#!/usr/bin/env python

import os, os.path, sys, time, getopt
import sxpar

""" 
rundaily:

Written by Gary Kushner (LBL).  Jan 2010.
"""

####
def usage():
	"""Display usage and exit"""
	
	print "usage:"
	print "rundaily -m path -s path -p path"
	print " "
	print \
"""
	rundaily is meant to be run on rieman via cron.  It will wait until the next MJD is
	downloaded and then run a script.  It will output the status or errors to stdout.
	
	Note : you must "setup trac" before running this script.  Also, anything the 
	       given script might need.

	The parameters are:

	  -m path to file to store next mjd to look for
	  -s path to file to exec on new mjd.  The file will be run like this "file $MJD"
	  -p path to getWikiMJD password file
	
	NOTE:  To avoid upsetting cron, rundaily always exists with zero.
"""

	sys.exit(0)
	
	
####
def screamAndDie(msg):
	"""Print a message to stdout and then exit"""

	print msg
	sys.exit(0)
	
####
def parseCmdLine(args):
	"""Parse command line arguments and return a (mjdFile, scriptFile, pwFile)"""

	# parse with options
	try:
		opts, pargs = getopt.gnu_getopt(args, "m:s:p:")
	except:
		usage()

	if len(pargs) != 0:
		print "wrong number of command line arguments.\n"
		usage()

	mjdFile    = ""
	scriptFile = ""
	pwFile     = ""

	#	Fill in the config
	for (opt, value) in opts:
		if opt == "-m":
			mjdFile = value
		if opt == "-s":
			scriptFile = value
		if opt == "-p":
			pwFile = value

	if mjdFile == "" or scriptFile == "" or pwFile == "":
		usage()
		
	return (mjdFile, scriptFile, pwFile)


####
def getMJD(mjdFile):
	"""Return the single number stored in the given file"""

#	with open(mjdFile) as f:
#		return int(f.read())
	
	return int(open(mjdFile).read())
	
####
def incrementMJD(mjdFile):
	"""Increment the single number in the given file by one"""
	
#	with open(mjdsFile) as f:
#		mjd = int(f.read())
#		f.seek(0)
#		f.write(str(++mjd))
#		f.truncate()

	f = open(mjdFile, "r+")
	mjd = int(f.read()) + 1
	f.seek(0)
	f.write(str(mjd))
	f.truncate()
	f.close()

	print "Next MJD to wait for will be " + str(mjd)
		 
####
def runScript(scriptFile, mjd):
	"""Run the script 'scriptFile $MJD'"""
	
	print "Running script " + scriptFile + " " + str(mjd)
	os.spawnl(os.P_NOWAIT, scriptFile, scriptFile, str(mjd))
	

####
def nextMJD(mjd, pwFile):
	"""Return true if the given MJD has been transfered"""
	
#	cmd = "getWikiMJD " + pwFile + " " + str(mjd) + " &> /dev/null"
#	rc = os.system(cmd)
#	return rc == 0

	path = os.path.join(os.getenv("DAILY_BOSS_SPECTRO_DATA"), str(mjd))
	print "Looking for %s" % path
	return os.path.isdir(path)
	
	
####
def main(args):
	(mjdFile, scriptFile, pwFile) = parseCmdLine(args)
	
	#	Some early sanity checks
	if not os.path.exists(mjdFile):
		screamAndDie("Can not find MJD file: " + mjdFile)
	if not os.path.exists(scriptFile):
		screamAndDie("Can not find script file: " + scriptFile)
	if not os.path.exists(pwFile):
		screamAndDie("Can not find password file: " + pwFile)

	#	Is the next MJD here?
	mjd = getMJD(mjdFile)
	if nextMJD(mjd, pwFile):
		print "New MJD transfered: " + str(mjd) + "."
		incrementMJD(mjdFile)
		runScript(scriptFile, mjd)
	else:
		print "MJD " + str(mjd) + " is not here yet."
	

#### Start of script

if __name__=='__main__':
	main(sys.argv[1:])