extends Node
## Autoload "PlayerNet": each player's character on a dedicated server (M2.4,
## docs/MULTIPLAYER_PLAN.md §5). Online, the server decides; offline (single
## player) there's no server and the game decides, exactly as before.
##
## - Your game sends what you want to do: `ask("eat", [slot])`,
##   `ask("hit", [tree uid, point])`... (Actions does this for every intent
##   while online, instead of acting itself).
## - The server runs the same Actions rule on your character there
##   (server_player.gd), and sends back your inventory (after every request,
##   and whenever it changes) and your stats (4 times a second).
## - Clicks in your own inventory are also done on your screen straight away,
##   so dragging items doesn't wait for the network; the server's copy
##   replaces it once it has caught up with every click you sent.
## - Characters are saved per player in the server's world:
##   worlds/<world>/players/<player id>.json.

signal cursor_changed(stack)      ## client: the server says this is on your cursor

const ServerPlayer = preload("res://scripts/net/server_player.gd")
const STATS_INTERVAL := 0.25

# Server.
var proxies: Dictionary = {}      ## peer -> server_player.gd
var _acting := 0                  ## the peer whose request is being run (for its messages)
var _dirty: Dictionary = {}       ## peers whose inventory changed
var _acks: Dictionary = {}        ## peer -> last request id handled
var _stats_left := 0.0
var _root: Node3D
var cheats := false               ## --debug-cheats (tests only): give items, set stats, die

# Client.
var _seq := 0                     ## id of the last request we sent
var world: Node3D

func _ready() -> void:
	Actions.notify.connect(_route_notify)
	cheats = Net.parse_args(OS.get_cmdline_user_args()).has("debug-cheats")

# --- server --------------------------------------------------------------------

func _route_notify(text: String) -> void:
	if Net.is_server() and _acting != 0 and proxies.has(_acting):
		_s2c_notify.rpc_id(_acting, text)

func _players_root() -> Node3D:
	if _root == null or not is_instance_valid(_root):
		_root = Node3D.new()
		_root.name = "Players"
		WorldNet.world.add_child(_root)
	return _root

func _file(id: String) -> String:
	return Saves.root_dir.path_join(Saves.current_id).path_join("players").path_join(id + ".json")

## A player came in: their character, from their save if they've been here
## before. Returns where they were (or INF for a new player).
func server_join(peer: int, id: String, display: String) -> Vector3:
	var p: Node3D = ServerPlayer.new()
	p.name = "P%d" % peer
	p.peer = peer
	p.player_id = id
	p.display = display
	_players_root().add_child(p)
	p.setup(WorldNet.world)
	proxies[peer] = p
	_acks[peer] = 0
	p.inventory.changed.connect(func(): _dirty[peer] = true; WorldNet.mark_changed())
	p.worn_changed.connect(func(): _dirty[peer] = true)
	p.survival.died.connect(_on_died.bind(peer))
	# A wolf bite or a boar: their screen flashes red, from the right side.
	p.survival.hurt.connect(func(amount, from):
		if proxies.has(peer):
			_s2c_hurt.rpc_id(peer, amount, from))
	var at := Vector3.INF
	var d := _read(_file(id))
	if not d.is_empty():
		p.load_data(d)
		var t: Node3D = WorldNet.world.terrain
		var pos := Vector3(d.pos[0], d.pos[1], d.pos[2]) if d.has("pos") else Vector3.INF
		if pos.is_finite() and t.inside_boundary(pos.x, pos.z, 1.0) and pos.y > t.sample_height(pos.x, pos.z) - 1.0:
			at = pos
		print("[server] %s's character loaded" % display)
	if at != Vector3.INF:
		p.global_position = at
	return at

func place_at(peer: int, pos: Vector3) -> void:
	if proxies.has(peer):
		proxies[peer].global_position = pos

func yaw_of(peer: int) -> float:
	return proxies[peer].rotation.y if proxies.has(peer) else 0.0

func server_leave(peer: int) -> void:
	var p: Node3D = proxies.get(peer)
	if p == null:
		return
	if p.survival.dead:
		_respawn(peer, false)   # left on the death screen: they come back alive
	_save(p)
	var w: Node3D = WorldNet.world
	if w != null and w.bobber_of(p) != null:
		w.end_fishing(p)
	proxies.erase(peer)
	_dirty.erase(peer)
	_acks.erase(peer)
	p.queue_free()
	_maybe_pass_night()   # (the last one awake leaving lets the others sleep)

func save_all() -> void:
	for p in proxies.values():
		_save(p)

func server_reset() -> void:
	proxies.clear()
	_dirty.clear()
	_acks.clear()
	_root = null

func _save(p: Node3D) -> void:
	var path := _file(p.player_id)
	DirAccess.make_dir_recursive_absolute(path.get_base_dir())
	var tmp := path + ".tmp"
	var f := FileAccess.open(tmp, FileAccess.WRITE)
	if f == null:
		printerr("[server] can't save %s's character" % p.display)
		return
	f.store_string(JSON.stringify(p.to_data(), "\t"))
	f.close()
	DirAccess.rename_absolute(tmp, path)

static func _read(path: String) -> Dictionary:
	if not FileAccess.file_exists(path):
		return {}
	var d: Variant = JSON.parse_string(FileAccess.get_file_as_string(path))
	return d if d is Dictionary else {}

func held(peer: int) -> String:
	return proxies[peer].held_item_id() if proxies.has(peer) else ""

## A move the server accepted: the character follows, and pays stamina for
## sprinting and jumping (the same costs as in your game).
func server_moved(peer: int, from: Vector3, to: Vector3, yaw: float, anim: int, dt: float) -> void:
	var p: Node3D = proxies.get(peer)
	if p == null:
		return
	var A := preload("res://scripts/net/avatar.gd").Anim
	if anim == A.RUN:
		p.survival.use_stamina(14.0 * dt, true)
	elif anim == A.AIR and p.anim != A.AIR and to.y > from.y + 0.05:
		p.survival.use_stamina(8.0)
	p.anim = anim
	p.velocity = (to - from) / maxf(dt, 0.001)
	p.global_position = to
	p.rotation.y = yaw
	if to.y < p.water_level - 0.6:
		p.survival.soak()
	if p.in_bed and to.distance_to(p.bed_at) > 1.5:
		p.in_bed = false
		tell(p.peer, "You got out of bed")

func _process(delta: float) -> void:
	if not Net.is_server() or proxies.is_empty():
		return
	for peer in _dirty.keys():
		_push_inv(peer)
	_dirty.clear()
	_stats_left -= delta
	if _stats_left <= 0.0:
		_stats_left = STATS_INTERVAL
		for peer in proxies:
			_push_stats(peer)

func push_all(peer: int) -> void:
	_push_inv(peer)
	_push_stats(peer)

func _push_inv(peer: int) -> void:
	var p: Node3D = proxies.get(peer)
	if p != null:
		_s2c_inv.rpc_id(peer, p.inventory.to_data(), p.cursor, p.worn, int(_acks.get(peer, 0)))

func _push_stats(peer: int) -> void:
	var p: Node3D = proxies.get(peer)
	if p == null:
		return
	var s: Node = p.survival
	_s2c_stats.rpc_id(peer, s.to_data(), s.statuses, [s.roofed, s.sheltered, s.heat],
		[p.has_bed_spawn, p.bed_spawn])

## Death on the server: everything goes into a grave where they fell (with
## their name on it), and they wake at their bed or the island start.
func _on_died(peer: int) -> void:
	var p: Node3D = proxies.get(peer)
	var w: Node3D = WorldNet.world
	if p == null or w == null:
		return
	_acting = peer
	var pos: Vector3 = p.global_position
	pos.y = w.terrain.sample_height(pos.x, pos.z)
	if pos.y < w.terrain.water_level:
		pos = w.terrain.find_spawn(Vector2(pos.x, pos.z))
	if not p.worn.is_empty() and p.inventory.add(p.worn, 1) == 0:
		p.worn = ""
	if p.cursor != null:
		p.inventory.add(p.cursor.id, p.cursor.count)
		p.cursor = null
	var has_items := false
	for st in p.inventory.slots:
		if st != null:
			has_items = true
	if has_items:
		var g: Node3D = w.spawn_piece(ItemDB.get_item("grave"), Transform3D(Basis(Vector3.UP, p.rotation.y), pos), {"owner_id": p.player_id, "owner_name": p.display})
		g.inventory.load_data(p.inventory.to_data())
		p.inventory.load_data(Inventory.new(p.inventory.size()).to_data())
	# They stay down on the death screen for a few seconds, then ask to respawn.
	p.died_at = Time.get_ticks_msec()
	_dirty[peer] = true
	_s2c_died.rpc_id(peer, p.survival.cause if not p.survival.cause.is_empty() else "You died", has_items, p.bed_piece(w) != null)
	_acting = 0

const RESPAWN_DELAY := 3.0

## Respawn (the death screen's button), once they've been down long enough:
## at their bed if it's still standing, otherwise the island start.
func _respawn(peer: int, tell: bool = true) -> void:
	var p: Node3D = proxies.get(peer)
	var w: Node3D = WorldNet.world
	if p == null or w == null or not p.survival.dead:
		return
	if tell and Time.get_ticks_msec() - p.died_at < RESPAWN_DELAY * 1000.0 - 100.0:
		return   # (too soon: the button only unlocks after the delay)
	var bed: Node3D = p.bed_piece(w)
	var at: Vector3
	var yaw := 0.0
	if bed != null:
		at = bed.global_position + Vector3(0, 0.9, 0)
		yaw = bed.global_basis.get_euler().y + PI
	else:
		if p.has_bed_spawn:
			p.has_bed_spawn = false
			Actions.notify.emit("Your bed is gone, so you woke at the island start")
		at = Net.island_spawn() + Vector3(0, 1.5, 0)
	p.survival.reset_after_death()
	p.global_position = at
	p.rotation.y = yaw
	Net.teleport(peer, at)
	_dirty[peer] = true
	if tell:
		_s2c_respawn.rpc_id(peer, at, yaw, "")
		_save(p)

# --- server: requests ------------------------------------------------------------

@rpc("any_peer", "call_remote", "reliable")
func _c2s_ask(seq: int, what: String, args: Array) -> void:
	var peer := multiplayer.get_remote_sender_id()
	var p: Node3D = proxies.get(peer)
	if not Net.is_server() or p == null or WorldNet.world == null:
		return
	_acting = peer
	if what == "respawn":
		_respawn(peer)
	elif not p.survival.dead:
		_run(p, what, args)
	_acting = 0
	_acks[peer] = maxi(int(_acks.get(peer, 0)), seq)
	_dirty[peer] = true   # (always answer, so the game knows we've caught up)

func _run(p: Node3D, what: String, a: Array) -> void:
	var w: Node3D = WorldNet.world
	match what:
		"select":
			p.select(_i(a, 0))
		"craft":
			Actions.craft(p, _s(a, 0))
		"eat":
			Actions.eat(p, _i(a, 0))
		"wear":
			Actions.wear(p, _i(a, 0))
		"take_off":
			Actions.take_off(p)
		"hit":
			var n: Node3D = w.props.resource_nodes.get(_s(a, 0))
			var at: Vector3 = _v(a, 1)
			if n != null and is_instance_valid(n) and at.is_finite() and Actions.harvest_hit(p, n, at):
				WorldNet.node_hit(n, at, p.global_position)
		"pickup":
			var key := _s(a, 0)
			var pk: Node3D = WorldNet.find_pickup(key)
			if pk != null and not pk.taken and Actions.pickup(p, pk):
				WorldNet.taken(key)
		"forage":
			var b: Node3D = w.props.forage.get(_s(a, 0))
			if b != null and Actions.forage(p, b):
				WorldNet.foraged(b)
		"place":
			var xf: Transform3D = a[1] if a.size() > 1 and a[1] is Transform3D else Transform3D()
			if xf.origin.is_finite() and xf.origin != Vector3.ZERO:
				Actions.place(p, _i(a, 0), xf.orthonormalized(), w)
		"dismantle":
			var piece := WorldNet.piece(_i(a, 0))
			if piece != null:
				Actions.dismantle(p, piece)
		"door":
			var d := WorldNet.piece(_i(a, 0))
			if d != null and d.get("open") != null and Actions.toggle_door(p, d):
				WorldNet.piece_state(d)
		"fuel":
			var f := WorldNet.piece(_i(a, 0))
			if f != null and f.get("fuel") != null and Actions.add_fuel(p, f):
				WorldNet.piece_state(f)
		"bed":
			var b := WorldNet.piece(_i(a, 0))
			if b != null and b.item_id == "bed":
				Actions.use_bed(p, b)
		"inv_click":
			# Slot `a[1]` of your own inventory (a[0] = 0) or a chest's.
			var inv: Inventory = p.inventory
			if _i(a, 0) != 0:
				var c := _container(p, _i(a, 0))
				if c == null:
					return
				inv = c.inventory
			var slot := _i(a, 1)
			if slot >= 0 and slot < inv.size():
				p.cursor = inv.click(slot, p.cursor, _b(a, 2))
		"transfer":
			# Shift-click: from your inventory into the chest, or the other way.
			var c := _container(p, _i(a, 0))
			if c == null:
				return
			var into_chest := _b(a, 2)
			var from: Inventory = p.inventory if into_chest else c.inventory
			var to: Inventory = c.inventory if into_chest else p.inventory
			var slot := _i(a, 1)
			if slot >= 0 and slot < from.size():
				Actions.transfer(p, from, slot, to, c)
		"close":
			# The inventory screen closed: what's on the cursor goes back in
			# your bag, or at your feet if it's full.
			if p.cursor != null:
				var left: int = p.inventory.add(p.cursor.id, p.cursor.count)
				if left > 0:
					w.drop_item(p.cursor.id, left, Transform3D(Basis(), p.global_position + Vector3(0, 0.1, 0)))
				p.cursor = null
		"debug_give":
			if cheats and not ItemDB.get_item(_s(a, 0)).is_empty():
				p.inventory.add(_s(a, 0), _i(a, 1))
		"debug_clear":
			if cheats:
				p.inventory.load_data(Inventory.new(p.inventory.size()).to_data())
		"debug_stats":
			if cheats and a.size() > 0 and a[0] is Dictionary:
				for k in a[0]:
					if k in ["health", "stamina", "hunger", "warmth"]:
						p.survival.set(k, float(a[0][k]))
					elif k == "diet" and a[0][k] is Dictionary:
						for g in a[0][k]:
							if p.survival.diet.has(g):
								p.survival.diet[g] = float(a[0][k][g])
		"debug_die":
			if cheats:
				p.survival.damage(10000.0, p.global_position)
		"debug_drop":
			if cheats and not ItemDB.get_item(_s(a, 0)).is_empty():
				w.drop_item(_s(a, 0), maxi(_i(a, 1), 1), Transform3D(Basis(), _v(a, 2)))
		# --- hunting and fishing (M2.5) ---
		# Arrows, spears and casts start from where the server knows you are
		# (your eyes), whatever your game says: only the aim comes from you.
		"melee":
			var c: Node3D = CreatureNet.creature(_i(a, 0))
			if c != null:
				Actions.melee(p, c)
		"butcher":
			var c: Node3D = CreatureNet.creature(_i(a, 0))
			if c != null:
				Actions.butcher(p, c)
		"shoot":
			var dir := _dir(a, 0)
			var power := clampf(float(a[1]) if a.size() > 1 and (a[1] is float or a[1] is int) else 0.0, 0.0, 1.0)
			if dir != Vector3.ZERO and Actions.can_draw(p):
				Actions.shoot(p, _eye(p) + dir * 0.5, dir, power, w)
		"throw":
			var dir := _dir(a, 1)
			if dir != Vector3.ZERO:
				Actions.throw_spear(p, _i(a, 0), _eye(p) + dir * 0.5 + Vector3(0, -0.05, 0), dir + Vector3(0, 0.06, 0), w)
		"cast":
			var dir := _dir(a, 0)
			if dir != Vector3.ZERO:
				Actions.cast_line(p, _eye(p) + dir * 0.6, dir, w)
		"reel":
			Actions.reel(p, w)
		"debug_spawn":
			if cheats and Creature.KINDS.has(_s(a, 0)) and _s(a, 0) != "wolf" and _v(a, 1).is_finite():
				w.creatures.spawn(_s(a, 0), _v(a, 1))
		"debug_time":
			if cheats:
				w.day_night.day = maxi(_i(a, 0), 1)
				w.day_night.time = clampf(float(a[1]) / 24.0, 0.0, 0.999) if a.size() > 1 else w.day_night.time
				w.day_night.apply(true)
				w.weather.snap()
				Net.push_clock()
		"debug_tp":
			var to := _v(a, 0)
			if cheats and to.is_finite():
				p.global_position = to
				Net.teleport(p.peer, to)
				_s2c_respawn.rpc_id(p.peer, to, p.rotation.y, "")
		"debug_hut":
			if cheats and _v(a, 0).is_finite():
				_debug_hut(_v(a, 0))
		_:
			Actions.notify.emit("Unknown request")

const Creature = preload("res://scripts/creatures/creature.gd")

static func _eye(p: Node3D) -> Vector3:
	return p.global_position + Vector3(0, 1.6, 0)

## A unit aim direction from the request, or ZERO.
static func _dir(a: Array, k: int) -> Vector3:
	var d := _v(a, k)
	return d.normalized() if d.is_finite() and d.length() > 0.01 else Vector3.ZERO

## Test hook: a closed hut (floors, walls, door, roof) with two beds in it.
func _debug_hut(center: Vector3) -> void:
	var w: Node3D = WorldNet.world
	var out: Dictionary = await w.build.debug_build_hut(center, 0.0)
	if out.pieces.is_empty():
		return
	var top: float = out.pieces[0].global_position.y
	for x in [-0.6, 0.6]:
		w.spawn_piece(ItemDB.get_item("bed"), Transform3D(Basis(), Vector3(center.x + x, top, center.z - 0.3)))

# --- server: messages, getting hurt, sleeping ----------------------------------------

func tell(peer: int, text: String) -> void:
	if proxies.has(peer):
		_s2c_notify.rpc_id(peer, text)

func tell_all(text: String) -> void:
	for peer in proxies:
		_s2c_notify.rpc_id(peer, text)

## The server's sleep rule (server.json "sleep"): how many of the players
## online must be in bed for the night to pass.
func _beds_needed(n: int) -> int:
	match String(Net.config.v("sleep")):
		"anyone": return 1
		"half": return ceili(n / 2.0)
	return n   # "all_online" (the default)

## Actions.use_bed decided `p` may sleep: they get into bed, and the night
## passes once enough players are in bed.
func go_to_bed(p: Node3D) -> void:
	p.in_bed = true
	p.bed_at = p.global_position
	if not _maybe_pass_night():
		var n: int = _alive().size()
		var asleep: int = _alive().filter(func(q): return q.in_bed).size()
		tell(p.peer, "You're in bed (%d of %d asleep). The night passes when %s." % [asleep, n,
			"everyone's in bed" if _beds_needed(n) >= n else "%d are" % _beds_needed(n)])
		for q in _alive():
			if q != p:
				tell(q.peer, "%s is in bed (%d of %d asleep)" % [p.display, asleep, n])

func _alive() -> Array:
	return proxies.values().filter(func(q): return not q.survival.dead)

## Everyone in bed (by the rule)? Then until 06:00 for all: the clock, fires,
## regrowth and weather move on; sleepers wake rested.
func _maybe_pass_night() -> bool:
	var w: Node3D = WorldNet.world
	var live := _alive()
	if w == null or live.is_empty():
		return false
	var asleep := live.filter(func(q): return q.in_bed)
	if asleep.size() < _beds_needed(live.size()):
		return false
	var secs: float = fposmod(6.0 - w.day_night.hours(), 24.0) / 24.0 * w.day_night.day_length
	w.skip_time(secs)
	for q in live:
		if q.in_bed:
			q.survival.after_sleep(secs)
		q.in_bed = false
		_s2c_slept.rpc_id(q.peer, asleep.has(q))
	Net.push_clock()
	WorldNet.save()
	return true

## The chest or grave `nid`, if this player may use it right now.
func _container(p: Node3D, nid: int) -> Node3D:
	var c := WorldNet.piece(nid)
	if c == null or c.get("inventory") == null or not Actions._in_reach(p, c, 1.0):
		return null
	var why: String = c.use_block_reason(p.player_id) if c.has_method("use_block_reason") else ""
	if not why.is_empty():
		Actions.notify.emit(why)
		return null
	return c

static func _i(a: Array, k: int) -> int:
	return int(a[k]) if a.size() > k and (a[k] is int or a[k] is float) else -1

static func _s(a: Array, k: int) -> String:
	return String(a[k]) if a.size() > k and a[k] is String else ""

static func _b(a: Array, k: int) -> bool:
	return a.size() > k and a[k] is bool and a[k]

static func _v(a: Array, k: int) -> Vector3:
	return a[k] if a.size() > k and a[k] is Vector3 else Vector3.INF

# --- client ----------------------------------------------------------------------

func is_client() -> bool:
	return WorldNet.is_client()

## Our world is online: follow the server's view of us.
func join_world(w: Node3D) -> void:
	world = w
	_seq = 0
	w.player.survival.set_process(false)   # the server runs our stats
	w.player.selected_changed.connect(_on_selected)
	_on_selected()

func leave_world() -> void:
	if world != null and is_instance_valid(world) and world.player.selected_changed.is_connected(_on_selected):
		world.player.selected_changed.disconnect(_on_selected)
	world = null

func _on_selected() -> void:
	if world != null:
		ask("select", [world.player.selected])

## Sends a request to the server (Actions calls this while online).
func ask(what: String, args: Array = []) -> void:
	if Net.state != "connected":
		return
	_seq += 1
	_c2s_ask.rpc_id(1, _seq, what, args)

@rpc("authority", "call_remote", "reliable")
func _s2c_inv(data: Array, cursor: Variant, worn: String, ack: int) -> void:
	if world == null or not is_instance_valid(world) or ack < _seq:
		return   # we've asked for more since: the next copy will include it
	var pl: CharacterBody3D = world.player
	pl.inventory.load_data(data)
	if pl.worn != worn:
		pl.worn = worn
		pl.worn_changed.emit()
	cursor_changed.emit(cursor)

@rpc("authority", "call_remote", "reliable")
func _s2c_stats(stats: Dictionary, statuses: Array, env: Array, bed: Array) -> void:
	if world == null or not is_instance_valid(world):
		return
	var s: Node = world.player.survival
	s.load_data(stats)
	s.statuses.assign(statuses)
	s.roofed = bool(env[0])
	s.sheltered = bool(env[1])
	s.heat = float(env[2])
	world.has_bed_spawn = bool(bed[0])
	world.bed_spawn = bed[1]

@rpc("authority", "call_remote", "reliable")
func _s2c_died(cause: String, has_items: bool, to_bed: bool) -> void:
	if world != null and is_instance_valid(world):
		world.died_online(cause, has_items, to_bed)

@rpc("authority", "call_remote", "reliable")
func _s2c_respawn(at: Vector3, yaw: float, text: String) -> void:
	if world == null or not is_instance_valid(world):
		return
	world.respawn_from_server(at, yaw)
	if not text.is_empty():
		Actions.notify.emit(text)

@rpc("authority", "call_remote", "reliable")
func _s2c_notify(text: String) -> void:
	Actions.notify.emit(text)

var hurts := 0   ## client: how often the server said we were hurt (tests read it)

@rpc("authority", "call_remote", "reliable")
func _s2c_hurt(amount: float, from: Vector3) -> void:
	hurts += 1
	if world != null and is_instance_valid(world):
		world.player.survival.hurt.emit(amount, from)

## The night passed (we were asleep, or up while the others slept).
@rpc("authority", "call_remote", "reliable")
func _s2c_slept(was_asleep: bool) -> void:
	if world == null or not is_instance_valid(world):
		return
	var text := "You slept until morning" if was_asleep else "The night passed while the others slept"
	if world.hud != null and was_asleep:
		world.hud.fade(func(): Actions.notify.emit(text))
	else:
		Actions.notify.emit(text)