVelocity.z);
		WRITE_ANGLE( rotation );
		WRITE_SHORT( model );
		WRITE_BYTE ( soundtype);
		WRITE_BYTE ( 25 );// 2.5 seconds
	MESSAGE_END();
}

/*
================
SpawnBlood
================
*/
void SpawnBlood(Vector vecSpot, int bloodColor, float flDamage)
{
	UTIL_BloodDrips( vecSpot, g_vecAttackDir, bloodColor, (int)flDamage );
}


int DamageDecal( CBaseEntity *pEntity, int bitsDamageType )
{
	if ( !pEntity )
		return (DECAL_GUNSHOT1 + RANDOM_LONG(0,4));
	
	return pEntity->DamageDecal( bitsDamageType );
}


//
// RadiusDamage - this entity is exploding, or otherwise needs to inflict damage upon entities within a certain range.
// 
// only damage ents that can clearly be seen by the explosion!

	
void RadiusDamage( Vector vecSrc, entvars_t *pevInflictor, entvars_t *pevAttacker, float flDamage, float flRadius, int iClassIgnore, int bitsDamageType )
{
	CBaseEntity *pEntity = NULL;
	TraceResult	tr;
	float		flAdjustedDamage, falloff;
	Vector		vecSpot;

	if ( flRadius )
		falloff = flDamage / flRadius;
	else
		falloff = 1.0;

	int bInWater = (UTIL_PointContents ( vecSrc ) == CONTENTS_WATER);

	vecSrc.z += 1;// in case grenade is lying on the ground

	if ( !pevAttacker )
		pevAttacker = pevInflictor;

	// iterate on all entities in the vicinity.
	while ((pEntity = UTIL_FindEntityInSphere( pEntity, vecSrc, flRadius )) != NULL)
	{
		if ( pEntity->pev->takedamage != DAMAGE_NO )
		{
			// UNDONE: this should check a damage mask, not an ignore
			if ( iClassIgnore != CLASS_NONE && pEntity->Classify() == iClassIgnore )
			{// houndeyes don't hurt other houndeyes with their attack
				continue;
			}

			// blast's don't tavel into or out of water
			if (bInWater && pEntity->pev->waterlevel == 0)
				continue;
			if (!bInWater && pEntity->pev->waterlevel == 3)
				continue;

			vecSpot = pEntity->BodyTarget( vecSrc );
			
			UTIL_TraceLine ( vecSrc, vecSpot, dont_ignore_monsters, ENT(pevInflictor), &tr );

			if ( tr.flFraction == 1.0 || tr.pHit == pEntity->edict() )
			{// the explosion can 'see' this entity, so hurt them!
				if (tr.fStartSolid)
				{
					// if we're stuck inside them, fixup the position and distance
					tr.vecEndPos = vecSrc;
					tr.flFraction = 0.0;
				}
				
				// decrease damage for an ent that's farther from the bomb.
				flAdjustedDamage = ( vecSrc - tr.vecEndPos ).Length() * falloff;
				flAdjustedDamage = flDamage - flAdjustedDamage;
			
				if ( flAdjustedDamage < 0 )
				{
					flAdjustedDamage = 0;
				}
			
				// ALERT( at_console, "hit %s\n", STRING( pEntity->pev->classname ) );
				if (tr.flFraction != 1.0)
				{
					ClearMultiDamage( );
					pEntity->TraceAttack( pevInflictor, flAdjustedDamage, (tr.vecEndPos - vecSrc).Normalize( ), &tr, bitsDamageType );
					ApplyMultiDamage( pevInflictor, pevAttacker );
				}
				else
				{
					pEntity->TakeDamage ( pevInflictor, pevAttacker, flAdjustedDamage, bitsDamageType );
				}
			}
		}
	}
}