#!/usr/bin/env python

"""
   Read the log file, returning the highest and lowest dates for each star_num
"""



import time
import sys
import os

##########
#Make sure we have an input file.
##########
try:
    input_file = sys.argv[1]
except IndexError:
    sys.stderr.write("No input file specified.")
    sys.exit(1)

##########
#Make sure we can open the file
##########
try :
    input = open(input_file, 'r')
except IOError:
    sys.stderr.write("File is invalid.")
    sys.exit(1)
    
def compareDates(x, y, prefer="high"):

    """
        Return higher or lower of two dates
    """

    x_epoch = time.mktime(time.strptime(x, "%m/%d/%Y"))
    y_epoch = time.mktime(time.strptime(y, "%m/%d/%Y"))

    if prefer == "high":
        if x_epoch <= y_epoch:
            myPick = y
        else:
            myPick = x
    else:
        if x_epoch >= y_epoch:
            myPick = y
        else:
            myPick = x

    return myPick


tracker = {}

for line in input:

    ################
    #strip newline
    ################
    line = line.rstrip("\n")

    ################
    #get fields
    ################
    star_num, location, date = line.split(",")

    ################
    #dictionary holding current min and max values
    ################
    minMax = tracker.get(star_num, {})

    old_min = minMax.get("min", "")
    old_max = minMax.get("max", "")

    if old_min == "":
        minMax["min"] = date
    else:
        minMax["min"] = compareDates(date, minMax["min"], "low")

    if old_max == "":
        minMax["max"] = date
    else:
        minMax["max"] = compareDates(date, minMax["max"], "high")

    tracker[star_num] = minMax

input.close()


################
#sort star_nums
################
keys = tracker.keys()
keys.sort()

for key in keys:

    print key, tracker[key]["min"]
    print key, tracker[key]["max"]