extends Node3D
## The barrow (docs/PROGRESSION_DESIGN.md §4): an ancient burial mound in a
## ring of standing stones, out on open ground. Scenery, like the wolf den:
## built from the seed on every machine, so it's the same for everyone.
##
## A stone-lined passage leads under the mound into a chamber with a stone
## coffin at the back. Three skeletal guards (guard.gd) stand inside. They
## wake when someone's inside the stone ring at night (or at any time after
## day WAKE_DAY), when the coffin is opened, or when one of them is hit.
## The coffin holds iron and a barrow key piece (three open the standing
## stones on the rim, P5). It fills again RESTOCK_DAYS after it was emptied,
## and fallen guards are back at their posts then too.
##
## Guards and loot run on the server (or in single-player): start().
## Saved with the world: when the coffin was emptied and which guards fell.
##
## Local space: +Z is the passage's mouth (facing the centre of the valley),
## the origin is the chamber floor.

const IM = preload("res://scripts/items/item_meshes.gd")
const P = preload("res://scripts/world/proc_mesh.gd")
const GuardScript = preload("res://scripts/creatures/guard.gd")

const MOUND_R := 6.5
const MOUND_H := 3.6
const RING_R := 10.0             ## the standing stones
const CLEAR_R := 11.5
const LEASH := 22.0              ## guards don't follow you further than this from the centre
const WAKE_DAY := 10             ## after this, they wake by day too
const RESTOCK_DAYS := 5
const PASSAGE_END := 6.4         ## the mouth, local z
const POSTS := [[Vector3(-1.4, 0, -0.4), 0.0], [Vector3(1.4, 0, -0.4), 0.0], [Vector3(0.0, 0, 1.2), 0.0]]
const LOOT := {"iron_bar": [1, 3], "iron_nugget": [3, 6], "barrow_key": [1, 1]}

const STONE := Color(0.5, 0.5, 0.47)
const MOSS := Color(0.32, 0.38, 0.22)
const TURF := Color(0.3, 0.4, 0.18)
const EARTH := Color(0.36, 0.3, 0.2)

var world: Node3D
var terrain: Node3D
var found := false
var yaw := 0.0
var alarmed := false             ## guards stirred (the coffin was opened, one was hit)
var loot_day := -1               ## the day it was emptied (-1: never)
var fallen: Array = []           ## post indices whose guard is dead
var guards: Array = []
var running := false             ## this machine runs the guards (server / single-player)
var _rng := RandomNumberGenerator.new()
var _mouth_drop := 0.0           ## how far the ground at the mouth is below the floor

# --- placing it -----------------------------------------------------------------------

func place(w: Node3D) -> bool:
	world = w
	terrain = w.terrain
	var site := _find_site()
	if site == Vector3.INF:
		push_warning("[barrow] no site for the barrow on this seed")
		return false
	found = true
	position = site
	yaw = atan2(-site.x, -site.z)   # mouth toward the middle of the valley
	rotation.y = yaw
	var mouth: Vector3 = position + Basis(Vector3.UP, yaw) * Vector3(0, 0, PASSAGE_END)
	_mouth_drop = maxf(position.y - terrain.sample_height(mouth.x, mouth.z), 0.0)
	_clear_area(w.props)
	_build(w.props._rock_mat)
	w.props.static_cuts.append([Transform3D(Basis(Vector3.UP, yaw), position), MOUND_R + 0.5, MOUND_R + 1.5])
	return true

## Open, fairly flat ground away from the spawn, the den and the sea. Where
## nothing qualifies (a lumpy island), later passes accept rougher ground
## nearer the spawn and the den; the first pass is the original search, so
## islands that had a site keep it.
func _find_site() -> Vector3:
	for pass_ in [[1.2, 55.0, 70.0], [2.0, 45.0, 50.0], [3.0, 40.0, 40.0]]:
		var c: Vector3 = _search(float(pass_[0]), float(pass_[1]), float(pass_[2]))
		if c != Vector3.INF:
			return c
	return Vector3.INF

func _search(max_spread: float, from_spawn: float, from_den: float) -> Vector3:
	_rng.seed = terrain.noise_seed + 555
	var spawn: Vector3 = world._spawn
	var den_at: Vector3 = world.den.position if world.den != null and world.den.found else Vector3(1e9, 0, 1e9)
	var best := Vector3.INF
	var best_score := INF
	for _i in range(600):
		var a := _rng.randf() * TAU
		var rr := _rng.randf_range(40.0, terrain.play_radius - 20.0)
		var c := Vector2(cos(a), sin(a)) * rr
		if not terrain.inside_boundary(c.x, c.y, CLEAR_R + 4.0) or terrain.sea_weight(c.x, c.y) > 0.02:
			continue
		if c.distance_to(Vector2(spawn.x, spawn.z)) < from_spawn or c.distance_to(Vector2(den_at.x, den_at.z)) < from_den:
			continue
		var hs: Array[float] = []
		for k in range(8):
			var b := TAU * k / 8.0
			for rad in [MOUND_R * 0.5, PASSAGE_END + 0.5]:
				hs.append(terrain.sample_height(c.x + cos(b) * rad, c.y + sin(b) * rad))
		var h0: float = terrain.sample_height(c.x, c.y)
		hs.append(h0)
		if hs.min() < terrain.water_level + 1.0:
			continue
		var spread: float = hs.max() - hs.min()
		if spread > max_spread:
			continue
		var trees := 0
		for n in world.props.resource_nodes.values():
			if Vector2(n.global_position.x - c.x, n.global_position.z - c.y).length() < CLEAR_R:
				trees += 1
		var score: float = spread * 4.0 + trees
		if score < best_score:
			best_score = score
			# Floor level: the highest ground inside the chamber, so the
			# terrain doesn't come up through the floor.
			var top := h0
			for d in [Vector2(-2, -2), Vector2(2, -2), Vector2(-2, 2), Vector2(2, 2)]:
				top = maxf(top, terrain.sample_height(c.x + d.x, c.y + d.y))
			best = Vector3(c.x, top + 0.03, c.y)
	return best

func _clear_area(props: Node3D) -> void:
	for dict in [props.resource_nodes, props.pickups, props.forage]:
		for uid in dict.keys():
			var n: Node3D = dict[uid]
			if not is_instance_valid(n):
				continue
			if Vector2(n.global_position.x - position.x, n.global_position.z - position.z).length() < CLEAR_R:
				if n.has_method("_set_instance"):
					n._set_instance(Transform3D(Basis(), n.global_position + Vector3(0, -1000, 0)))
				dict.erase(uid)
				n.queue_free()

# --- building it -----------------------------------------------------------------------

var _body: StaticBody3D
var _st: SurfaceTool
var _stone_rng := RandomNumberGenerator.new()

## A dressed stone block: drawn and solid.
func _block(c: Vector3, s: Vector3, basis: Basis = Basis()) -> void:
	var col := P._mul(STONE, _stone_rng.randf_range(0.8, 1.05)).lerp(MOSS, _stone_rng.randf() * 0.35)
	IM._box(_st, c, s, col, basis)
	var cs := CollisionShape3D.new()
	var box := BoxShape3D.new()
	box.size = s
	cs.shape = box
	cs.transform = Transform3D(basis, c)
	_body.add_child(cs)

func _build(rock_mat: Material) -> void:
	_stone_rng.seed = terrain.noise_seed + 556
	_body = StaticBody3D.new()
	_body.name = "Stones"
	_body.collision_layer = 1 | 4   # solid, and a roof for shelter checks
	add_child(_body)
	_st = P._begin()
	# Chamber: 4 x 4 m inside, 2.4 m high, a slab roof.
	_block(Vector3(0, -0.15, 0), Vector3(4.8, 0.36, 4.8))                 # floor (top at 0.03)
	_block(Vector3(0, 1.2, -2.2), Vector3(4.8, 2.4, 0.4))                 # back
	for s in [-1.0, 1.0]:
		_block(Vector3(s * 2.2, 1.2, 0), Vector3(0.4, 2.4, 4.0))          # sides
		_block(Vector3(s * 1.4, 1.2, 2.2), Vector3(1.6, 2.4, 0.4))        # front, either side of the passage
	_block(Vector3(0, 2.6, 0), Vector3(4.8, 0.4, 4.8))                    # roof
	_block(Vector3(0, 2.15, 2.2), Vector3(1.2, 0.5, 0.4))                 # over the passage's inner end
	# Passage: 1.2 m wide, 1.95 m high, from the chamber to the mouth. Its
	# floor slopes down to the ground at the mouth.
	var plen := PASSAGE_END - 2.4
	var mid := 2.4 + plen * 0.5
	var tilt := atan2(_mouth_drop, plen)
	_block(Vector3(0, -0.15 - _mouth_drop * 0.5, mid), Vector3(1.6, 0.36, sqrt(plen * plen + _mouth_drop * _mouth_drop)), Basis(Vector3.RIGHT, tilt))
	for s in [-1.0, 1.0]:
		_block(Vector3(s * 0.8, 1.0 - _mouth_drop * 0.5, mid), Vector3(0.4, 2.0 + _mouth_drop, plen))
	_block(Vector3(0, 2.1, mid), Vector3(2.0, 0.3, plen))
	# The mouth: two tall jambs and a lintel.
	for s in [-1.0, 1.0]:
		_block(Vector3(s * 0.95, 1.1 - _mouth_drop * 0.5, PASSAGE_END + 0.1), Vector3(0.5, 2.6 + _mouth_drop, 0.5))
	_block(Vector3(0, 2.45, PASSAGE_END + 0.1), Vector3(2.6, 0.45, 0.6))
	# The coffin at the back: a stone chest with a lid.
	_coffin = Coffin.new()
	_coffin.barrow = self
	_coffin.collision_layer = 1
	_coffin.position = Vector3(0, 0, -1.45)   # (its origin is what reach is measured to)
	add_child(_coffin)
	var ccs := CollisionShape3D.new()
	var cbox := BoxShape3D.new()
	cbox.size = Vector3(1.9, 0.85, 0.8)
	ccs.shape = cbox
	ccs.position = Vector3(0, 0.45, 0)
	_coffin.add_child(ccs)
	IM._box(_st, Vector3(0, 0.4, -1.45), Vector3(1.8, 0.75, 0.75), P._mul(STONE, 0.85))
	IM._box(_st, Vector3(0, 0.82, -1.45), Vector3(1.95, 0.12, 0.85), STONE)
	IM._box(_st, Vector3(0, 0.9, -1.45), Vector3(0.9, 0.05, 0.3), MOSS)
	var mi := MeshInstance3D.new()
	mi.mesh = P._commit(_st)
	mi.material_override = ItemDB.item_material()
	add_child(mi)
	_build_mound()
	_build_ring(rock_mat)

## The grass mound over the chamber: a dome that meets the ground at its
## edge, open where the passage goes in. Its surface is solid (you can climb
## onto it); inside it you see the stone.
func _build_mound() -> void:
	var st := P._begin()
	var faces := PackedVector3Array()
	var rings := 9
	var segs := 36
	var nz := FastNoiseLite.new()
	nz.seed = terrain.noise_seed + 557
	var b := Basis(Vector3.UP, yaw)
	var pt := func(i: int, j: int) -> Vector3:
		var rr: float = MOUND_R * float(i) / rings
		var a: float = TAU * float(j) / segs
		var x: float = sin(a) * rr
		var z: float = cos(a) * rr
		var w: Vector3 = position + b * Vector3(x, 0, z)
		var ground: float = terrain.sample_height(w.x, w.z) - position.y
		var k: float = rr / MOUND_R
		return Vector3(x, lerpf(MOUND_H, ground - 0.3, k * k) + nz.get_noise_2d(x * 3.0, z * 3.0) * 0.12 * (1.0 - k), z)
	for i in range(rings):
		for j in range(segs):
			var q := [pt.call(i, j), pt.call(i + 1, j), pt.call(i + 1, j + 1), pt.call(i, j + 1)]
			for tri in [[q[0], q[1], q[2]], [q[0], q[2], q[3]]]:
				var c: Vector3 = (tri[0] + tri[1] + tri[2]) / 3.0
				if absf(c.x) < 1.05 and c.z > 2.0:
					continue   # the passage
				if (tri[0] as Vector3).distance_to(tri[1]) < 0.001 or (tri[1] as Vector3).distance_to(tri[2]) < 0.001:
					continue   # (degenerate, at the top)
				var col := TURF.lerp(EARTH, clampf(0.4 - c.y * 0.12, 0.0, 0.5))
				P._tri(st, tri[0], tri[1], tri[2], c - Vector3(0, -3, 0), P._mul(col, 0.9 + 0.2 * nz.get_noise_2d(c.x * 7.0, c.z * 7.0)))
				var nrm: Vector3 = ((tri[1] as Vector3) - tri[0]).cross((tri[2] as Vector3) - tri[0])
				if nrm.dot(c - Vector3(0, -3, 0)) < 0.0:
					faces.append_array(PackedVector3Array([tri[0], tri[2], tri[1]]))
				else:
					faces.append_array(PackedVector3Array([tri[0], tri[1], tri[2]]))
	var mi := MeshInstance3D.new()
	mi.name = "Mound"
	mi.mesh = P._commit(st)
	mi.material_override = ItemDB.item_material()
	add_child(mi)
	var shape := ConcavePolygonShape3D.new()
	shape.set_faces(faces)
	shape.backface_collision = true
	var cs := CollisionShape3D.new()
	cs.shape = shape
	var body := StaticBody3D.new()
	body.name = "MoundBody"
	body.collision_layer = 1 | 4
	body.add_child(cs)
	add_child(body)

## Standing stones round the mound, with a gap in front of the mouth.
func _build_ring(rock_mat: Material) -> void:
	var body := StaticBody3D.new()
	body.name = "Ring"
	body.collision_layer = 1
	add_child(body)
	var n := 11
	for i in range(n):
		var a := TAU * (i + 0.5) / n
		if absf(wrapf(a, -PI, PI)) < 0.3:
			continue   # (the mouth faces +Z: a = 0)
		var lp := Vector3(sin(a) * RING_R, 0, cos(a) * RING_R)
		var w: Vector3 = position + Basis(Vector3.UP, yaw) * lp
		var radii := Vector3(0.55, 1.5 + 0.35 * sin(i * 2.3), 0.4)
		var y: float = terrain.sample_height(w.x, w.z) - position.y + radii.y * 0.8 - 0.3
		var mesh := P.rock(terrain.noise_seed + 5200 + i, false)
		var turn := Basis(Vector3.UP, a + 0.2 * sin(i * 1.7)) * Basis(Vector3.RIGHT, 0.05 * sin(i * 3.1))
		var mi := MeshInstance3D.new()
		mi.mesh = mesh
		mi.material_override = rock_mat
		mi.transform = Transform3D(turn.scaled(radii), Vector3(lp.x, y, lp.z))
		add_child(mi)
		var hull := mesh.create_convex_shape(true, true) as ConvexPolygonShape3D
		var pts := PackedVector3Array()
		for p: Vector3 in hull.points:
			pts.append(turn * (p * radii))
		hull.points = pts
		var cs := CollisionShape3D.new()
		cs.shape = hull
		cs.position = Vector3(lp.x, y, lp.z)
		body.add_child(cs)

# --- where things are --------------------------------------------------------------------

func center() -> Vector3:
	return position

func to_world(lp: Vector3) -> Vector3:
	return position + Basis(Vector3.UP, yaw) * lp

func to_local_pos(p: Vector3) -> Vector3:
	return Basis(Vector3.UP, yaw).inverse() * (p - position)

## Inside the chamber or passage.
func inside(p: Vector3) -> bool:
	var l := to_local_pos(p)
	return (absf(l.x) < 2.0 and absf(l.z) < 2.0 or absf(l.x) < 0.6 and l.z > 1.9 and l.z < PASSAGE_END + 0.3) and l.y > -1.0 and l.y < 2.6

## The stone floor's height at `p` (world), or -INF outside.
func floor_y_at(p: Vector3) -> float:
	var l := to_local_pos(p)
	if absf(l.x) < 2.0 and absf(l.z) < 2.0:
		return position.y + 0.03
	if absf(l.x) < 0.6 and l.z >= 2.0 and l.z < PASSAGE_END:
		return position.y + 0.03 - _mouth_drop * (l.z - 2.4) / (PASSAGE_END - 2.4) * float(l.z > 2.4)
	return -INF

func mouth() -> Vector3:
	var m := to_world(Vector3(0, 0, PASSAGE_END + 1.2))
	m.y = terrain.sample_height(m.x, m.z)
	return m

# --- guards ---------------------------------------------------------------------------

func is_night() -> bool:
	var h: float = world.day_night.hours()
	return h >= 19.5 or h < 5.5

## Whether being where `p` is wakes the guards right now.
func wakes_for(p: Node3D) -> bool:
	if alarmed:
		return true
	if p.survival.dead:
		return false
	var near := Vector2(p.global_position.x - position.x, p.global_position.z - position.z).length() < RING_R
	if near and (is_night() or world.day_night.day > WAKE_DAY):
		alarmed = true
	return alarmed

func alarm() -> void:
	alarmed = true

func guards_alive() -> Array:
	return guards.filter(func(g): return is_instance_valid(g) and not g.is_dead())

## Starts the guards (on the machine that runs creatures).
func start() -> void:
	if not found:
		return
	running = true
	_spawn_guards()

func _spawn_guards() -> void:
	for g in guards:
		if is_instance_valid(g) and not g.is_dead():
			g.queue_free()
	guards.clear()
	for i in range(POSTS.size()):
		if fallen.has(i):
			continue
		var g: AnimatableBody3D = GuardScript.new()
		var post: Vector3 = to_world(POSTS[i][0])
		g.setup("guard", world, post, terrain.noise_seed + 600 + i)
		g.barrow = self
		g.post = Vector3(post.x, position.y + 0.03, post.z)
		# Facing the mouth (+Z local); a creature's forward is -Z, so turn by PI.
		g.post_yaw = yaw + PI + float(POSTS[i][1])
		g.state = "rest"
		g.yaw = g.post_yaw
		g.rotation.y = g.yaw
		g.set_meta("post", i)
		g.died.connect(_on_guard_died)
		add_child(g)
		g.global_position = g.post
		guards.append(g)

func _on_guard_died(g: Node) -> void:
	var i := int(g.get_meta("post", -1))
	if i >= 0 and not fallen.has(i):
		fallen.append(i)

func _physics_process(_delta: float) -> void:
	if running:
		step()

func step() -> void:
	# Everyone's gone: the guards settle (they walk back to their posts).
	if alarmed:
		var anyone := false
		for p in world.players():
			if not p.survival.dead and p.global_position.distance_to(position) < LEASH:
				anyone = true
		if not anyone:
			alarmed = false
	# The coffin fills again (and the fallen are back) a few days after it
	# was emptied, at dawn, with nobody about.
	if loot_day >= 0 and world.day_night.day >= loot_day + RESTOCK_DAYS:
		var h: float = world.day_night.hours()
		if h >= 6.0 and h < 10.0:
			for p in world.players():
				if p.global_position.distance_to(position) < 30.0:
					return
			loot_day = -1
			fallen.clear()
			alarmed = false
			_spawn_guards()

# --- the coffin ---------------------------------------------------------------------------

var _coffin: StaticBody3D

func stocked() -> bool:
	return loot_day < 0

func days_to_restock() -> int:
	return maxi(loot_day + RESTOCK_DAYS - int(world.day_night.day), 1)

## Opens the coffin for `player` (Actions.loot_barrow). Wakes the guards.
## Returns what was taken ({} if it was empty).
func loot(player: Node3D) -> Dictionary:
	alarm()
	if not stocked():
		Actions.tell(player, "The coffin is empty. Come back in %d days." % days_to_restock())
		return {}
	var r := RandomNumberGenerator.new()
	r.seed = terrain.noise_seed * 31 + int(world.day_night.day)
	var got := {}
	for id in LOOT:
		got[id] = r.randi_range(int(LOOT[id][0]), int(LOOT[id][1]))
	loot_day = int(world.day_night.day)
	Actions.tell(player, "You lift the coffin lid... and something stirs behind you!")
	return got

func coffin_prompt() -> String:
	return "Stone coffin  [E] Open"

func save_data() -> Dictionary:
	return {"loot_day": loot_day, "fallen": fallen.duplicate()} if found else {}

func load_data(d: Dictionary) -> void:
	if not found or d.is_empty():
		return
	loot_day = int(d.get("loot_day", -1))
	fallen = []
	for i in d.get("fallen", []):
		fallen.append(int(i))
	if running:
		_spawn_guards()

class Coffin extends StaticBody3D:
	var barrow: Node
	func interact_prompt(_p: Node) -> String:
		return barrow.coffin_prompt()
	func interact(p: Node) -> void:
		Actions.loot_barrow(p, barrow)