#!/usr/bin/env python
import fig, sys, re, os.path

from optparse import OptionParser

op = OptionParser(
	usage = "%prog [options] <infile> <layers> [<layers> ...]",
	description=
	"""Extracts layers from XFig files.
(The <layers> specifications may be for example '10-50', '30-', '1,25', ...)

For each layer spec., an output file is saved with a -<number> postfix by default. (The reason being that the result can be used with [x]mpmulti.sty for easy LaTeX inclusion.)

The input filename may be '-' for stdin, and if no output filename is given, the output will be sent to stdout.""")
op.add_option("-v", "--verbose", action="store_true", default=True,
			  dest="verbosity", help="verbose output (default)")
op.add_option("-q", "--quiet", action="store_false",
			  dest="verbosity", help="quite mode (only errors)")
op.add_option("-1", action="store_false", default=True,
			  dest="zeroBased", help="start numbering with 1 (default: 0)")
op.add_option("-o", "--output", action="store", dest="filename",
			  help="Output filename.  If more than one layer spec is given, must contain %d, which will be replaced by an index starting with 1.")
options, args = op.parse_args()

if len(args) < 2:
	op.error("No file/layers given - nothing to do!")

# --------------------------------------------------------------------
# 					 setup filenames and logging
# --------------------------------------------------------------------

if options.verbosity:
	log = sys.stdout
else:
	class DummyOut:
		def write(*args):
			pass
		def flush(*args):
			pass
	
	log = DummyOut()

filename = args[0]
specs = args[1:]

outfileName = options.filename

if filename == "-":
	if not outfileName:
		# output to stdout
		if len(specs) > 1:
			op.error("more than one spec cannot go to stdout! (use -o option?)\n")
		if options.verbosity:
			log = sys.stderr

	filename = sys.stdin # constructor parameter for fig.File
else:
	basename, ext = os.path.splitext(filename)
	if not outfileName:
		outfileName = basename + "-%d" + ext

# --------------------------------------------------------------------
# 							 parse specs
# --------------------------------------------------------------------

re_specpart = re.compile("([0-9]*)(-?)([0-9]*)")

def parseSpec(spec):
	parts = spec.split(",")
	result = []
	for part in parts:
		if not part: continue # support shell expansions like 10,20,{,21,22}
		ma = re_specpart.match(part)
		if not ma:
			op.error("could not parse spec part '%s'!\n" % part)
		if len(ma.group(2)):
			s = None
			if ma.group(1):
				s = int(ma.group(1))
			e = None
			if ma.group(3):
				e = int(ma.group(3))
		else:
			s = int(ma.group(1))
			e = s
		result.append((s, e))
	return result

def layerInSpec(layer, spec):
	for s, e in spec:
		if s == None:
			if layer <= e:
				return True
		elif e == None:
			if layer >= s:
				return True
		elif s <= layer and layer <= e:
			return True
	return False

specs = map(parseSpec, specs)

# --------------------------------------------------------------------
# 				  copy fig objects to output file(s)
# --------------------------------------------------------------------

infig = fig.File(filename)

i = 0
if options.zeroBased:
	i -= 1

for spec in specs:
	i += 1
	log.write("spec %d: " % i)

	outfig = fig.File()

	for color in infig.colors:
		outfig.append(color)

	for object in infig.allObjects():
		if layerInSpec(object.depth, spec):
			outfig.append(object)
			log.write(".")

	log.write("\n")

	if not outfileName:
		sys.stdout.write(str(outfig))
	else:
		if outfileName.find("%d") >= 0:
			outfig.save(outfileName % i)
		else:
			outfig.save(outfileName)