class_name StateMachine extends Node

#export (NodePath) var starting_state
export var debug_state_machine: bool = false

# I guess I would declare a number of states here
#export (Reference) var states # Doesn't work
#var starting_state: State

signal state_changed(old_state_name, new_state)


var current_state: State
#var state_modifiers: Array
export var starting_state_name = 'default'
export(Array,Resource) var states
var states_index :Dictionary

# Initialize the state machine by giving each child state a reference to the
# parent object it belongs to and enter the default starting_state.
func _init() -> void:
	print ("init state machine.")

func _ready():
	print ("ready state machine.")
	for s in states:
		print ("sname: ", s.name)
		var this_state = s
		if this_state is State:
			print("Adding state ", this_state.name)
			#check for empty state name 
			if this_state.name != '':
				#check for unique state name
				if !(states_index.has(this_state.name)):
					# call setup
					this_state.setup()
					if debug_state_machine:
						print("Initializing State Node: ", s)
						this_state.debug_state = true
					if this_state.state_timeout != null:
						add_child(this_state.state_timeout)
					# Add to state index
					states_index[this_state.name] = this_state
				else:
					push_error("Multiple states with same name in: ")
			else:
				print("State missing name in: " )

	if states_index.has(starting_state_name):
		change_state(states_index[starting_state_name])
	else:
		push_error("State machine cannot find starting state: " + starting_state_name)


# Change to the new state by first calling any exit logic on the current state.
func change_state(new_state: State) -> void:
	var current_state_name :String
	if current_state:
		current_state.exit()
		current_state_name = current_state.name

	current_state = new_state
	current_state.enter()
	emit_signal("state_changed",current_state_name,current_state)
#	if(state_modifiers.size() > 0 and debug_state_machine):
#		print("Active Modifiers:")
#		for mods in state_modifiers:
#			print(mods.name)

func change_to_known_state(new_state_name: String) -> void:
	if new_state_name.empty() == false:
		if states_index.has(new_state_name):
			change_state(states_index[new_state_name])
		else:
			push_warning(get_parent().name + ": Attempt to switch state to unknown: " + new_state_name)
			change_state(states_index["default"])

# Disable to test whether actually needed.	
## Pass through functions for the Player to call,
## handling state changes as needed.
#func process_physics(delta: float) -> void:
#	change_to_known_state( current_state.process_physics(delta) )
#
#func process_input(event: InputEvent) -> void:
#	var new_state = current_state.process_input(event)
#	if new_state:
#		change_state(new_state)
#
#func process_frame(delta: float) -> void:
#	var new_state = current_state.process_frame(delta)
#	if new_state:
#		change_state(new_state)