class_name TerrainPropDefinition
extends Resource

@export var stable_id: StringName
@export var label := ""
@export var packed_scene: PackedScene
## Empty means the prop is available for deliberate placement only.
@export var procedural_group: StringName
@export var required_chunk_tags := PackedStringArray()
@export_range(0.01, 100.0, 0.01) var selection_weight := 1.0
## Manhattan distance in chunks from the forced center spawn. Two keeps the
## spawn chunk and its four immediate neighbors clear of this prop.
@export_range(0, 16, 1) var minimum_spawn_chunk_distance := 0
## These groups influence placement selection but are not a hard requirement.
## A nearby match multiplies this prop's weight; an absent match divides it by
## the same amount.
@export var preferred_nearby_prop_groups := PackedStringArray()
@export_range(0.0, 100.0, 0.5) var preferred_nearby_radius := 0.0
@export_range(1.0, 10.0, 0.1) var nearby_preference_weight_multiplier := 1.0
@export_range(0.0, 10.0, 0.05) var clearance_radius := 0.5
## Procedural instances use a deterministic uniform scale in this range.
@export_range(0.1, 4.0, 0.05) var minimum_visual_scale := 1.0
@export_range(0.1, 4.0, 0.05) var maximum_visual_scale := 1.0
## Values above one create a loose group of separately anchored instances.
## Cluster members are distributed across the configured scale range so a
## three-member cluster naturally contains a small, medium, and large prop.
@export_range(1, 4, 1) var minimum_cluster_size := 1
@export_range(1, 4, 1) var maximum_cluster_size := 1
@export_range(0.0, 10.0, 0.05) var minimum_cluster_radius := 0.0
@export_range(0.0, 10.0, 0.05) var maximum_cluster_radius := 0.0
## Presentation-only offset. The prop root remains exactly terrain-aligned.
@export var visual_offset := Vector3.ZERO
## A single material is chosen per prop and applied only to matching imported
## material slots. This keeps trunks untouched while varying foliage.
@export var variant_material_slot_names := PackedStringArray()
@export var material_variants: Array[Material] = []
## An independent second material channel, used when both foliage and wood
## should vary without coupling their color choices.
@export var secondary_variant_material_slot_names := PackedStringArray()
@export var secondary_material_variants: Array[Material] = []
## Some asymmetric props can loosely face an authored ocean edge. The local
## direction describes the model's natural overhang in Godot X/Z space.
@export var prefer_ocean_facing := false
@export var local_overhang_direction := Vector2(0.0, -1.0)
@export_range(0.0, 180.0, 1.0) var ocean_facing_spread_degrees := 45.0
@export_range(0.0, 5.0, 0.05) var collision_radius := 0.0
@export_range(0.0, 20.0, 0.05) var collision_height := 0.0
@export var collision_box_size := Vector3.ZERO
@export var collision_offset := Vector3.ZERO
@export_category("Gatherable Surface")
## Non-empty values explicitly designate this prop's matching mesh surfaces as
## valid attachment geometry. Unlisted props and materials are never sampled.
@export var gatherable_surface_material_names := PackedStringArray()
## Accessibility band measured upward from this prop's planted origin. It
## follows the tree onto hills/cliffs while keeping anchors within net reach.
@export_range(0.0, 20.0, 0.05) var gatherable_surface_minimum_height := 0.7
@export_range(0.0, 20.0, 0.05) var gatherable_surface_maximum_height := 1.5
## Reject upward-facing branches and foliage so attachments favor trunk-like
## faces. Zero accepts only vertical faces; one accepts every orientation.
@export_range(0.0, 1.0, 0.05) var gatherable_surface_maximum_up_dot := 0.35
## Keep camera-facing creature billboards clear of the sampled trunk as they
## rotate. This is a physical anchor offset, so creatures remain hidden by the
## rest of the tree instead of rendering through it as an overlay.
@export_range(0.0, 0.25, 0.005) var gatherable_surface_clearance := 0.12


func supports_chunk_tags(chunk_tags: PackedStringArray) -> bool:
	for required_tag: String in required_chunk_tags:
		if required_tag not in chunk_tags:
			return false
	return true


func has_collision() -> bool:
	return has_cylinder_collision() or has_box_collision()


func has_cylinder_collision() -> bool:
	return collision_radius > 0.0 and collision_height > 0.0


func has_box_collision() -> bool:
	return (
		collision_box_size.x > 0.0
		and collision_box_size.y > 0.0
		and collision_box_size.z > 0.0
	)


func has_gatherable_surface() -> bool:
	return (
		not gatherable_surface_material_names.is_empty()
		and gatherable_surface_maximum_height
		> gatherable_surface_minimum_height
	)


func is_procedural() -> bool:
	return procedural_group != &""