#!/usr/local/bin/python

import os,sys
import subprocess
import tempfile
import logging
import topdl

import os.path

from util import *
from fedid import fedid
from remote_service import xmlrpc_handler, soap_handler
from service_error import *
from authorizer import authorizer, abac_authorizer


class nullHandler(logging.Handler):
    def emit(self, record): pass

fl = logging.getLogger("fedd.splitter")
fl.addHandler(nullHandler())

class ns2topdl_local:
    def __init__(self, config=None, auth=None):
	"""
	Intialize the various attributes, most from the config object
	"""
	self.debug = config.getboolean("ns2topdl", "debug")
	self.muxmax = config.getint("ns2topdl", "muxmax", 3)
	self.tclsh = config.get("ns2topdl", "tclsh", 
		"/usr/local/bin/otclsh")
	self.tcl_splitter = config.get("ns2topdl", "tcl_splitter",
		"/usr/testbed/lib/ns2ir/parse.tcl")
	self.auth_type = config.get('ns2topdl', 'auth_type') or 'legacy'
	access_db = config.get("ns2topdl", "accessdb", None)
	self.allow_any = config.getboolean("ns2topdl", "allow_any", False)
	auth_dir = config.get('ns2topdl', 'auth_dir')

	self.log = logging.getLogger("fedd.ns2topdl")
	set_log_level(config, "ns2topdl", self.log)
	self.trace_file = sys.stderr

	set_log_level(config, "ns2topdl", self.log)

	if auth:
	    self.auth= auth
	else:
	    self.auth = authorizer()
	    self.log.warning("[ns2topdl] No authorizer passed in, " +\
		    "using local one")


	if self.auth_type == 'legacy':
	    if access_db and self.allow_any: 
		raise service_error(service_error.internal, 
			"Cannot specify both an access database and " + 
			"allow_any for ns2topdl")
	    
	    if access_db:
		try:
		    read_simple_accessdb(access_db, self.auth, 'ns2topdl')
		except EnvironmentError, e:
		    raise service_error(service_error.internal,
			    "Error reading accessDB %s: %s" % (access_db, e))
		except ValueError:
		    raise service_error(service_error.internal, "%s" % e)
	    elif self.allow_any:
		auth.set_global_attribute("ns2topdl")
	elif self.auth_type == 'abac':
	    self.auth = abac_authorizer(load=auth_dir)
	else:
	    raise service_error(service_error.internal, 
		    "Unknown auth_type: %s" % self.auth_type)


	# Dispatch tables
	self.soap_services = {\
		'Ns2Topdl': soap_handler("Ns2Topdl", self.run_ns2topdl),
	}

	self.xmlrpc_services = {\
		'Ns2Topdl': xmlrpc_handler('Ns2Topdl', self.run_ns2topdl),
	}

    def run_ns2topdl(self, req, fid):
	"""
	The external interface to tcl to topdl translation.

	Creates a working directory, translates the incoming description using
	the tcl script.
	"""

	if self.allow_any:
	    self.auth.set_attribute(fid, 'ns2topdl')

	access_ok, proof = self.auth.check_attribute(fid, 'ns2topdl',
	    with_proof=True)

	if not access_ok:
	    raise service_error(service_error.access, "Access Denied", 
		proof=proof)

	try:
	    tmpdir = tempfile.mkdtemp(prefix="ns2topdl-")
	except EnvironmentError:
	    raise service_error(service_error.internal, "Cannot create tmp dir")

	tclfile = os.path.join(tmpdir, "experiment.tcl")
	# save error output in case the parse fails.
	errfile = os.path.join(tmpdir, "errfile")
	pid = "dummy"
	gid = "dummy"
	eid = "dummy"
	master = "dummy"

	req = req.get('Ns2TopdlRequestBody', None)
	if not req:
	    raise service_error(service_error.req,
		    "Bad request format (no Ns2TopdlRequestBody)")
	# The tcl parser needs to read a file so put the content into that file
	descr=req.get('description', None)
	if descr:
	    file_content=descr.get('ns2description', None)
	    if file_content:
		try:
		    f = open(tclfile, 'w')
		    f.write(file_content)
		    f.close()
		    ef = open(errfile, 'w')
		except EnvironmentError:
		    raise service_error(service_error.internal,
			    "Cannot write temp experiment description")
	    else:
		raise service_error(service_error.req, 
			"Only ns2descriptions supported")
	else:
	    raise service_error(service_error.req, "No description")

	
	tclcmd = [self.tclsh, self.tcl_splitter, '-t', '-x', 
	    str(self.muxmax), '-m', master]
	tclcmd.extend([pid, gid, eid, tclfile])
	self.log.debug("Calling splitter %s" % " ".join(tclcmd))
	tclparser = subprocess.Popen(tclcmd, stdout=subprocess.PIPE, stderr=ef)

	try:
	    top = topdl.topology_from_xml(file=tclparser.stdout, 
		    top="experiment")
	except:
	    top = None

	if top is None:
	    # There was an ns parsing error, gather up the error from the
	    # errfile and raise a service_error containing the error text
	    try:
		ef = open(errfile, 'r')
		parse_err = ef.read()
		ef.close()
	    except EnvironmentError:
		raise service_error(service_error.internal,
			"Cannot read error string")

	    raise service_error(service_error.req, 
		    "Cannot parse ns file: %s" % parse_err)

	# Walk up tmpdir, deleting as we go
	for path, dirs, files in os.walk(tmpdir, topdown=False):
	    for f in files:
		os.remove(os.path.join(path, f))
	    for d in dirs:
		os.rmdir(os.path.join(path, d))
	os.rmdir(tmpdir)

	resp = { 
		'experimentdescription':  { 
		    'topdldescription': top.to_dict(),
		    },
		'proof': proof.to_dict(),
		}

	return resp