extends Node3D
## The player's hands: what you're looking at, what you're holding, and what
## clicking does. Lives under the camera.
##
## - Looking at something interactable shows its prompt (E to interact).
## - LMB with a tool swings it; the hit lands mid-swing via Actions.harvest_hit.
## - Holding a placeable shows a ghost preview: green = valid, red = blocked.
##   R rotates, LMB places (Actions.place).
## - Keys 1-8 / mouse wheel pick the hotbar slot.

signal prompt_changed(text: String)

const Campfire = preload("res://scripts/building/campfire.gd")
const REACH := 3.2
const PLACE_REACH := 6.0
const SWING_TIME := 0.5

var player: CharacterBody3D
var _ray: RayCast3D
var _view: MeshInstance3D           ## held item, first-person
var _view_rest := Transform3D()
var _swing_cd := 0.0
var _ghost: MeshInstance3D
var _ghost_ok_mat: StandardMaterial3D
var _ghost_bad_mat: StandardMaterial3D
var _ghost_yaw := 0.0
var _place_xf := Transform3D()
var _place_ok := false
var _prompt := ""
var _held_shown := "~"
var _torch_light: OmniLight3D
var _torch_flame: CPUParticles3D
var _t := 0.0

func _ready() -> void:
	_ray = RayCast3D.new()
	_ray.target_position = Vector3(0, 0, -REACH)
	_ray.collision_mask = 1 | 2
	_ray.collide_with_areas = true
	_ray.add_exception(player)
	add_child(_ray)

	_view = MeshInstance3D.new()
	_view.material_override = ItemDB.item_material()
	_view.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
	_view_rest = Transform3D(Basis.from_euler(Vector3(deg_to_rad(-25), deg_to_rad(-10), deg_to_rad(-20))), Vector3(0.36, -0.42, -0.62))
	_view.transform = _view_rest
	add_child(_view)

	_ghost_ok_mat = _ghost_material(Color(0.3, 1.0, 0.4, 0.45))
	_ghost_bad_mat = _ghost_material(Color(1.0, 0.25, 0.2, 0.45))
	_ghost = MeshInstance3D.new()
	_ghost.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
	_ghost.visible = false
	_ghost.top_level = true
	add_child(_ghost)

	_torch_light = OmniLight3D.new()
	_torch_light.light_color = Color(1.0, 0.65, 0.35)
	_torch_light.omni_attenuation = 1.3
	_torch_light.shadow_enabled = true
	_torch_light.position = Vector3(0, 0.62, 0)
	_torch_light.visible = false
	_view.add_child(_torch_light)
	_torch_flame = Campfire._particles(
		"TorchFlame", 14, 0.4, Vector3(0, 0.58, 0), 0.2, 0.5, 0.25, 0.5,
		Campfire._gradient([
			[0.0, Color(1.0, 0.8, 0.35, 0.0)], [0.2, Color(1.0, 0.6, 0.2, 0.8)], [1.0, Color(0.6, 0.1, 0.02, 0.0)]]),
		true, 0.12, 0.03)
	_torch_flame.local_coords = false
	_torch_flame.emitting = false
	_view.add_child(_torch_flame)

	player.inventory.changed.connect(_refresh_held)
	player.selected_changed.connect(_refresh_held)
	_refresh_held()

static func _ghost_material(c: Color) -> StandardMaterial3D:
	var m := StandardMaterial3D.new()
	m.albedo_color = c
	m.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	m.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	m.no_depth_test = false
	return m

func _held_def() -> Dictionary:
	return ItemDB.get_item(player.held_item_id())

func _refresh_held() -> void:
	var id: String = player.held_item_id()
	if id == _held_shown:
		return
	_held_shown = id
	var def := _held_def()
	_view.visible = not id.is_empty() and not def.has("place")
	if _view.visible:
		_view.mesh = ItemDB.mesh_for(id)
		var s := 0.85 if def.category in ["tool", "weapon"] else 0.6
		_view.scale = Vector3.ONE * s
	if def.has("place"):
		_ghost.mesh = ItemDB.mesh_for(id)
		_ghost_yaw = 0.0
	else:
		_ghost.visible = false
	# Torch: a flickering light at the head of the held torch.
	var light: Dictionary = def.get("light", {})
	_torch_light.visible = not light.is_empty()
	_torch_flame.emitting = not light.is_empty()
	if not light.is_empty():
		_torch_light.omni_range = float(light.get("range", 8.0))
		_torch_light.light_energy = float(light.get("energy", 1.5))

## 0..1 warmth from what's held (a torch).
func held_heat() -> float:
	return float(_held_def().get("light", {}).get("heat", 0.0))

func _set_prompt(t: String) -> void:
	if t != _prompt:
		_prompt = t
		prompt_changed.emit(t)

func _target() -> Object:
	if not _ray.is_colliding():
		return null
	var c := _ray.get_collider()
	if c == null or not c.has_method("interact_prompt"):
		return null
	if c.get("depleted") == true:
		return null
	return c

func _physics_process(delta: float) -> void:
	_swing_cd = maxf(_swing_cd - delta, 0.0)
	if player.ui_open:
		_ghost.visible = false
		_set_prompt("")
		return
	var def := _held_def()
	if def.has("place"):
		_update_ghost(def)
		_set_prompt("[LMB] Place %s   [R] Rotate" % def.name)
		return
	_ghost.visible = false
	if _torch_light.visible:
		_t += delta
		_torch_light.light_energy = float(def.get("light", {}).get("energy", 1.5)) * (0.85 + 0.15 * sin(_t * 17.0) * sin(_t * 5.3))
	var t := _target()
	if t != null:
		_set_prompt(t.interact_prompt(player))
	elif def.has("food"):
		_set_prompt("[RMB] Eat %s" % def.name)
	else:
		_set_prompt("")

func _update_ghost(def: Dictionary) -> void:
	var cam := get_parent() as Camera3D
	var from := cam.global_position
	var to := from - cam.global_basis.z * PLACE_REACH
	var q := PhysicsRayQueryParameters3D.create(from, to, 1, [player.get_rid()])
	var hit := cam.get_world_3d().direct_space_state.intersect_ray(q)
	if hit.is_empty():
		_ghost.visible = false
		_place_ok = false
		return
	var yaw := player.rotation.y + _ghost_yaw   # piece's front (+Z) faces the player
	_place_xf = Transform3D(Basis(Vector3.UP, yaw), hit.position)
	_place_ok = player.get_parent().placement_valid(def, _place_xf)
	_ghost.global_transform = _place_xf
	_ghost.material_override = _ghost_ok_mat if _place_ok else _ghost_bad_mat
	_ghost.visible = true

func _unhandled_input(event: InputEvent) -> void:
	if player.ui_open:
		return
	for i in range(8):
		if event.is_action_pressed("hotbar_%d" % (i + 1)):
			player.select(i)
			return
	if event is InputEventMouseButton and event.pressed and Input.mouse_mode == Input.MOUSE_MODE_CAPTURED:
		if event.button_index == MOUSE_BUTTON_WHEEL_UP:
			player.select(player.selected - 1)
		elif event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
			player.select(player.selected + 1)
	if event.is_action_pressed("use_item") and Input.mouse_mode == Input.MOUSE_MODE_CAPTURED:
		if _held_def().has("food"):
			Actions.eat(player, player.selected)
	elif event.is_action_pressed("rotate_piece"):
		_ghost_yaw += deg_to_rad(22.5)
	elif event.is_action_pressed("interact"):
		var t := _target()
		if t != null and t.has_method("interact"):
			t.interact(player)
	elif event.is_action_pressed("attack") and Input.mouse_mode == Input.MOUSE_MODE_CAPTURED:
		if _held_def().has("place"):
			if _place_ok:
				Actions.place(player, player.selected, _place_xf, player.get_parent())
			else:
				Actions.notify.emit("Can't place that here")
		else:
			swing()

## Swings the held item (or fist). The hit is applied at the peak of the swing.
func swing() -> void:
	if _swing_cd > 0.0:
		return
	_swing_cd = SWING_TIME
	var tw := create_tween()
	var wind := Transform3D(_view_rest.basis.rotated(Vector3.RIGHT, deg_to_rad(35)), _view_rest.origin + Vector3(0, 0.08, 0.05))
	var strike := Transform3D(_view_rest.basis.rotated(Vector3.RIGHT, deg_to_rad(-70)), _view_rest.origin + Vector3(-0.05, -0.05, -0.15))
	tw.tween_property(_view, "transform", wind, 0.1).set_ease(Tween.EASE_OUT)
	tw.tween_property(_view, "transform", strike, 0.1).set_ease(Tween.EASE_IN)
	tw.tween_callback(_apply_hit)
	tw.tween_property(_view, "transform", _view_rest, 0.25).set_trans(Tween.TRANS_SINE)

func _apply_hit() -> void:
	_ray.force_raycast_update()
	if not _ray.is_colliding():
		return
	var c := _ray.get_collider()
	if c != null and c.is_in_group("harvestable"):
		Actions.harvest_hit(player, c, _ray.get_collision_point())