import os
import sys
import platform
import ConfigParser


_platdir = 'platform'


def read_plat(env, args, fn):
	envdict = env.Dictionary().copy()
	# can't feed ConfigParser the original dict, because it also
	# contains non-string values.
	for k,v in envdict.items():
		if not isinstance(v, str):
			del envdict[k]
	cfig = ConfigParser.ConfigParser(envdict)
	cfig.read(fn)
	buildvars = [['CC',
			'TIFFINCLUDE', # where to find preinstalled tifflib headers
			'TIFFLIB',     # where to find a preinstalled tifflib library
			], # replace
			['CPPPATH', 'CPPDEFINES', 'CPPFLAGS', 'CCFLAGS',
			'LIBPATH', 'LINKFLAGS',
			'EZXML_CPPDEFINES', # build flags specific to ezxml.c
			]] # append
	vars = [
		['install',
			['RAD_BASEDIR', 'RAD_BINDIR', 'RAD_RLIBDIR', 'RAD_MANDIR'],
			[]],
		['code',
			[   # replace
			],
			[   # append
			'RAD_COMPAT',     # theoretically obsolete (src/common/strcmp.c)
			'RAD_MATHCOMPAT', # erf.c floating point error function
			'RAD_ARGSCOMPAT', # fixargv0.c for Windows
			'RAD_NETCOMPAT',  # [win_]netproc.c for ranimate
			'RAD_MLIB',       # usually 'm', or any fastlib available
			'RAD_SOCKETLIB',  # ws_2_32 on Windows (VC links it automatically)
			'RAD_PROCESS',    # our process abstraction and win_popen()
			'RAD_PCALLS',     # more custom process abstraction
			]],
	]
	if args.get('RAD_DEBUG',0):
		vars.insert(0, ['debug'] + buildvars)
	else: vars.insert(0, ['build'] + buildvars)
	for section in vars:
		if cfig.has_section(section[0]):
			for p in section[1]: # single items to replace
				try: v = cfig.get(section[0], p)
				except ConfigParser.NoOptionError: continue
				if section[0] == 'install' and '{' in v:
					try:
						vv = v.format(**os.environ)
					except KeyError: vv = v
					else: v = vv
				env[p] = v
				#print('%s: %s' % (p, env[p]))
			for p in section[2]: # multiple items to append
				try: v = cfig.get(section[0], p)
				except ConfigParser.NoOptionError: continue
				apply(env.Append,[],{p:env.Split(v)})
	# XXX Check that basedir exists.
	for k in ['RAD_BINDIR', 'RAD_RLIBDIR', 'RAD_MANDIR']:
		if (env.has_key('RAD_BASEDIR') and env.has_key(k)
				and not os.path.isabs(env[k])):
			env[k] = os.path.join(env['RAD_BASEDIR'],env[k])


def load_plat(env, args, arch=None):
	cfgname = 'posix'
	memmodel, binformat = platform.architecture()
	platsys = platform.system()
	print 'Detected platform "%s" (%s).' % (platsys, memmodel)
	cfgname = platsys + '_' + memmodel[:2]
	env['RAD_BUILDBIN'] = os.path.join('#scbuild', cfgname, 'bin')
	env['RAD_BUILDLIB']  = os.path.join('#scbuild', cfgname, 'lib')
	env['RAD_BUILDOBJ']  = os.path.join('#scbuild', cfgname, 'obj')

	pfn = os.path.join(_platdir, cfgname + '_custom.cfg')
	if os.path.isfile(pfn):
		print 'Reading configuration "%s"' % pfn
		read_plat(env, args, pfn)
		return 1
	pfn = os.path.join(_platdir, cfgname + '.cfg')
	if os.path.isfile(pfn):
		print 'Reading configuration "%s"' % pfn
		read_plat(env, args, pfn)
		return 1

	if os.name == 'posix':
		pfn = os.path.join(_platdir, 'posix.cfg')
		if os.path.isfile(pfn):
			print 'Reading generic configuration "%s".' % pfn
			read_plat(env, args, pfn)
			return 1

	print 'Platform "%s", system "%s" not supported yet' % (os.name, sys.platform)
	sys.exit(2)