# -*-python-*-
'''
Options  (see scons -h)
    scons build=DIR        # clean srcdir build, output below DIR
    scons out=DIR          # write output for alterative config to DIR
'''
import os

srcdir = Dir ('.').srcnode ().abspath

env = Environment ()


config_cache = 'scons.cache'
opts = Options ([config_cache, 'custom.py'], ARGUMENTS)
opts.Add ('prefix', 'Install prefix', '/usr/')
opts.Add ('out', 'Output directory', 'out-scons')
opts.Add ('build', 'Build directory', '.')

usage = 'help'
Help (usage + opts.GenerateHelpText (env))

config_vars = ['PYTHON']

# Add all config_vars to opts, so that they will be read and saved
# together with the other configure options.
map (lambda x: opts.AddOptions ((x,)), config_vars)
opts.Update (env)

atvars = ['PYTHON']
def at_copy_ext (target, source, env):
    n = str (source[0])
    s = open (n).read ()
    for i in atvars:
        if env.has_key (i):
            s = s.replace ('@%s@'% i, env[i])
    e = os.path.splitext (n)[1]
    t = str (target[0]) + e
    open (t, 'w').write (s)

AT_COPY_EXT = Builder (action = at_copy_ext, src_suffix=['.py', '.sh',])
env.Append (BUILDERS = {'AT_COPY_EXT': AT_COPY_EXT})

env.Alias ('minimal', ['python'])
env.Alias ('all', ['minimal', '.'])

Export ('env')

# Without target arguments, do minimal build
if not COMMAND_LINE_TARGETS:
    env.Default (['minimal'])

subdirs = ['python']

if not os.path.isdir ('python'):
    os.mkdir ('python')
    s = '''
Import ('env')
py = ['foo.py']
pym = map (env.AT_COPY_EXT, py)
pym
'''
    open ('python/SConscript', 'w').write (s)
    open ('python/foo.py', 'w').write ('#! @PYTHON@')

print 'build:', env['build']
# Note: SConscripts are only needed in directories where something needs
# to be done, building or installing
for d in subdirs:
    if os.path.exists (os.path.join (d, 'SConscript')):
        b = os.path.join (env['build'], d, env['out'])
        # Support clean sourcetree build (--srcdir build)
        # and ./out build.
        if os.path.abspath (b) != os.path.abspath (d):
            env.BuildDir (b, d, duplicate = 0)
        SConscript (os.path.join (b, 'SConscript'))