#! /usr/bin/python

# USAGE:   MosaicFileTxFromTowerToDaq.py <no arguments>
# PURPOSE: Performs FTP data-acquisition file transfers from MOSAiC tower computer to the ship computer
# AUTHOR:  Dan Gottas (NOAA/PSD)

import ftplib, time, datetime, os, sys

####  begin user defined variables ####
LogFilePath  = 'C:\\Noaa\\Logs\\MosaicFileTxFromTowerToDaq'

FtpServer    = '192.168.202.4'
FtpPort      = 21
FtpUserName  = 'mosaic_tower'
FtpPassword  = 'mosaic_tower'

# FTP transfer parameter dictionary
# SYNTAX: { SessionName : [ FtpInputPath, OutputPath, BeginHourOffset, EndHourOffset, [ FileTxList ] ] }
# DESCRIPTION:  SessionName     = name of the parameter set (no impact on the file transfers)
#               FtpPath         = source path on the remote FTP server where files to be transferred exist
#               OutputPath      = destination path on the local computer where files will be transferred to
#               BeginHourOffset = hour offset from the execution time that specifies the begin time of the files to transfer
#               EndHourOffset   = hour offset from the execution time that specifies the end time of the files to transfer
#               FileTxList      = list of files to transfer; dynamic time elements in file name are defined by strftime
#
FtpTxParmDict = { 'Tower Clasp (02m)' :  [ '/Clasp02m'            , 'd:/tower/Clasp02m'           ,  6, 0, ['msc0%y%j%H_raw.txt']],
                  'Tower Ozone'       :  [ '/Ozone'               , 'd:/tower/Ozone'              ,  6, 0, ['msc0%y%j%H_raw.txt']],
                  'Tower Picarro'     :  [ '/Picarro'             , 'd:/tower/Picarro'            ,  6, 0, ['msc0%y%j%H_raw.txt']],
                  'Tower CR1000X'     :  [ '/CR1000X/daily_files' , 'd:/tower/CR1000X/daily_files',  6, 0, ['cr1000x_tower_%m%d%Y_%H%M.dat']],
                  'Tower CR1000X_now' :  [ '/CR1000X'             , 'd:/tower/CR1000X'            ,  6, 0, ['cr1000x_tower.dat']],
                  'Tower Licor (02m)' :  [ '/Licor02m'            , 'd:/tower/Licor02m'           ,  6, 0, ['msc0%y%j%H_raw.txt', 'msc0%y%j%H_stats.txt']],
                  'Tower Metek (02m)' :  [ '/Metek02m'            , 'd:/tower/Metek02m'           ,  6, 0, ['msc0%y%j%H_raw.txt', 'msc0%y%j%H_stats.txt']],
                  'Tower Metek (06m)' :  [ '/Metek06m'            , 'd:/tower/Metek06m'           ,  6, 0, ['msc0%y%j%H_raw.txt', 'msc0%y%j%H_stats.txt']],
                  'Tower Metek (10m)' :  [ '/Metek10m'            , 'd:/tower/Metek10m'           ,  6, 0, ['msc0%y%j%H_raw.txt', 'msc0%y%j%H_stats.txt']],
                  'Tower Metek (30m)' :  [ '/Metek30m'            , 'd:/tower/Metek30m'           ,  6, 0, ['msc0%y%j%H_raw.txt', 'msc0%y%j%H_stats.txt']]
                }
#### end user defined variables ####


def WriteMessage(LogFilePath, Message):

  LogTime = datetime.datetime.utcnow()
  
  LogFile = LogFilePath + LogTime.strftime('\\MosaicFileTxFromTowerToDaq_%y%j.log')
  
  # output to stdout 
  print(Message)
  
  # output to log file
  with open(LogFile, 'a') as fout:
  
    fout.write(Message + '\n')

### main ####
InputPathIndex             = 0
OutputPathIndex            = 1
FileTxBeginHourOffsetIndex = 2
FileTxEndHourOffsetIndex   = 3
FileListIndex              = 4

WriteMessage(LogFilePath, '\nRunning MosaicFileTxFromTowerToDaq.py on ' + time.ctime() + '\n')

# create ftp object 
try:

  f = ftplib.FTP()

except:

  WriteMessage(LogFilePath, 'Error creating FTP object',)
  sys.exit()

# connect to ftp server
try:

  f.connect(FtpServer, FtpPort)

except:

  WriteMessage(LogFilePath, 'Error connecting to FTP server ' + FtpServer + ' on port ' + str(FtpPort))
  sys.exit()

# ftp authentication
try:

  f.login(FtpUserName, FtpPassword)

except:

  WriteMessage(LogFilePath, 'Error logging into FTP server as ' + FtpUserName)
  sys.exit()

WriteMessage(LogFilePath, 'FTP connection connection established with ' + FtpServer + ' on port ' + str(FtpPort) + ' as user ' + FtpUserName)

# cycle through each ftp file transfer session
for FtpTxSession in sorted(FtpTxParmDict):

  WriteMessage(LogFilePath, '\nLoading FTP transfer parameters for session \'' + FtpTxSession + '\':\n')

  # assign dictionary elements
  FtpBasePath           = FtpTxParmDict[FtpTxSession][InputPathIndex]
  OutputBasePath        = FtpTxParmDict[FtpTxSession][OutputPathIndex]
  FtpTxFileList         = FtpTxParmDict[FtpTxSession][FileListIndex]
  FileTxBeginHourOffset = FtpTxParmDict[FtpTxSession][FileTxBeginHourOffsetIndex]
  FileTxEndHourOffset   = FtpTxParmDict[FtpTxSession][FileTxEndHourOffsetIndex]

  # create time objects for the begin and end time of the file transfer
  CurrentTime = datetime.datetime.utcnow()
  BeginTxTime = CurrentTime - datetime.timedelta(hours=FileTxBeginHourOffset)
  EndTxTime   = CurrentTime - datetime.timedelta(hours=FileTxEndHourOffset)
  FileTxTime  = EndTxTime
 
  try:
  
    # change directory on the FTP server
    f.cwd(FtpBasePath)
    
  except:
  
    WriteMessage(LogFilePath, 'FTP directory ' + FtpBasePath + ' does not exist; skipping')
    continue

  # cycle through all file transfer hours 
  while(FileTxTime >= BeginTxTime):
      
    # cycle through each file transfer expression
    for FtpTxFile in FtpTxFileList:

      File = FileTxTime.strftime(FtpTxFile)

      InputFile = FtpBasePath + '/' + File

      OutputFile = OutputBasePath + '/' + File
      
      try:

        # get remote file size
        try:
        
          InputFileSize = f.size(InputFile)
          
        except:
        
          InputFileSize = 0
  
        # get local file size
        try:
        
          statinfo = os.stat(OutputFile)
          OutputFileSize = statinfo.st_size
          
        except:
        
          OutputFileSize = 0
        
        # transfer the file
        if(InputFileSize > 0):
  
          if(InputFileSize != OutputFileSize):
  
            # create output path if it doesn't exist
            if(os.path.isdir(os.path.dirname(OutputFile)) == False):
              os.makedirs(os.path.dirname(OutputFile))
  
            WriteMessage(LogFilePath, 'Transferring ' + InputFile + ' to ' + OutputFile)
	  
            # transfer file in binary mode
            f.retrbinary('RETR ' + InputFile, open(OutputFile,'wb').write)

          else:
	
            WriteMessage(LogFilePath, 'Skipping ' + InputFile + '; local and remote files are the same size')
	  
        else:
  
          WriteMessage(LogFilePath, 'Input file ' + InputFile + ' does not exist; skipping')
  
      except:

        WriteMessage(LogFilePath, 'Error transferring ' + InputFile)

    # decrease the time by one hour
    FileTxTime -= datetime.timedelta(hours=1) 
  
WriteMessage(LogFilePath, '\nMosaicFileTxFromTowerToDaq.py finished on ' + time.ctime())