// The proc you should always use to set the light of this atom.
// Nonesensical value for l_color default, so we can detect if it gets set to null.
#define NONSENSICAL_VALUE -99999
/atom/proc/set_light(l_range, l_power, l_color = NONSENSICAL_VALUE)
	if(l_range > 0 && l_range < MINIMUM_USEFUL_LIGHT_RANGE)
		l_range = MINIMUM_USEFUL_LIGHT_RANGE	//Brings the range up to 1.4, which is just barely brighter than the soft lighting that surrounds players.
	if (l_power != null)
		light_power = l_power

	if (l_range != null)
		light_range = l_range

	if (l_color != NONSENSICAL_VALUE)
		light_color = l_color

	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT, l_range, l_power, l_color)

	update_light()

#undef NONSENSICAL_VALUE

// Will update the light (duh).
// Creates or destroys it if needed, makes it update values, makes sure it's got the correct source turf...
/atom/proc/update_light()
	set waitfor = FALSE
	if (QDELETED(src))
		return

	if(light_system != STATIC_LIGHT)
		CRASH("update_light() for [src] with following light_system value: [light_system]")

	if (!light_power || !light_range) // We won't emit light anyways, destroy the light source.
		QDEL_NULL(light)
	else
		if (!ismovable(loc)) // We choose what atom should be the top atom of the light here.
			. = src
		else
			. = loc

		if (light) // Update the light or create it if it does not exist.
			light.update(.)
		else
			light = new/datum/light_source(src, .)


/**
  * Updates the atom's opacity value.
  *
  * This exists to act as a hook for associated behavior.
  * It notifies (potentially) affected light sources so they can update (if needed).
  */
/atom/proc/set_opacity(new_opacity)
	if (new_opacity == opacity)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_OPACITY, new_opacity)
	. = opacity
	opacity = new_opacity


/atom/movable/set_opacity(new_opacity)
	. = ..()
	if(isnull(.) || !isturf(loc))
		return

	if(opacity)
		AddElement(/datum/element/light_blocking)
	else
		RemoveElement(/datum/element/light_blocking)


/turf/set_opacity(new_opacity)
	. = ..()
	if(isnull(.))
		return
	recalculate_directional_opacity()


/atom/movable/Moved(atom/OldLoc, Dir)
	. = ..()
	var/datum/light_source/L
	var/thing
	for (thing in light_sources) // Cycle through the light sources on this atom and tell them to update.
		L = thing
		L.source_atom.update_light()

/atom/vv_edit_var(var_name, var_value)
	switch (var_name)
		if (NAMEOF(src, light_range))
			if(light_system == STATIC_LIGHT)
				set_light(l_range = var_value)
			else
				set_light_range(var_value)
			datum_flags |= DF_VAR_EDITED
			return TRUE

		if (NAMEOF(src, light_power))
			if(light_system == STATIC_LIGHT)
				set_light(l_power = var_value)
			else
				set_light_power(var_value)
			datum_flags |= DF_VAR_EDITED
			return TRUE

		if (NAMEOF(src, light_color))
			if(light_system == STATIC_LIGHT)
				set_light(l_color = var_value)
			else
				set_light_color(var_value)
			datum_flags |= DF_VAR_EDITED
			return TRUE

	return ..()


/atom/proc/flash_lighting_fx(_range = FLASH_LIGHT_RANGE, _power = FLASH_LIGHT_POWER, _color = COLOR_WHITE, _duration = FLASH_LIGHT_DURATION)
	return


/turf/flash_lighting_fx(_range = FLASH_LIGHT_RANGE, _power = FLASH_LIGHT_POWER, _color = COLOR_WHITE, _duration = FLASH_LIGHT_DURATION)
	if(!_duration)
		stack_trace("Lighting FX obj created on a turf without a duration")
	new /obj/effect/dummy/lighting_obj (src, _range, _power, _color, _duration)


/obj/flash_lighting_fx(_range = FLASH_LIGHT_RANGE, _power = FLASH_LIGHT_POWER, _color = COLOR_WHITE, _duration = FLASH_LIGHT_DURATION)
	if(!_duration)
		stack_trace("Lighting FX obj created on a obj without a duration")
	new /obj/effect/dummy/lighting_obj (get_turf(src), _range, _power, _color, _duration)


/mob/living/flash_lighting_fx(_range = FLASH_LIGHT_RANGE, _power = FLASH_LIGHT_POWER, _color = COLOR_WHITE, _duration = FLASH_LIGHT_DURATION)
	mob_light(_range, _power, _color, _duration)


/mob/living/proc/mob_light(_range, _power, _color, _duration)
	var/obj/effect/dummy/lighting_obj/moblight/mob_light_obj = new (src, _range, _power, _color, _duration)
	return mob_light_obj


/atom/proc/set_light_range(new_range)
	if(new_range == light_range)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT_RANGE, new_range)
	. = light_range
	light_range = new_range


/atom/proc/set_light_power(new_power)
	if(new_power == light_power)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT_POWER, new_power)
	. = light_power
	light_power = new_power


/atom/proc/set_light_color(new_color)
	if(new_color == light_color)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT_COLOR, new_color)
	. = light_color
	light_color = new_color


/atom/proc/set_light_on(new_value)
	if(new_value == light_on)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT_ON, new_value)
	. = light_on
	light_on = new_value


/atom/proc/set_light_flags(new_value)
	if(new_value == light_flags)
		return
	SEND_SIGNAL(src, COMSIG_ATOM_SET_LIGHT_FLAGS, new_value)
	. = light_flags
	light_flags = new_value