#/usr/bin/env python2.5
#Noah Gift 06/21/08
#tweaks by Mike Bayer 06/22/08  
import os

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Table, Column, Integer, String, MetaData, ForeignKey
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.orm import scoped_session

from pyinotify import *

path = "/tmp"

#SQLAlchemy
engine = create_engine('sqlite:///meta.db', echo=True)
Base = declarative_base()
Session = scoped_session(sessionmaker(bind=engine))

class Filesystem(Base):
    __tablename__ = 'filesystem'

    path = Column(String, primary_key=True)
    name = Column(String)

    def __init__(self, path,name):
        self.path = path
        self.name = name

    def __repr__(self):
        return "<Metadata('%s','%s')>" % (self.path,self.name)

def transactional(fn):
    """add transactional semantics to a method."""

    def transact(self, *args):
        session = Session()
        try:
            fn(self, session, *args)
            session.commit()
        except:
            session.rollback()
            raise
    transact.__name__ = fn.__name__
    return transact


class ProcessDir(ProcessEvent):
    """Performs Actions based on mask values"""

    @transactional
    def process_IN_CREATE(self, session, event):
        print "Creating File and File Record:", event.pathname
        create_record = Filesystem(event.pathname, event.path)
        session.add(create_record)

    @transactional
    def process_IN_DELETE(self, session, event):
        print "Removing:", event.pathname
        delete_record = session.query(Filesystem).\
            filter_by(path=event.pathname).one()
        session.delete(delete_record)

def init_repository():
    #Drop the table, then create again with each run
    Base.metadata.drop_all(engine)
    Base.metadata.create_all(engine)
    session = Session()

    #Initial Directory Walking Addition Brute Force
    for dirpath, dirnames, filenames in os.walk(path):
        for file in filenames:
            fullpath = os.path.join(dirpath, file)
            record = Filesystem(fullpath, file)
            session.add(record)
        session.flush()

    for record in session.query(Filesystem):
        print "Database Record Number: Path: %s , File: %s " \
        % (record.path, record.name)

    session.commit()

if __name__ ==  "__main__":

    init_repository()

    #Pyionotify
    wm = WatchManager()
    mask = IN_DELETE | IN_CREATE
    notifier = ThreadedNotifier(wm, ProcessDir())
    notifier.start()

    wdd = wm.add_watch(path, mask, rec=True)