/*  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.
*/


/*

A monster is in fight mode if it thinks it can effectively attack its
enemy.

When it decides it can't attack, it goes into hunt mode.

*/

float(float v) anglemod;

void() knight_atk1;
void() knight_runatk1;
void() ogre_smash1;
void() ogre_swing1;

void() sham_smash1;
void() sham_swingr1;
void() sham_swingl1;

float()	DemonCheckAttack;
void(float side)	Demon_Melee;

void(vector dest) ChooseTurn;

void() ai_face;


float	enemy_vis, enemy_infront, enemy_range;
float	enemy_yaw;


void() knight_attack =
{
	local float		len;
	
// decide if now is a good swing time
	len = vlen(self.enemy.origin+self.enemy.view_ofs - (self.origin+self.view_ofs));
	
	if (len<80)
		knight_atk1 ();
	else
		knight_runatk1 ();
};

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

/*
===========
CheckAttack

The player is in view, so decide to move or launch an attack
Returns FALSE if movement should continue
============
*/
float() CheckAttack =
{
	local vector	spot1, spot2;	
	local entity	targ;
	local float		chance;

	targ = self.enemy;
	
// see if any entities are in the way of the shot
	spot1 = self.origin + self.view_ofs;
	spot2 = targ.origin + targ.view_ofs;

	traceline (spot1, spot2, FALSE, self);

	if (trace_ent != targ)
		return FALSE;		// don't have a clear shot
	if (trace_inopen && trace_inwater)
		return FALSE;			// sight line crossed contents

	if (enemy_range == RANGE_MELEE)
	{	// melee attack
		if (self.th_melee)
		{
			if (self.classname == "monster_knight")
				knight_attack ();
			else
				self.th_melee ();
			return TRUE;
		}
	}
	
// missile attack
	if (!self.th_missile)
		return FALSE;
		
	if (time < self.attack_finished)
		return FALSE;
		
	if (enemy_range == RANGE_FAR)
		return FALSE;
		
	if (enemy_range == RANGE_MELEE)
	{
		chance = 0.9;
		self.attack_finished = 0;
	}
	else if (enemy_range == RANGE_NEAR)
	{
		if (self.th_melee)
			chance = 0.2;
		else
			chance = 0.4;
	}
	else if (enemy_range == RANGE_MID)
	{
		if (self.th_melee)
			chance = 0.05;
		else
			chance = 0.1;
	}
	else
		chance = 0;

	if (random () < chance)
	{
		self.th_missile ();
		SUB_AttackFinished (2*random());
		return TRUE;
	}

	return FALSE;
};


/*
=============
ai_face

Stay facing the enemy
=============
*/
void() ai_face =
{
	self.ideal_yaw = vectoyaw(self.enemy.origin - self.origin);
	ChangeYaw ();
};

/*
=============
ai_charge

The monster is in a melee attack, so get as close as possible to .enemy
=============
*/
float (entity targ) visible;
float(entity targ) infront;
float(entity targ) range;

void(float d) ai_charge =
{
	ai_face ();	
	movetogoal (d);		// done in C code...
};

void() ai_charge_side =
{
	local	vector	dtemp;
	local	float	heading;
	
// aim to the left of the enemy for a flyby

	self.ideal_yaw = vectoyaw(self.enemy.origin - self.origin);
	ChangeYaw ();

	makevectors (self.angles);
	dtemp = self.enemy.origin - 30*v_right;
	heading = vectoyaw(dtemp - self.origin);
	
	walkmove(heading, 20);
};


/*
=============
ai_melee

=============
*/
void() ai_melee =
{
	local vector	delta;
	local float 	ldmg;

	if (!self.enemy)
		return;		// removed before stroke
		
	delta = self.enemy.origin - self.origin;

	if (vlen(delta) > 60)
		return;
		
	ldmg = (random() + random() + random()) * 3;
	T_Damage (self.enemy, self, self, ldmg);
};


void() ai_melee_side =
{
	local vector	delta;
	local float 	ldmg;

	if (!self.enemy)
		return;		// removed before stroke
		
	ai_charge_side();
	
	delta = self.enemy.origin - self.origin;

	if (vlen(delta) > 60)
		return;
	if (!CanDamage (self.enemy, self))
		return;
	ldmg = (random() + random() + random()) * 3;
	T_Damage (self.enemy, self, self, ldmg);
};


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

/*
===========
SoldierCheckAttack

The player is in view, so decide to move or launch an attack
Returns FALSE if movement should continue
============
*/
float() SoldierCheckAttack =
{
	local vector	spot1, spot2;	
	local entity	targ;
	local float		chance;

	targ = self.enemy;
	
// see if any entities are in the way of the shot
	spot1 = self.origin + self.view_ofs;
	spot2 = targ.origin + targ.view_ofs;

	traceline (spot1, spot2, FALSE, self);

	if (trace_inopen && trace_inwater)
		return FALSE;			// sight line crossed contents

	if (trace_ent != targ)
		return FALSE;	// don't have a clear shot
			
	
// missile attack
	if (time < self.attack_finished)
		return FALSE;
		
	if (enemy_range == RANGE_FAR)
		return FALSE;
		
	if (enemy_range == RANGE_MELEE)
		chance = 0.9;
	else if (enemy_range == RANGE_NEAR)
		chance = 0.4;
	else if (enemy_range == RANGE_MID)
		chance = 0.05;
	else
		chance = 0;

	if (random () < chance)
	{
		self.th_missile ();
		SUB_AttackFinished (1 + random());
		if (random() < 0.3)
			self.lefty = !self.lefty;

		return TRUE;
	}

	return FALSE;
};
//=============================================================================

/*
===========
ShamCheckAttack

The player is in view, so decide to move or launch an attack
Returns FALSE if movement should continue
============
*/
float() ShamCheckAttack =
{
	local vector	spot1, spot2;	
	local entity	targ;
	local float		chance;
	local float		enemy_yaw;

	if (enemy_range == RANGE_MELEE)
	{
		if (CanDamage (self.enemy, self))
		{
			self.attack_state = AS_MELEE;
			return TRUE;
		}
	}

	if (time < self.attack_finished)
		return FALSE;
	
	if (!enemy_vis)
		return FALSE;
		
	targ = self.enemy;
	
// see if any entities are in the way of the shot
	spot1 = self.origin + self.view_ofs;
	spot2 = targ.origin + targ.view_ofs;

	if (vlen(spot1 - spot2) > 600)
		return FALSE;

	traceline (spot1, spot2, FALSE, self);

	if (trace_inopen && trace_inwater)
		return FALSE;			// sight line crossed contents

	if (trace_ent != targ)
	{
		return FALSE;	// don't have a clear shot
	}
			
// missile attack
	if (enemy_range == RANGE_FAR)
		return FALSE;
		
	self.attack_state = AS_MISSILE;
	SUB_AttackFinished (2 + 2*random());
	return TRUE;
};

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

/*
===========
OgreCheckAttack

The player is in view, so decide to move or launch an attack
Returns FALSE if movement should continue
============
*/
float() OgreCheckAttack =
{
	local vector	spot1, spot2;	
	local entity	targ;
	local float		chance;

	if (enemy_range == RANGE_MELEE)
	{
		if (CanDamage (self.enemy, self))
		{
			self.attack_state = AS_MELEE;
			return TRUE;
		}
	}

	if (time < self.attack_finished)
		return FALSE;
	
	if (!enemy_vis)
		return FALSE;
		
	targ = self.enemy;
	
// see if any entities are in the way of the shot
	spot1 = self.origin + self.view_ofs;
	spot2 = targ.origin + targ.view_ofs;

	traceline (spot1, spot2, FALSE, self);

	if (trace_inopen && trace_inwater)
		return FALSE;			// sight line crossed contents

	if (trace_ent != targ)
	{
		return FALSE;	// don't have a clear shot
	}
			
// missile attack
	if (time < self.attack_finished)
		return FALSE;
		
	if (enemy_range == RANGE_FAR)
		return FALSE;
		
	else if (enemy_range == RANGE_NEAR)
		chance = 0.10;
	else if (enemy_range == RANGE_MID)
		chance = 0.05;
	else
		chance = 0;

	self.attack_state = AS_MISSILE;
	SUB_AttackFinished (1 + 2*random());
	return TRUE;
};