#!/usr/bin/env python
"""
Run sasview in place.  This allows sasview to use the python
files in the source tree without having to call setup.py install
first.  A rebuild is still necessary when working on sans models
or c modules.

Usage:

./run.py [args]
"""

import os
import sys
import imp
from glob import glob
from contextlib import contextmanager
from os.path import abspath, dirname, join as joinpath


def addpath(path):
    """
    Add a directory to the python path environment, and to the PYTHONPATH
    environment variable for subprocesses.
    """
    path = abspath(path)
    if 'PYTHONPATH' in os.environ:
        PYTHONPATH = path + os.pathsep + os.environ['PYTHONPATH']
    else:
        PYTHONPATH = path
    os.environ['PYTHONPATH'] = PYTHONPATH
    sys.path.insert(0, path)

@contextmanager
def cd(path):
    """
    Change directory for duration of "with" context.
    """
    old_dir = os.getcwd()
    os.chdir(path)
    yield
    os.chdir(old_dir)

def import_package(modname, path):
    """Import a package into a particular point in the python namespace"""
    mod = imp.load_source(modname, abspath(joinpath(path,'__init__.py')))
    sys.modules[modname] = mod
    mod.__path__ = [abspath(path)]
    return mod

def import_dll(modname):
    """Import a DLL from the build directory"""
    # build_path comes from context
    path = glob(joinpath(build_path, *modname.split('.'))+'.*')[0]
    #print "importing", modname, "from", path
    return imp.load_dynamic(modname, path)

def prepare():
    # Don't create *.pyc files
    sys.dont_write_bytecode = True

    # Debug numpy warnings
    #import numpy; numpy.seterr(all='raise')

    # find the directories for the source and build
    from distutils.util import get_platform
    root = abspath(dirname(__file__))
    platform = '%s-%s'%(get_platform(),sys.version[:3])
    build_path = joinpath(root, 'build','lib.'+platform)

    # Make sure that we have a private version of mplconfig
    mplconfig = joinpath(abspath(dirname(__file__)), '.mplconfig')
    os.environ['MPLCONFIGDIR'] = mplconfig
    if not os.path.exists(mplconfig): os.mkdir(mplconfig)
    #import matplotlib
    #matplotlib.use('Agg')
    #print matplotlib.__file__
    #import pylab; pylab.hold(False)
    # add periodictable to the path
    try: import periodictable
    except: addpath(joinpath(root, '..','periodictable'))

    # select wx version
    #addpath(os.path.join(root, '..','wxPython-src-3.0.0.0','wxPython'))

    # Build project if the build directory does not already exist.
    if not os.path.exists(build_path):
        import subprocess
        with cd(root):
            subprocess.call((sys.executable, "setup.py", "build"), shell=False)

    # Put the source trees on the path
    addpath(joinpath(root, 'src'))
    addpath(joinpath(root, 'park-1.2.1'))

    # Import the sansview package from root/sansview as sans.sansview.  It would
    # be better to just store the package in src/sans/sansview.
    import sans
    sans.sansview = import_package('sans.sansview', joinpath(root,'sansview'))

    # The sans.models package Compiled Model files should be pulled in from the build directory even though
    # the source is stored in src/sans/models.

    # Compiled modules need to be pulled from the build directory.
    # Some packages are not where they are needed, so load them explicitly.
    import sans.pr
    sans.pr.core = import_package('sans.pr.core',
                                  joinpath(build_path, 'sans', 'pr', 'core'))
    #import_dll('park._modeling')

    #park = import_package('park',os.path.join(build_path,'park'))

    # Pull the entire sans.models package from the build directory since it contains
    # a mixture of autogenerated python and C.  Any changes in models will require
    # a rebuild with setup.py build
    sans.models = import_package('sans.models', joinpath(build_path, 'sans', 'models'))

    sys.path.append(build_path)

    #print "\n".join(sys.path)
    #from sans.models import SphereModel

if __name__ == "__main__":
    # start sasview
    #import multiprocessing
    #multiprocessing.freeze_support()
    prepare()
    from sans.sansview.sansview import SasView
    SasView()