#! /usr/bin/env python
# encoding: UTF-8
# Petar Forai
# Thomas Nagy 2008-2010 (ita)

import re
from waflib import Task, Utils, Logs
from waflib.TaskGen import extension, feature, after_method
from waflib.Configure import conf
from waflib.Tools import c_preproc

"""
tasks have to be added dynamically:
- swig interface files may be created at runtime
- the module name may be unknown in advance
"""

SWIG_EXTS = ['.swig', '.i']

re_module = re.compile('%module(?:\s*\(.*\))?\s+(.+)', re.M)

re_1 = re.compile(r'^%module.*?\s+([\w]+)\s*?$', re.M)
re_2 = re.compile('%include "(.*)"', re.M)
re_3 = re.compile('#include "(.*)"', re.M)

class swig(Task.Task):
	color   = 'BLUE'
	run_str = '${SWIG} ${SWIGFLAGS} ${SWIGPATH_ST:INCPATHS} ${DEFINES_ST:DEFINES} ${SRC}'
	ext_out = ['.h'] # might produce .h files although it is not mandatory

	def runnable_status(self):
		for t in self.run_after:
			if not t.hasrun:
				return Task.ASK_LATER

		if not getattr(self, 'init_outputs', None):
			self.init_outputs = True
			if not getattr(self, 'module', None):
				# search the module name
				txt = self.inputs[0].read()
				m = re_module.search(txt)
				if not m:
					raise ValueError("could not find the swig module name")
				self.module = m.group(1)

			swig_c(self)

			# add the language-specific output files as nodes
			# call funs in the dict swig_langs
			for x in self.env['SWIGFLAGS']:
				# obtain the language
				x = x[1:]
				try:
					fun = swig_langs[x]
				except KeyError:
					pass
				else:
					fun(self)

		return super(swig, self).runnable_status()

	def scan(self):
		"scan for swig dependencies, climb the .i files"
		env = self.env

		lst_src = []

		seen = []
		to_see = [self.inputs[0]]

		while to_see:
			node = to_see.pop(0)
			if node in seen:
				continue
			seen.append(node)
			lst_src.append(node)

			# read the file
			code = node.read()
			code = c_preproc.re_nl.sub('', code)
			code = c_preproc.re_cpp.sub(c_preproc.repl, code)

			# find .i files and project headers
			names = re_2.findall(code) + re_3.findall(code)
			for n in names:
				for d in self.generator.includes_nodes + [node.parent]:
					u = d.find_resource(n)
					if u:
						to_see.append(u)
						break
				else:
					Logs.warn('could not find %r' % n)

		return (lst_src, [])

# provide additional language processing
swig_langs = {}
def swigf(fun):
	swig_langs[fun.__name__.replace('swig_', '')] = fun
swig.swigf = swigf

def swig_c(self):
	ext = '.swigwrap_%d.c' % self.generator.idx
	flags = self.env['SWIGFLAGS']
	if '-c++' in flags:
		ext += 'xx'
	out_node = self.inputs[0].parent.find_or_declare(self.module + ext)

	if '-c++' in flags:
		c_tsk = self.generator.cxx_hook(out_node)
	else:
		c_tsk = self.generator.c_hook(out_node)

	c_tsk.set_run_after(self)

	ge = self.generator.bld.producer
	ge.outstanding.insert(0, c_tsk)
	ge.total += 1

	try:
		ltask = self.generator.link_task
	except AttributeError:
		pass
	else:
		ltask.set_run_after(c_tsk)
		ltask.inputs.append(c_tsk.outputs[0])

	self.outputs.append(out_node)

	if not '-o' in self.env['SWIGFLAGS']:
		self.env.append_value('SWIGFLAGS', ['-o', self.outputs[0].abspath()])

@swigf
def swig_python(tsk):
	tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.py'))

@swigf
def swig_ocaml(tsk):
	tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.ml'))
	tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.mli'))

@extension(*SWIG_EXTS)
def i_file(self, node):
	# the task instance
	tsk = self.create_task('swig')
	tsk.set_inputs(node)
	tsk.module = getattr(self, 'swig_module', None)

	flags = self.to_list(getattr(self, 'swig_flags', []))
	tsk.env.append_value('SWIGFLAGS', flags)

	# looks like this is causing problems
	#if not '-outdir' in flags:
	#	tsk.env.append_value('SWIGFLAGS', ['-outdir', node.parent.abspath()])

@conf
def check_swig_version(self):
	"""Check for a minimum swig version like conf.check_swig_version('1.3.28')
	or conf.check_swig_version((1,3,28)) """
	reg_swig = re.compile(r'SWIG Version\s(.*)', re.M)
	swig_out = self.cmd_and_log('%s -version' % self.env['SWIG'])

	swigver = tuple([int(s) for s in reg_swig.findall(swig_out)[0].split('.')])
	self.env['SWIG_VERSION'] = swigver
	msg = 'Checking for swig version'
	self.msg(msg, '.'.join(map(str, swigver)))
	return swigver

def configure(conf):
	swig = conf.find_program('swig', var='SWIG')
	conf.env.SWIGPATH_ST = '-I%s'

