import os
import sys
import py_compile

# Function to build a .pyc from a .py
def build_pyc(target, source, env):
    py_compile.compile(str(source[0]), str(target[0]), doraise=True)
    return None

# Read in build options
opts = Options('build_options.py')
opts.Add('GCCFLAGS', 'Flags passed to GCC')
opts.Add('MSVCFLAGS', 'Flags passed to the MSVC compiler')

# Create the .pyc builder
pyc_builder = Builder(action = build_pyc,
	              suffix = '.pyc',
		      src_suffix = '.py')

env = Environment(options = opts)
env.Append(BUILDERS={'Pyc' : pyc_builder})

Help(opts.GenerateHelpText(env))

# Find the path for Python.h and then share it to other SConscripts later on
# Where to find the Python.h
if sys.platform == 'win32':
    # Prefer MinGW over MSVC
    Tool('mingw')(env)

    python_include = os.path.join(sys.exec_prefix, 'include')
    # Windows installs need to be told the lib path and the python library name
    # else it won't work right.
    python_libdir = os.path.join(sys.exec_prefix, 'libs')
    env.Append(LIBPATH=[python_libdir])
    python_libname = 'python%d%d' % (sys.version_info[0:2])
    env.Append(LIBS=[python_libname])
else:
    python_include = os.path.join(os.path.join(sys.exec_prefix, 'include'),
                                  'python' + sys.version[:3])
    
# Check existence of Python.h
headerfile = python_include + os.sep + 'Python.h'
try:
    open(headerfile, 'r')
except:
    raise """Did not find Python header file %s.
    Make sure files for Python C-extensions are installed.
    In debian linux, for example, you need to install a
    package called something like python2.3-dev""" %headerfile

env.Append(CPPPATH=[python_include])

# Set appropriate CCFLAGS for the compiler.
if env['CC'] == 'gcc':
    env.Append(CCFLAGS=['${GCCFLAGS}'])
elif env['CC'] == 'cl':
    env.Append(CCFLAGS=['${MSVCFLAGS}'])

Export('env')

# Build .pyc files of every .py in here and below.
files = []
dirs = filter(os.path.isdir, os.listdir('.'))
while(dirs != []):
    dirs += filter(os.path.isdir, map(lambda x : dirs[0] + os.sep + x, os.listdir(dirs[0])))
    files += filter(lambda x : x[-3:] == '.py', map(lambda x : dirs[0] + os.sep + x, os.listdir(dirs[0])))
    dirs = dirs[1:]
for x in files:
    env.Pyc(x + 'c', x)

SConscript(['inundation/SConscript'])