# Economy is a game entity that tracks money.

# How money is minted, how money changes hands, and which
# money is valid is all controlled by Economy. When an
# in-game item is purchased, the money does not disappear
# but rather goes to the Market, an economic entity which
# can give back to players through investments or other means.

# Economy also tracks GDP, which is the total amount of
# money that has changed hands so far during the game.
class_name Economy extends Node

# Participant in the game economy
@abstract class Participant:
	var participant_name = "Unnamed participant"
	var _tokens = PackedInt32Array()

	func balance():
		return _tokens.size()

	func hold_tokens(tokens):
		_tokens.append_array(tokens)
		on_balance_update(balance())

	func pop_tokens(amount):
		if balance() < amount:
			return []

		var dropped = []
		for i in range(amount):
			dropped.append(_tokens[_tokens.size() - 1])
			_tokens.remove_at(_tokens.size() - 1)
		on_balance_update(balance())
		return dropped

	@abstract func message(string)
	@abstract func on_balance_update(bal)

class Market extends Participant:
	func _init():
		participant_name = "Market"
	func message(_s):
		pass
	func on_balance_update(_bal):
		pass

const max_money_supply = 1_000_000

var _gdp = 0
var _market = Market.new()
var _participants = []
var _token_ptr = 0

# register a Participant to receive benefits
func register(p: Participant):
	_participants.append(p)

func transfer(amount, sender: Participant, recipient: Participant):
	if sender.balance() < amount:
		return false
	recipient.hold_tokens(sender.pop_tokens(amount))
	_gdp += amount

func mint(amount):
	var tokens = PackedInt32Array()
	if _token_ptr + amount > max_money_supply:
		return false
	for i in range(amount):
		tokens.append(_token_ptr)
		_token_ptr += 1
	_market.hold_tokens(tokens)
	return true

func _ready():
	while true:
		if len(_participants) > 0:
			mint(1000)
			transfer(1000, _market, _participants[0])
			break