extends StaticBody3D
## A harvestable tree or boulder.
##
## The visible mesh is one instance inside a MultiMesh batch (props.gd), so this
## body only holds collision plus a reference to its instance. Hits shake or
## shrink that instance. When depleted the instance is hidden; a tree is
## replaced by a falling copy and a stump.
##
## Game rules (damage, drops) run through Actions.harvest_hit, which calls hit().

const ProcMesh = preload("res://scripts/world/proc_mesh.gd")

var uid := ""                       ## stable id for saves (see props.gd)
var kind := "tree"                  ## "tree" | "rock"
var tool_kind := "axe"
var min_tier := 1
var max_hp := 5.0
var hp := 5.0
var drops_per_hit: Dictionary = {}  ## id -> count, given on every hit
var drops_final: Dictionary = {}    ## id -> [min, max], given when depleted
var depleted := false
var chip_color := Color(0.6, 0.45, 0.28)

var mmi: MultiMeshInstance3D        ## batch holding the visual
var index := -1                     ## instance index in that batch
var base_xf := Transform3D()
var stump_material: Material
var rng := RandomNumberGenerator.new()

var _shake := 0.0
var _shake_axis := Vector3.RIGHT
var _stump: MeshInstance3D
var _orig_shapes: Array = []        ## [CollisionShape3D, shape, position] before the stump

## Emitted when a player fells or mines this (not when a save restores it).
signal depleted_now(node: Node)

func display_name() -> String:
	return "Tree" if kind == "tree" else "Boulder"

func interact_prompt(player: Node) -> String:
	var tool: Dictionary = ItemDB.get_item(player.held_item_id()).get("tool", {})
	var verb := "Chop" if kind == "tree" else "Mine"
	if tool.get("kind", "") == tool_kind:
		return "%s  [LMB] %s" % [display_name(), verb]
	# Tell new players how to get the tool, not just that they lack it.
	var tool_id := "stone_" + tool_kind
	var r: Dictionary = ItemDB.recipes.get(tool_id, {})
	var parts: Array[String] = []
	for id in r.get("inputs", {}):
		parts.append("%d %s" % [int(r.inputs[id]), ItemDB.item_name(id).to_lower()])
	if player.inventory.count(tool_id) > 0:
		return "%s  (select your %s on the hotbar)" % [display_name(), ItemDB.item_name(tool_id)]
	return "%s  (needs a %s: Tab to craft from %s)" % [display_name(), ItemDB.item_name(tool_id), ", ".join(parts)]

## Applies one hit. Returns the items earned by this hit.
func hit(damage: float, point: Vector3, from: Vector3) -> Dictionary:
	var out := {}
	for id in drops_per_hit:
		out[id] = drops_per_hit[id]
	if hp - damage <= 0.0:
		for id in drops_final:
			var r: Array = drops_final[id]
			out[id] = out.get(id, 0) + rng.randi_range(int(r[0]), int(r[1]))
	_show_hit(hp - damage, point, from)
	return out

## A hit someone else's game reported, via the server (world_net.gd): the
## same chips, shake and fall, with no drops.
func apply_remote(new_hp: float, point: Vector3, from: Vector3) -> void:
	if not depleted:
		_show_hit(new_hp, point, from)

func _show_hit(new_hp: float, point: Vector3, from: Vector3) -> void:
	hp = new_hp
	_burst(point, chip_color, 14)
	if hp <= 0.0:
		depleted = true
		_deplete(from)
	else:
		_shake = 1.0
		var away := (global_position - from)
		away.y = 0.0
		_shake_axis = away.normalized().cross(Vector3.UP) if away.length() > 0.01 else Vector3.RIGHT
		if kind == "rock":
			_set_instance(_rock_xf())

func _process(delta: float) -> void:
	if _shake <= 0.0 or depleted:
		return
	_shake = maxf(_shake - delta * 3.5, 0.0)
	var base := _rock_xf() if kind == "rock" else base_xf
	var wobble := sin(_shake * 40.0) * 0.035 * _shake
	_set_instance(Transform3D(Basis(_shake_axis, wobble) * base.basis, base.origin))

## Rocks shrink toward 55% of their size as they're mined.
func _rock_xf() -> Transform3D:
	var k := 0.55 + 0.45 * clampf(hp / max_hp, 0.0, 1.0)
	return Transform3D(base_xf.basis.scaled_local(Vector3.ONE * k), base_xf.origin)

func _set_instance(xf: Transform3D) -> void:
	if mmi != null and index >= 0:
		mmi.multimesh.set_instance_transform(index, xf)

## Restores saved damage when a world loads. hp <= 0 = already felled/mined
## (no animation, no drops).
func restore(saved_hp: float) -> void:
	hp = saved_hp
	if hp <= 0.0:
		depleted = true
		_deplete(global_position, false)
	elif kind == "rock":
		_set_instance(_rock_xf())

func _deplete(from: Vector3, animate: bool = true) -> void:
	# Hide the batched instance (moved far below ground: a zero scale would
	# give the wind shaders a non-invertible matrix).
	_set_instance(Transform3D(base_xf.basis, base_xf.origin + Vector3(0, -1000, 0)))
	collision_layer = 0
	if kind == "tree" and mmi != null:
		_fell(from, animate)
	else:
		if animate:
			_burst(global_position + Vector3(0, 0.8, 0), chip_color, 40)
		# Kept (hidden, no collision) so it can regrow later.
		set_process(false)
		remove_from_group("harvestable")
	if animate:
		depleted_now.emit(self)

## Brings a felled tree or mined boulder back, growing in over a few seconds.
func regrow() -> void:
	if not depleted:
		return
	depleted = false
	hp = max_hp
	if _stump != null:
		_stump.queue_free()
		_stump = null
	for e in _orig_shapes:
		e[0].shape = e[1]
		e[0].position = e[2]
	_orig_shapes.clear()
	if has_meta("is_stump"):
		remove_meta("is_stump")
	collision_layer = 1
	add_to_group("harvestable")
	set_process(true)
	if is_inside_tree() and DisplayServer.get_name() != "headless":
		var tw := create_tween()
		tw.tween_method(func(k: float): _set_instance(Transform3D(base_xf.basis.scaled_local(Vector3.ONE * k), base_xf.origin)),
			0.15, 1.0, 4.0).set_trans(Tween.TRANS_SINE)
	else:
		_set_instance(base_xf)

func _fell(from: Vector3, animate: bool) -> void:
	var world := get_parent()
	if animate:
		_fall_animation(world, from)
	_make_stump(world)

func _fall_animation(world: Node, from: Vector3) -> void:
	var falling := MeshInstance3D.new()
	falling.mesh = mmi.multimesh.mesh
	world.add_child(falling)
	falling.global_transform = base_xf
	var away := base_xf.origin - from
	away.y = 0.0
	var axis := away.normalized().cross(Vector3.DOWN) if away.length() > 0.01 else Vector3.RIGHT
	var start := base_xf.basis
	var tw := falling.create_tween()
	tw.tween_method(func(a: float): falling.global_basis = Basis(axis, a) * start, 0.0, deg_to_rad(86.0), 1.6) \
		.set_trans(Tween.TRANS_QUAD).set_ease(Tween.EASE_IN)
	tw.tween_callback(func(): _burst(falling.global_position + away.normalized() * 3.0, Color(0.3, 0.45, 0.2), 30))
	tw.tween_interval(1.2)
	tw.tween_property(falling, "position:y", falling.position.y - 4.0, 1.5)
	tw.tween_callback(falling.queue_free)

func _make_stump(world: Node) -> void:
	var stump := MeshInstance3D.new()
	var s := base_xf.basis.get_scale().x
	stump.mesh = ProcMesh.stump_mesh(rng.randi(), 0.45, 0.3 * s)
	stump.material_override = stump_material
	world.add_child(stump)
	stump.global_position = base_xf.origin
	_stump = stump
	# Keep collision as a short stump.
	for c in get_children():
		if c is CollisionShape3D and c.shape is CapsuleShape3D:
			_orig_shapes.append([c, c.shape, c.position])
			var cyl := CylinderShape3D.new()
			cyl.radius = (c.shape as CapsuleShape3D).radius
			cyl.height = 0.6
			c.shape = cyl
			c.position = Vector3(0, 0.3, 0)
	collision_layer = 1
	set_process(false)
	remove_from_group("harvestable")
	set_meta("is_stump", true)

static func _burst_material(color: Color) -> StandardMaterial3D:
	var m := StandardMaterial3D.new()
	m.albedo_color = color
	m.roughness = 1.0
	m.vertex_color_use_as_albedo = false
	return m

func _burst(pos: Vector3, color: Color, amount: int) -> void:
	var p := CPUParticles3D.new()
	var box := BoxMesh.new()
	box.size = Vector3.ONE * 0.06
	box.material = _burst_material(color)
	p.mesh = box
	p.amount = amount
	p.one_shot = true
	p.explosiveness = 0.95
	p.lifetime = 0.9
	p.direction = Vector3.UP
	p.spread = 70.0
	p.initial_velocity_min = 2.0
	p.initial_velocity_max = 4.5
	p.gravity = Vector3(0, -12, 0)
	p.scale_amount_min = 0.6
	p.scale_amount_max = 1.4
	p.angular_velocity_min = -400.0
	p.angular_velocity_max = 400.0
	get_parent().add_child(p)
	p.global_position = pos
	p.emitting = true
	p.finished.connect(p.queue_free)