// ai_subs.qc: subroutines for think frames

void() sub_null = {};
void(entity attacker, float damage) sub_pain_null = {};
void() sub_remove = {remove(self);};

/*
QuakeEd only writes a single float for angles(bad idea), so up and down are
just constant angles.
*/
void() set_move_dir = {
	if(self.angles == '0 -1 0') {
		self.movedir = '0 0 1';
	} else if(self.angles == '0 -2 0') {
		self.movedir = '0 0 -1';
	} else {
		make_vectors(self.angles);
		self.movedir = v_forward;
	}

	self.angles = VEC_ORIGIN;
};

/*
================
init_trigger
================
*/
void() init_trigger = {
	// trigger angles are used for one-way touches. An angle of 0 is assumed
	// to mean no restrictions, so use a yaw of 360 instead.
	if(self.angles != VEC_ORIGIN) {
		set_move_dir();
	}
	self.solid = SOLID_TRIGGER;
	set_model(self, self.model); // set size and link into world
	self.movetype = MOVETYPE_NONE;
	self.modelindex = 0;
	self.model = string_null;
};

/*
=============
sub_calc_move

calculate self.velocity and self.nextthink to reach dest from
self.origin traveling at speed
===============
*/
void(entity ent, vector tdest, float tspeed, void() func) sub_calc_move_ent = {
	entity stemp;
	stemp = self;
	self = ent;

	sub_calc_move(tdest, tspeed, func);
	self = stemp;
};

void(vector tdest, float tspeed, void() func) sub_calc_move = {
	vector vdestdelta;
	float len, traveltime;

	if(!tspeed) {
		error_obj("No speed is defined!");
	}

	self.think1 = func;
	self.finaldest = tdest;
	self.think = sub_calc_move_done;

	if(tdest == self.origin) {
		self.velocity = VEC_ORIGIN;
		self.nextthink = self.ltime + 0.1;
		return;
	}

	// set destdelta to the vector needed to move
	vdestdelta = tdest - self.origin;

	// calculate length of vector
	len = vec_len(vdestdelta);

	// divide by speed to get time to reach dest
	traveltime = len / tspeed;

	if(traveltime < 0.1) {
		self.velocity = VEC_ORIGIN;
		self.nextthink = self.ltime + 0.1;
		return;
	}

	// set nextthink to trigger a think when dest is reached
	self.nextthink = self.ltime + traveltime;

	// scale the destdelta vector by the time spent traveling to get velocity
	self.velocity = vdestdelta * (1 / traveltime); // qcc won't take vec/float
};

/*
============
After moving, set origin to exact final destination
============
*/
void() sub_calc_move_done = {
	set_origin(self, self.finaldest);
	self.velocity = VEC_ORIGIN;
	self.nextthink = -1;
	if(self.think1) {
		self.think1();
	}
};

/*
=============
sub_calc_angle_move

calculate self.avelocity and self.nextthink to reach destangle from
self.angles rotating

The calling function should make sure self.think is valid
===============
*/
void(entity ent, vector destangle, float tspeed, void() func) sub_calc_angle_moveEnt = {
	entity stemp;
	stemp = self;
	self = ent;
	sub_calc_angle_move(destangle, tspeed, func);
	self = stemp;
};

void(vector destangle, float tspeed, void() func) sub_calc_angle_move = {
	vector destdelta;
	float len, traveltime;

	if(!tspeed) {
		error_obj("No speed is defined!");
	}

	// set destdelta to the vector needed to move
	destdelta = destangle - self.angles;

	// calculate length of vector
	len = vec_len(destdelta);

	// divide by speed to get time to reach dest
	traveltime = len / tspeed;

	// set nextthink to trigger a think when dest is reached
	self.nextthink = self.ltime + traveltime;

	// scale the destdelta vector by the time spent traveling to get velocity
	self.avelocity = destdelta * (1 / traveltime);

	self.think1 = func;
	self.finalangle = destangle;
	self.think = sub_calc_angle_move_done;
};

/*
============
After rotating, set angle to exact final angle
============
*/
void() sub_calc_angle_move_done = {
	self.angles = self.finalangle;
	self.avelocity = VEC_ORIGIN;
	self.nextthink = -1;
	if(self.think1) {
		self.think1();
	}
};

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

void() delay_think = {
	activator = self.enemy;
	sub_use_targets();
	remove(self);
};

/*
==============================
sub_use_targets

the global "activator" should be set to the entity that initiated the firing.

If self.delay is set, a DelayedUse entity will be created that will actually
do the sub_use_targets after that many seconds have passed.

Centerprints any self.message to the activator.

Removes all entities with a targetname that match self.killtarget,
and removes them, so some events can remove other triggers.

Search for(string)targetname in all entities that
match(string)self.target and call their .use function

==============================
*/
void() sub_use_targets = {
	entity t, stemp, otemp, act;

	//
	// check for a delay
	//
	if(self.delay) {
		// create a temp object to fire at a later time
		t = spawn();
		t.classname = "DelayedUse";
		t.nextthink = time + self.delay;
		t.think = delay_think;
		t.enemy = activator;
		t.message = self.message;
		t.killtarget = self.killtarget;
		t.target = self.target;
		return;
	}

	//
	// print the message
	//
	if(activator.classname == "player" && self.message != string_null) {
		print_center(activator, self.message);
		if(!self.noise) {
			sound(activator, CHAN_VOICE, "misc/talk.wav", 1, ATTN_NORM);
		}
	}

	//
	// kill the killtagets
	//
	if(self.killtarget) {
		t = world;
		do {
			t = find(t, targetname, self.killtarget);
			if(!t) {
				return;
			}
			remove(t);
		} while(1);
	}

	//
	// fire targets
	//
	if(self.target) {
		act = activator;
		t = world;
		do {
			t = find(t, targetname, self.target);
			if(!t) {
				return;
			}
			stemp = self;
			otemp = other;
			self = t;
			other = stemp;
			if(self.use != sub_null) {
				if(self.use) {
					self.use();
				}
			}
			self = stemp;
			other = otemp;
			activator = act;
		} while(1);
	}

};

/*

in nightmare mode, all attack_finished times become 0
some monsters refire twice automatically

*/

void(float normal) sub_attack_finished = {
	self.cnt = 0; // refire count for nightmare
	if(skill != 3) {
		self.attack_finished = time + normal;
	}
};

void(void() thinkst) sub_check_refire = {
	if(skill != 3) {
		return;
	}
	if(self.cnt == 1) {
		return;
	}
	if(!visible(self.enemy)) {
		return;
	}
	self.cnt = 1;
	self.think = thinkst;
};