added firebase and rudimentary leaderboard support

addons/godot-firebase/functions/function_task.gd

@@ -0,0 +1,59 @@
+## @meta-authors Nicolò 'fenix' Santilio,
+## @meta-version 1.2
+##
+## ex.
+## [code]var task : FirestoreTask = Firebase.Firestore.query(query)[/code]
+## [code]var result : Array = await task.task_finished[/code]
+## [code]var result : Array = await task.result_query[/code]
+## [code]var result : Array = await Firebase.Firestore.task_finished[/code]
+## [code]var result : Array = await Firebase.Firestore.result_query[/code]
+##
+## @tutorial https://github.com/GodotNuts/GodotFirebase/wiki/Firestore#FirestoreTask
+
+@tool
+class_name FunctionTask
+extends RefCounted
+
+## Emitted when a request is completed. The request can be successful or not successful: if not, an [code]error[/code] Dictionary will be passed as a result.
+## @arg-types Variant
+signal task_finished(result)
+
+## Emitted when a cloud function is correctly executed, returning the Response Code and Result Body
+## @arg-types FirestoreDocument
+signal function_executed(response, result)
+
+## Emitted when a request is [b]not[/b] successfully completed.
+## @arg-types Dictionary
+signal task_error(code, status, message)
+
+## A variable, temporary holding the result of the request.
+var data: Dictionary
+var error: Dictionary
+
+## Whether the data came from cache.
+var from_cache : bool = false
+
+var _response_headers : PackedStringArray = PackedStringArray()
+var _response_code : int = 0
+
+var _method : int = -1
+var _url : String = ""
+var _fields : String = ""
+var _headers : PackedStringArray = []
+
+func _on_request_completed(result : int, response_code : int, headers : PackedStringArray, body : PackedByteArray) -> void:
+	var bod = Utilities.get_json_data(body)
+	if bod == null:
+		bod = {content = body.get_string_from_utf8()} # I don't understand what this line does at all. What the hell?!
+
+	var offline: bool = typeof(bod) == TYPE_NIL
+	from_cache = offline
+
+	data = bod
+	if response_code == HTTPClient.RESPONSE_OK and data!=null:
+		function_executed.emit(result, data)
+	else:
+		error = {result=result, response_code=response_code, data=data}
+		task_error.emit(result, response_code, str(data))
+
+	task_finished.emit(data)