Extract API calls to separate class

plugins/UM3NetworkPrinting/src/Network/ClusterApiClient.py

@@ -0,0 +1,61 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+from typing import Callable, List, Optional
+
+from PyQt5.QtCore import QUrl
+from PyQt5.QtNetwork import QNetworkAccessManager, QNetworkRequest, QNetworkReply
+
+
+## The ClusterApiClient is responsible for all network calls to local network clusters.
+class ClusterApiClient:
+
+    PRINTER_API_VERSION = "1"
+    PRINTER_API_PREFIX = "/api/v" + PRINTER_API_VERSION
+
+    CLUSTER_API_VERSION = "1"
+    CLUSTER_API_PREFIX = "/cluster-api/v" + CLUSTER_API_VERSION
+
+    ## Initializes a new cluster API client.
+    #  \param address: The network address of the cluster to call.
+    #  \param on_error: The callback to be called whenever we receive errors from the server.
+    def __init__(self, address: str, on_error: Callable) -> None:
+        super().__init__()
+        self._manager = QNetworkAccessManager()
+        self._address = address
+        self._on_error = on_error
+        self._upload = None  # type: # Optional[ToolPathUploader]
+        # In order to avoid garbage collection we keep the callbacks in this list.
+        self._anti_gc_callbacks = []  # type: List[Callable[[], None]]
+
+    ## Get printer system information.
+    #  \param on_finished: The callback in case the response is successful.
+    def getSystem(self, on_finished: Callable) -> None:
+        url = f"{self.PRINTER_API_PREFIX}/system"
+        reply = self._manager.get(self._createEmptyRequest(url))
+        self._addCallback(reply, on_finished)
+
+    ## We override _createEmptyRequest in order to add the user credentials.
+    #  \param url: The URL to request
+    #  \param content_type: The type of the body contents.
+    def _createEmptyRequest(self, path: str, content_type: Optional[str] = "application/json") -> QNetworkRequest:
+        request = QNetworkRequest(QUrl(self._address + path))
+        if content_type:
+            request.setHeader(QNetworkRequest.ContentTypeHeader, content_type)
+        return request
+
+    ## Creates a callback function so that it includes the parsing of the response into the correct model.
+    #  The callback is added to the 'finished' signal of the reply.
+    #  \param reply: The reply that should be listened to.
+    #  \param on_finished: The callback in case the response is successful.
+    def _addCallback(self, reply: QNetworkReply, on_finished: Callable) -> None:
+        def parse() -> None:
+            # Don't try to parse the reply if we didn't get one
+            if reply.attribute(QNetworkRequest.HttpStatusCodeAttribute) is None:
+                return
+            status_code = reply.attribute(QNetworkRequest.HttpStatusCodeAttribute)
+            response = bytes(reply.readAll()).decode()
+            self._anti_gc_callbacks.remove(parse)
+            on_finished(int(status_code), response)
+            return
+        self._anti_gc_callbacks.append(parse)
+        reply.finished.connect(parse)