extends Node


signal cache_done


var _req_headers

var _consts = preload("res://data/consts.gd")

func _init() -> void:
	_req_headers = PackedStringArray(["User-Agent: " + _consts.APP_NAME + "/" + _consts.APP_VERSION, "Accept: */*"])


func _cache_error(err: String) -> String:
	return "CACHE::ERROR::" + err + "\n"
	

func _get_dict_from_file(filepath: String) -> Dictionary:
	var file = FileAccess.open(filepath, FileAccess.READ)
	var data = JSON.parse_string(file.get_as_text())
	
	return data

## get_card_data_from_name
##
## _name: String [br]
## A wrapper for searching for a card by name. Use **get_card_data_from_id** where possible, as it avoids an expensive search for the new card, if the card has been cached already.
func get_card_data_from_name(_name: String) -> Dictionary:
	return _get_card_data_from_bulk("name", _name)


## get_card_data_from_id
##
## id: String [br]
## This is the preferred wrapper to use when fetching card data, it checks the cache for preexisting data and uses that if it's available. Otherwise, it will search the bulk json for the data.
func get_card_data_from_id(id: String) -> Dictionary:
	if FileAccess.file_exists("user://card_cache/" + id + "/card.json"):
		return _get_dict_from_file("user://card_cache/" + id + "/card.json")
	return _get_card_data_from_bulk("id", id)


func _get_card_data_from_bulk(field: String, search_query: String) -> Dictionary:
	var file = FileAccess.open("user://card_cache/bulk.json", FileAccess.READ)
	var bulk_json = JSON.parse_string(file.get_as_text())
	
	var selected_entry = null
	for entry in bulk_json:
		if entry[field] == search_query:
			selected_entry = entry
			break
		continue
	file = null
	
	if selected_entry == null:
		return {}
	
	if selected_entry["image_status"] != "missing":
		_fetch_card_img(selected_entry)
	
	var dir = DirAccess.open("user://")
	dir.make_dir_recursive("user://card_cache/" + selected_entry["id"] + "/")
	dir = null
	
	file = FileAccess.open("user://card_cache/" + selected_entry["id"] + "/card.json", FileAccess.WRITE)
	file.store_line(JSON.stringify(selected_entry, "\t"))
	file = null
	
	return selected_entry

func _fetch_card_img(data: Dictionary) -> Error:
	if FileAccess.file_exists("user://card_cache/" + data["id"] + "card.png"):
		return OK
	
	var httpr = HTTPRequest.new()
	add_child(httpr)
	
	var err = httpr.request((data["image_uris"])["png"], _req_headers)
	if err != OK:
		push_error(_cache_error("GET_REQUEST") + "An error occured in the Scryfall request.")
		return FAILED
	var resp = await httpr.request_completed
	
	var img = Image.new()
	err = img.load_png_from_buffer(resp[3])
	if err != OK:
		push_error(_cache_error("IMG_LOADING") + "Couldn't load the image.")
		return FAILED
		
	var dir = DirAccess.open("user://")
	dir.make_dir_recursive("user://card_cache/" + data["id"] + "/")
	dir = null
	
	img.save_png("user://card_cache/" + data["id"] + "/card.png")
	img = null
	
	return OK

func get_bulk_data(force: bool) -> Error:
	if FileAccess.file_exists("user://card_cache/bulk.json"):
		if force:
			DirAccess.remove_absolute("user://card_cahce/bulk.json")
		else:
			return OK
	
	var httpr = HTTPRequest.new()
	add_child(httpr)
	
	var error = httpr.request("https://api.scryfall.com/bulk-data/unique-artwork", _req_headers)
	if error != OK:
		push_error(_cache_error("GET_REQUEST") + "An error occurred in the Scryfall request.")
		return FAILED
	
	var response = await httpr.request_completed
	if response[0] != HTTPRequest.RESULT_SUCCESS:
		push_error(_cache_error("GET_REQUEST") + "Failed to fetch card data from Scryfall")
		return FAILED
		
	var unprocessed_body = response[3].get_string_from_utf8()
	var card_content = JSON.parse_string(unprocessed_body)
	if card_content == null:
		push_error(_cache_error("PARSING") + "Failed to parse the Scryfall card results.")
		return FAILED
	
	
	error = httpr.request(card_content["download_uri"], _req_headers)
	if error != OK:
		push_error(_cache_error("GET_REQUEST") + "An error occurred in the Scryfall request.")
		return FAILED
	
	response = await httpr.request_completed
	if response[0] != HTTPRequest.RESULT_SUCCESS:
		push_error(_cache_error("GET_REQUEST") + "Failed to fetch card data from Scryfall")
		return FAILED
		
	unprocessed_body = response[3].get_string_from_utf8()
	card_content = JSON.parse_string(unprocessed_body)
	if card_content == null:
		push_error(_cache_error("PARSING") + "Failed to parse the Scryfall card results.")
		return FAILED
	
	var dir = DirAccess.open("user://")
	dir.make_dir_recursive("user://card_cache/")  # lets ensure the path is there
	dir = null
	
	var data_cache = FileAccess.open("user://card_cache/bulk.json", FileAccess.WRITE)
	data_cache.store_string(unprocessed_body)
	data_cache = null
	
	cache_done.emit()
	
	return OK