#!/usr/bin/env python

import argparse
import ConfigParser
import sys

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker


class FakeSecHead(object):
    def __init__(self, fp):
        self.fp = fp
        self.sechead = '[dcache]\n'

    def readline(self):
        if self.sechead:
            try:
                return self.sechead
            finally:
                self.sechead = None
        else:
            return self.fp.readline()


if __name__ == '__main__':

    PARSER = argparse.ArgumentParser()
    PARSER.add_argument('-d', '--dry-run', action='store_true')
    PARSER.add_argument('poolnames',
                        type=str,
                        action='store',
                        help='List of pool names separated by a comma')
    ARGS = PARSER.parse_args()
    poolnames = ARGS.poolnames.split(',')

    # read dcache configuration
    config = ConfigParser.ConfigParser()
    config.readfp(FakeSecHead(open('/etc/dcache/dcache.conf')))
    user = config.get('dcache', 'dcache.db.user')
    password = config.get('dcache', 'dcache.db.password')
    host = config.get('dcache', 'dcache.db.host')
    host = host.split(',')[0]  # Consider only the first host
    url = 'postgresql://%(user)s:%(password)s@%(host)s/chimera' % locals()

    # db connection
    engine = create_engine(url)
    Session = sessionmaker(bind=engine)
    session = Session()
    try:
        for poolname in poolnames:

            print 'Checking pool', poolname
            query = '''select count(1)
            from t_locationinfo
            where t_locationinfo.iLocation=:poolname'''
            n = session.execute(query, {'poolname': poolname}).fetchone()[0]
            print n, 'files found in t_locationinfo'

            if n > 0:
                fname = '.'.join((poolname, 'csv'))
                f = open(fname, 'w+')
                query = '''select inumber2path(t1.inumber), t2.isize, t1.inumber
                    from t_locationinfo t1, t_inodes t2
                    where iLocation=:poolname
                    and t1.inumber = t2.inumber
                    and not exists (select 1 from t_locationinfo t2
                                    where t1.inumber = t2.inumber
                                      and t1.ilocation != t2.ilocation)'''
                n = 0
                for path, size, inumber in session.execute(query, {'poolname': poolname}):
                    f.write(','.join([path, str(size), str(inumber)]) + '\n')
                    n += 1
                f.close()
                print n, 'Unique files found on the pool'
                print 'File %(fname)s created' % locals()

                query = 'delete from  t_locationinfo where iLocation=:poolname'
                if not ARGS.dry_run:
                    rowcount = session.execute(query, {'poolname': poolname}).rowcount
                    session.commit()
                    print rowcount, 'files deleted from t_locationinfo'
                else:
                    print 'dry_run:', query.replace(':poolname', "'" + poolname + "'")

            query = '''select count(1)
               from t_locationinfo_trash
               where iLocation=:poolname'''
            n = session.execute(query, {'poolname': poolname}).fetchone()[0]
            print n, 'files found in t_locationinfo_trash'

            if n > 0:
                query = 'delete from  t_locationinfo_trash where iLocation=:poolname'
                if not ARGS.dry_run:
                    rowcount = session.execute(query, {'poolname': poolname}).rowcount
                    session.commit()
                    print rowcount, 'files deleted from t_locationinfo_trash'
                else:
                    print 'dry_run:', query.replace(':poolname', "'" + poolname + "'")
    finally:
        session.close()

    sys.exit(0)