#!/usr/bin/env python2.6
# Copyright (c) 2010, Neville-Neil Consulting
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# Neither the name of Neville-Neil Consulting nor the names of its 
# contributors may be used to endorse or promote products derived from 
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Author: George V. Neville-Neil
#
# Description: This program reads a pair of PTPd quality files,
# generated with the -R option, correlates and graphs the differences
# between the time each host saw a SYNC which is an easy way to
# measure the quality of time synchronization between two clients
# a timing service.

import sys

from numpy import *

import Gnuplot, Gnuplot.funcutils

import gzip
import os

def main():

    from optparse import OptionParser
    
    parser = OptionParser()
    parser.add_option("-y", "--ymin", dest="ymin", default=0,
                      help="minimum y value")
    parser.add_option("-Y", "--ymax", dest="ymax", default=1000000,
                      help="maximum y value")
    parser.add_option("-N", "--Names", dest="hosts", nargs=2, default=None,
                      help="host list for sync graph")
    parser.add_option("-s", "--start", dest="start", type="int", default=0,
                      help="starting sequence number")
    parser.add_option("-p", "--print", dest="png", default=None,
                      help="print the graph to a file")
    parser.add_option("-o", "--output", dest="output", default=None,
                      help="save the correlated data to a file.")
    parser.add_option("-d", "--debug", dest="debug", type="int", default=0,
                      help="print debugging info (verbose)")
    (options, args) = parser.parse_args()
    
    if (options.output != None):
        try:
            outfile = open(options.output, "w")
        except:
            print "cannot open %s for writing" % options.output

    files = []
    for filename in options.hosts:
        if (os.path.splitext(filename)[1] == '.gz'):
            file = gzip.open(filename)
        else:
            file = open(filename)
        
        trace = {}
        done = False
        while not done:
            try:
                (seq, ts) = file.readline().split()
                sequence = int(seq)
                timestamp = long(ts)
            except StopIteration:
                done = True
            except:
                break
                
            trace[sequence] = timestamp

        files.append(trace)

    sequences = []
    sequences.append(sorted(files[0].keys()))
    sequences.append(sorted(files[1].keys()))
    
    if ((min(sequences[0]) > max(sequences[1])) or
        (min(sequences[1]) > max(sequences[1]))):
        print "sequences do not overlap"
        sys.exit(1)
    
    # Trim the dictionaries of non overlapping elements

    index = 0
    if ((min(sequences[0]) < min(sequences[1]))):
        start = min(sequences[0])
        end = min(sequences[1])
        index = 0
    else:
        start = min(sequences[1])
        end = min(sequences[0])
        index = 1
        
    for i in range(start, end):
        del files[index][i]

    if ((max(sequences[0]) > max(sequences[1]))):
        start = max(sequences[1])
        end = max(sequences[0])
        index = 0
    else:
        start = max(sequences[0])
        end = max(sequences[1])
        index = 1
        
    for i in range(start, end):
        del files[index][i]

    if options.start == 0:
        options.start = min(files[0].keys())

    graph = []

    minimum = sys.maxint
    maximum = -sys.maxint -1
    
    for i in range(options.start,options.start + len(files[0])):
        try:
            delta = abs(files[1][i] - files[0][i])
        except KeyError:
            print "9:99:99.000900"
            print "missing packet %d" % i
            continue
            
        if delta > maximum:
            maximum = delta
        if delta < minimum:
            minimum = delta

        if (options.output != None):
            outfile.write(("%d %d\n" % (delta, (files[0][i] / 1000000000))))

        graph.append(delta)

    if (options.output != None):
        outfile.close()

    print "min %d, max %d" % (minimum, maximum)

    # if (minimum.seconds > 1):
    #     print "Time difference exceeded one second maximum, " \
    #           "cannot graph differences"
    #     sys.exit(1)
        
    plotter = Gnuplot.Gnuplot(debug=1)

    if ((options.ymin != 0) or (options.ymax != 10)):
        plotter.set_range('yrange', [options.ymin, options.ymax])

    plotter.ylabel('Time Difference\\nNanoseconds')
    plotter.xlabel('Sample Number')
    plotter.plot(graph)

    if (options.png != None):
        plotter.hardcopy(options.png + ".png", terminal='png')
        raw_input('Press return to exit')
    else:
        raw_input('Press return to exit')

# The canonical way to make a python module into a script.
# Remove if unnecessary.
 
if __name__ == "__main__":
    main()