from pyjamas.ui.VerticalPanel import VerticalPanel
from pyjamas.ui.HorizontalPanel import HorizontalPanel
from pyjamas.ui.Button import Button
from pyjamas.ui.HTML import HTML
from pyjamas.ui import HasAlignment
from pyjamas.ui.Label import Label
from pyjamas.ui.ListBox import ListBox
from pyjamas.ui.TextBox import TextBox

from lxml import etree

##
# Extracts information from a RSpec and turns it
# into a dictionary.
# @return A dict
def extractRSpec(rspec):
    rspecXML = etree.XML(rspec)
    data = {}
    data['images'] = {}
    data['images']['kernel'] = []
    data['images']['ramdisk'] = []
    data['images']['machine'] = []
    images = rspecXML.findall('.//image')
    for img in images:
        imgType = ''
        location = ''
        for element in img.iter():
            if element.tag == 'type': imgType = element.text
            if element.tag == 'location': location = element.text
        data['images'][imgType].append((img.get('id'), location))

    data['keys'] = []
    keys = rspecXML.findall('.//keypair')
    for key in keys:
        data['keys'].append(key.text)

    data['vmtypes'] = []
    vmtypes = rspecXML.findall('.//vm_type')
    for vmtype in vmtypes:
        data['vmtypes'].append(vmtype.get('name'))

    return data

##
# A panel that represents a request stanza.
class RequestInstanceWidget(VerticalPanel):
    def __init__(self, rdata):
        VerticalPanel.__init__(self)
        self.setBorderWidth(1)
        self.rspecData = rdata
    
        self.createKeyPanel()
        self.createVmTypePanel()
        self.createImagePanels()
        self.createNumPanel()
    
    ##
    # Creates the horizontal panels for kernel, ramdisk, 
    # and disk images.
    def createImagePanels(self):
        self.add(self.__createImagePanel('machine'))
        self.add(self.__createImagePanel('kernel'))
        self.add(self.__createImagePanel('ramdisk'))

    ##
    # Helper method to create individual panel for each image
    # types.
    # @param[String] The image type.
    # @return An instance of HorizontalPanel with a label and 
    #         a droplist box.
    def __createImagePanel(self, image):
        hp = HorizontalPanel()
        panelLabel = Label(image.capitalize())
        lb = ListBox()
        for imgData in self.rspecData['images'][image]:
            lb.addItem(imgData[1], imgData[0])
        hp.add(panelLabel)
        hp.add(lb)

        return hp

    ##
    # Creates a H. panel for key pairs.
    def createKeyPanel(self):
        hp = HorizontalPanel()
        panelLabel = Label('Key Pairs')
        lb = ListBox()
        for kp in self.rspecData['keys']:
            lb.addItem(kp)
        hp.add(panelLabel)
        hp.add(lb)
        self.add(hp)
        
    ##
    # Creates a H. panel for Vm Types.
    # TODO: refactor by combining this with createKeyPanel()
    def createVmTypePanel(self):
        hp = HorizontalPanel()
        panelLabel = Label('VM Types')
        lb = ListBox()
        for vt in self.rspecData['vmtypes']:
            lb.addItem(vt)
        hp.add(panelLabel)
        hp.add(lb)
        self.add(hp)

    ##
    # Creates a panel for specifying the number of instances 
    # to create.
    def createNumPanel(self):
        hp = HorizontalPanel()
        panelLabel = Label('VM Types')
        tb = TextBox()
        hp.add(panelLabel)
        hp.add(tb)
        self.add(hp)

class RequestPanel(VerticalPanel):
    def __init__(self, sfadata):
        VerticalPanel.__init__(self)
        self.sfadata = sfadata
        self.setStyleName("ks-layouts")

        self.rspec = self.sfadata.getRSpec()
        self.rspecData = extractRSpec(self.rspec)

        self.add(RequestInstanceWidget(self.rspecData))
        
    def refresh(self):
        pass
                    
    def apply(self, sender):
        self.sfadata.applyRSpec()

    def reset(self, sender):
        self.sfadata.refreshRSpec()
        self.rspecData = extractRSpec(self.rspec)