# !/Library/Frameworks/Python.framework/Versions/3.3/bin/python3
# !/usr/bin/env python3

#Copyright 2013 Embedded Data Systems, LLC
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.

import os
import xml.etree.ElementTree as ET
#from xml.etree.ElementTree import XML,fromstring, tostring
import tkinter as tk
import datetime
import threading
#import cProfile
import queue
from tkinter import *
from tkinter import filedialog
from tkinter import messagebox
import urllib.request

def CreateMainWin(master,dftURL,dftEUI,dftTag):
    # Create GUI
    global outputDisp,eURL,eEUI,eTag,eTag2,eTag3,eLF,oUnits,bBegin,bLF,omUnits
    
    bgnd = '#E0E0E0'
    
    frm = tk.Frame(master, borderwidth=10, bg=bgnd)
    
    tk.Label(frm, text='Read and parse XML data from an '\
    'OW Server or MeshNet Controller', background=bgnd).grid(row=0, columnspan=5, sticky=W)
    tk.Button(frm, text='Help', command=Help, background=bgnd, highlightbackground=bgnd).grid(row=0, column=5)
    
    tk.Label(frm, text='URL:', background=bgnd).grid(row=1, sticky=W)
    eURL = tk.Entry(frm, highlightbackground=bgnd)
    eURL.grid(row=1, column=1, columnspan=5, sticky=EW)
    eURL.insert(0,dftURL)
    
    tk.Label(frm, text='EUI:', background=bgnd).grid(row=2, columnspan=6, sticky=W)
    eEUI = tk.Entry(frm, highlightbackground=bgnd)
    eEUI.grid(row=2, column=1, columnspan=5, sticky=EW)
    eEUI.insert(0,dftEUI)
    
    tk.Label(frm, text='Tag1:', background=bgnd).grid(row=3, columnspan=6, sticky=W)
    eTag = tk.Entry(frm, highlightbackground=bgnd)
    eTag.grid(row=3, column=1, columnspan=5, sticky=EW)
    eTag.insert(0,dftTag)
    
    tk.Label(frm, text='Tag2:', background=bgnd).grid(row=4, columnspan=6, sticky=W)
    eTag2 = tk.Entry(frm, highlightbackground=bgnd)
    eTag2.grid(row=4, column=1, columnspan=5, sticky=EW)
    
    tk.Label(frm, text='Tag3:', background=bgnd).grid(row=5, columnspan=6, sticky=W)
    eTag3 = tk.Entry(frm, highlightbackground=bgnd)
    eTag3.grid(row=5, column=1, columnspan=5, sticky=EW)
    
    tk.Label(frm, text='Log File:', background=bgnd).grid(row=6, columnspan=6, sticky=W)
    eLF = tk.Entry(frm, highlightbackground=bgnd)
    eLF.grid(row=6, column=1, columnspan=5, sticky=EW)

    bLF = tk.Button(frm, text='Select Log File', command=GetFN, background=bgnd, highlightbackground=bgnd)
    bLF.grid(row=7, column=0, columnspan=2, sticky=W)
    
    oUnits = tk.StringVar(frm)
    oUnits.set("English")
    omUnits = tk.OptionMenu(frm, oUnits, "English", "Metric")
    omUnits.grid(row=7, column=2)
    omUnits.config(bg=bgnd, highlightbackground=bgnd)
    
    bBegin = tk.Button(frm, text='Start', command=BeginReading, background=bgnd, highlightbackground=bgnd)
    bBegin.grid(row=7, column=4, sticky=E)
    tk.Button(frm, text='Quit', command=lambda master=master:End(master), background=bgnd, highlightbackground=bgnd).grid(row=7, column=5)
    
    outputDisp = tk.Text(frm, height=30, background='white', highlightbackground='grey', highlightthickness=1)
    outputDisp.grid(row=8, column=0, columnspan=6, sticky=N+S+E+W)
    sb = tk.Scrollbar(frm)
    sb.grid(row=8, column=6, sticky=N+S)
    sb.config(command=outputDisp.yview)
    outputDisp.config(yscrollcommand=sb.set)
    frm.pack(fill=BOTH, expand=1)

    master.configure(background='#F0F0F0')
    master.title("EDS XML Reader - v1.00")
    master.resizable(0,0)

def Help():
    # Display help message
    helpMsg = 'This program reads the XML file from a OW Server or MeshNet controller and displays the information in one of two formats:\n\
    A) Using just URL and Tag1, it retrieves and displays 1 field from all the devices in the XML file\n\
    B) Using URL, EUI and Tags 1-3, it retrieves and displays from 1 to 3 fields from a single device in the XML file\n\n\
    To operate in mode A:\n\
    1) Enter the URL in the URL field (eg. http://192.168.1.61/details.xml)\n\
    2) Enter the Tag in the Tag1 field (eg. Temperature)\n\
    3) Make certain the EUI field has no characters, including spaces\n\
    4) Click the Start button\n\n\
    See the readme.pdf file for more information'
    tk.messagebox.showinfo("Help", helpMsg)

def GetFN():
    # Get log file name by displaying file dialog box
    fn = tk.filedialog.asksaveasfilename()
    if fn != '':
        eLF.delete(0,END)
        eLF.insert(0,fn)

def WrTextLine(inclTimeStamp, msg):
    # Write text to the output queue and optionally, if enabled, the log file
    # Optionally include a timestamp
    global filenm
    if inclTimeStamp == True:
        now = datetime.datetime.now()
        ts = now.strftime("%Y.%m.%d_%H:%M:%S")
        os = ts + ',' + msg + '\n'
    else:
        os = msg + '\n'
    wQueue.put(os)

#    outputDisp.insert(END, os)
#    outputDisp.yview(END)
#    # Delete lines when display fills up
#    while True:
#        i = outputDisp.index('end')
#        if float(i) > 200:
#            outputDisp.delete(3.0, 4.0)
#        else:
#            break
    
    # Write filename if enabled
    try:
        if filenm != '':
            f=open(filenm, 'a')
            f.write(os)
            f.close
    except:
        filenm = ''

def ConvUnits(val, name):
    # Convert units between metric and english (imperial)
    global dunits
    if dunits == 'Metric':
        return val
    elif name == 'Temperature':
        return (val * 9/5) + 32
    elif name == 'BarometricPressure':
        return (val * 0.0295301)
    else:
        return val

def End(rt):
    # End the program
    global sysQuit
    sysQuit = True
    rt.destroy()

def ReadDevice():
    # Repeatedly read sensors and display information
    global sysQuit

    if sysQuit == False:
        try:
            XMLData = webGetXMLData(url)
            doc=ET.fromstring(XMLData)
            
            # Get up to 3 different tag values from 1 sensor using its EUI
            if sysMode > 0: 
                myDevice = xmlGetDeviceByEUI(doc, eui)
                # Write data from sensors if it exists
                if myDevice != None:
                    outstr = doc.findtext("./UpTime")
                    if outstr == None:
                        outstr = doc.findtext("./PollCount")
                    outstr = outstr + ',' + str(ConvUnits(float(myDevice.findtext("./" + tag)), tag))
                    if sysMode > 1:
                        outstr = outstr + ',' + str(ConvUnits(float(myDevice.findtext("./" + tag2)), tag2))
                    if sysMode > 2:
                        outstr = outstr + ',' + str(ConvUnits(float(myDevice.findtext("./" + tag3)), tag3))
                else:
                    # Write empty fields in output file if sensor disappears
                    outstr = ','
                    if sysMode > 1:
                        outstr = outstr + ','
                    if sysMode > 2:
                        outstr = outstr + ','
        
            # Get 1 tag value from multiple sensors
            # read the sensors in the EUI order we saved when first started
            else:
                outstr = doc.findtext("./UpTime")
                if outstr == None:
                    outstr = doc.findtext("./PollCount")
                for curEUI in EUIList:
                    outstr = outstr + ','
                    myDevice = xmlGetDeviceByEUI(doc, curEUI)
                    if myDevice != None:
                        myVal = myDevice.findtext("./" + tag)
                        # Print an empty field if tag is not at this EUI
                        if myVal != None:
                            outstr = outstr + str(ConvUnits(float(myVal), tag))

            WrTextLine(True, outstr)
            tmr = threading.Timer(1, ReadDevice)
            tmr.start()
        except:
            WrTextLine(True, " ERROR: Cannot read information")
            BeginReading()


def BeginReading():
    # Begin reading. Determine reading type by validity of EUI field, type can be:
    #  1) Read from 1 to 3 tags from one sensor (requires EUI and at least first tag field to be valid)
    #  2) Read 1 tag from multiple sensors (requires first tag field to be valid and EUI to be invalid or empty) 
    # If called when running, return to idle state
    global sysQuit,dunits,tag,tag2,tag3,eui,url,filenm,sysMode,EUIList

    try:
        # If we are running, stop and return to idle state
        if bBegin['text'] == 'Stop':
            sysQuit = True
            # Set GUI to idle mode
            bBegin.configure(text='Start')
            bLF.configure(state=NORMAL)
            omUnits.configure(state=NORMAL)
            eTag.configure(state=NORMAL)
            eTag2.configure(state=NORMAL)
            eTag3.configure(state=NORMAL)
            eLF.configure(state=NORMAL)
            eEUI.configure(state=NORMAL)
            eURL.configure(state=NORMAL)
            return
        
        # Save user information in local fields 
        tag = eTag.get()
        tag2 = eTag2.get()
        tag3 = eTag3.get()
        eui = eEUI.get()
        url = eURL.get()
        dunits = oUnits.get()
        filenm = eLF.get()
        
        # Verify log file can be opened, on error empty the string so we don't use it
        try:
            if filenm != '':
                with open(filenm, 'a'):
                    pass
        except:
            WrTextLine(False, "WARNING: Log file cannot be opened, logging is disabled")
            filenm = ''
            
        # Check if we can get the XML data from the URL
        try:
            XMLData = webGetXMLData(url)
        except:
            WrTextLine(False, "ERROR: URL cannot be found")
            raise
        
        # Try to read the first tag from the EUI, if it fails try to read the first tag from anything
        try:
            tagstr = tag
            root=ET.fromstring(XMLData)    
            myDevice = xmlGetDeviceByEUI(root, eui)
            # Display error if the eui field had chars but could not be found in the XML file
            if myDevice == None and eui != '':
                raise
            # If the EUI the user entered gave us data, try reading 1 or more tags from it
            if myDevice != None:
                result = myDevice.findtext("./" + tag)
                if result == []:
                    WrTextLine(False, "ERROR: Tag1 cannot be found")
                    raise
                sysMode = 1
                if len(tag2):
                    tagstr = tagstr + ', ' + tag2
                    result = myDevice.findtext("./" + tag2)
                    if result == None or (len(result) == 0):
                        WrTextLine(False, "ERROR: Tag2 cannot be found")
                        raise
                    sysMode += 1
                if len(tag2) and len(tag3):
                    tagstr = tagstr + ', ' + tag3
                    result = myDevice.findtext("./" + tag3)
                    if result == None or (len(result) == 0):
                        WrTextLine(False, "ERROR: Tag3 cannot be found")
                        raise
                    sysMode += 1
                    
            # The EUI did not give us data, try reading any data that matches the first tag
            else:
                result = xmlGetTextByTag(root, tag)
                if result == []:
                    raise
                # Get EUI or ROMId list (MeshNet controller or OW Server)
                result = xmlGetTextByTag(root, "EUI")
                if result == []:
                    result = xmlGetTextByTag(root, "ROMId")
                if result == []:
                    raise
                # Store only EUI's that have the tag of interest
                EUIList = list()
                for curEUI in result:
                    myDevice = xmlGetDeviceByEUI(root, curEUI.text)
                    myVal = myDevice.findtext("./" + tag)
                    if myVal != None:     
                        EUIList.append(curEUI.text)
                if len(EUIList) == 0:
                    raise
                sysMode = 0
        except:
            WrTextLine(False, "ERROR: EUI and/or Tag(s) cannot be found")
            raise
        
        if result is None:
            WrTextLine(False, "ERROR: Tag cannot be found")
        else:
            sysQuit = False           
            if sysMode > 0:
                # Reading 1 or more tags from one sensor, display header
                WrTextLine(False, 'Reading ' + eui + ' for ' + tagstr)
                WrTextLine(False, 'Date/Time, UpTime, ' + tagstr)
            else:
                # Reading one tag from 1 or more sensors, display header
                WrTextLine(False, 'Reading multiple sensors for ' + tagstr)
                headerStr = 'Date/Time, UpTime'
                for hs in EUIList:
                    headerStr = headerStr + ', ' + hs
                WrTextLine(False, headerStr)
            
            # Set GUI to run mode
            bBegin.configure(text='Stop')
            bLF.configure(state=DISABLED)
            omUnits.configure(state=DISABLED)
            eTag.configure(state=DISABLED)
            eTag2.configure(state=DISABLED)
            eTag3.configure(state=DISABLED)
            eLF.configure(state=DISABLED)
            eEUI.configure(state=DISABLED)
            eURL.configure(state=DISABLED)
            ReadDevice()
    except:  
        pass      


def ReadQueue():
    # Read the output queue in the GUI loop to avoid threading problems
    while wQueue.empty() == FALSE:
        os = wQueue.get()
        outputDisp.insert(END, os)
        outputDisp.yview(END)
        # Delete lines when display fills up
#        while True:
#            i = outputDisp.index('end')
#            if float(i) > 200:
#                outputDisp.delete(3.0, 4.0)
#            else:
#                break
    
    rt.after(500, ReadQueue)

def webGetXMLData(url):
    "Get the XML data from web appliance"
    usock = urllib.request.urlopen(url, timeout=3)
    XMLD = usock.read().decode('utf-8')
    usock.close()
    #strip schema information to make code more readable
    return '<Devices-Detail-Response>' + XMLD[XMLD.find('">')+2:]

def xmlGetDeviceByEUI( xmlData, searchEUI):
    "Get a device XML data with specified EUI or ROMId"
    for devices in xmlData.findall("./*/[EUI]"):
        if devices.findtext("./EUI") == searchEUI:
            return devices
    for devices in xmlData.findall("./*/[ROMId]"):  
        if devices.findtext("./ROMId") == searchEUI:
            return devices

def xmlGetTextByTag( xmlData, tagName):
    "Get a list of tags by name in the entire XML doc"
    return xmlData.findall(".//" + tagName) 

def main():
    # Program starts here
    global rt,wQueue,url,eui,tag,dunits,filenm
    
    # Defaults
    url = 'http://192.168.1.17/details.xml'
    eui = ''
    tag = 'Temperature'
    
    wQueue = queue.Queue()
    
    rt = tk.Tk()
    CreateMainWin(rt,url,eui,tag)
    rt.after(100,ReadQueue)
    rt.mainloop()   

    sysQuit = True
    sys.exit(0)

if __name__ == "__main__":
    main()
#    cProfile.run('main()')