"""
Lane Emden Routines

f2py -m _laneemden -h _laneemden.pyf laneemden.f90 --overwrite-signature
f2py --f90exec=/usr/bin/gfortran --f90flags='-fPIC -O3 -funroll-loops -fno-second-underscore' -L. -lgfortran -c -m _laneemden laneemden.f90

gfortran laneemden.f90 -o laneemden
laneemden

This may require to create a link to libgefortran.so

ln -s /usr/lib64/libgfortran.so.3 libgfortran.so

Or, for all users:
[root]# cd /usr/lib64
[root]# ln -s libgfortran.so.3 libgfortran.so

"""

from __future__ import division
from __future__ import print_function
from __future__ import with_statement

import os
import subprocess

path = os.path.dirname(__file__)
so_file = os.path.join(path,'_laneemden.so')

def _build_module():
    """
    Build the Lane Emden FOTRTAN module.

    We also do a test of the executable version
    """
    cwd = os.getcwd()
    os.chdir(path)

    import numpy as np
    import glob

    # test executable
    try:
        subprocess.check_call("gfortran laneemden.f90 -o laneemden.exe",shell=True)
    except subprocess.CalledProcessError:
        print("executable compilation failed")
        raise
    try:
        result = subprocess.check_output("laneemden.exe")
    except subprocess.CalledProcessError:
        print("module executable failed")
        raise
    a = np.array([float(x) for x in result.split()])
    b = np.array([6.8968486193938672,0.,-4.24297576045549740e-2])
    print('Test result OK?: ',np.all(np.equal(a,b)))
    try:
        os.remove("laneemden.exe")
    except:
        pass

    # make module
    libs = glob.glob('/usr/lib64/libgfortran.so*')
    if len(libs) > 0:        
        try:
            os.stat("libgfortran.so")
        except:
            try:
                os.remove("libgfortran.so")
            except:
                pass        
            lib = libs[0]
            print('Trying to link '+lib)
            try:
                os.symlink(lib,"libgfortran.so")
            except:
                print("Could not create link")
    try:
        subprocess.check_call("f2py -m _laneemden -h _laneemden.pyf laneemden.f90 --overwrite-signature",shell=True)
    except subprocess.CalledProcessError:
        print("creating f2py signature failed")
        raise
    try:
        subprocess.check_call("f2py --f90exec=/usr/bin/gfortran --f90flags='-fPIC -O3 -funroll-loops -fno-second-underscore' -L. -lgfortran -c -m _laneemden laneemden.f90",shell=True)
    except subprocess.CalledProcessError:
        print("creating module failed")
        raise
    os.chdir(cwd)

build = False
if not os.path.exists(so_file):
    build = True
else:
    f90_file = os.path.join(path,'laneemden.f90')
    if (os.path.getctime(so_file) <  
        os.path.getctime(f90_file)):        
        build = True
    if not build:
        try:
            import laneemden
        except ImportError:
            build = True

    # check for changed compiler version (works on Fedora 18)
    if not build:
        try:
            result = subprocess.check_output("gcc --version", shell=True)
            compiler_version = (result.splitlines()[0]).split(' ',2)[2]
            result = subprocess.check_output("strings - " + so_file + " | grep GCC", shell=True)
            library_version = result.splitlines()[0].split(' ',2)[2]
            if compiler_version != library_version:
                build = True
        except:
            pass
        
if build:
    _build_module()

from laneemden import *