extends Node2D
## One greybox arena, one screen (640x360), fixed camera. Draws its own
## floor and wall slabs; tracks kills and chemistry procs; conducts the
## authorship-loud chemistry feedback stack (canon: brief hitstop + the
## two tag hues meeting at the point of contact + a per-pair sting —
## no proc text, the light and the sting are the noun).

const CHEM_FX := preload("res://scripts/chemistry_fx.gd")
const SALVAGE := preload("res://scripts/salvage.gd")

## Run structure: rooms with a spawn budget; clear a room -> node fork
## (card draft vs scrap) -> next room; final room or death -> tally.
@export var rooms_enabled := true
@export var rooms_per_run := 4
@export var room_budget_base := 8
@export var room_budget_per_room := 4

var kills: int = 0
var chem_procs: int = 0
var room: int = 1
var rooms_cleared: int = 0


func _ready() -> void:
	add_to_group("arena")
	$Spawner.grunt_spawned.connect(_on_grunt_spawned)
	$Mech.hull_changed.connect(_on_hull_changed)
	$Mech.destroyed.connect(_on_mech_destroyed)
	$Interstitial.fork_chosen.connect(_on_fork_chosen)
	$Interstitial.draft_chosen.connect(_on_draft_chosen)
	$Interstitial.restart_requested.connect(func() -> void: get_tree().reload_current_scene())
	if rooms_enabled:
		_begin_room()


func _physics_process(_delta: float) -> void:
	if not rooms_enabled or $Interstitial.active:
		return
	if $Spawner.room_exhausted() and get_tree().get_nodes_in_group("enemies").is_empty():
		_room_cleared()


func _begin_room() -> void:
	$Spawner.begin_room(room_budget_base + (room - 1) * room_budget_per_room)


func _room_cleared() -> void:
	rooms_cleared += 1
	$Hand.force_close()
	if room >= rooms_per_run:
		$Interstitial.open_tally(_stats(), false)
	else:
		$Interstitial.open_fork()


func _on_fork_chosen(kind: String) -> void:
	if kind == "scrap":
		$Hand.add_salvage($Interstitial.fork_scrap_reward)
		_advance()
	else:
		var opts: Array[int] = []
		for i in 3:
			opts.append(randi() % $Hand.CARD_TYPES.size())
		$Interstitial.open_draft(opts)


func _on_draft_chosen(card_id: int) -> void:
	if card_id >= 0:
		$Hand.belt_append(card_id)
	else:
		$Hand.add_salvage($Interstitial.draft_decline_scrap)
	_advance()


func _advance() -> void:
	room += 1
	_begin_room()


func _on_mech_destroyed() -> void:
	$Hand.force_close()
	$Interstitial.open_tally(_stats(), true)


func _stats() -> Dictionary:
	return {
		"rooms": rooms_cleared,
		"kills": kills,
		"scrap": $Hand.salvage_total,
		"chem": chem_procs,
	}


func chemistry_proc(at: Vector2, axis: Vector2) -> void:
	chem_procs += 1
	var hand := get_tree().get_first_node_in_group("hand")
	if hand != null:
		hand.hitstop()
	var fx: Node2D = CHEM_FX.new()
	fx.position = at
	fx.axis = axis
	add_child(fx)
	$Sting.play()


func _on_grunt_spawned(grunt: Node) -> void:
	grunt.died.connect(func() -> void: _on_grunt_died(grunt))


func _on_grunt_died(grunt: Node2D) -> void:
	# died fires before queue_free, so position/value are still valid.
	kills += 1
	var hand := get_tree().get_first_node_in_group("hand")
	if hand != null:
		hand.on_kill()
	var s: Area2D = SALVAGE.new()
	s.position = grunt.global_position
	s.value = grunt.salvage_value
	# Deferred: death can fire inside a physics signal flush (projectile
	# body_entered), where Area2D collision setup is blocked.
	add_child.call_deferred(s)


func _on_hull_changed(hull: float, hull_max: float) -> void:
	$HUD/HullFill.size.x = 118.0 * (hull / hull_max)


func _draw() -> void:
	draw_rect(Rect2(0, 0, 640, 360), Color(0.1, 0.11, 0.13))
	for x in range(0, 641, 32):
		draw_line(Vector2(x, 0), Vector2(x, 360), Color(0.13, 0.145, 0.17))
	for y in range(0, 361, 32):
		draw_line(Vector2(0, y), Vector2(640, y), Color(0.13, 0.145, 0.17))
	var wall := Color(0.3, 0.32, 0.36)
	draw_rect(Rect2(0, 0, 640, 16), wall)
	draw_rect(Rect2(0, 344, 640, 16), wall)
	draw_rect(Rect2(0, 0, 16, 360), wall)
	draw_rect(Rect2(624, 0, 16, 360), wall)