#!/usr/bin/env python

##   Network Programming Project 3
##   zip code lookup
##   see - http://zip4.usps.com/zip4/citytown_zip.jsp
##   The resulting URL from clicking submit on the above form is like:
##   http://zip4.usps.com/zip4/zcl_3_results.jsp?zip5=67401

import urllib, urllib2
import wx
import wx.html

class ZipPanel(wx.Panel):
    """
    class ZipPanel inherits wx.Panel and adds HtmlWindow
    """
    def __init__(self, parent, id):
        # default pos is (0, 0) and size is (-1, -1) which fills the frame
        wx.Panel.__init__(self, parent, id)
        self.SetBackgroundColour("purple")
        self.html1 = wx.html.HtmlWindow(self, id, pos=(0,30), size=(610,370))
        
        self.btn2 = wx.Button(self, -1, "Zip Code", pos=(0,0))
        self.btn2.Bind(wx.EVT_BUTTON, self.OnNewZip)
        
    def OnNewZip(self, event):
        dlg = wx.TextEntryDialog(self, "Enter a Zip Code", 
                                        "Zip Code for City, State Lookup",
                                        style=wx.OK | wx.CANCEL )
        if dlg.ShowModal() == wx.ID_OK:
            self.load_zip(dlg.GetValue())
        dlg.Destroy()
        
    def load_zip(self, zipcode=None):
        if zipcode:
            if len(zipcode) == 5 and zipcode.isdigit():
                self.zipcode = zipcode
                self.html1.SetPage(getzip(self.zipcode))
            else:
                dlg = wx.MessageDialog(self, 
                            "The Zip Code must be consist of 5 digits",
                            "Invalid Zip Code",
                            style = wx. OK)
                dlg.ShowModal()
                dlg.Destroy()
                return
        
def getzip(zipcode='67401'):
    url = "http://zip4.usps.com/zip4/zcl_3_results.jsp"
    data = urllib.urlencode([('zip5', zipcode)])
    req = urllib2.Request(url)

    html = urllib2.urlopen(req, data).read()
    #print html
    return html

if __name__ == '__main__':
    app = wx.PySimpleApp()
    # create a window/frame, no parent, -1 is default id, title, size
    frame = wx.Frame(None, -1, "Zip Code Lookup", size=(610, 400))
    # call the derived class, -1 is default id
    win = ZipPanel(frame,-1)
    # show the frame
    frame.Show(True)
    # start the event loop
    app.MainLoop()