Getting the ID of the polygon which circumscribes a point

import sys
import os
from qgis.core import *
import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as patches

LATITUDE = 1.29306
LONGITUDE = 103.856

QgsApplication.setPrefixPath("/usr", True)
QgsApplication.initQgis()

layer=QgsVectorLayer("/home/shubham/SMART/zones/mtz1092p.shp", "mtz1092p", "ogr")
if not layer.isValid():
  print "Layer failed to load!"
provider = layer.dataProvider()

def printFeatures():
  feat = QgsFeature()
  #print feat
  allAttrs = provider.attributeIndexes()
  provider.select(allAttrs)
  while provider.nextFeature(feat):
    geom = feat.geometry()
    #print "Feature ID %d: " % feat.id(),
    x = geom.asPolygon()
    numPts = 0
    for ring in x:
      numPts += len(ring)
    #print "Polygon: %d rings with %d points" % (len(x), numPts)
    #if len(x) > 1:
    #  print "Feature ID %d has more than one ring" % feat.id()
    if len(x) == 0:
      print "Feature ID %d has no ring" % feat.id()
    else:
      print "Polygon for feature ID %d => " %(feat.id()), x[0]
    attrs = feat.attributeMap()
    #for (k, attr) in attrs.iteritems():
    #  print "%d: %s" % (k, attr.toString())

#def findFeatureId(lat, long):
def findFeatureId(point):
  feat = QgsFeature()
  allAttrs = provider.attributeIndexes()
  provider.select(allAttrs)
  while provider.nextFeature(feat):
    geom = feat.geometry()
    x = geom.asPolygon()
    if len(x) == 0:
      print "Feature ID %d has no ring" % feat.id()
    else:
    #  if x[0][0][0] != x[0][len(x) - 1][0] and x[0][0][1] != x[0][len(x) - 1][1]:
    #    print "Polygon at feature ID %d violates the sameness rule\n" %(feat.id())
    #  else:
    #    print "First element => ", x[0][0], "\nLast  element => ", x[0][len(x) - 1], "\n"
      codes = []
      codes.append(Path.MOVETO)
      for i in range (0, len(x[0]) - 2):
        codes.append(Path.LINETO)
      codes.append(Path.CLOSEPOLY)
    #  print "Length = ", len(codes), codes
      path = Path(x[0], codes)
      if (path.contains_point(point, None, 0.0)):
        print "Point contained in feature ID %d" %feat.id()
    #  print "Polygon for feature ID %d => " %(feat.id()), x[0], "\n"


if __name__ == "__main__":
  crsSrc = QgsCoordinateReferenceSystem(4326) # WGS84
  crsDest = QgsCoordinateReferenceSystem(3414)# SVY21
  xform = QgsCoordinateTransform(crsSrc, crsDest)
  #pt = xform.transform(QgsPoint(LATITUDE, LONGITUDE))
  pt = xform.transform(QgsPoint(LONGITUDE, LATITUDE))
  findFeatureId(pt)
  #findFeatureId(1.275927800000000000, 103.804237500000000000)