configure

#!/usr/bin/env python2
import os, sys

directory = os.path.dirname(os.path.abspath(__file__))
makefile_lines = []
makefile_cflags = ""
makefile_pkgs = ""
makefile_cflags_index = -1
makefile_pkgs_index = -1

try:
	makefile = open("%s/make.conf" % directory)
	for n, line in enumerate(makefile):
		line = line.rstrip("\r\n")
		makefile_lines.append(line)
		if line.startswith("CXXFLAGS") or line.startswith("override CXXFLAGS "):
			makefile_cflags = line.rstrip() + " "
			makefile_cflags_index = n
		elif line.startswith("PKGS "):
			makefile_pkgs = line.rstrip() + " "
			makefile_pkgs_index = n
	makefile.close()
except Exception as e:
	# this is the thing printed when it can't read the makefile
	sys.stderr.write("Failed to open make.conf;\n%s\n" % e)
	sys.exit(1)

args = {}
def add_arg(text, **kwargs):
	args.setdefault(text, {"PKGS": {}, "CXXFLAGS": {}})
	if "PKGS" in kwargs:
		for pkg in kwargs["PKGS"]:
			if pkg.startswith("+"):
				args[text]["PKGS"][pkg[1:]] = True
			elif pkg.startswith("-"):
				args[text]["PKGS"][pkg[1:]] = False
	if "CXXFLAGS" in kwargs:
		for cflag in kwargs["CXXFLAGS"]:
			if cflag.startswith("+"):
				args[text]["CXXFLAGS"][cflag[1:]] = True
			elif cflag.startswith("-"):
				args[text]["CXXFLAGS"][cflag[1:]] = False
	if "about" in kwargs:
		args[text]["about"] = kwargs["about"]

# the first argument (eg "disable-zlib") is the command line arg that
# will be prepended with --
# the CXXFLAGS keyword argument expects a list of things to add or remove to CXXFLAGS
# the PKGS keyword argument expects a list of things to add or remove
# from PKGS, if the package name is prepended with -, it is removed
# if it is prepended with +, it is added
add_arg("disable-zlib", CXXFLAGS=["+-D_NO_GZIP"], PKGS=["-zlib"], about="Disable zlib")
add_arg("enable-zlib", CXXFLAGS=["--D_NO_GZIP"], PKGS=["+zlib"], about="Enable zlib")
add_arg("disable-lzma", CXXFLAGS=["+-D_NO_LZMA"], PKGS=["-liblzma"], about="Disable lzma")
add_arg("enable-lzma", CXXFLAGS=["--D_NO_LZMA"], PKGS=["+liblzma"], about="Enable lzma")
add_arg("disable-postgres", CXXFLAGS=["+-D_NO_POSTGRES"], PKGS=["-libpq"], about="Disable postgres")
add_arg("enable-postgres", CXXFLAGS=["--D_NO_POSTGRES"], PKGS=["+libpq"], about="Enable postgres")
add_arg("disable-libevent-threads", CXXFLAGS=["+-D_NO_LIBEVENT_THREADS"], PKGS=["-libevent_pthreads"], about="Disable libevent threads support")
add_arg("enable-libevent-threads", CXXFLAGS=["--D_NO_LIBEVENT_THREADS"], PKGS=["+libevent_pthreads"], about="Enable libevent threads support")
add_arg("enable-c++11", CXXFLAGS=["+-std=c++11"], about="Enable C++11 specify features")
add_arg("disable-c++11", CXXFLAGS=["--std=c++11"], about="Disable C++11 specify features")

help_set = set(["--help", "-h"])
if len(set(sys.argv) & set(["--help", "-h"])) > 0:
	print "Configuration options:"
	for option in args:
		if "about" in args[option]:
			print "   --%s: %s" % (option, args[option]["about"])

made_changes = False
def parse_arg(program_arg):
	global made_changes
	global makefile_cflags
	global makefile_pkgs
	if program_arg in help_set:
		return
	if not program_arg.startswith("--"):
		sys.stderr.write("wrongly formatted arg '%s'!\n" % program_arg)
		sys.exit(1)
	program_arg = program_arg[2:]
	if program_arg == "disable-all":
		for available_option in args:
			if available_option.startswith("disable-"):
				parse_arg("--%s" % available_option)
		return False
	if program_arg == "enable-all":
		for available_option in args:
			if available_option.startswith("enable-"):
				parse_arg("--%s" % available_option)
		return False
	if program_arg in args:
		cflags = args[program_arg]["CXXFLAGS"]
		for cflag in cflags:
			if cflags[cflag]:
				if not " %s " % cflag in makefile_cflags:
					# this is printed when a clag is added
					print "Adding '%s' to CXXFLAGS" % cflag
					makefile_cflags += "%s " % cflag
					made_changes = True
				else:
					# this is the thing printed when a CFLAG is already added
					print "'%s' is already added to CXXFLAGS" % cflag
			else:
				if " %s " % cflag in makefile_cflags:
					# this is the thing printed when removing a CFLAG
					print "Removing '%s' from CXXFLAGS" % cflag
					makefile_cflags = makefile_cflags.replace(" %s" % cflag, "")
					made_changes = True
				else:
					# this is the thing printed when a CFLAG is already removed
					print "'%s' is already removed from CXXFLAGS" % cflag
		makefile_lines[makefile_cflags_index] = makefile_cflags
		pkgs = args[program_arg]["PKGS"]
		for pkg in pkgs:
			if pkgs[pkg]:
				if not " %s " % pkg in makefile_pkgs:
					# this is the thing printed when adding a package
					print "Adding '%s' to PKGS" % pkg
					makefile_pkgs += "%s " % pkg
					made_changes = True
				else:
					# this is the thing printed when a package is already added
					print "'%s' is already added to PKGS" % pkg
			else:
				if " %s " % pkg in makefile_pkgs:
					# this is the thing printed when removing a package
					print "Removing '%s' from PKGS" % pkg
					makefile_pkgs = makefile_pkgs.replace(" %s" % pkg, "")
					made_changes = True
				else:
					# this is the thing printed when a package is already removed
					print "'%s' is already removed from PKGS" % pkg
		makefile_lines[makefile_pkgs_index] = makefile_pkgs
	else:
		sys.stderr.write("Uknown arg provided: '%s'\n" % program_arg)

for arg in sys.argv[1:]:
	if not parse_arg(arg) == None:
		break

if not made_changes:
	# this is the thing printed when nothing is changed in the makefile
	sys.stderr.write("Nothing changed\n")
	sys.exit(0)

try:
	makefile = open("%s/make.conf" % directory, "w")
	for line in makefile_lines:
		makefile.write("%s\n" % line)
	makefile.close()
	# this is the thing printed when everything is done
	print "Done!"
except Exception as e:
	# this is the thing printed when it can't write the makefile
	sys.stderr.write("Failed to open make.conf to write configuration;\n%s\n" % e)
	sys.exit(1)