extends Node

## Autoload: central sound playback with variation + pitch randomization.
##
## Why: identical samples played back-to-back sound robotic. Real games ship
## 3-5 variations per event and randomize pitch a few percent per shot. This
## manager makes that the default for every sound in the game.
##
## Usage:
##   AudioManager.play_3d("ak47_fire", muzzle_global_pos)
##   AudioManager.play_ui("hit_confirm")
##   AudioManager.register_sound("footstep_metal", [
##       "res://assets/sounds/footstep_metal_01.wav",
##       "res://assets/sounds/footstep_metal_02.wav",
##   ], "Footsteps")
##
## Sounds are auto-registered from assets/sounds/*.wav on startup (the file
## stem is the sound id). Drop variations next to the original with _01/_02/…
## suffixes and they are picked up as one id with random selection:
##   footstep.wav, footstep_01.wav, footstep_02.wav -> id "footstep" (3 vars)
##
## Buses: Master <- SFX <- {Weapons, Explosions, Footsteps, Movement, UI,
## Wind}, Master <- Music.  The master hard limiter is a safety net, not a
## loudness tool: checked-in assets are already mastered with headroom.

const SOUNDS_DIR := "res://assets/sounds"
const POOL_SIZE_3D := 32
const POOL_SIZE_2D := 8

# id -> { "streams": Array[AudioStream], "bus": String, "pitch_var": float, "volume_db": float }
var _library: Dictionary = {}
var _pool_3d: Array[AudioStreamPlayer3D] = []
var _pool_2d: Array[AudioStreamPlayer] = []
var _next_3d: int = 0
var _next_2d: int = 0
var _last_ui_play_ms: Dictionary = {}
var _last_variant: Dictionary = {}

# Default routing/tuning per id prefix (applied during auto-registration).
const BUS_HINTS := {
	"footstep": "Footsteps",
	"explosion": "Explosions",
	"movement": "Movement",
	"projectile": "Movement",
	"ui_": "UI",
	"weapon": "Weapons",
	"fire": "Weapons",
	"reload": "Weapons",
}

## Old gameplay ids remain API-compatible while resolving to the remastered
## event families.  Keeping aliases here avoids sound-path knowledge spreading
## back into every weapon and HUD script.
const PREMIUM_ALIASES := {
	"ak47_fire": "weapon_ak47",
	"m4_fire": "weapon_m4",
	"mp7_fire": "weapon_mp7",
	"dmr_fire": "weapon_dmr",
	"awp_fire": "weapon_awp",
	"shotgun_fire": "weapon_shotgun",
	"nailgun_fire": "weapon_nailgun",
	"plasma_fire": "weapon_plasma",
	"rocket_fire": "weapon_rocket",
	"swarm_fire": "weapon_swarm",
	"mortar_fire": "weapon_mortar",
	"knife_swing": "weapon_knife",
	"shotgun_reload": "weapon_reload",
	"explosion": "explosion_deep",
	"bullet_impact": "impact_bullet",
	"footstep": "footstep_concrete",
	"wind": "movement_wind",
	"slide": "movement_slide_concrete",
	"wallrun": "movement_wallrun",
	"dash": "movement_dash",
	"jump": "movement_jump",
	"double_jump": "movement_double_jump",
	"vault": "movement_vault",
	"land": "movement_land",
	"grapple_launch": "movement_grapple_launch",
	"grapple_latch": "movement_grapple_latch",
	"grapple_reel": "movement_grapple_reel",
	"rocket_flight": "projectile_rocket_loop",
	"swarm_flight": "projectile_swarm_loop",
	"hit_confirm": "ui_confirm_premium",
	"kill_confirm": "ui_kill_premium",
	"ui_hover": "ui_hover_premium",
	"ui_click": "ui_click_premium",
	"ui_confirm": "ui_confirm_premium",
	"ui_error": "ui_error_premium",
	"ui_equip": "ui_equip_premium",
}

## Mix intent belongs beside event registration.  Source files have controlled
## peaks; these values establish hierarchy and variation without per-call magic
## numbers.  Loops opt into sample-accurate looping when loaded.
const EVENT_TUNING := {
	"weapon_ak47": {"bus": "Weapons", "pitch": 0.025, "db": -3.0},
	"weapon_m4": {"bus": "Weapons", "pitch": 0.022, "db": -3.5},
	"weapon_mp7": {"bus": "Weapons", "pitch": 0.028, "db": -5.0},
	"weapon_dmr": {"bus": "Weapons", "pitch": 0.018, "db": -2.5},
	"weapon_awp": {"bus": "Weapons", "pitch": 0.015, "db": -1.5},
	"weapon_shotgun": {"bus": "Weapons", "pitch": 0.020, "db": -2.0},
	"weapon_nailgun": {"bus": "Weapons", "pitch": 0.025, "db": -4.0},
	"weapon_plasma": {"bus": "Weapons", "pitch": 0.025, "db": -4.0},
	"weapon_rocket": {"bus": "Weapons", "pitch": 0.018, "db": -3.0},
	"weapon_swarm": {"bus": "Weapons", "pitch": 0.025, "db": -4.0},
	"weapon_mortar": {"bus": "Weapons", "pitch": 0.015, "db": -2.0},
	"weapon_knife": {"bus": "Weapons", "pitch": 0.035, "db": -5.0},
	"weapon_reload": {"bus": "Weapons", "pitch": 0.018, "db": -7.0},
	"explosion_deep": {"bus": "Explosions", "pitch": 0.018, "db": 0.5},
	"impact_bullet": {"bus": "Impacts", "pitch": 0.045, "db": -5.0},
	"footstep_concrete": {"bus": "Footsteps", "pitch": 0.035, "db": -4.0},
	"footstep_metal": {"bus": "Footsteps", "pitch": 0.030, "db": -5.0},
	"footstep_wood": {"bus": "Footsteps", "pitch": 0.040, "db": -4.0},
	"footstep_glass": {"bus": "Footsteps", "pitch": 0.025, "db": -6.0},
	"movement_wind": {"bus": "Wind", "pitch": 0.0, "db": 0.0, "loop": true},
	"movement_slide_concrete": {"bus": "Movement", "pitch": 0.0, "db": 0.0, "loop": true},
	"movement_slide_metal": {"bus": "Movement", "pitch": 0.0, "db": -1.0, "loop": true},
	"movement_slide_wood": {"bus": "Movement", "pitch": 0.0, "db": 0.0, "loop": true},
	"movement_slide_glass": {"bus": "Movement", "pitch": 0.0, "db": -2.0, "loop": true},
	"movement_wallrun": {"bus": "Movement", "pitch": 0.0, "db": -1.0, "loop": true},
	"movement_grapple_reel": {"bus": "Movement", "pitch": 0.0, "db": -4.0, "loop": true},
	"movement_grapple_launch": {"bus": "Movement", "pitch": 0.010, "db": -3.0},
	"movement_grapple_latch": {"bus": "Movement", "pitch": 0.008, "db": -3.0},
	"movement_dash": {"bus": "Movement", "pitch": 0.015, "db": -2.5},
	"movement_jump": {"bus": "Movement", "pitch": 0.010, "db": -3.5},
	"movement_double_jump": {"bus": "Movement", "pitch": 0.010, "db": -3.2},
	"movement_vault": {"bus": "Movement", "pitch": 0.025, "db": -6.0},
	"movement_land": {"bus": "Movement", "pitch": 0.025, "db": -4.0},
	"projectile_rocket_loop": {"bus": "Movement", "pitch": 0.015, "db": -4.0, "loop": true},
	"projectile_swarm_loop": {"bus": "Movement", "pitch": 0.020, "db": -6.0, "loop": true},
	"ui_hover_premium": {"bus": "UI", "pitch": 0.008, "db": -5.0, "cooldown": 55},
	"ui_click_premium": {"bus": "UI", "pitch": 0.006, "db": -3.5, "cooldown": 30},
	"ui_confirm_premium": {"bus": "UI", "pitch": 0.005, "db": -3.0},
	"ui_kill_premium": {"bus": "UI", "pitch": 0.005, "db": -1.5},
	"ui_error_premium": {"bus": "UI", "pitch": 0.005, "db": -3.0},
	"ui_equip_premium": {"bus": "UI", "pitch": 0.006, "db": -3.0},
}

## weapon_name (as broadcast in fire RPCs) -> fire sound id.
const WEAPON_SOUND_IDS := {
	"AK-47": "ak47_fire", "M4": "m4_fire", "MP7": "mp7_fire",
	"DMR": "dmr_fire", "AWP": "awp_fire",
	"Double Barrel": "shotgun_fire", "Nail Gun": "nailgun_fire",
	"Plasma Gun": "plasma_fire", "Rocket Launcher": "rocket_fire",
	"Rocket Swarm": "swarm_fire", "Mortar": "mortar_fire",
	"Knife": "knife_swing",
}

## Sounds loud enough to slap back off nearby walls (early reflections).
const OCCLUSION_TICK := 0.12
var _occlusion_accum := 0.0


func _ready() -> void:
	_setup_buses()
	_build_pools()
	_auto_register_sounds()
	print("AudioManager: %d sounds registered" % _library.size())


func _physics_process(delta: float) -> void:
	# Re-filter playing positional sounds as the listener/source move so
	# walking behind a wall audibly muffles loops and long tails too.
	_occlusion_accum += delta
	if _occlusion_accum < OCCLUSION_TICK:
		return
	_occlusion_accum = 0.0
	var cam := get_viewport().get_camera_3d()
	if cam == null:
		return
	var listener := cam.global_position
	for p in _pool_3d:
		if p.playing and not p.get_meta("is_reflection", false):
			Acoustics.apply_occlusion(p, Acoustics.occlusion(
				cam.get_world_3d(), listener, p.global_position))
	# External looping players (projectile flight sounds, etc.) opt in by
	# joining this group.
	for node in get_tree().get_nodes_in_group("acoustic_occluded"):
		if node is AudioStreamPlayer3D and node.playing and node.is_inside_tree():
			Acoustics.apply_occlusion(node, Acoustics.occlusion(
				cam.get_world_3d(), listener, node.global_position))


func weapon_sound_id(weapon_name: String) -> String:
	return WEAPON_SOUND_IDS.get(weapon_name, "")


# ── Bus layout ────────────────────────────────────────────────────────────────

func _setup_buses() -> void:
	_ensure_bus("SFX", "Master")
	_ensure_bus("Weapons", "SFX")
	_ensure_bus("Explosions", "SFX")
	_ensure_bus("Impacts", "SFX")
	_ensure_bus("Footsteps", "SFX")
	_ensure_bus("Movement", "SFX")
	_ensure_bus("Ambience", "SFX")
	_ensure_bus("UI", "SFX")
	_ensure_bus("Music", "Master")
	_ensure_bus("Wind", "SFX")
	_install_mix_effects()


func _ensure_bus(bus_name: String, send_to: String) -> void:
	var idx := AudioServer.get_bus_index(bus_name)
	if idx == -1:
		idx = AudioServer.bus_count
		AudioServer.add_bus(idx)
		AudioServer.set_bus_name(idx, bus_name)
	if bus_name != "Master":
		AudioServer.set_bus_send(idx, send_to)


func _install_mix_effects() -> void:
	var master := AudioServer.get_bus_index("Master")
	if master >= 0 and not _bus_has_effect(master, "AudioEffectHardLimiter"):
		var limiter := AudioEffectHardLimiter.new()
		limiter.ceiling_db = -1.0
		limiter.pre_gain_db = 0.0
		limiter.release = 0.10
		AudioServer.add_bus_effect(master, limiter)

	var weapons := AudioServer.get_bus_index("Weapons")
	if weapons >= 0 and not _bus_has_effect(weapons, "AudioEffectCompressor"):
		var punch := AudioEffectCompressor.new()
		punch.threshold = -9.0
		punch.ratio = 2.0
		punch.attack_us = 1800.0
		punch.release_ms = 95.0
		punch.gain = 0.5
		punch.mix = 0.42
		AudioServer.add_bus_effect(weapons, punch)

	var explosions := AudioServer.get_bus_index("Explosions")
	if explosions >= 0 and not _bus_has_effect(explosions, "AudioEffectCompressor"):
		var depth := AudioEffectCompressor.new()
		depth.threshold = -10.0
		depth.ratio = 1.8
		depth.attack_us = 2000.0
		depth.release_ms = 240.0
		depth.gain = 0.5
		depth.mix = 0.35
		AudioServer.add_bus_effect(explosions, depth)


func _bus_has_effect(bus: int, effect_class: String) -> bool:
	for i in AudioServer.get_bus_effect_count(bus):
		var effect := AudioServer.get_bus_effect(bus, i)
		if effect and effect.is_class(effect_class):
			return true
	return false


func set_bus_volume_linear(bus_name: String, linear: float) -> void:
	var idx := AudioServer.get_bus_index(bus_name)
	if idx != -1:
		AudioServer.set_bus_volume_db(idx, linear_to_db(clampf(linear, 0.0001, 1.0)))


# ── Registration ──────────────────────────────────────────────────────────────

func register_sound(id: String, paths: Array, bus: String = "SFX",
		pitch_var: float = 0.06, volume_db: float = 0.0) -> void:
	var streams: Array = []
	for p in paths:
		if ResourceLoader.exists(p):
			var s = load(p)
			if s:
				streams.append(s)
	if streams.is_empty():
		return
	_library[id] = {
		"streams": streams,
		"bus": bus,
		"pitch_var": pitch_var,
		"volume_db": volume_db,
	}


func _auto_register_sounds() -> void:
	var dir := DirAccess.open(SOUNDS_DIR)
	if not dir:
		return
	# Group files: "footstep_01.wav" and "footstep.wav" both map to "footstep".
	var groups: Dictionary = {}
	for fname in dir.get_files():
		if not (fname.ends_with(".wav") or fname.ends_with(".ogg") or fname.ends_with(".mp3")):
			continue
		var stem := fname.get_basename()
		var base := stem
		var parts := stem.rsplit("_", true, 1)
		if parts.size() == 2 and parts[1].is_valid_int():
			base = parts[0]
		if not groups.has(base):
			groups[base] = []
		groups[base].append(SOUNDS_DIR + "/" + fname)

	for id in groups:
		var bus := "SFX"
		for hint in BUS_HINTS:
			if id.findn(hint) != -1:
				bus = BUS_HINTS[hint]
				break
		var tuning: Dictionary = EVENT_TUNING.get(id, {})
		register_sound(id, groups[id],
			str(tuning.get("bus", bus)),
			float(tuning.get("pitch", 0.045)),
			float(tuning.get("db", 0.0)))


func has_sound(id: String) -> bool:
	return _library.has(_resolve_id(id))


func _resolve_id(id: String) -> String:
	var premium: String = str(PREMIUM_ALIASES.get(id, id))
	return premium if _library.has(premium) else id


## Build an AudioStreamRandomizer for a registered id: every play() picks a
## random variation with random pitch. For nodes that own their own player
## (weapons) instead of going through the pools. Falls back to a plain load
## of fallback_path if the id isn't registered.
func stream_for(id: String, fallback_path: String = "") -> AudioStream:
	var resolved := _resolve_id(id)
	var entry = _library.get(resolved)
	if entry == null:
		return load(fallback_path) if fallback_path != "" and ResourceLoader.exists(fallback_path) else null
	var r := AudioStreamRandomizer.new()
	r.random_pitch = 1.0 + entry["pitch_var"]
	for s in entry["streams"]:
		if bool(EVENT_TUNING.get(resolved, {}).get("loop", false)):
			_enable_loop(s)
		r.add_stream(-1, s)
	return r


## Configure an owned AudioStreamPlayer/AudioStreamPlayer3D from the same event
## metadata used by pooled playback.  This erases the old per-weapon gain/bus
## lottery while letting weapons keep their existing player nodes.
func configure_player(player: Node, id: String, fallback_path: String = "",
		volume_db_offset: float = 0.0) -> void:
	if player == null:
		return
	var resolved := _resolve_id(id)
	var entry = _library.get(resolved)
	player.set("stream", stream_for(id, fallback_path))
	if entry:
		player.set("bus", entry["bus"])
		player.set("volume_db", float(entry["volume_db"]) + volume_db_offset)
	if player is AudioStreamPlayer3D:
		var spatial := player as AudioStreamPlayer3D
		spatial.unit_size = 7.0
		spatial.max_distance = 85.0
		# Automatic fire must not amputate the body/tail of the previous shot.
		# Godot defaults to one voice per player, which was making every rifle
		# turn into a dry click train under sustained fire.
		spatial.max_polyphony = 8 if resolved.begins_with("weapon_") \
			and resolved != "weapon_reload" else 1
	elif player is AudioStreamPlayer:
		(player as AudioStreamPlayer).max_polyphony = 4


func _enable_loop(stream: AudioStream) -> void:
	if stream is AudioStreamWAV:
		var wav := stream as AudioStreamWAV
		wav.loop_mode = AudioStreamWAV.LOOP_FORWARD
		wav.loop_begin = 0
		wav.loop_end = maxi(1, roundi(wav.get_length() * wav.mix_rate))
	elif stream is AudioStreamOggVorbis:
		(stream as AudioStreamOggVorbis).loop = true


func _pick_stream(id: String, entry: Dictionary) -> AudioStream:
	var streams: Array = entry["streams"]
	if streams.size() <= 1:
		return streams[0]
	var previous := int(_last_variant.get(id, -1))
	var pick := randi_range(0, streams.size() - 2)
	if pick >= previous:
		pick += 1
	_last_variant[id] = pick
	return streams[pick]


# ── Playback ──────────────────────────────────────────────────────────────────

func _build_pools() -> void:
	for i in POOL_SIZE_3D:
		var p := AudioStreamPlayer3D.new()
		p.name = "Pool3D_%d" % i
		p.max_distance = 80.0
		p.unit_size = 8.0
		add_child(p)
		_pool_3d.append(p)
	for i in POOL_SIZE_2D:
		var p := AudioStreamPlayer.new()
		p.name = "Pool2D_%d" % i
		add_child(p)
		_pool_2d.append(p)


## Play a positional sound with material-aware occlusion; loud sounds also
## spawn early reflections off nearby surfaces so they can be located.
## Safe to call every frame — players are pooled.
func play_3d(id: String, global_pos: Vector3, volume_db_offset: float = 0.0,
		pitch_scale: float = 1.0) -> AudioStreamPlayer3D:
	var resolved := _resolve_id(id)
	var entry = _library.get(resolved)
	if entry == null:
		return null
	var player := _pool_3d[_next_3d]
	_next_3d = (_next_3d + 1) % POOL_SIZE_3D
	player.stream = _pick_stream(resolved, entry)
	player.bus = entry["bus"]
	player.volume_db = entry["volume_db"] + volume_db_offset
	player.pitch_scale = pitch_scale * randf_range(1.0 - entry["pitch_var"], 1.0 + entry["pitch_var"])
	player.global_position = global_pos
	player.set_meta("is_reflection", false)
	var cam := get_viewport().get_camera_3d()
	if cam:
		var occ := Acoustics.occlusion(cam.get_world_3d(), cam.global_position, global_pos)
		Acoustics.apply_occlusion(player, occ)
		if _is_loud(resolved):
			_spawn_reflections(player.stream, global_pos, cam, entry, volume_db_offset)
	else:
		Acoustics.apply_occlusion(player, { "db": 0.0, "cutoff": Acoustics.OPEN_CUTOFF, "surfaces": 0 })
	player.play()
	return player


func _is_loud(id: String) -> bool:
	return id.begins_with("weapon_") or id.begins_with("explosion")


## Delayed, filtered copies of a loud sound from nearby wall mirror points.
func _spawn_reflections(stream: AudioStream, source: Vector3, cam: Camera3D,
		entry: Dictionary, volume_db_offset: float) -> void:
	var refls := Acoustics.reflections(cam.get_world_3d(), source, cam.global_position)
	for r in refls:
		get_tree().create_timer(r.delay).timeout.connect(func():
			var p := _pool_3d[_next_3d]
			_next_3d = (_next_3d + 1) % POOL_SIZE_3D
			p.stream = stream
			p.bus = entry["bus"]
			p.volume_db = entry["volume_db"] + volume_db_offset + r.db
			p.pitch_scale = randf_range(0.97, 1.0)
			p.global_position = r.point
			p.set_meta("is_reflection", true)
			p.attenuation_filter_cutoff_hz = r.cutoff
			p.attenuation_filter_db = Acoustics.DEFAULT_FILTER_DB
			p.play()
		)


## Play a non-positional event on its authored bus.  Local movement feedback
## uses this too; play_ui adds hover/click rate limiting on top.
func play_local(id: String, volume_db_offset: float = 0.0,
		pitch_scale: float = 1.0) -> AudioStreamPlayer:
	var resolved := _resolve_id(id)
	var entry = _library.get(resolved)
	if entry == null:
		return null
	var player := _pool_2d[_next_2d]
	_next_2d = (_next_2d + 1) % POOL_SIZE_2D
	player.stream = _pick_stream(resolved, entry)
	player.bus = entry["bus"]
	player.volume_db = entry["volume_db"] + volume_db_offset
	player.pitch_scale = pitch_scale * randf_range(
		1.0 - entry["pitch_var"], 1.0 + entry["pitch_var"])
	player.play()
	return player


## Play a non-positional UI sound.  A small per-event cooldown stops a pointer
## sweeping across a dense menu from turning gentle hovers into a grating buzz.
func play_ui(id: String, volume_db_offset: float = 0.0) -> AudioStreamPlayer:
	var resolved := _resolve_id(id)
	var cooldown := int(EVENT_TUNING.get(resolved, {}).get("cooldown", 0))
	var now := Time.get_ticks_msec()
	if cooldown > 0 and now - int(_last_ui_play_ms.get(resolved, -cooldown)) < cooldown:
		return null
	_last_ui_play_ms[resolved] = now
	return play_local(id, volume_db_offset)