a4.in

#!@PYTHON@
import os, argparse, pathlib, sys, platform, shutil

DEBUG=0
def MSG(*args):
	if DEBUG:
		print(*args)
	else:
		pass
PYTHON=pathlib.Path(r'@PYTHON@')

def add_at_start(envvar,pathcomponents):
	"""
	Add path components at start of envvar, but only if they're not already in the path somewhere.
	@return 1 if changes made, 0 otherwise
	@TODO what about Windows path munging?
	"""

	# convert pathcomponents to absolute paths
	pathcomponents = [i.resolve() for i in pathcomponents]

	if not os.environ.get(envvar):
		# env var is not yet set; simply set it to requested value
		v = SEP.join([str(p) for p in pathcomponents])
		MSG("CREATED %s=%s" % (envvar,v))
		os.environ[envvar]=v
		return 1

	changed = 0
	# convert what's in there to absolute paths for comparison
	envvals = [pathlib.Path(i).resolve() for i in os.environ[envvar].split(SEP)]
	oldenv = os.environ[envvar]
	found = []
	for p in reversed(pathcomponents):
		if p not in envvals:
			envvals.insert(0,p)
			MSG("INSERTED into %s: %s"%(envvar,p))
			changed = 1

	# TODO if changes made, let's check for repeated path components and remove them (PyGTK All-in-one does this)	
			
	os.environ[envvar]=SEP.join([str(i) for i in envvals])
	if not changed:
		MSG("VAR %s UNCHANGED" % envvar)
	else:
		MSG("VAR %s CHANGED" % envvar)
		MSG("OLD %s = %s" % (envvar,oldenv))
		MSG("NEW %s = %s" % (envvar,os.environ[envvar]))
		
	return changed

def shebang(script,args):
	"""This excessively complex function allows us to launch shebang-encoded scripts when 'a4' is
	run on Windows. It depends on the 'cygpath' program, which in turn depends on some of the 
	MSYS2 environment variables. Does nothing on Linux. Arguably it would be much easier to just
	ask MSYS2 bash to look after all this directly."""
	if not platform.system()== "Windows":
		return [script] + args

	p = pathlib.Path(script)
	if not p.is_file() or not os.access(p, os.X_OK):
		MSG("checking PATHEXT extensions...")
		found = None
		for pe in os.environ.get('PATHEXT').split(";"):
			exe = pathlib.Path(str(script) + pe)
			MSG(f"checking for {exe}")
			if exe.is_file():
				found = exe
				break
		if not found:
			raise RuntimeError(f"script '{script}' either doesn't exist is or not executable")
		return [found]+args
	with open(p,'r') as f:
		line1 = f.readline()
		if line1.startswith("#!"):
			interp = line1[2:].strip().split()
			if interp:
				pi = pathlib.Path(interp[0])
				if str(pi)[0] == "/":
					# MSYS path... convert to Windows
					wp = subprocess.run([shutil.which('cygpath'),'-w',pi],capture_output=True,check=True,encoding='utf-8')
					MSG(f"WP = {wp.stdout}")
					pi = pathlib.Path(wp.stdout.strip())
				if not pi.is_absolute():
					raise RuntimeError(f"in script {p}, the shebang line must contain an absolute path (got: '{pi}')")
				if not pi.is_file() or not os.access(pi, os.X_OK):
					raise RuntimeError(f"in script {p}, interpreter '{pi}' is not a file or is not flagged as executable")
				return [pi] + interp[1:] + [script] + args
			raise RuntimeError(f"Invalid shebang line in {script}")
	# does not start with shebang, could be natively executable (we'll just try)
	return [script]+args

if __name__ == "__main__":
	p = argparse.ArgumentParser(description='ASCEND launcher')

	p.add_argument('--debug',action='store_true',help='Show launcher debug output')
	g = p.add_mutually_exclusive_group()
	g.add_argument('--gdb',action='store_true',help='Run action via GDB')
	g.add_argument('--valgrind',action='store_true',help='Run action via Valgrind')

	s = p.add_subparsers(help='sub-command help')
	
	p_open = s.add_parser('open',help = 'Open file in ASCEND GUI')
	p_open.set_defaults(action='open')
	p_open.add_argument('file',type=pathlib.Path)
	p_open.add_argument('--model','-m', help="Name of MODEL to instantiate");
	
	p_gui = s.add_parser('gui',help = 'Simply open the ASCEND GUI')
	p_gui.set_defaults(action='gui')

	p_run = s.add_parser('run',help = 'Run model and solve (without GUI, via QRSlv solver)')

	if sys.version_info.major == 3 and sys.version_info.minor < 8:
		class ExtendAction(argparse.Action):
			def __call__(self, parser, namespace, values, option_string=None):
				items = getattr(namespace, self.dest) or []
				items.extend(values)
				setattr(namespace, self.dest, items)
		p_run.register('action', 'extend', ExtendAction)

	p_run.set_defaults(action='run')
	p_run.add_argument('file',type=pathlib.Path,help='ASCEND model file to be opened')
	p_run.add_argument('--model','-m', help="Name of MODEL to instantiate (defaults to filename without extension)");
	p_run.add_argument('-p', '--print', dest='printvars', action='extend', nargs='+', help='Variables to print (can be used multiple times). Implies --no-test.')
	p_run.add_argument('--no-test','-n', help="Suppress running of 'self_test' method after solving");

	p_scr = s.add_parser('script',help = 'Run a Python or other script within ASCEND development environment')
	p_scr.set_defaults(action='script')
	p_scr.add_argument('file',type=pathlib.Path,help='Script file to be run')
	p_scr.add_argument('rest',nargs=argparse.REMAINDER,help='Additional arguments to be passed to the script')
	
	p_sh = s.add_parser('env',help = 'Create a sub-shell in which ASCEND environment variables are set.')
	p_sh.set_defaults(action='env')
	p_sh.add_argument('--shell',default='bash',help='Shell to run')
	p_sh.add_argument('--label',action='store_false',default=True,help="Suppress adding 'a4>' text at start of prompt")
	p_sh.add_argument('rest',nargs=argparse.REMAINDER,help='Extra arguments to send to shell')

	p_sh = s.add_parser('q',help = 'Quick shortcut test -- test a4.in source for details.')
	p_sh.set_defaults(action='q')

	args = p.parse_args()

	if args.debug:
		DEBUG=1
		MSG("Debugging output turned on!")
	else:
		sys.tracebacklimit=0

	import subprocess, os
	sourceroot=pathlib.Path("@SOURCE_ROOT@")
	script=os.path.join(sys.argv[0])
	SEP = os.pathsep
	
	if platform.system()=="Windows":
		LD_LIBRARY_PATH="PATH"
	elif platform.system()=="Darwin":
		LD_LIBRARY_PATH="DYLD_LIBRARY_PATH"
	else:
		LD_LIBRARY_PATH="LD_LIBRARY_PATH"

	restart = []

	# for Mac, add our local PyGTK libraries at start of Python path:
	#if platform.system()=="Darwin":
	#	sys.path.insert(0,'dist/gtk.bundle/python')

	# ensure that we have our 'models' dir in the ASCENDLIBRARY path
	modeldirs = [sourceroot / 'models']
	if add_at_start('ASCENDLIBRARY',modeldirs):
		restart.append('ASCENDLIBRARY')

	solverdir = sourceroot / 'solvers'
	solverdirs = [solverdir / d.lower() for d in "@WITH_SOLVERS@".split(",")]
	if add_at_start('ASCENDSOLVERS',solverdirs):
		restart.append('ASCENDSOLVERS')

	# ensure that we have our shared libraries in the LD_LIBRARY_PATH
	libdirs = [sourceroot, pathlib.Path.home() / '.local/lib']
	if add_at_start(LD_LIBRARY_PATH,libdirs):
		restart.append(LD_LIBRARY_PATH)

	# ensure our pygtk dir is in the PYTHONPATH
	pypath = [sourceroot / 'ascxx', sourceroot / 'pygtk']
	# also FPROPS
	pypath += [sourceroot / 'models' / 'johnpye' / 'fprops' / 'python']
	if add_at_start('PYTHONPATH',pypath):
		restart.append('PYTHONPATH')

	MSG("ARGS",args)
		
	precmd = []
	if args.gdb:
		precmd = ['gdb','--args']
	elif args.valgrind:
		VALGRIND = shutil.which('valgrind')
		if VALGRIND == None:
			raise RuntimeError("Could not locate 'valgrind' in the PATH")
		precmd = [VALGRIND]+ '--suppressions=tools/valgrind/suppressions --tool=memcheck --leak-check=full --show-reachable=yes'.split(' ')
	
	cmd = precmd
	if not hasattr(args,'action') or args.action == 'gui':
		MSG("launching GUI...")
		cmd += [PYTHON,sourceroot/'pygtk'/'ascdev']
	elif args.action == 'open':
		cmd += [PYTHON,sourceroot/'pygtk'/'ascdev', args.file]
		if args.model:
			cmd += ['-m',args.model]
	elif args.action == 'run':
		# note that we cannot avoid invoking a subprocess here, because
		# we cannot update LD_LIBRARY_PATH for the running process, which means
		# that ascpy cannot successfully load libascend.so.
		cmd += [PYTHON,sourceroot/'ascxx'/'runmodel.py',args.file]
		if args.model:
			cmd += ["--model",args.model]
		if args.printvars:
			cmd += ["--print"] + args.printvars
		if args.no_test:
			cmd += ["--no-test"]
		#print(f"CMD = {cmd}")
	elif args.action == 'q':
		# for the convenience of the developer -- hack this for your temporary needs
		cmd += [PYTHON,sourceroot/'pygtk'/'ascdev', sourceroot/'models'/'johnpye'/'extpy'/'extpytest.a4c']
	elif args.action == 'script':
		cmd += shebang(args.file,args.rest)
	elif args.action == 'env' :
		shargs = []
		if os.environ.get('ASCEND_SHELL'):
			raise RuntimeError("You are already inside an ASCEND shell")
		if args.label:
			assert(args.shell=='bash')
			os.environ['PS1'] = r'a4> \[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
			shargs += ['--norc']
		os.environ['ASCEND_SHELL'] = '1'
		cmd += [args.shell] + shargs + args.rest
	else:
		print("unrecognised command")
		sys.exit(1);
		
	MSG("CMD =",cmd)
	proc = subprocess.run(cmd)

# vim:syntax=python:ts=4:sw=4:noet