extends Node
# save_game.gd - Responsible for saving and loading the game using a SaveData resource

const SAVE_GAME_PATH := "user://savegame.save"
const VERSION: int = 1

func save() -> void:
	var save_file = FileAccess.open(SAVE_GAME_PATH, FileAccess.WRITE)
	
	# Save the meta data like save game version and timestamps
	var meta_data = {
		"meta": {
			"version" : VERSION,
			"timestamp" : Time.get_datetime_string_from_system()
		}
	}
	var meta_json_string = JSON.stringify(meta_data)
	save_file.store_line(meta_json_string)
		
	# Save the player node's position
	var player = get_tree().get_root().find_child("Player", true, false)
	var player_node_data = player.save()
	var player_json = JSON.stringify(player_node_data)
	save_file.store_line(player_json)
	
	# Save all other stuff from the SaveData
	var save_data = SaveData.call("save")
	var json_string = JSON.stringify(save_data)
	save_file.store_line(json_string)

func load() -> void:
	if not FileAccess.file_exists(SAVE_GAME_PATH):
		print("No save file exists.")
		return
		
	# NEXT STEP: How to load correctly and in which order?
	# first the current world, then the player and their position and then the inventory?
	
	# Load the save file line by line and process the dictionary to restore
	# the object it represents
	var save_file = FileAccess.open(SAVE_GAME_PATH, FileAccess.READ)
	while save_file.get_position() < save_file.get_length():
		var json_string = save_file.get_line()
		
		# Creates the helper class to interact with JSON
		var json = JSON.new()
		
		# Check if there is any error while parsing the JSON string, skip in case of failure
		var parse_result = json.parse(json_string)
		if not parse_result == OK:
			print("JSON Parse Error: ", json.get_error_message(), " in ", json_string, " at line", json.get_error_line())
			continue
		
		# Get the data from the JSON object
		var node_data = json.get_data()
		
		if node_data.has("meta"):
			print("Meta data ignored.")

		# handle the player data (name, money, etc.)
		if node_data.has("player_data"):
			var world_to_load = load(node_data["player_data"].world)
			var instance = world_to_load.instantiate()
			instance.add_child(load("res://scenes/player/player.tscn").instantiate())
			var level_container = get_tree().get_root().find_child("CurrentLevel", true, false)
			level_container.add_child(instance)


func savegame_exists() -> bool:
	return FileAccess.file_exists(SAVE_GAME_PATH)