/*  Copyright (C) 1996-2022 id Software LLC

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    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, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

    See file, 'COPYING', for details.
*/

// Yoder Sept24 2021 Horde Merge
void() horde_spawn_powerup;

void() T_MissileTouch;
void() info_player_start;
void(entity targ, entity attacker) ClientObituary;

void() monster_death_use;

//============================================================================

/*
============
CanDamage

Returns true if the inflictor can directly damage the target.  Used for
explosions and melee attacks.
============
*/
float(entity targ, entity inflictor) CanDamage =
{
// bmodels need special checking because their origin is 0,0,0
	if (targ.movetype == MOVETYPE_PUSH)
	{
		traceline(inflictor.origin, 0.5 * (targ.absmin + targ.absmax), TRUE, self);
		if (trace_fraction == 1)
			return TRUE;
		if (trace_ent == targ)
			return TRUE;
		return FALSE;
	}
	
	traceline(inflictor.origin, targ.origin, TRUE, self);
	if (trace_fraction == 1)
		return TRUE;
	traceline(inflictor.origin, targ.origin + '15 15 0', TRUE, self);
	if (trace_fraction == 1)
		return TRUE;
	traceline(inflictor.origin, targ.origin + '-15 -15 0', TRUE, self);
	if (trace_fraction == 1)
		return TRUE;
	traceline(inflictor.origin, targ.origin + '-15 15 0', TRUE, self);
	if (trace_fraction == 1)
		return TRUE;
	traceline(inflictor.origin, targ.origin + '15 -15 0', TRUE, self);
	if (trace_fraction == 1)
		return TRUE;

	return FALSE;
};


/*
============
Killed
============
*/
void(entity targ, entity attacker) Killed =
{
	local entity oself;

	oself = self;
	self = targ;
	
	if (self.health < -99)
		self.health = -99;		// don't let sbar look bad if a player

	if (self.movetype == MOVETYPE_PUSH || self.movetype == MOVETYPE_NONE)
	{	// doors, triggers, etc
		if (self.classname == "misc_explobox" || self.classname == "misc_explobox2") // yoder add, 27/09/202 to let the SUB_UseTarges work
			self.enemy = attacker;
		self.th_die ();
		self = oself;
		return;
	}

	self.enemy = attacker;
	
	// Yoder March04 2022, punish team killspree
	if (cvar("horde") && (attacker.classname) == "player" && (targ.classname == "player"))
	{
		dprint("punish teamkill\n");
		attacker.killtime = 0;
		attacker.frags -= 2;
	}

// bump the monster counter
	if (self.flags & FL_MONSTER)
	{
		// Yoder Sept24, 2021 Horde Merge
		if (horde_ent)
		{
			if (self.classname != "monster_zombie") // zombies don't count
			{
				killed_monsters = killed_monsters + 1;
				WriteByte (MSG_ALL, SVC_KILLEDMONSTER); 
			}
			
			// check kill spree
			if (attacker.classname == "player")
			{
				attacker.killspree++;
				attacker.killtime = time + KILLSPREE_GAP;
					
				if (time < attacker.killtime)
				{
					if (attacker.killspree >= 14)
						sprint(attacker, "$qc_horde_streak_generic", ftos(attacker.killspree));
					else if (attacker.killspree == 13)
						sprint(attacker, "$qc_horde_streak_13");
					else if (attacker.killspree == 12)
						sprint(attacker, "$qc_horde_streak_12");
					else if (attacker.killspree == 11)
						sprint(attacker, "$qc_horde_streak_11");
					else if (attacker.killspree == 10)
						sprint(attacker, "$qc_horde_streak_10");
					else if (attacker.killspree == 9)
						sprint(attacker, "$qc_horde_streak_9");
					else if (attacker.killspree == 8)
						sprint(attacker, "$qc_horde_streak_8");
					else if (attacker.killspree == 7)
						sprint(attacker, "$qc_horde_streak_7");
					else if (attacker.killspree == 6)
						sprint(attacker, "$qc_horde_streak_6");
					else if (attacker.killspree == 5)
						sprint(attacker, "$qc_horde_streak_5");
					else if (attacker.killspree == 4)
						sprint(attacker, "$qc_horde_streak_4");
					else if (attacker.killspree == 3)
						sprint(attacker, "$qc_horde_streak_3");
					else if (attacker.killspree == 2)
						sprint(attacker, "$qc_horde_streak_2");
				}
			}
			
			// check to see about spawning a powerup
			horde_spawn_powerup();
		}
		else // standard behavior
		{
			killed_monsters = killed_monsters + 1;
			WriteByte (MSG_ALL, SVC_KILLEDMONSTER);
		}
		if (attacker.classname == "player")
			attacker.frags = attacker.frags + 1;

		if (attacker != self && attacker.flags & FL_MONSTER)
		{
			WriteByte (MSG_ALL, SVC_ACHIEVEMENT);
			WriteString(MSG_ALL, "ACH_FRIENDLY_FIRE");
		}
	}

	ClientObituary(self, attacker);
	
	self.takedamage = DAMAGE_NO;
	self.touch = SUB_Null;

	monster_death_use();
	self.th_die ();
	
	self = oself;
};


/*
============
T_Damage

The damage is coming from inflictor, but get mad at attacker
This should be the only function that ever reduces health.
============
*/
void(entity targ, entity inflictor, entity attacker, float damage) T_Damage=
{
	local	vector	dir;
	local	entity	oldself;
	local	float	save;
	local	float	take;

	if (!targ.takedamage)
		return;
		
	// Yoder add, September 9 2020
	if (targ.is_frozen)
		return;

// used by buttons and triggers to set activator for target firing
	damage_attacker = attacker;

// check for quad damage powerup on the attacker
	if (attacker.super_damage_finished > time)
		damage = damage * 4;

// save damage based on the target's armor level

	save = ceil(targ.armortype*damage);
	if (save >= targ.armorvalue)
	{
		save = targ.armorvalue;
		targ.armortype = 0;	// lost all armor
		targ.items = targ.items - (targ.items & (IT_ARMOR1 | IT_ARMOR2 | IT_ARMOR3));
	}
	
	targ.armorvalue = targ.armorvalue - save;
	take = ceil(damage-save);

// add to the damage total for clients, which will be sent as a single
// message at the end of the frame
	if (targ.flags & FL_CLIENT)
	{
		targ.dmg_take = targ.dmg_take + take;
		targ.dmg_save = targ.dmg_save + save;
		targ.dmg_inflictor = inflictor;
	}

// figure momentum add
	if ( (inflictor != world) && (targ.movetype == MOVETYPE_WALK) )
	{
		dir = targ.origin - (inflictor.absmin + inflictor.absmax) * 0.5;
		dir = normalize(dir);
		targ.velocity = targ.velocity + dir*damage*8;
	}

// check for godmode or invincibility
	if (targ.flags & FL_GODMODE)
		return;
	if (targ.invincible_finished >= time)
	{
		if (self.invincible_sound < time)
		{
			sound (targ, CHAN_ITEM, "items/protect3.wav", 1, ATTN_NORM);
			self.invincible_sound = time + 2;
		}
		return;
	}

// team play damage avoidance
	if ( (teamplay == 1 && targ != attacker) && (targ.team > 0)&&(targ.team == attacker.team) )
		return;
		
	// special case for killable chthon (yoder, december 16 2020)
	if ((targ.classname == "monster_boss") && (targ.spawnflags & 2)) // is killable chthon
	{
		
		if (attacker.weapon == IT_LIGHTNING)
		{
			// TODO: Spawn blood
			dprint("Player has LG! Damage Chthon!\n");
		}
		else
		{
			dprint("player attacked with non-lightning weapon. Do nothing.\n");
			return;
		}
	}
	
// do the damage
	targ.health = targ.health - take;
			
	if (targ.health <= 0)
	{
		Killed (targ, attacker);
		return;
	}

// react to the damage
	oldself = self;
	self = targ;

	if ( (self.flags & FL_MONSTER) && attacker != world)
	{
	// get mad unless of the same class (except for soldiers)
		if (self != attacker && attacker != self.enemy)
		{
			if ( (self.classname != attacker.classname) 
			|| (self.classname == "monster_army" ) )
			{
				// yoder Sept24, 2021
				// if in horde mode, have enemies obey a reaggro time
				// TODO: Evaluate if we want this as default in co-op?
				if (cvar("horde"))
				{
					if ((self.enemy.classname == "player") &&  // current and new enemy are both players, check reaggro times
						(attacker.classname == "player"))
					{
						// check reaggro times
						if ((!self.aggro_time) ||
							(self.aggro_time + AGGRO_MIN + (random() * AGGRO_ADD < time)))
						{
							self.oldenemy = self.enemy;
							self.enemy = attacker;
							self.aggro_time = time;
							FoundTarget ();
						}
						else
						{
							// ignore new aggro from this hit
							dprint("ignore new aggro\n");
						}
					}
					else // immediately aggro, store the player if previous was player
					{
						if (self.enemy.classname == "player")
							self.oldenemy = self.enemy;
						self.enemy = attacker;
						FoundTarget ();
					}
				}
				else // original behavior
				{
					if (self.enemy.classname == "player")
						self.oldenemy = self.enemy;
					self.enemy = attacker;
					FoundTarget ();
				}
			}
		}
	}

	if (self.th_pain)
	{
		self.th_pain (attacker, take);
	// nightmare mode monsters don't go into pain frames often
		if (skill == 3)
			self.pain_finished = time + 5;		
	}
	
	self = oldself;
};

/*
============
T_RadiusDamage
============
*/
void(entity inflictor, entity attacker, float damage, entity ignore) T_RadiusDamage =
{
	local	float 	points;
	local	entity	head;
	local	vector	org;

	#ifdef GIB_DOWNED_ZOMBIES
	//Look for downed zombies and gib them if possible
	if(damage >= 60)
	{
		head = find(world, classname, "monster_zombie");
		while(head)
		{
			if(head.solid == SOLID_NOT)
			{
				org = head.origin + (head.mins + head.maxs)*0.5;
				points = 0.5*vlen (inflictor.origin - org);
				if (points < 0)
				{
					points = 0;
				}
				points = damage - points;
				if (points > 60)
				{
					if (CanDamage (head, inflictor))
					{	
						Killed (head, attacker);
					}
				}
			}
			head = find(head, classname, "monster_zombie");
		}
	}
	#endif

	head = findradius(inflictor.origin, damage+40);
	
	while (head)
	{
		if (head != ignore)
		{
			if (head.takedamage)
			{
				org = head.origin + (head.mins + head.maxs)*0.5;
				points = 0.5*vlen (inflictor.origin - org);
				if (points < 0)
					points = 0;
				points = damage - points;
				if (head == attacker)
					points = points * 0.5;
				if (points > 0)
				{
					if (CanDamage (head, inflictor))
					{	// shambler takes half damage from all explosions
						if (head.classname == "monster_shambler")						
							T_Damage (head, inflictor, attacker, points*0.5);
						else
							T_Damage (head, inflictor, attacker, points);
					}
				}
			}
		}
		head = head.chain;
	}
};

/*
============
T_BeamDamage
============
*/
void(entity attacker, float damage) T_BeamDamage =
{
	local	float 	points;
	local	entity	head;
	
	head = findradius(attacker.origin, damage+40);
	
	while (head)
	{
		if (head.takedamage)
		{
			points = 0.5*vlen (attacker.origin - head.origin);
			if (points < 0)
				points = 0;
			points = damage - points;
			if (head == attacker)
				points = points * 0.5;
			if (points > 0)
			{
				if (CanDamage (head, attacker))
				{
					if (head.classname == "monster_shambler")						
						T_Damage (head, attacker, attacker, points*0.5);
					else
						T_Damage (head, attacker, attacker, points);
				}
			}
		}
		head = head.chain;
	}
};