import os
import sys
import subprocess
import shlex
import shutil
import sys
import time
import datetime

HERE = os.path.abspath(os.path.dirname(__file__))

# ------------------------------------------------------------------------------


# we do not use the nicer sys.version_info.major
# for compatibility with Python < 2.7
if sys.version_info[0] > 2:
    import urllib.request

    class URLopener(urllib.request.FancyURLopener):
        def http_error_default(self, url, fp, errcode, errmsg, headers):
            sys.stderr.write("ERROR: could not fetch %s\n" % url)
            sys.exit(-1)
else:
    import urllib

    class URLopener(urllib.FancyURLopener):
        def http_error_default(self, url, fp, errcode, errmsg, headers):
            sys.stderr.write("ERROR: could not fetch %s\n" % url)
            sys.exit(-1)

# ------------------------------------------------------------------------------


def fetch_url(src, dst):
    """
    Fetch file from URL src and save it to dst.
    """
    dirname = os.path.dirname(dst)
    if dirname != '':
        if not os.path.isdir(dirname):
            os.makedirs(dirname)

    opener = URLopener()
    opener.retrieve(src, dst)

# ------------------------------------------------------------------------------


def exe(command):
    """
    Executes command and returns string representations of stdout and stderr captured from the console.
    When universal_newlines=True stdout and stderr are opened in text mode.
    Otherwise, they are opened in binary mode. In that case captured stdout and stderr
    are not strings and Python 3 throws type error when compared against strings later in tests.
    Note:
    This feature is only available if Python is built with universal newline support (the default).
    Also, the newlines attribute of the file objects stdout, stdin and stderr are not updated by the
    communicate() method.
    See https://docs.python.org/2/library/subprocess.html
    """
    stdout, stderr = subprocess.Popen(shlex.split(command),
                                      stdout=subprocess.PIPE,
                                      stderr=subprocess.PIPE,
                                      universal_newlines=True).communicate()

    if stderr:
        sys.stderr.write(stderr)

    return stdout, stderr

# ------------------------------------------------------------------------------


def configure_build_and_exe(name, setup_command):

    stamp = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d-%H-%M-%S')

    os.chdir(os.path.join(HERE, name, 'cmake'))
    shutil.copy(os.path.join('..', '..', '..', 'update.py'), 'update.py')
    if not os.path.exists('lib'):
        os.makedirs('lib')
    shutil.copy(os.path.join('..', '..', '..', 'lib', 'config.py'), 'lib')
    fetch_url(src='https://github.com/docopt/docopt/raw/master/docopt.py',
              dst='lib/docopt.py')
    stdout, stderr = exe('python update.py ..')
    os.chdir(os.path.join(HERE, name))

    if sys.platform == 'win32':
        setup_command += ' --generator="MinGW Makefiles"'

    setup_command += ' build-%s' % stamp

    stdout, stderr = exe(setup_command)

    os.chdir(os.path.join(HERE, name, 'build-%s' % stamp))

    if sys.platform == 'win32':
        stdout, stderr = exe('mingw32-make')
        stdout, stderr = exe('bin\\\example.exe')
    else:
        stdout, stderr = exe('make')
        stdout, stderr = exe('./bin/example')

    return stdout, stderr

# ------------------------------------------------------------------------------


def test_cxx_custom():
    stdout, stderr = configure_build_and_exe('cxx_custom', 'python setup.py --cxx=g++')
    assert 'Hello World!' in stdout

# ------------------------------------------------------------------------------


def test_cxx():
    stdout, stderr = configure_build_and_exe('cxx', 'python setup.py --cxx=g++')
    assert 'Hello World!' in stdout

# ------------------------------------------------------------------------------


def test_fc():
    stdout, stderr = configure_build_and_exe('fc', 'python setup.py --fc=gfortran')
    assert 'Hello World!' in stdout

# ------------------------------------------------------------------------------


def test_fc_blas():
    if sys.platform != 'win32':
        stdout, stderr = configure_build_and_exe('fc_blas', 'python setup.py --fc=gfortran --blas=auto')
        assert 'dgemm test ok' in stdout
    else:
        pass