"""Cross tabulate old and large files on specified file system

Usage

python diskreport.py /d/cit/7


will generate things like

find . -xdev -type f -atime +365 -exec ls -la {} \; | gawk '{printf("%s %s %s\n", $3x, $5, $9)}'  | sort -k 1,1 -k2,2nr

"""


#Constants
days = 365
filesize = 1000000  #One megabyte



#Useful Unix commands
ls_cmd = '-exec ls -la {} \\;'
filter_cmd = 'gawk \'{printf("%s %s %s\\n", $3x, $5, $9)}\' '
sort_cmd = 'sort -k 1,1 -k2,2nr ' #Sort on name and reversely by size


def make_filename(s):
    """Transform argument string into a suitable filename
    """

    s = s.strip()
    s = s.replace(' ', '_')
    #s = s.replace('(', '{')
    #s = s.replace(')', '}')
    s = s.replace('(', '')
    s = s.replace(')', '')
    s = s.replace('__', '_')
    s = s.replace('/', '_')                    
        
    return s


def diskstat(findcommand, outfile, headline):

    import time

    tempfile = '/tmp/diskreport_' + str(time.time())

    #Find files
    cmd = findcommand
    cmd += ls_cmd + ' | ' + filter_cmd + ' | ' + sort_cmd
    cmd += ' > %s 2>/dev/null' %tempfile #Redirect
    print cmd
    os.system(cmd)

    #sort_and_clean(tempfile)

    #Organise them by name (with totals)
    fid = open(tempfile)
    lines = fid.readlines()
    fid.close()

    D = {}
    for line in lines:
        fields = line.strip().split()

        username = fields[0]
        size = long(fields[1])
        filename = fields[2]
        if not D.has_key(username):
            D[username] = []
        D[username].append( [filename, size] )

    #Find totals per user
    grand_total = 0
    totals = {}
    for username in D:
        total = 0
        for filename, size in D[username]:
            total += size

        totals[username] = total
        grand_total += total


    #Sort users by diskusage
    S = [(totals[username], username) for username in totals] #List comprehension    
    S.sort()
    S.reverse()
    users = [x[1] for x in S] #Users by diskusage


    #Write final result to disk
    fid = open(outfile, 'w')

    print
    txt = headline
    txt += '(%.3f MB):' %(grand_total/1.0e6)
    fid.write(txt + '\n')
    print '--------------------------------------------------'
    print txt
    print '--------------------------------------------------'    
    

    fid.write('\n')
    for username in users:
        fid.write('------------------------------------------------------\n')
        txt = '%s (%.3f MB)' %(username, totals[username]/1.0e6)
        fid.write(txt + '\n')
        fid.write('------------------------------------------------------\n')
        print txt

        for filename, size in D[username]:
            fid.write('    %s (%.3f MB)\n' %(filename, size/1.0e6))
        fid.write('\n')    


    fid.close()





import os, time, sys


if len(sys.argv) > 1:
    dir = sys.argv[1]
else:   
    dir = '.'
    

print 'DISKREPORT FOR DIRECTORY %s' %dir

# Find the largest directories
topname = 'top50_%s.txt' %(make_filename(dir))
txt = 'Top 50 largest directories on %s (stated in kilo bytes)' %dir
os.system('echo "%s" > %s' %(txt, topname))

#Divide into two (had problems with broken pipe)
cmd = 'du -k "%s" | sort -nr | head -50 >> %s' %(dir, topname)
os.system(cmd)
#cmd = 'du -k "%s" | sort -nr >> %s' %(dir, topname)
#os.system(cmd)
#cmd = 'cat %s | head -50 > %s' %(topname, topname)
#os.system(cmd)



#################################################################
# Find old files
#################################################################
diskstat('find %s -xdev -type f -atime +%d ' %(dir, days),
         'oldfiles_%s.txt' %make_filename(dir),
         'Statistics for files on disk %s that haven\'t been accessed for at least %d days '\
         %(dir, days))



#################################################################
# Find all files
#################################################################
diskstat('find %s -xdev -type f ' %(dir),
         'allfiles_%s.txt' %make_filename(dir),         
         'Statistics for all files on disk %s '\
         %(dir))



import sys; sys.exit()          
#################################################################
# Find large files
#################################################################
diskstat('find %s -xdev -type f -size +%dc ' %(dir, filesize),
         'bigfiles_%s.txt' %make_filename(dir),         
         'Statistics for files on disk %s that are larger than %.3f MB '\
         %(dir, filesize/1.0e6))


#################################################################
# Find old and large files
#################################################################
diskstat('find %s -xdev -type f -atime +%d -size +%dc '\
         %(dir, days, filesize),
         'oldbigfiles_%s.txt' %make_filename(dir),
         'Statistics for files on disk %s that haven\'t been accessed for at least %d days and that are larger than %.3f kB '\
         %(dir, days, filesize/1.0e6))