extends Node

var _req_headers: PackedStringArray

var _bulk_data: Array

signal fetch_done
var _emitted_done = 0
signal fetch_start
var _emitted_start = 0


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

func _all_downloads_done() -> bool:
	return _emitted_done == _emitted_start

func _setup_cache_in_mem():
	var file = FileAccess.open("user://bulk.json", FileAccess.READ)
	_bulk_data = JSON.parse_string(file.get_as_text())
	file.close()
	

func setup() -> Error:
	if !FileAccess.file_exists("user://bulk.json"):
		get_bulk_data(false)
		push_error("Bulk Data was not downloaded! Downloading now!")
		return FAILED
	
	if !_all_downloads_done():
		push_error("Not done downloading Bulk Data.")
		return FAILED
		
	_setup_cache_in_mem()
	return OK

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


func _on_start_emit() -> void:
	_emitted_start += 1


func _on_end_emit() -> void:
	_emitted_done += 1

func has_emitted_all() -> bool:
	return _emitted_start == _emitted_done


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(_search_results_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(_search_results_generic("id", id))

func _search_results_name(search_query: String) -> Dictionary:
	var selected_entry = null
	for entry in _bulk_data:
		if entry["layout"] == "art_series":
			continue
		var entry_name = entry["name"]
		if entry_name.contains("//"):
			entry_name = entry_name.left(entry_name.find("//") - 1)
		if entry_name == search_query:
			return entry
	push_error("Could not find desired card {" + search_query + "}")
	return {}
		

func _search_results_generic(field: String, search_query: String) -> Dictionary:
	var selected_entry = null
	for entry in _bulk_data:
		if entry["layout"] == "art_series":
			continue
		if entry[field] == search_query:
			return entry[field]
	
	push_error("Could not find desired card {" + search_query + "}")
	return {}
	

func _get_card_data_from_bulk(dict_entry: Dictionary) -> Dictionary:
	if dict_entry["image_status"] != "missing":
		_fetch_card_img(dict_entry)
	
	var dir = DirAccess.open("user://")
	dir.make_dir_recursive("user://card_cache/" + dict_entry["id"] + "/")
	dir = null
	
	var file = FileAccess.open("user://card_cache/" + dict_entry["id"] + "/card.json", FileAccess.WRITE)
	file.store_line(JSON.stringify(dict_entry, "\t"))
	file.close()
	
	print("Card: " + dict_entry["name"] + " (" + dict_entry["id"] + ") found, and cached.")
	
	return dict_entry

func _fetch_card_img(data: Dictionary) -> Error:
	fetch_start.emit()
	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
	
	fetch_done.emit()
	
	return OK

func get_bulk_data(force: bool) -> Error:
	if FileAccess.file_exists("user://bulk.json"):
		if force:
			DirAccess.remove_absolute("user://bulk.json")
		else:
			return OK
	print("downloading ")
	
	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 data_cache = FileAccess.open("user://bulk.json", FileAccess.WRITE)
	data_cache.store_string(unprocessed_body)
	data_cache.close()
	
	fetch_done.emit()
	
	return OK

func _notification(what):
	if what == NOTIFICATION_PREDELETE:
		if !_all_downloads_done():
			push_error("ERR::MEM::CACHE\nCache being deleted before all threads have finished processing!")