#! /usr/bin/env python3
# coding: latin-1

#===========================================================================
# Copyright (C) 2016  Max-Planck-Institut für Radioastronomie, Bonn, Germany
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#===========================================================================
# SVN properties (DO NOT CHANGE)
#
# $Id$
# $HeadURL$
# $LastChangedRevision$
# $Author$
# $LastChangedDate$
#
#============================================================================

import os
import sys
import string
import argparse
import logging
from logging.handlers import TimedRotatingFileHandler
from  datetime import datetime
from difxdb.difxdbconfig import DifxDbConfig
from difxdb.model.dbConnection import Schema, Connection
from difxdb.business.filedataaction import *
#from difxdb.business.experimentaction import *
from difxdb.model import model

__author__="Helge Rottmann <rottmann@mpifr-bonn.mpg.de>"
__prog__ = os.path.basename(__file__)
__build__= "$Revision$"
__date__ ="$Date$"
__lastAuthor__="$Author$"

logger = None

description = "A script to sync the database contents of file-based correlator data (FileData table) with the contents of the file-system."
description += "If the files are not found on the file-system anymore the database is updated accordingly"
epilog = "NOTE: %(prog)s requires the DIFXROOT environment to be defined.\n" 
epilog += "The program reads the database configuration from difxdb.ini located under $DIFXROOT/conf.\n"
epilog += "If the configuration is not found a template will be created for you.\n\n"
epilog += "The output is logged to file (see also --log-path option)"
version = "revision = {} author = {}  last changed by = {}".format(__build__, __author__, __lastAuthor__)

    
def setupLoggers(logPath):


    if args.verbose:
        level = logging.DEBUG
    else:
        level = logging.INFO

    logger = logging.getLogger("difxdbSyncFiles")
    logger.setLevel(level)

    # logging to file
    #fh = logging.FileHandler(logPath + "/difxdbParseFiles_{:%Y-%m-%d_%H:%M:%S}.log".format(datetime.now()))
    fh = TimedRotatingFileHandler(logPath+"/difxdbSyncFiles.log", when="midnight", interval=1, backupCount=7)

    fh.setLevel(level)
    fh.setFormatter(logging.Formatter('%(asctime)s - %(levelname)-7s - %(message)s'))

    # console handler
    ch = logging.StreamHandler()
    ch.setLevel(level)
    ch.setFormatter(logging.Formatter('%(levelname)-7s - %(message)s'))

    logger.addHandler(fh)
    logger.addHandler(ch)
 
    return logger

def storeItem(session, storedFiles, exp, item):

        if not item:
                return

        logger.debug("Validating {}".format(item["location"]))
                
        # check if this is a new entry
        update = False
        for f in storedFiles:
                if f.location == item["location"]:
                        # compare sizes and number of files
                        if f.size == item["totalSize"] and f.numScans == item["fileCount"]:
                                logger.debug("Not updating: Identical entry in database for path={}".format(f.location))
                                return

                        # record needs to be updated
                        update = True
                        break
                        
        if update:
                fileData = f
                fileData.size = item["totalSize"]
                fileData.numScans = item["fileCount"]
                fileData.received = datetime.now()
        else: # new record
                fileData = model.FileData()
                fileData.stationCode = item["stationCode"]
                fileData.location = item["location"]
                fileData.experimentID = item["expId"]
                fileData.size = item["totalSize"]
                fileData.numScans = item["fileCount"]
                session.add(fileData)

        if not args.dryRun:
                session.commit()
                session.flush()
                
        if update:
                logger.info("Updated database entry for path={}".format(f.location))
        else:
                logger.info("Added database entry for path={}".format(item["location"]))
                
        
        
def syncFiles(session):

        logger.info("Syncing started.")
        # assume to level directory is equal to experiment code
        for row in getFileData(session):
                dataDir = row.location
                logger.debug("Validating {}".format(dataDir))
                

                # check if data dir has been deleted
                if not os.path.isdir(dataDir):
                        session.delete(row)
                        session.commit()
                        session.flush()
                        logger.info("Removed dataset {} from database".format(dataDir))         
                        continue
                # check if there any changes
                fileCount = 0
                totalSize = 0
                for file in os.listdir(dataDir):
                        filePath = dataDir + "/" + file

                        if not os.path.isfile(filePath):
                                continue

                        fileCount += 1
                        totalSize += os.path.getsize(filePath)

                if totalSize != row.size:
                        logger.info("Updating size for {} from {} to {}".format(dataDir, row.size, totalSize))
                        row.size = totalSize
                        session.commit()
                        session.flush()

                if fileCount != row.numScans:
                        logger.info("Updating numScans for {} from {} to {}".format(dataDir, row.numScans, fileCount))
                        row.numScans = fileCount
                        session.commit()
                        session.flush()


                        
        session.close
        return

if __name__ == "__main__":
    
    
    parser = argparse.ArgumentParser(description=description, epilog=epilog ,formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("--verbose", action="store_true", default=False, help="verbose output.")
    parser.add_argument("--log-path", dest="logPath",  default="/tmp", help="path where the log files will be written to (default: /tmp).")
    parser.add_argument('--version', action='version', version=version)

    if len(sys.argv) == 0:
        parser.print_help()
        sys.exit(1)
        
    args = parser.parse_args()

    try:
        if (os.getenv("DIFXROOT") == None):
            sys.exit("Error: DIFXROOT environment must be defined.")

        configPath = os.getenv("DIFXROOT") + "/conf/difxdb.ini"


        config = DifxDbConfig(configPath, create=True)

        # try to open the database connection
        connection = Connection()
        connection.type = config.get("Database", "type")
        connection.server = config.get("Database", "server")
        connection.port = config.get("Database", "port")
        connection.user = config.get("Database", "user")
        connection.password = config.get("Database", "password")
        connection.database = config.get("Database", "database")
        connection.echo = False

        dbConn = Schema(connection)
        session = dbConn.session()

        logger = setupLoggers(args.logPath)
        syncFiles(session)
        exit(0)

    except Exception as e:
       
        sys.exit(e)