#define DREAMING_SOURCE "dreaming_source"

/**
 * Begins the dreaming process on a sleeping carbon.
 *
 * Checks a 10% chance and whether or not the carbon this is called on is already dreaming. If
 * the prob() passes and there are no dream images left to display, a new dream is constructed.
 */

/mob/living/carbon/proc/handle_dreams()
	if(!HAS_TRAIT(src, TRAIT_DREAMING) && prob(10))
		dream()

/**
 * Generates a dream sequence to be displayed to the sleeper.
 *
 * Generates the "dream" to display to the sleeper. A dream consists of a subject, a verb, and (most of the time) an object, displayed in sequence to the sleeper.
 * Dreams are generated as a list of strings stored inside dream_fragments, which is passed to and displayed in dream_sequence().
 * Bedsheets on the sleeper will provide a custom subject for the dream, pulled from the dream_messages on each bedsheet.
 */

/mob/living/carbon/proc/dream()
	set waitfor = FALSE
	var/datum/dream/chosen_dream

	if (IS_HERETIC(src) && !mob_mood.get_mood_event("mansus_dream_fatigue") && GLOB.reality_smash_track.smashes.len)
		chosen_dream = new /datum/dream/heretic(pick(GLOB.reality_smash_track.smashes))
	else
		chosen_dream = pick_weight(GLOB.dreams)

	ADD_TRAIT(src, TRAIT_DREAMING, DREAMING_SOURCE)
	dream_sequence(chosen_dream.GenerateDream(src), chosen_dream)

/**
 * Displays the passed list of dream fragments to a sleeping carbon.
 *
 * Displays the first string of the passed dream fragments, then either ends the dream sequence
 * or performs a callback on itself depending on if there are any remaining dream fragments to display.
 *
 * Arguments:
 * * dream_fragments - A list of strings, in the order they will be displayed.
 * * current_dream - The dream datum used for the current dream
 */

/mob/living/carbon/proc/dream_sequence(list/dream_fragments, datum/dream/current_dream)
	if(stat != UNCONSCIOUS || HAS_TRAIT(src, TRAIT_CRITICAL_CONDITION))
		REMOVE_TRAIT(src, TRAIT_DREAMING, DREAMING_SOURCE)
		current_dream.OnDreamEnd(src)
		return
	var/next_message = dream_fragments[1]
	dream_fragments.Cut(1,2)

	if(istype(next_message, /datum/callback))
		var/datum/callback/something_happens = next_message
		next_message = something_happens.InvokeAsync(src)

	to_chat(src, span_notice("<i>... [next_message] ...</i>"))

	if(LAZYLEN(dream_fragments))
		var/next_wait = rand(10, 30)
		if(current_dream.sleep_until_finished)
			AdjustSleeping(next_wait)
		addtimer(CALLBACK(src, PROC_REF(dream_sequence), dream_fragments, current_dream), next_wait)
	else
		REMOVE_TRAIT(src, TRAIT_DREAMING, DREAMING_SOURCE)
		current_dream.OnDreamEnd(src)

//-------------------------
// DREAM DATUMS

GLOBAL_LIST_INIT(dreams, populate_dream_list())

/proc/populate_dream_list()
	var/list/output = list()
	for(var/datum/dream/dream_type as anything in subtypesof(/datum/dream))
		output[new dream_type] = initial(dream_type.weight)
	return output

/**
 * Contains all the behavior needed to play a kind of dream.
 * All dream types get randomly selected from based on weight when an appropriate mobs dreams.
 */
/datum/dream
	/// The relative chance this dream will be randomly selected
	var/weight = 0

	/// Causes the mob to sleep long enough for the dream to finish if begun
	var/sleep_until_finished = FALSE

/**
 * Called when beginning a new dream for the dreamer.
 * Gives back a list of dream events. Events can be text or callbacks that return text.
 */
/datum/dream/proc/GenerateDream(mob/living/carbon/dreamer)
	return list()

/**
 * Called when the dream ends or is interrupted.
 */
/datum/dream/proc/OnDreamEnd(mob/living/carbon/dreamer)
	return

/// The classic random dream of various words that might form a cohesive narrative, but usually wont
/datum/dream/random
	weight = 1000

/datum/dream/random/GenerateDream(mob/living/carbon/dreamer)
	var/list/custom_dream_nouns = list()
	var/fragment = ""

	for(var/obj/item/bedsheet/sheet in dreamer.loc)
		custom_dream_nouns += sheet.dream_messages

	. = list()
	. += "you see"

	//Subject
	if(custom_dream_nouns.len && prob(90))
		fragment += pick(custom_dream_nouns)
	else
		fragment += pick(GLOB.dream_strings)

	if(prob(50)) //Replace the adjective space with an adjective, or just get rid of it
		fragment = replacetext(fragment, "%ADJECTIVE%", pick(GLOB.adjectives))
	else
		fragment = replacetext(fragment, "%ADJECTIVE% ", "")
	if(findtext(fragment, "%A% "))
		fragment = "\a [replacetext(fragment, "%A% ", "")]"
	. += fragment

	//Verb
	fragment = ""
	if(prob(50))
		if(prob(35))
			fragment += "[pick(GLOB.adverbs)] "
		fragment += pick(GLOB.ing_verbs)
	else
		fragment += "will "
		fragment += pick(GLOB.verbs)
	. += fragment

	if(prob(25))
		return

	//Object
	fragment = ""
	fragment += pick(GLOB.dream_strings)
	if(prob(50))
		fragment = replacetext(fragment, "%ADJECTIVE%", pick(GLOB.adjectives))
	else
		fragment = replacetext(fragment, "%ADJECTIVE% ", "")
	if(findtext(fragment, "%A% "))
		fragment = "\a [replacetext(fragment, "%A% ", "")]"
	. += fragment

/// Dream plays a random sound at you, chosen from all sounds in the folder
/datum/dream/hear_something
	weight = 500

	var/reserved_sound_channel

/datum/dream/hear_something/New()
	. = ..()
	RegisterSignal(SSsounds, COMSIG_SUBSYSTEM_POST_INITIALIZE, PROC_REF(ReserveSoundChannel))

/datum/dream/hear_something/GenerateDream(mob/living/carbon/dreamer)
	. = ..()
	. += pick("you wind up a toy", "you hear something strange", "you pick out a record to play", "you hit shuffle on your music player")
	. += CALLBACK(src, PROC_REF(PlayRandomSound))
	. += "it reminds you of something"

/datum/dream/hear_something/OnDreamEnd(mob/living/carbon/dreamer)
	. = ..()
	// In case we play some long ass music track
	addtimer(CALLBACK(src, PROC_REF(StopSound), dreamer), 5 SECONDS)

/datum/dream/hear_something/proc/ReserveSoundChannel()
	reserved_sound_channel = SSsounds.reserve_sound_channel(src)
	UnregisterSignal(SSsounds, COMSIG_SUBSYSTEM_POST_INITIALIZE)

/datum/dream/hear_something/proc/PlayRandomSound(mob/living/carbon/dreamer)
	var/sound/random_sound = sound(pick(SSsounds.all_sounds), channel=reserved_sound_channel)
	random_sound.status = SOUND_STREAM
	SEND_SOUND(dreamer, random_sound)
	return "you hear something you weren't expecting!"

/datum/dream/hear_something/proc/StopSound(mob/living/carbon/dreamer)
	SEND_SOUND(dreamer, sound(channel=reserved_sound_channel))

/// Heretics can see dreams about random machinery from the perspective of a random unused influence
/datum/dream/heretic
	sleep_until_finished = TRUE
	/// The influence we will be dreaming about
	var/obj/effect/heretic_influence/influence
	/// The distance to the objects visible from the influence during the dream
	var/dream_view_range = 5
	var/list/what_you_can_see = list(
		/obj/item,
		/obj/structure,
		/obj/machinery,
	)
	var/static/list/what_you_cant_see = typecacheof(list(
		// Underfloor stuff and default wallmounts
		/obj/item/radio/intercom,
		/obj/structure/cable,
		/obj/structure/disposalpipe/segment,
		/obj/machinery/atmospherics/pipe/smart/manifold4w,
		/obj/machinery/atmospherics/components/unary/vent_scrubber,
		/obj/machinery/atmospherics/components/unary/vent_pump,
		/obj/machinery/duct,
		/obj/machinery/navbeacon,
		/obj/machinery/power/terminal,
		/obj/machinery/power/apc,
		/obj/machinery/light_switch,
		/obj/machinery/light,
		/obj/machinery/camera,
		/obj/machinery/door/firedoor,
		/obj/machinery/firealarm,
		/obj/machinery/airalarm,
		/obj/structure/window/fulltile,
		/obj/structure/window/reinforced/fulltile,
	))
	/// Cached list of allowed typecaches for each type in what_you_can_see
	var/static/list/allowed_typecaches_by_root_type = null

/datum/dream/heretic/New(obj/effect/heretic_influence/found_influence)
	influence = found_influence

/datum/dream/heretic/GenerateDream(mob/living/carbon/dreamer)
	. = list()
	. += "You wander through the forest of Mansus"
	. += "There is a " + pick("pond", "well", "lake", "puddle", "stream", "spring", "brook", "marsh")

	dreamer.add_mood_event("mansus_dream_fatigue", /datum/mood_event/mansus_dream_fatigue)

	if(isnull(allowed_typecaches_by_root_type))
		allowed_typecaches_by_root_type = list()
		for(var/type in what_you_can_see)
			allowed_typecaches_by_root_type[type] = typecacheof(type) - what_you_cant_see

	var/list/all_objects = oview(dream_view_range, influence)
	var/something_found = FALSE
	for(var/object_type in allowed_typecaches_by_root_type)
		var/list/filtered_objects = typecache_filter_list(all_objects, allowed_typecaches_by_root_type[object_type])
		if(filtered_objects.len)
			if (!something_found)
				. += "Its waters reflect"
				something_found = TRUE
			var/obj/found_object = pick(filtered_objects)
			. += initial(found_object.name)
	if(!something_found)
		. += pick("It's pitch black", "The reflections are vague", "You stroll aimlessly")
	else
		. += "The images fade in the ripples"
	. += "You feel exhausted"

/datum/mood_event/mansus_dream_fatigue
	description = "I must recover before I can dream of Mansus again."
	mood_change = -2
	timeout = 5 MINUTES

#undef DREAMING_SOURCE