#!/usr/bin/env python
#   -*- encoding: UTF-8 -*-

# Copyright:    Thuswise Ltd
# Author:       D. Haynes

import os
import sys
from time import strptime, mktime
import cProfile, pstats
import struct
from optparse import OptionParser

fmt = "2IB"
blocksize = struct.calcsize(fmt)

class FilmFile:

    def __init__(self, fObj):
        self.fObj = fObj
        l = fObj.readline()
        self.filmId = int(l[:l.find(':')])

    def __iter__(self):
        return self

    def next(self):
        """
            Generate tuples of ticks, reviewerId, score
        """
        l = self.fObj.next() 
        id, score, date = l.split(',')
        return int(mktime(strptime(date, "%Y-%m-%d\n"))), int(id), int(score)

def data(fObj):
    while True:
        s = fObj.read(blocksize)
        if not s: raise StopIteration
        yield struct.unpack(fmt, s)
 
def parser():
    p = OptionParser("%prog textfile binary")
    p.add_option("-u", help = "unpack a packed file",
    dest = "unpack", action = "store_true", default = False) 
    return p

   
def main(opts, args):
    try:
        fIn = file(args[0],'rU')
        fOut = file(args[1],'wb')
    except IndexError:
        sys.stderr.write("Not enough arguments\n")
        return 2
    if opts.unpack:
        fOut.writelines(("%010d\t%07d\t%d\n" % i for i in data(fIn))) 
    else:
        ff = FilmFile(fIn)
        fOut.writelines((struct.pack(fmt,*i) for i in ff))
    fIn.close()
    fOut.close()
    return 0

# Normal operation
# c:\Python25\python.exe pack.py    d:\data\netflix\download\subset\mv_0000001.txt
#                                   d:\data\netflix\download\subset\mv_0000001.bin
# Test mode
# c:\Python25\python.exe pack.py    d:\data\netflix\download\subset\mv_0000001.txt
#                                   d:\data\netflix\download\subset\mv_0000001.bin
# c:\Python25\python.exe pack.py -u d:\data\netflix\download\subset\mv_0000001.bin
#                                   d:\data\netflix\download\subset\mv_0000001.tsv
if __name__ == "__main__":
    p = parser()
    opts, args = p.parse_args()
    sys.exit(main(opts, args))