#!/usr/bin/env python
################################################################################
#\defgroup difxls DiFXls
#
#\brief Run a simple "ls" file operation on the DiFX server.
#
#   Usage:  <b><code>DiFXls [ls arguments] [path]</code></b>
#
#   <i>DiFXls</i> can be used to run an <i>ls</i> command on the DiFX server with an
#  (almost) complete set of <i>ls</i> arguments.  The returned output will be
#  identical to that which would be seen if running from the
#  command line as the DiFX user (the user running the server).
#
#  The final argument to <i>DiFXls</i> is interpreted as a path.  Any preceding
#  arguments that are not recoginized as <a href=#DIFXLS_ARGS>DiFXls-specific arguments</a> are passed
#  verbatim to the <i>ls</i> command on the server.  Running
#  <i>DiFXls</i> without any arguments at all also works.
#
#  <a name=DIFXLS_ARGS><h3>Command Line Arguments Not Passed to <i>ls</i></h3></a>
#
#  <i>DiFXls</i> intercepts a small number of command line arguments for its own
#  purposes (all others are sent to the server as arguments to the <i>ls</i>
#  command).  Some of these override <i>ls</i> arguments, including -D, -h, -H,
#  and -P.  Hopefully this does not amount to a critical loss of functionality.
#
#  <table border="0" cellspacing="25">
#  <tr><td><pre><b>-D, --difx <i>VERSION</i></b></pre>    <td>Run using a specific DiFX version.  If not specified
#                                                          the value of the DIFX_VERSION environment variable will
#                                                          be used.  Failing that, "DIFX-DEVEL" will be used.
#  <tr><td><pre><b>-h, --help</b></pre>                   <td>Print help information and quit.
#  <tr><td><pre><b>-H, --hostname <i>NAME</i></b></pre>   <td>Use <i>NAME</i> as the host of the difxServer program.
#                                                          Default is to use DIFX_CONTROL_HOST environment variable.
#  <tr><td><pre><b>-P, --port <i>PORT</i></b></pre>       <td>Use <i>PORT</i> as the TCP port to communicated with the difxServer.
#                                                          Default is to use DIFX_CONTROL_PORT environment variable.
#  </table
#
################################################################################
program = 'DiFXls'
version = '0.1'
author  = 'John Spitzak'
verdate = '20150909'

import sys
import time
import DiFXControl

#===============================================================================
#  MAIN
#===============================================================================
host = None
port = None

#  Locate a "default" DiFX Version from environment variables.  User may change this
#  with command line arguments.
try:
	DiFXVersion = os.environ["DIFX_VERSION"]
except:
	DiFXVersion = "DIFX-DEVEL"

try:
	i = 1
	otherArgs = []
	argStr = None
	pathStr = None
	while i < len( sys.argv ):
		#  Check against legal argument types.  Anything we don't recognize is assumed
		#  to be an argument or a path.
		if sys.argv[i] in [ "-h", "--help" ]:
			print '\n%s ver %s  %s  %s' % (program, version, author, verdate)
			print "Runs an \"ls\" on a specified path on the DiFX software correlator."
			print "Usage: %s [options] [ls arguments] [path]" % ( sys.argv[0] )
			print ""
			print "Options can include:"
			print ""
			print "   --difx VERSION"
			print "   -D VERSION Run using a specific DiFX version.  If not specified"
			print "              the value of the DIFX_VERSION environment variable will"
			print "              be used.  Failing that, \"DIFX-DEVEL\" will be used."
			print ""
			print "   --help"
			print "   -h         Print this help information and quit."
			print ""
			print "   --hostname NAME"
			print "   -H NAME    Use NAME as the host of the difxServer program."
			print "              Default is to use DIFX_CONTROL_HOST environment variable."
			print ""
			print "   --port PORT"
			print "   -P PORT    Use PORT as the TCP port to communicated with the difxServer."
			print "              Default is to use DIFX_CONTROL_PORT environment variable."
			print ""
			exit( 0 )
		elif sys.argv[i] in [ "-H", "--hostname" ]:
			host = sys.argv[i+1]
			i = i + 1
		elif sys.argv[i] in [ "-D", "--difx" ]:
			DiFXVersion = sys.argv[i+1]
			i = i + 1
		elif sys.argv[i] in [ "-P", "--port" ]:
			port = int( sys.argv[i+1] )
			i = i + 1
		else:
			#  Store other arguments to be parsed below.  These can include command-line
			#  arguments directed at the "ls" command on the server - note that because
			#  we have a few of our own arguments, -D, -h, -H, and -P won't work.  Not
			#  a big deal I hope?
			otherArgs.append( sys.argv[i] )
		i = i + 1
		
	#  All other arguments form passed arguments to the server or the path name(s)
	#  used for the ls.  We decide which is which based on the preceding hyphen.
	for arg in otherArgs:
		if arg[0] == "-":
			if argStr == None:
				argStr = arg
			else:
				argStr += " " + arg
		else:
			if pathStr == None:
				pathStr = arg
			else:
				pathStr = " " + arg

except RuntimeError:
	print "Usage: %s [options] <path>" % ( sys.argv[0] )
	exit( 0 )
	
#  Open a new connection to the difxServer...
difx = DiFXControl.Client()
difx.connect( host, port )

if difx.socketOK:
	difx.monitor()
	difx.version( DiFXVersion )
	#  Do the "ls" with optional arguments.  If no path is given the current path
	#  of the server will be used...whatever that is.
	if pathStr == None:
		pathStr = "."
	dirlist = difx.ls( pathStr, argStr )
	if dirlist == None:
		print "No such file or directory"
	else:
		for item in dirlist:
			print item	

difx.close()