MqttMonitor/MqttMonitorWidget.py

# -*- coding: utf-8 -*-

# Copyright (c) 2018 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the MQTT Monitor widget.
"""

from __future__ import unicode_literals

try:
    str = unicode       # __IGNORE_EXCEPTION__
except NameError:
    pass

import os
import collections

from PyQt5.QtCore import pyqtSlot, QTimer
from PyQt5.QtGui import QTextCursor
from PyQt5.QtWidgets import QWidget, QDialog

from E5Gui import E5MessageBox

from .Ui_MqttMonitorWidget import Ui_MqttMonitorWidget

from .MqttClient import MqttClient, mqttConnackMessage, mqttErrorMessage

import UI.PixmapCache
import Utilities


class MqttMonitorWidget(QWidget, Ui_MqttMonitorWidget):
    """
    Class implementing the MQTT Monitor widget.
    """
    BrokerStatusTopicPrefix = "$SYS/broker/"
    BrokerStatusTopic = "$SYS/broker/#"
    BrokerStatusTopicLoadPrefix = "$SYS/broker/load/"
    
    def __init__(self, plugin, parent=None):
        """
        Constructor
        
        @param plugin reference to the plug-in object
        @type MqttMonitorPlugin
        @param parent reference to the parent widget
        @type QWidget
        """
        super(MqttMonitorWidget, self).__init__(parent)
        self.setupUi(self)
        
        self.__plugin = plugin
        
        self.__connectedToBroker = False
        self.__brokerStatusTopicSubscribed = False
        
        self.pixmapLabel.setPixmap(UI.PixmapCache.getPixmap(
            os.path.join("MqttMonitor", "icons", "mqtt48.png")))
        
        self.brokerWidget.setCurrentIndex(0)
        
        self.connectButton.setIcon(UI.PixmapCache.getIcon("ircConnect.png"))
        self.brokerConnectionOptionsButton.setIcon(UI.PixmapCache.getIcon(
            os.path.join("MqttMonitor", "icons", "connectionOptions.png")))
        self.__populateBrokerComboBoxes()
        self.brokerStatusLabel.hide()
        
        self.subscribeButton.setIcon(UI.PixmapCache.getIcon("plus.png"))
        self.subscribeButton.setEnabled(False)
        self.unsubscribeButton.setIcon(UI.PixmapCache.getIcon("minus.png"))
        
        self.__subscribedTopics = []
        self.__topicQueue = {}
        self.__updateUnsubscribeTopicComboBox()
        
        self.__publishedTopics = []
        self.__updatePublishTopicComboBox()
        self.publishButton.setEnabled(False)
        
        self.__connectionOptions = None
        
        prefix = MqttMonitorWidget.BrokerStatusTopicPrefix
        self.__statusLabelMapping = {
            # broker
            prefix + "version": self.versionLabel,
            prefix + "timestamp": self.timestampLabel,
            prefix + "uptime": self.uptimeLabel,
            prefix + "subscriptions/count": self.subscriptionsLabel,
            # clients
            prefix + "clients/connected": self.clientsConnectedLabel,
            prefix + "clients/disconnected": self.clientsDisconnectedLabel,
            prefix + "clients/expired": self.clientsExpiredLabel,
            prefix + "clients/maximum": self.clientsMaximumLabel,
            prefix + "clients/total": self.clientsTotalLabel,
            # messages
            prefix + "messages/sent": self.messagesSentLabel,
            prefix + "messages/received": self.messagesReceivedLabel,
            prefix + "messages/stored": self.messagesStoredLabel,
            prefix + "store/messages/count": self.messagesStoredLabel,
            prefix + "messages/inflight": self.messagesInflightLabel,
            prefix + "retained messages/count": self.messagesRetainedLabel,
            # publish messages
            prefix + "publish/messages/sent": self.publishMessagesSentLabel,
            prefix + "publish/messages/received":
                self.publishMessagesReceivedLabel,
            prefix + "publish/messages/dropped":
                self.publishMessagesDroppedLabel,
            # traffic
            prefix + "bytes/sent": self.bytesSentLabel,
            prefix + "bytes/received": self.bytesReceivedLabel,
            # load
            prefix + "load/bytes/sent": self.loadBytesSentLabel,
            prefix + "load/bytes/received": self.loadBytesReceivedLabel,
            prefix + "load/messages/sent": self.loadMessagesSentLabel,
            prefix + "load/messages/received": self.loadMessagesReceivedLabel,
            prefix + "load/publish/sent": self.loadPublishSentLabel,
            prefix + "load/publish/received": self.loadPublishReceivedLabel,
            prefix + "load/publish/dropped": self.loadPublishDroppedLabel,
            prefix + "load/connections": self.loadConnectionsLabel,
            prefix + "load/sockets": self.loadSocketsLabel,
        }
        
        self.__statusLoadValues = collections.defaultdict(
            self.__loadDefaultDictFactory)
        
        self.__client = MqttClient()
        
        # connect the MQTT client signals
        self.__client.onConnect.connect(self.__brokerConnected)
        self.__client.onDisconnected.connect(self.__brokerDisconnected)
        self.__client.onMessage.connect(self.__messageReceived)
        self.__client.onPublish.connect(self.__messagePublished)
        self.__client.onSubscribe.connect(self.__topicSubscribed)
        self.__client.onUnsubscribe.connect(self.__topicUnsubscribed)
    
    #######################################################################
    ## Slots handling MQTT related signals
    #######################################################################
    
    @pyqtSlot(dict, int)
    def __brokerConnected(self, flags, rc):
        """
        Private slot to handle being connected to a broker.
        
        @param flags flags set for the connection
        @type dict
        @param rc CONNACK result code
        @type int
        """
        if rc == 0:
            self.__connectedToBroker = True
            self.__connectionOptions = None
        
        msg = mqttConnackMessage(rc)
        self.__flashBrokerStatusLabel(msg)
        
        self.connectButton.setIcon(UI.PixmapCache.getIcon("ircDisconnect.png"))
        
        self.subscribeGroup.setEnabled(True)
        self.unsubscribeGroup.setEnabled(True)
        self.publishGroup.setEnabled(True)
        self.brokerStatusButton.setEnabled(True)
        
        self.__statusLoadValues.clear()
        self.__clearBrokerStatusLabels()
        self.__setBrokerStatusSubscribed(False)
    
    @pyqtSlot(int)
    def __brokerDisconnected(self, rc):
        """
        Private slot to handle a disconnection from the broker.
        
        @param rc MQTT error result code
        @type int
        """
        self.__connectedToBroker = False
        
        # ensure, the client loop is stopped
        self.__client.stopLoop()
        
        if rc != 0:
            msg = mqttErrorMessage(rc)
        else:
            msg = self.tr("Connection to Broker shut down cleanly.")
        self.__flashBrokerStatusLabel(msg)
        
        self.connectButton.setIcon(UI.PixmapCache.getIcon("ircConnect.png"))

        self.__subscribedTopics = []
        self.__topicQueue = {}
        self.__updateUnsubscribeTopicComboBox()
        self.__updatePublishTopicComboBox()
        
        self.subscribeGroup.setEnabled(False)
        self.unsubscribeGroup.setEnabled(False)
        self.publishGroup.setEnabled(False)
        self.brokerStatusButton.setEnabled(False)
        
        self.__statusLoadValues.clear()
    
    @pyqtSlot(str, bytes, int, bool)
    def __messageReceived(self, topic, payload, qos, retain):
        """
        Private slot to handle the receipt of a message.
        
        @param topic topic of the message
        @type str
        @param payload payload (i.e. data) of the message
        @type bytes
        @param qos quality of service indicator
        @type int
        @param retain flag indicating a retained message
        @type bool
        """
        if topic.startswith(MqttMonitorWidget.BrokerStatusTopicPrefix):
            # handle broker status messages
            self.__handleBrokerStatusMessage(topic, payload)
        else:
            self.__appendMessage(topic, payload)
    
    @pyqtSlot(int)
    def __messagePublished(self, mid):
        """
        Private slot to handle a message being published.
        
        @param mid ID of the published message
        @type int
        """
        pass
    
    @pyqtSlot(int, tuple)
    def __topicSubscribed(self, mid, grantedQos):
        """
        Private slot to handle being subscribed to topics.
        
        @param mid ID of the subscribe request
        @type int
        @param grantedQos tuple of granted quality of service
        @type tuple of int
        """
        if mid in self.__topicQueue:
            topic = self.__topicQueue.pop(mid)
            self.__subscribedTopics.append(topic)
            self.subscribeTopicEdit.clear()
            
            self.__updateUnsubscribeTopicComboBox()
            self.__updatePublishTopicComboBox()
    
    @pyqtSlot(int)
    def __topicUnsubscribed(self, mid):
        """
        Private slot to handle being unsubcribed from a topic.
        
        @param mid ID of the unsubscribe request
        @type int
        """
        if mid in self.__topicQueue:
            topic = self.__topicQueue.pop(mid)
            try:
                self.__subscribedTopics.remove(topic)
                self.__updateUnsubscribeTopicComboBox()
                self.__updatePublishTopicComboBox()
            except ValueError:
                # ignore it
                pass
    
    #######################################################################
    ## Slots handling UI interactions
    #######################################################################
    
    @pyqtSlot()
    def __flashBrokerStatusLabel(self, message):
        """
        Private slot to show the broker status label with some text for
        5 seconds.
        
        @param message message to be shown
        @type str
        """
        self.brokerStatusLabel.setText(message)
        self.brokerStatusLabel.show()
        QTimer.singleShot(5000, self.brokerStatusLabel.hide)
    
    @pyqtSlot(str)
    def on_brokerComboBox_editTextChanged(self, host):
        """
        Private slot to handling entering or selecting a broker host name.
        
        @param host host name of the broker
        @type str
        """
        if not self.__connectedToBroker and not host:
            self.connectButton.setEnabled(False)
        else:
            self.connectButton.setEnabled(True)
    
    @pyqtSlot()
    def on_brokerConnectionOptionsButton_clicked(self):
        """
        Private slot to show a dialog to modify connection options.
        """
        from .MqttConnectionOptionsDialog import MqttConnectionOptionsDialog
        dlg = MqttConnectionOptionsDialog(
            self.__client, self.__connectionOptions, parent=self)
        if dlg.exec_() == QDialog.Accepted:
            self.__connectionOptions = dlg.getConnectionOptions()
    
    @pyqtSlot()
    def on_connectButton_clicked(self):
        """
        Private slot to handle a connect or disconnect request.
        """
        if self.__connectedToBroker:
            self.__client.disconnectFromServer()
        else:
            host = self.brokerComboBox.currentText()
            port = self.brokerPortComboBox.currentText().strip()
            try:
                port = int(port)
            except ValueError:
                # use standard port at 1883
                port = 1883
            if host:
                self.__addBrokerToRecent(host, port)
                if self.__connectionOptions is None:
                    self.__client.connectToServer(host, port=port)
                else:
                    self.__client.connectToServerWithOptions(
                        host, port=port, options=self.__connectionOptions)
    
    @pyqtSlot(str)
    def on_subscribeTopicEdit_textChanged(self, topic):
        """
        Private slot to handle a change of the entered topic.
        
        @param topic entered topic text
        @type str
        """
        self.subscribeButton.setEnabled(bool(topic))
    
    @pyqtSlot()
    def on_subscribeTopicEdit_returnPressed(self):
        """
        Private slot handling the user pressing the return button to subscribe
        a topic.
        """
        self.on_subscribeButton_clicked()
    
    @pyqtSlot()
    def on_subscribeButton_clicked(self):
        """
        Private slot to subscribe to the entered topic.
        """
        topic = self.subscribeTopicEdit.text()
        qos = self.subscribeQosSpinBox.value()
        if topic:
            if topic.startswith(MqttMonitorWidget.BrokerStatusTopicPrefix):
                E5MessageBox.warning(
                    self,
                    self.tr("Subscribe to Topic"),
                    self.tr("Subscriptions to the Status topic '$SYS' shall"
                            " be done on the 'Status' tab."))
            else:
                self.__topicQueue[
                    self.__client.subscribe(topic, qos)[1]] = topic
    
    @pyqtSlot(str)
    def on_unsubscribeTopicComboBox_currentIndexChanged(self, topic):
        """
        Private slot to handle the selection of a topic to unsubscribe from.
        
        @param topic topic text
        @type str
        """
        self.unsubscribeButton.setEnabled(bool(topic))
    
    @pyqtSlot()
    def on_unsubscribeButton_clicked(self):
        """
        Private slot to unsubscribe from the selected topic.
        """
        topic = self.unsubscribeTopicComboBox.currentText()
        if topic:
            self.__topicQueue[
                self.__client.unsubscribe(topic)[1]] = topic
    
    @pyqtSlot(str)
    def on_publishTopicComboBox_editTextChanged(self, topic):
        """
        Private slot to handle changes of the publish topic name.
        
        @param topic topic text
        @type str
        """
        self.publishButton.setEnabled(bool(topic))
    
    @pyqtSlot()
    def on_publishButton_clicked(self):
        """
        Private slot to publish the entered message.
        """
        topic = self.publishTopicComboBox.currentText()
        qos = self.publishQosSpinBox.value()
        retain = self.publishRetainCheckBox.isChecked()
        payloadStr = self.publishPayloadEdit.toPlainText()
        if not payloadStr:
            # use empty string together with the retain flag to clean
            # a retained message by sending None instead
            payloadStr = None
        
        msgInfo = self.__client.publish(topic, payloadStr, qos, retain)
        if msgInfo.rc == 0:
            if topic not in self.__publishedTopics:
                self.__publishedTopics.append(topic)
            self.__updatePublishTopicComboBox(resetTopic=False)
            if self.clearPublishCheckBox.isChecked():
                self.on_publishClearButton_clicked()
    
    @pyqtSlot()
    def on_publishClearButton_clicked(self):
        """
        Private slot to clear the publish data fields.
        """
        self.publishTopicComboBox.clearEditText()
        self.publishPayloadEdit.clear()
        self.publishQosSpinBox.setValue(0)
        self.publishRetainCheckBox.setChecked(False)
    
    @pyqtSlot()
    def on_brokerStatusButton_clicked(self):
        """
        Private slot to subscribe or unsubscribe the broker status topic.
        """
        if self.__brokerStatusTopicSubscribed:
            # unsubscribe status topic
            rc, _ = self.__client.unsubscribe(
                MqttMonitorWidget.BrokerStatusTopic)
            if rc == 0:
                # successfully sent
                self.__setBrokerStatusSubscribed(False)
        else:
            # subscribe status topic
            rc, _ = self.__client.subscribe(
                MqttMonitorWidget.BrokerStatusTopic)
            if rc == 0:
                # successfully sent
                self.__setBrokerStatusSubscribed(True)
    
    def __setBrokerStatusSubscribed(self, subscribed):
        """
        Private method to set the subscription status for the broker status
        topics.
        
        @param subscribed subscription status for the broker status topics
        @type bool
        """
        self.__brokerStatusTopicSubscribed = subscribed
        if subscribed:
            self.brokerStatusButton.setText(self.tr("Unsubscribe"))
            self.brokerStatusButton.setToolTip(
                self.tr("Press to deactivate the status display"))
        else:
            self.brokerStatusButton.setText(self.tr("Subscribe"))
            self.brokerStatusButton.setToolTip(
                self.tr("Press to activate the status display"))
    
    #######################################################################
    ## Utility methods
    #######################################################################
    
    def __addBrokerToRecent(self, host, port):
        """
        Private method to add a host name to the list of recently connected
        brokers.
        
        @param host host name of broker
        @type str
        @param port port number of the connection
        @type int
        """
        brokerList = self.__plugin.getPreferences("RecentBrokersWithPort")
        hostAndPort = [host, port]
        if hostAndPort in brokerList:
            brokerList.remove(hostAndPort)
        brokerList.insert(0, hostAndPort)
        self.__plugin.setPreferences("RecentBrokersWithPort", brokerList)
        
        self.__populateBrokerComboBoxes()
    
    def __populateBrokerComboBoxes(self):
        """
        Private method to populate the broker name and port combo boxes.
        """
        brokerList = self.__plugin.getPreferences("RecentBrokersWithPort")
        
        # step 1: clear combo boxes
        self.brokerComboBox.clear()
        self.brokerPortComboBox.clear()
        
        # step 2a: populate the broker name list
        self.brokerComboBox.addItems([b[0].strip() for b in brokerList])
        
        # step 2b: populate the broker ports list
        if brokerList:
            currentPort = brokerList[0][1]
        else:
            currentPort = 1883
        currentPortStr = "{0:5}".format(currentPort)
        portsSet = {b[1] for b in brokerList}
        portsSet.update({1883, 8883})
        self.brokerPortComboBox.addItems(
            sorted("{0:5}".format(p) for p in portsSet))
        index = self.brokerPortComboBox.findText(currentPortStr)
        self.brokerPortComboBox.setCurrentIndex(index)
    
    def __updateUnsubscribeTopicComboBox(self):
        """
        Private method to update the unsubcribe topic combo box.
        """
        self.unsubscribeTopicComboBox.clear()
        self.unsubscribeTopicComboBox.addItems(sorted(self.__subscribedTopics))
        self.unsubscribeButton.setEnabled(len(self.__subscribedTopics) > 0)
    
    def __updatePublishTopicComboBox(self, resetTopic=True):
        """
        Private method to update the publish topic combo box.
        
        @param resetTopic flag indicating to reset the topic
        @type bool
        """
        currentTopic = self.publishTopicComboBox.currentText()
        self.publishTopicComboBox.clear()
        self.publishTopicComboBox.addItems(
            list(set(self.__publishedTopics + self.__subscribedTopics)))
        if resetTopic:
            self.publishTopicComboBox.clearEditText()
        else:
            topicIndex = self.publishTopicComboBox.findText(currentTopic)
            self.publishTopicComboBox.setCurrentIndex(topicIndex)
    
    def __appendMessage(self, topic, payload):
        """
        Private method to append a received message to the output.
        
        @param topic topic of the received message
        @type str
        @param payload payload of the received message
        @type bytes
        """
        payloadStr = str(payload, encoding="utf-8", errors="replace")
        txt = self.tr("{0} -> {1}").format(topic, payloadStr)
        if not txt.endswith(("\r\n", "\r", "\n")):
            txt += "\n"
        
        tc = self.messagesEdit.textCursor()
        tc.movePosition(QTextCursor.End)
        self.messagesEdit.setTextCursor(tc)
        self.messagesEdit.insertPlainText(Utilities.filterAnsiSequences(txt))
        self.messagesEdit.ensureCursorVisible()
    
    def __handleBrokerStatusMessage(self, topic, payload):
        """
        Private method to append a received message to the output.
        
        @param topic topic of the received message
        @type str
        @param payload payload of the received message
        @type bytes
        """
        payloadStr = str(payload, encoding="utf-8", errors="replace").strip()
        topic = topic.strip()
        
        if topic.startswith(MqttMonitorWidget.BrokerStatusTopicLoadPrefix):
            self.__handleBrokerLoadStatusMessage(topic, payloadStr)
        else:
            try:
                label = self.__statusLabelMapping[topic]
                label.setText(payloadStr)
            except KeyError:
                # ignore topics not shown in display
                pass
    
    def __handleBrokerLoadStatusMessage(self, topic, payloadStr):
        """
        Private method to append a received message to the output.
        
        @param topic topic of the received message
        @type str
        @param payloadStr string representation of the payload of the
            received message
        @type str
        """
        subtopic, topicElement = topic.rsplit("/", 1)
        self.__statusLoadValues[subtopic][topicElement] = payloadStr
        
        try:
            label = self.__statusLabelMapping[subtopic]
            label.setText("{0} / {1} / {2}".format(
                self.__statusLoadValues[subtopic]["1min"],
                self.__statusLoadValues[subtopic]["5min"],
                self.__statusLoadValues[subtopic]["15min"],
            ))
        except KeyError:
            # ignore topics not shown in display
            pass
    
    def __clearBrokerStatusLabels(self):
        """
        Private method to clear the broker status labels.
        """
        for statusLabelKey in self.__statusLabelMapping:
            if statusLabelKey.startswith(
                    MqttMonitorWidget.BrokerStatusTopicLoadPrefix):
                label = "- / - / -"
            else:
                label = "-"
            self.__statusLabelMapping[statusLabelKey].setText(label)
    
    def __loadDefaultDictFactory(self):
        """
        Private method to populate non-existing load items.
        
        @return default dictionary entry
        @rtype dict
        """
        return {
            "1min": "-",
            "5min": "-",
            "15min": "-",
        }