## Represents a 3D tetromino (tower block) with shape, position, and rotation.
##
## Manages 3D grid cell data, mesh instances, position/rotation state,
## synergy detection, and material effects.
class_name Tetromino
extends Node3D

signal hovered(tetromino: Tetromino)
signal unhovered(tetromino: Tetromino)
signal selected(tetromino: Tetromino)
signal deselected(tetromino: Tetromino)


# Data
@export var resource: TetrominoDefinition

# Visual
var _mesh_color: Color = Color.WHITE
var _material: StandardMaterial3D
var _is_ghost: bool = false
var _original_color: Color = Color.WHITE

# Runtime
@onready var base_damage: int = resource.base_damage
@onready var fire_rate: float = resource.fire_rate
@onready var synergy_radius: float = resource.synergy_radius
@onready var synergy_tags: PackedStringArray = resource.synergy_tags
@onready var _mesh_instance: MeshInstance3D = get_node("Visuals/MeshInstance3D")

# Grid state
var grid_position: Vector3i = Vector3i.ZERO
var rotation_quat: Quaternion = Quaternion.IDENTITY
var _grid_cells: PackedVector3Array = []  # Relative cell coordinates


func _ready() -> void:
	_initialize_material()
	_set_mesh_representation()
	pass


## Initializes the material for visual representation.
func _initialize_material() -> void:
	_material = StandardMaterial3D.new()
	_material.albedo_color = Color.RED
	_material.metallic = 0.3
	_material.roughness = 0.7


## Creates a simple mesh representation based on shape type.
func _set_mesh_representation() -> void:
	_mesh_instance.mesh = resource.mesh
	_mesh_instance.set_surface_override_material(0, _material)
	$SelectionArea/CollisionShape3D.shape = _mesh_instance.mesh.create_trimesh_shape()
	_grid_cells = resource.grid_cells


## Gets the grid cells occupied by this tetromino at its current position.
func get_grid_cells(at_position: Vector3i = grid_position) -> PackedVector3Array:
	var result = PackedVector3Array()
	for cell in _grid_cells:
		result.append(at_position + Vector3i(cell.x, cell.y, cell.z))
	return result


## Gets grid cells with a specific rotation applied.
func get_grid_cells_with_rotation(at_position: Vector3i, rot: Quaternion) -> PackedVector3Array:
	var result = PackedVector3Array()
	
	# Apply rotation to relative grid cells
	for cell in _grid_cells:
		var rotated = rot * Vector3(cell)
		var rotated_int = Vector3i(rotated.round())
		result.append(at_position + rotated_int)
	
	return result


## Gets the bounds (AABB) of this tetromino.
func get_bounds() -> AABB:
	var min_cell = Vector3i.ZERO
	var max_cell = Vector3i.ZERO
	
	for cell in _grid_cells:
		min_cell = min_cell.min(cell)
		max_cell = max_cell.max(cell)
	
	var size = Vector3(max_cell - min_cell) + Vector3.ONE
	var pos = grid_position + min_cell
	
	return AABB(Vector3(pos), size)


## Sets the color/material of the tetromino.
func set_color(color: Color) -> void:
	_mesh_color = color
	_original_color = color
	if _material:
		_material.albedo_color = color


## Enables/disables ghost mode (semi-transparent, movable state).
func set_ghost_mode(enabled: bool) -> void:
	_is_ghost = enabled
	
	if enabled:
		# Create material if needed
		if not _material:
			_initialize_material()
		
		# Make semi-transparent
		var ghost_color = _original_color
		ghost_color.a = 0.5
		_material.albedo_color = ghost_color
		_mesh_instance.set_surface_override_material(0, _material)
	else:
		# Restore original appearance
		if _material:
			_material.albedo_color = _original_color
			_material.albedo_color.a = 1.0
			_mesh_instance.set_surface_override_material(0, _material)


## Enables/disables highlight for visual feedback.
func set_highlighted(enabled: bool) -> void:
	if _material:
		_material.emission_enabled = enabled
		if enabled:
			_material.emission = _mesh_color
			_material.emission_energy_multiplier = 2.0
		else:
			_material.emission_energy_multiplier = 0.0


## Returns string representation for debugging.
func _to_string() -> String:
	return "Tetromino3D[type=%s, pos=%v, cells=%d]" % [
		resource.shape_type,
		grid_position,
		_grid_cells.size()
	]

## Callback used to handle tetromino selection and deselection
func _on_selection_area_input_event(camera: Node, event: InputEvent, event_position: Vector3, normal: Vector3, shape_idx: int) -> void:
	if event is InputEventMouseButton:
		if event.pressed and event.button_index == MOUSE_BUTTON_LEFT:
			selected.emit(self)
		elif event.pressed and event.button_index == MOUSE_BUTTON_RIGHT:
			deselected.emit(self)


## Callback used to handle tetromino hovering
func _on_selection_area_mouse_entered() -> void:
	print("Tetromino hovered")
	set_highlighted(true)
	hovered.emit(self)

## Callback used to handle tetromino unhovering
func _on_selection_area_mouse_exited() -> void:
	print("Tetromino unhovered")
	set_highlighted(false)
	unhovered.emit(self)