## WaveManager.gd
## Loads wave definitions and orchestrates creep spawning along the lane path.
extends Node

const WAVE_DATA_PATH := "res://data/waves.json"
const TOTAL_WAVES    := 31

var _waves: Array       = []
var _active_creeps: int = 0

func _ready() -> void:
	_load_waves()
	EventBus.creep_died.connect(_on_creep_removed)
	EventBus.creep_reached_exit.connect(_on_creep_removed)

func _load_waves() -> void:
	_waves = DataLoader.load_waves()
	if _waves.is_empty():
		push_error("WaveManager: waves.json failed to load or is empty")

func start_wave(wave_number: int, lane: Node) -> void:
	if wave_number < 1 or wave_number > _waves.size():
		push_error("WaveManager: invalid wave number %d" % wave_number)
		return

	var wave_data: Dictionary = _waves[wave_number - 1]
	GameState.advance_wave()
	GameState.set_phase(GameState.Phase.COMBAT)
	EventBus.wave_started.emit(wave_number)

	var count: int  = wave_data.get("creep_count", 1)
	_active_creeps += count

	var path_pts: PackedVector2Array = lane.get_path_points() if lane.has_method("get_path_points") else PackedVector2Array()

	# Spawn creeps spaced 0.5 s apart
	for i in range(count):
		await get_tree().create_timer(0.5 * i).timeout
		_spawn_creep(wave_data, lane, path_pts)

func _spawn_creep(wave_data: Dictionary, lane: Node, path_pts: PackedVector2Array) -> void:
	var creep_scene := load("res://scenes/gameplay/Creep.tscn") as PackedScene
	if not creep_scene:
		push_error("WaveManager: Creep.tscn not found")
		_active_creeps -= 1
		return
	var creep: Node = creep_scene.instantiate()
	lane.add_child(creep)
	creep.setup(wave_data)
	if path_pts.size() > 0:
		# Convert lane-local path to global coords for the creep
		var global_pts := PackedVector2Array()
		for pt in path_pts:
			global_pts.append(lane.to_global(pt))
		creep.assign_path(global_pts)

func _on_creep_removed(_creep: Node, _value) -> void:
	_active_creeps = max(0, _active_creeps - 1)
	if _active_creeps == 0:
		_wave_complete()

func _wave_complete() -> void:
	var wn := GameState.wave_number
	EventBus.wave_completed.emit(wn)
	Economy.process_income_phase()
	if wn < TOTAL_WAVES:
		GameState.set_phase(GameState.Phase.BUILD)
	# If wave 31, GameOver.gd listens to wave_completed and handles victory