class_name InputBindings
extends RefCounted
## Key/button remaps persisted through the settings panel. Games keep working
## with the defaults in `project.godot`; only actions the player rebinds are
## rewritten, and remaps never remove mouse or gamepad axis events.

const REMAPPABLE := [
	"move_forward", "move_back", "move_left", "move_right",
	"walk_slow", "inspect", "wand", "radio_emergency", "action_menu",
]

## Turn an input event into a storable descriptor, or {} when it is not a key or
## pad button (mouse buttons and axes are deliberately not remappable here).
static func descriptor_from_event(event: InputEvent) -> Dictionary:
	if event is InputEventKey:
		var key := event as InputEventKey
		var code := key.physical_keycode if key.physical_keycode != 0 else key.keycode
		if code == 0:
			return {}
		return {"type": "key", "code": int(code)}
	if event is InputEventJoypadButton:
		return {"type": "joy", "button": int((event as InputEventJoypadButton).button_index)}
	return {}

static func label_for(descriptor: Dictionary) -> String:
	match str(descriptor.get("type", "")):
		"key":
			return OS.get_keycode_string(int(descriptor.get("code", 0)))
		"joy":
			return "Pad %d" % int(descriptor.get("button", 0))
		_:
			return ""

## First key/button currently bound to the action, used to label the UI.
static func current_descriptor(action: String) -> Dictionary:
	if not InputMap.has_action(action):
		return {}
	for event in InputMap.action_get_events(action):
		var descriptor := descriptor_from_event(event)
		if not descriptor.is_empty():
			return descriptor
	return {}

## Rewrite the actions present in `bindings`. Existing key/button events for
## those actions are replaced; mouse and joypad-axis events are left alone.
static func apply(bindings: Dictionary) -> void:
	for action in bindings.keys():
		if not InputMap.has_action(action):
			continue
		var descriptor: Dictionary = bindings[action]
		if descriptor.is_empty():
			continue
		for event in InputMap.action_get_events(action):
			if event is InputEventKey or event is InputEventJoypadButton:
				InputMap.action_erase_event(action, event)
		InputMap.action_add_event(action, event_for(descriptor))

static func event_for(descriptor: Dictionary) -> InputEvent:
	match str(descriptor.get("type", "")):
		"joy":
			var button := InputEventJoypadButton.new()
			button.button_index = int(descriptor.get("button", 0))
			return button
		_:
			var key := InputEventKey.new()
			key.physical_keycode = int(descriptor.get("code", 0))
			return key