# Copyright (c) 2018 Ultimaker B.V.
# Cura is released under the terms of the LGPLv3 or higher.
from typing import Dict, List

from PyQt5.QtCore import QTimer

from UM import i18nCatalog
from UM.Logger import Logger
from UM.Message import Message
from cura.API import Account
from cura.CuraApplication import CuraApplication
from cura.Settings.GlobalStack import GlobalStack
from .CloudApiClient import CloudApiClient
from .CloudOutputDevice import CloudOutputDevice
from .Models.CloudClusterResponse import CloudClusterResponse
from .Models.CloudError import CloudError
from .Utils import findChanges


##  The cloud output device manager is responsible for using the Ultimaker Cloud APIs to manage remote clusters.
#   Keeping all cloud related logic in this class instead of the UM3OutputDevicePlugin results in more readable code.
#
#   API spec is available on https://api.ultimaker.com/docs/connect/spec/.
#
class CloudOutputDeviceManager:
    META_CLUSTER_ID = "um_cloud_cluster_id"

    # The interval with which the remote clusters are checked
    CHECK_CLUSTER_INTERVAL = 50.0  # seconds

    # The translation catalog for this device.
    I18N_CATALOG = i18nCatalog("cura")

    def __init__(self) -> None:
        # Persistent dict containing the remote clusters for the authenticated user.
        self._remote_clusters = {}  # type: Dict[str, CloudOutputDevice]

        application = CuraApplication.getInstance()
        self._output_device_manager = application.getOutputDeviceManager()

        self._account = application.getCuraAPI().account  # type: Account
        self._api = CloudApiClient(self._account, self._onApiError)

        # Create a timer to update the remote cluster list
        self._update_timer = QTimer(application)
        self._update_timer.setInterval(int(self.CHECK_CLUSTER_INTERVAL * 1000))
        self._update_timer.setSingleShot(False)

        self._running = False

    #  Called when the uses logs in or out
    def _onLoginStateChanged(self, is_logged_in: bool) -> None:
        Logger.log("d", "Log in state changed to %s", is_logged_in)
        if is_logged_in:
            if not self._update_timer.isActive():
                self._update_timer.start()
            self._getRemoteClusters()
        else:
            if self._update_timer.isActive():
                self._update_timer.stop()

            # Notify that all clusters have disappeared
            self._onGetRemoteClustersFinished([])

    ##  Gets all remote clusters from the API.
    def _getRemoteClusters(self) -> None:
        Logger.log("d", "Retrieving remote clusters")
        self._api.getClusters(self._onGetRemoteClustersFinished)

    ##  Callback for when the request for getting the clusters. is finished.
    def _onGetRemoteClustersFinished(self, clusters: List[CloudClusterResponse]) -> None:
        online_clusters = {c.cluster_id: c for c in clusters if c.is_online}  # type: Dict[str, CloudClusterResponse]

        removed_devices, added_clusters, updates = findChanges(self._remote_clusters, online_clusters)

        Logger.log("d", "Parsed remote clusters to %s", [cluster.toDict() for cluster in online_clusters.values()])
        Logger.log("d", "Removed: %s, added: %s, updates: %s", len(removed_devices), len(added_clusters), len(updates))

        # Remove output devices that are gone
        for removed_cluster in removed_devices:
            if removed_cluster.isConnected():
                removed_cluster.disconnect()
            removed_cluster.close()
            self._output_device_manager.removeOutputDevice(removed_cluster.key)
            del self._remote_clusters[removed_cluster.key]

        # Add an output device for each new remote cluster.
        # We only add when is_online as we don't want the option in the drop down if the cluster is not online.
        for added_cluster in added_clusters:
            device = CloudOutputDevice(self._api, added_cluster)
            self._remote_clusters[added_cluster.cluster_id] = device

        for device, cluster in updates:
            device.clusterData = cluster

        self._connectToActiveMachine()

    ##  Callback for when the active machine was changed by the user or a new remote cluster was found.
    def _connectToActiveMachine(self) -> None:
        active_machine = CuraApplication.getInstance().getGlobalContainerStack()
        if not active_machine:
            return

        # Remove all output devices that we have registered.
        for stored_cluster_id in self._remote_clusters:
            self._output_device_manager.removeOutputDevice(stored_cluster_id)

        # Check if the stored cluster_id for the active machine is in our list of remote clusters.
        stored_cluster_id = active_machine.getMetaDataEntry(self.META_CLUSTER_ID)
        if stored_cluster_id in self._remote_clusters:
            device = self._remote_clusters[stored_cluster_id]
            self._connectToOutputDevice(device)
            Logger.log("d", "Device connected by metadata cluster ID %s", stored_cluster_id)
        else:
            self._connectByNetworkKey(active_machine)

    ## Tries to match the local network key to the cloud cluster host name.
    def _connectByNetworkKey(self, active_machine: GlobalStack) -> None:
        # Check if the active printer has a local network connection and match this key to the remote cluster.
        local_network_key = active_machine.getMetaDataEntry("um_network_key")
        if not local_network_key:
            return

        device = next((c for c in self._remote_clusters.values() if c.matchesNetworkKey(local_network_key)), None)
        if not device:
            return

        Logger.log("i", "Found cluster %s with network key %s", device, local_network_key)
        active_machine.setMetaDataEntry(self.META_CLUSTER_ID, device.key)
        self._connectToOutputDevice(device)

    ## Connects to an output device and makes sure it is registered in the output device manager.
    def _connectToOutputDevice(self, device: CloudOutputDevice) -> None:
        device.connect()
        self._output_device_manager.addOutputDevice(device)

    ## Handles an API error received from the cloud.
    #  \param errors: The errors received
    def _onApiError(self, errors: List[CloudError]) -> None:
        text = ". ".join(e.title for e in errors)  # TODO: translate errors
        message = Message(
            text = text,
            title = self.I18N_CATALOG.i18nc("@info:title", "Error"),
            lifetime = 10
        )
        message.show()

    ## Starts running the cloud output device manager, thus periodically requesting cloud data.
    def start(self):
        if self._running:
            return
        application = CuraApplication.getInstance()
        self._account.loginStateChanged.connect(self._onLoginStateChanged)
        # When switching machines we check if we have to activate a remote cluster.
        application.globalContainerStackChanged.connect(self._connectToActiveMachine)
        self._update_timer.timeout.connect(self._getRemoteClusters)
        self._onLoginStateChanged(is_logged_in = self._account.isLoggedIn)

    ## Stops running the cloud output device manager.
    def stop(self):
        if not self._running:
            return
        application = CuraApplication.getInstance()
        self._account.loginStateChanged.disconnect(self._onLoginStateChanged)
        # When switching machines we check if we have to activate a remote cluster.
        application.globalContainerStackChanged.disconnect(self._connectToActiveMachine)
        self._update_timer.timeout.disconnect(self._getRemoteClusters)
        self._onLoginStateChanged(is_logged_in = False)