#! /usr/bin/env python

#
# Just type:
#
#      ./get_LiNox.py -h
#
# 27 Aug 2013 - P. Le Sager - V0
# 


import os
import sys
import glob
import re
import time
import argparse

def total_linox(file):
    '''Return total LiNOx in "Tg N" from one log file'''

    # open file
    f=open(file,'r')

    r1='dynamics step from.*(\d{4}/\d{2}/\d{2} *\d+:\d+)'
    r2='global.*lightning emission *: *(\d+\.\d+) *Tg\[N\]/a'
    r3='--> second half : \d{4}/\d{2}/\d{2} *\d+:\d+ - (\d{4}/\d{2}/\d{2} *\d+:\d+)'

    total=0.
    line='abc'
    while line !='':
        line=f.readline()
        match=re.search(r1,line)
        if match:
            date1=match.group(1)
            while line !='':
                line=f.readline()
                emiss=re.search(r2,line)
                if emiss:
                    while line !='':
                        line=f.readline()
                        half=re.search(r3,line)
                        if half:
                            date1_p=time.mktime(time.strptime(date1,"%Y/%m/%d %H:%M"))
                            date2_p=time.mktime(time.strptime(half.group(1),"%Y/%m/%d %H:%M"))
                            delta_sec = date2_p-date1_p
                            total+=float(emiss.group(1))*delta_sec/(365.*24*60*60)
                            break
                    break
                    
    return total


############################################################################################
# MAIN : process all the files in specific directory                                       #
############################################################################################
if __name__ == "__main__":

    # --- Options: DIR and MASK
    parser = argparse.ArgumentParser(description='Compute Lightning NOx emissions total.')

    parser.add_argument('-d', '--dir', default=os.getcwd(),
                        help='directory with log files to process. Default=current working dir.')
    
    parser.add_argument('-m', '--mask', default='*.out',
                        help='mask to find the log files. Default="*.out"')

    args = parser.parse_args()

    directory = args.dir
    mask = args.mask

    # --- Get list of files
    print ""
    print "Looking for files in %s directory" % directory
    print ""

    try:
        os.chdir(directory)
    except:
        print "Cannot switch to %s directory" % directory
        sys.exit(1)

    files=glob.glob(os.path.join(directory,mask))

    if not files:
        print "No '%s' files in %s" % (mask, directory)
        sys.exit(0)

    # --- Proceed
    summ=0.
    for f in files:
        month=total_linox(f)
        print os.path.basename(f), month, 'Tg [N]'
        summ+=month

    print ""
    print 'Total: %s Tg[N]' % summ