weather.dm

/**
  * Causes weather to occur on a z level in certain area types
  *
  * The effects of weather occur across an entire z-level. For instance, lavaland has periodic ash storms that scorch most unprotected creatures.
  * Weather always occurs on different z levels at different times, regardless of weather type.
  * Can have custom durations, targets, and can automatically protect indoor areas.
  *
  */

/datum/weather
	/// name of weather
	var/name = "space wind"
	/// description of weather
	var/desc = "Heavy gusts of wind blanket the area, periodically knocking down anyone caught in the open."
    /// The message displayed in chat to foreshadow the weather's beginning
	var/telegraph_message = "<span class='warning'>The wind begins to pick up.</span>"
	/// In deciseconds, how long from the beginning of the telegraph until the weather begins
	var/telegraph_duration = 300
	/// The sound file played to everyone on an affected z-level
	var/telegraph_sound
	/// The overlay applied to all tiles on the z-level
	var/telegraph_overlay

	/// Displayed in chat once the weather begins in earnest
	var/weather_message = "<span class='userdanger'>The wind begins to blow ferociously!</span>"
	/// In deciseconds, how long the weather lasts once it begins
	var/weather_duration = 1200
	/// See above - this is the lowest possible duration
	var/weather_duration_lower = 1200
	/// See above - this is the highest possible duration
	var/weather_duration_upper = 1500
	/// Looping sound while weather is occuring
	var/weather_sound
	/// Area overlay while the weather is occuring
	var/weather_overlay
	/// Color to apply to the area while weather is occuring
	var/weather_color = null

	/// Displayed once the weather is over
	var/end_message = "<span class='danger'>The wind relents its assault.</span>"
	/// In deciseconds, how long the "wind-down" graphic will appear before vanishing entirely
	var/end_duration = 300
	/// Sound that plays while weather is ending
	var/end_sound
	/// Area overlay while weather is ending
	var/end_overlay

	/// Types of area to affect
	var/area_type = /area/space
	/// TRUE value protects areas with outdoors marked as false, regardless of area type
	var/protect_indoors = FALSE
	/// Areas to be affected by the weather, calculated when the weather begins
	var/list/impacted_areas = list()
	/// Areas that are protected and excluded from the affected areas.
	var/list/protected_areas = list()
	/// The list of z-levels that this weather is actively affecting
	var/impacted_z_levels

    /// Since it's above everything else, this is the layer used by default. TURF_LAYER is below mobs and walls if you need to use that.
	var/overlay_layer = AREA_LAYER
	/// Plane for the overlay
	var/overlay_plane = BLACKNESS_PLANE
	/// If the weather has no purpose other than looks
	var/aesthetic = FALSE
	/// Used by mobs to prevent them from being affected by the weather
	var/immunity_type = "storm"

    /// The stage of the weather, from 1-4
	var/stage = END_STAGE

	/// Weight amongst other eligible weather. If zero, will never happen randomly.
	var/probability = 0
	/// The z-level trait to affect when run randomly or when not overridden.
	var/target_trait = ZTRAIT_STATION

	/// Whether a barometer can predict when the weather will happen
	var/barometer_predictable = FALSE
	/// For barometers to know when the next storm will hit
	var/next_hit_time = 0

/datum/weather/New(z_levels)
	..()
	impacted_z_levels = z_levels

/**
  * Telegraphs the beginning of the weather on the impacted z levels
  *
  * Sends sounds and details to mobs in the area
  * Calculates duration and hit areas, and makes a callback for the actual weather to start
  *
  */
/datum/weather/proc/telegraph()
	if(stage == STARTUP_STAGE)
		return
	stage = STARTUP_STAGE
	var/list/affectareas = list()
	for(var/V in get_areas(area_type))
		affectareas += V
	for(var/V in protected_areas)
		affectareas -= get_areas(V)
	for(var/V in affectareas)
		var/area/A = V
		if(protect_indoors && !A.outdoors)
			continue
		if(A.z in impacted_z_levels)
			impacted_areas |= A
	weather_duration = rand(weather_duration_lower, weather_duration_upper)
	START_PROCESSING(SSweather, src)
	update_areas()
	for(var/M in GLOB.player_list)
		var/turf/mob_turf = get_turf(M)
		if(mob_turf && (mob_turf.z in impacted_z_levels))
			if(telegraph_message)
				to_chat(M, telegraph_message)
			if(telegraph_sound)
				SEND_SOUND(M, sound(telegraph_sound))
	addtimer(CALLBACK(src, .proc/start), telegraph_duration)

/**
  * Starts the actual weather and effects from it
  *
  * Updates area overlays and sends sounds and messages to mobs to notify them
  * Begins dealing effects from weather to mobs in the area
  *
  */
/datum/weather/proc/start()
	if(stage >= MAIN_STAGE)
		return
	stage = MAIN_STAGE
	update_areas()
	for(var/M in GLOB.player_list)
		var/turf/mob_turf = get_turf(M)
		if(mob_turf && (mob_turf.z in impacted_z_levels))
			if(weather_message)
				to_chat(M, weather_message)
			if(weather_sound)
				SEND_SOUND(M, sound(weather_sound))
	addtimer(CALLBACK(src, .proc/wind_down), weather_duration)

/**
  * Weather enters the winding down phase, stops effects
  *
  * Updates areas to be in the winding down phase
  * Sends sounds and messages to mobs to notify them
  *
  */
/datum/weather/proc/wind_down()
	if(stage >= WIND_DOWN_STAGE)
		return
	stage = WIND_DOWN_STAGE
	update_areas()
	for(var/M in GLOB.player_list)
		var/turf/mob_turf = get_turf(M)
		if(mob_turf && (mob_turf.z in impacted_z_levels))
			if(end_message)
				to_chat(M, end_message)
			if(end_sound)
				SEND_SOUND(M, sound(end_sound))
	addtimer(CALLBACK(src, .proc/end), end_duration)

/**
  * Fully ends the weather
  *
  * Effects no longer occur and area overlays are removed
  * Removes weather from processing completely
  *
  */
/datum/weather/proc/end()
	if(stage == END_STAGE)
		return 1
	stage = END_STAGE
	STOP_PROCESSING(SSweather, src)
	update_areas()

/**
  * Returns TRUE if the living mob can be affected by the weather
  *
  */
/datum/weather/proc/can_weather_act(mob/living/L)
	var/turf/mob_turf = get_turf(L)
	if(mob_turf && !(mob_turf.z in impacted_z_levels))
		return
	if(immunity_type in L.weather_immunities)
		return
	if(!(get_area(L) in impacted_areas))
		return
	return TRUE

/**
  * Affects the mob with whatever the weather does
  *
  */
/datum/weather/proc/weather_act(mob/living/L)
	return

/**
  * Updates the overlays on impacted areas
  *
  */
/datum/weather/proc/update_areas()
	for(var/V in impacted_areas)
		var/area/N = V
		N.layer = overlay_layer
		N.plane = overlay_plane
		N.icon = 'icons/effects/weather_effects.dmi'
		N.color = weather_color
		switch(stage)
			if(STARTUP_STAGE)
				N.icon_state = telegraph_overlay
			if(MAIN_STAGE)
				N.icon_state = weather_overlay
			if(WIND_DOWN_STAGE)
				N.icon_state = end_overlay
			if(END_STAGE)
				N.color = null
				N.icon_state = ""
				N.icon = 'icons/turf/areas.dmi'
				N.layer = initial(N.layer)
				N.plane = initial(N.plane)
				N.set_opacity(FALSE)