from RssReader import generateRsses
from Tkinter import *
from tkFileDialog import askopenfilename

currentFeeds = {}
rssDisplay = None
chooseChannel = None
currentChannel = None
currentFeeds = None

# The overall window

def rssWindow():
  root = Tk()
  root.title("Rss Reader")
  root.geometry("750x500")
  root = channelFrame(root)
  root = buttonFrame(root)
  return root

# The upper window with the dropdown and listbox

def channelFrame(parent):
  channelFrame = Frame(parent)
  channelSelectFrame = Frame(channelFrame)
  channelSelectFrame = channelLabel(channelSelectFrame)
  channelSelectFrame = channelSelect(channelSelectFrame)
  channelSelectFrame.pack(side=LEFT)
  channelFrame = rssDisplay(channelFrame)
  channelFrame.pack(side=TOP, expand=YES, fill=BOTH)
  return parent 

def rssDisplay(parent):
  global rssDisplay
  rssDisplay = Listbox(parent)
  rssDisplay.pack(side=RIGHT, expand=YES, fill=BOTH)
  return parent

def channelLabel(parent):
  label = Label(parent, text="Select a channel:")
  label.pack(side=TOP)
  return parent

def channelSelect(parent):
  global chooseChannel, currentChannel
  currentChannel = StringVar(parent)
  channelList = ["None"]
  currentChannel.set(channelList[0])
  chooseChannel = OptionMenu(parent, currentChannel, *channelList)
  chooseChannel.pack(side=BOTTOM)
  return parent

# The lower window with the two buttons

def buttonFrame(parent):
  buttonFrame = Frame(parent)
  buttonFrame = setConfigFileButton(buttonFrame)
  buttonFrame = loadRssButton(buttonFrame)
  buttonFrame.pack(side=RIGHT, expand=YES, fill=X)
  return parent

def setConfigFileButton(parent):
  button = Button(parent, command=setConfigFile)
  button["text"] = "Set Config File"
  button.pack(side=LEFT)
  return parent

def loadRssButton(parent):
  button = Button(parent, command=loadRss)
  button["text"] = "Load Feeds"
  button.pack(side=RIGHT)
  return parent

# Commands called by various elements

def loadRss():
  global chooseChannel, currentChannel
  chooseChannel["menu"].delete(0, END)
  channelList = currentFeeds.keys()
  for channelName in channelList:
    chooseChannel["menu"].add_command(label=channelName, 
        command=lambda temp = channelName: selectChannel(temp))
  selectChannel(channelList[0])

## Lambda, functions are first class objects

def selectChannel(channelName):
  global chooseChannel, rssDisplay
  chooseChannel.setvar(chooseChannel.cget("textvariable"), value = channelName)
  rssDisplay.delete(0, END)
  for feed in currentFeeds[channelName]:
    rssDisplay.insert(END, feed)
# http://www.prasannatech.net/2009/06/tkinter-optionmenu-changing-choices.html 

def setConfigFile():
  global currentFeeds
  currentFeedFile = askopenfilename(filetypes=[("allfiles", "*"), 
                                                ("textfiles","*.txt")])
  currentFeeds = combineFeeds(currentFeedFile)
  loadRss()

def combineFeeds(fileName):
  feeds = {}
  for feed in generateRsses(fileName):
    for channelName in feed.keys():
      if feeds.has_key(channelName):
        feeds[channelName] += feed[channelName]
      else:
        feeds[channelName] = feed[channelName]
  return feeds

if __name__ == "__main__":
  rssWindow().mainloop()