import gzip
from glob import glob
import re
import os
import sys
import shutil
import time

def zcat_compress(gzfile, files):
    with gzip.open(gzfile+'z', 'wo') as out:
        out.write('ZCAT')
        n = 0
        for filename in files:
            with open(filename) as f:
                content = f.read()
            if re.match(r'#20\d\d-\d\d-\d\d ', content) is None:
                print('%s is not a sea log file' % filename)
                os.rename(filename, filename + ".bad")
            else:
                out.write("\n%d %s\n" % (len(content), filename))
                out.write(content)
            n += 1
    os.rename(gzfile+'z', gzfile)
    print("%d files compressed to %s" % (n, gzfile))

def zcat_expand(gzfile):
    with gzip.open(gzfile) as f:
        line = f.readline()
        assert(line.startswith('ZCAT'))
        line = f.readline()
        n = 0
        m = 0
        while line != '':
            size, filename = line[:-1].split(' ',1)
            content = f.read(int(size))
            try:
                with open(filename) as g:
                    c = g.read()
                if content != c:
                    print('%s does not match' % filename)
                m += 1
            except IOError:
                with open(filename, 'w') as g:
                    g.write(content)
                n += 1
            line = f.readline()
            line = f.readline()
        print("%s extracted from %s, (%d files already there)" % (n,gzfile,m))

def instdir(instrument=''):
    if instrument != '':
        instrument += '/'
    return '%s/sea/%s' % (os.path.expanduser("~"), instrument)
        
def compress(logdir, gzdir, variable):
    os.chdir(logdir + variable)
    if not os.path.isdir(gzdir):
        os.makedirs(gzdir)
    gzfile = '%s%s.gz' % (gzdir, variable)
    if os.path.isfile(gzfile):
        # expand already compressed files (for not loosing them)
        expand(logdir, gzdir, variable)
    files = sorted(glob('*.log'))
    if files:
        zcat_compress(gzfile, files)

def expand(logdir, gzdir, variable):
    if not os.path.isdir(logdir):
        os.makedirs(logdir)
    os.chdir(logdir + variable)
    gzfile = '%s%s.gz' % (gzdir, variable)
    zcat_expand(gzfile)

COMPRESS = 1
EXPAND = 2

def treat(action, instrument='', years='past', vars=None):
    logbase = '%slogger/' % instdir(instrument)
    gzbase = '%sgzlogger/' % instdir(instrument)
    os.chdir(logbase)
    print('chdir', logbase, gzbase)
    if years == 'all':
        yrs = list(glob('20*'))
    elif years == 'past':
        yrs = list(glob('20*'))
        try:
            yrs.remove(time.strftime("%Y"))
        except ValueError:
            pass
    else:
        yrs = years
    for year in yrs:
        logdir = logbase + year + '/'
        gzdir = gzbase + year + '/'
        os.chdir(logdir)
        if not vars:
            varlist = list(glob('*'))
        else:
            varlist = vars
        for variable in varlist:
            if action == COMPRESS:
                if os.path.isdir(logdir+variable):
                    if not os.path.isfile(gzdir + variable + '.gz'):
                        t0 = time.time()
                        compress(logdir, gzdir, variable)
                        time.sleep(min(1.0, time.time()-t0)) # be nice
            elif action == EXPAND:
                os.makedirs(logdir+variable)
                print(gzdir, variable, '.gz')
                if os.path.isfile(gzdir + variable + '.gz'):
                    expand(logdir, gzdir, variable)
                else:
                    print(gzdir + variable + '.gz', 'is missing')

if __name__ == '__main__':
    action = COMPRESS
    years = []
    instruments = []
    vars = []
    cleanup = True
    addto = instruments
    for opt in sys.argv[1:]:
        if opt == '-x':
            action = EXPAND
            cleanup = False
        elif opt == '-c':
            cleanup = False
        elif opt == '-n':
            action = None
        elif opt == '-i':
            addto = instruments
        elif opt == '-p':
            years = 'past'
        elif opt == '-a':
            years = 'all'
        elif opt == '-v':
            addto = vars
        elif opt == '-y':
            addto = years
        else:
            addto.append(opt)
    if len(years) == 0:
        years = 'past'
    if years not in ('past', 'all'):
        for year in years:
            assert(2007 <= int(year) <= 2030)
    if len(instruments) == 0:
        instruments = ['']
    for instrument in instruments:
        if not os.path.isdir(instdir(instrument)):
            raise ValueError('%s is not an instrument on this machine' % instrument)
    removedirs = (
        'device.force_status_save',
        'nv.autoflow.*buf',
        'nv.autoflow.*min',
        'nv.autoflow.*max',
        'table.val_*',
        '*.*.stddev',
        'device.ccu4version',
        'cc.f',
        'cc.nfb',
        'cc.hfb',
        'graph_*',
    )
    print("instruments: %s" % ", ".join(instruments))
    print("years: %s" % repr(years))
    print("vars: %s" % ", ".join(vars))
    for instrument in instruments:
        print('instrument:', instdir(instrument))
        if cleanup:
            for pat in removedirs:
                print('remove', pat)
                gap = 0
                t0 = time.time()
                t1 = t0
                for dir in glob(instdir(instrument)+'logger/*/'+pat):
                    shutil.rmtree(dir)
                    now = time.time()
                    if now > t0 + 5:
                        if gap > 0:
                            print("+%d" % gap)
                        print(dir)
                    else:
                        gap += 1
                    time.sleep(min(1.0, now - t1)) # be nice
                    t1 = now
        if action:
            treat(action, instrument, years, vars)