"""
Nose test running.

This module implements ``test()`` and ``bench()`` functions for NumPy modules.

"""
from __future__ import division, absolute_import, print_function

import os
import sys
import warnings
from numpy.compat import basestring
import numpy as np

from .utils import import_nose, suppress_warnings


__all__ = ['get_package_name', 'run_module_suite', 'NoseTester',
           '_numpy_tester', 'get_package_name', 'import_nose',
           'suppress_warnings']


def get_package_name(filepath):
    """
    Given a path where a package is installed, determine its name.

    Parameters
    ----------
    filepath : str
        Path to a file. If the determination fails, "numpy" is returned.

    Examples
    --------
    >>> np.testing.nosetester.get_package_name('nonsense')
    'numpy'

    """

    fullpath = filepath[:]
    pkg_name = []
    while 'site-packages' in filepath or 'dist-packages' in filepath:
        filepath, p2 = os.path.split(filepath)
        if p2 in ('site-packages', 'dist-packages'):
            break
        pkg_name.append(p2)

    # if package name determination failed, just default to numpy/scipy
    if not pkg_name:
        if 'scipy' in fullpath:
            return 'scipy'
        else:
            return 'numpy'

    # otherwise, reverse to get correct order and return
    pkg_name.reverse()

    # don't include the outer egg directory
    if pkg_name[0].endswith('.egg'):
        pkg_name.pop(0)

    return '.'.join(pkg_name)


def run_module_suite(file_to_run=None, argv=None):
    """
    Run a test module.

    Equivalent to calling ``$ nosetests <argv> <file_to_run>`` from
    the command line

    Parameters
    ----------
    file_to_run : str, optional
        Path to test module, or None.
        By default, run the module from which this function is called.
    argv : list of strings
        Arguments to be passed to the nose test runner. ``argv[0]`` is
        ignored. All command line arguments accepted by ``nosetests``
        will work. If it is the default value None, sys.argv is used.

        .. versionadded:: 1.9.0

    Examples
    --------
    Adding the following::

        if __name__ == "__main__" :
            run_module_suite(argv=sys.argv)

    at the end of a test module will run the tests when that module is
    called in the python interpreter.

    Alternatively, calling::

    >>> run_module_suite(file_to_run="numpy/tests/test_matlib.py")  # doctest: +SKIP

    from an interpreter will run all the test routine in 'test_matlib.py'.
    """
    if file_to_run is None:
        f = sys._getframe(1)
        file_to_run = f.f_locals.get('__file__', None)
        if file_to_run is None:
            raise AssertionError

    if argv is None:
        argv = sys.argv + [file_to_run]
    else:
        argv = argv + [file_to_run]

    nose = import_nose()
    from .noseclasses import KnownFailurePlugin
    nose.run(argv=argv, addplugins=[KnownFailurePlugin()])


class NoseTester(object):
    """
    Nose test runner.

    This class is made available as numpy.testing.Tester, and a test function
    is typically added to a package's __init__.py like so::

      from numpy.testing import Tester
      test = Tester().test

    Calling this test function finds and runs all tests associated with the
    package and all its sub-packages.

    Attributes
    ----------
    package_path : str
        Full path to the package to test.
    package_name : str
        Name of the package to test.

    Parameters
    ----------
    package : module, str or None, optional
        The package to test. If a string, this should be the full path to
        the package. If None (default), `package` is set to the module from
        which `NoseTester` is initialized.
    raise_warnings : None, str or sequence of warnings, optional
        This specifies which warnings to configure as 'raise' instead
        of being shown once during the test execution.  Valid strings are:

          - "develop" : equals ``(Warning,)``
          - "release" : equals ``()``, don't raise on any warnings.

        Default is "release".
    depth : int, optional
        If `package` is None, then this can be used to initialize from the
        module of the caller of (the caller of (...)) the code that
        initializes `NoseTester`. Default of 0 means the module of the
        immediate caller; higher values are useful for utility routines that
        want to initialize `NoseTester` objects on behalf of other code.

    """
    def __init__(self, package=None, raise_warnings="release", depth=0,
                 check_fpu_mode=False):
        # Back-compat: 'None' used to mean either "release" or "develop"
        # depending on whether this was a release or develop version of
        # numpy. Those semantics were fine for testing numpy, but not so
        # helpful for downstream projects like scipy that use
        # numpy.testing. (They want to set this based on whether *they* are a
        # release or develop version, not whether numpy is.) So we continue to
        # accept 'None' for back-compat, but it's now just an alias for the
        # default "release".
        if raise_warnings is None:
            raise_warnings = "release"

        package_name = None
        if package is None:
            f = sys._getframe(1 + depth)
            package_path = f.f_locals.get('__file__', None)
            if package_path is None:
                raise AssertionError
            package_path = os.path.dirname(package_path)
            package_name = f.f_locals.get('__name__', None)
        elif isinstance(package, type(os)):
            package_path = os.path.dirname(package.__file__)
            package_name = getattr(package, '__name__', None)
        else:
            package_path = str(package)

        self.package_path = package_path

        # Find the package name under test; this name is used to limit coverage
        # reporting (if enabled).
        if package_name is None:
            package_name = get_package_name(package_path)
        self.package_name = package_name

        # Set to "release" in constructor in maintenance branches.
        self.raise_warnings = raise_warnings

        # Whether to check for FPU mode changes
        self.check_fpu_mode = check_fpu_mode

    def _test_argv(self, label, verbose, extra_argv):
        ''' Generate argv for nosetest command

        Parameters
        ----------
        label : {'fast', 'full', '', attribute identifier}, optional
            see ``test`` docstring
        verbose : int, optional
            Verbosity value for test outputs, in the range 1-10. Default is 1.
        extra_argv : list, optional
            List with any extra arguments to pass to nosetests.

        Returns
        -------
        argv : list
            command line arguments that will be passed to nose
        '''
        argv = [__file__, self.package_path, '-s']
        if label and label != 'full':
            if not isinstance(label, basestring):
                raise TypeError('Selection label should be a string')
            if label == 'fast':
                label = 'not slow'
            argv += ['-A', label]
        argv += ['--verbosity', str(verbose)]

        # When installing with setuptools, and also in some other cases, the
        # test_*.py files end up marked +x executable. Nose, by default, does
        # not run files marked with +x as they might be scripts. However, in
        # our case nose only looks for test_*.py files under the package
        # directory, which should be safe.
        argv += ['--exe']

        if extra_argv:
            argv += extra_argv
        return argv

    def _show_system_info(self):
        nose = import_nose()

        import numpy
        print("NumPy version %s" % numpy.__version__)
        relaxed_strides = numpy.ones((10, 1), order="C").flags.f_contiguous
        print("NumPy relaxed strides checking option:", relaxed_strides)
        npdir = os.path.dirname(numpy.__file__)
        print("NumPy is installed in %s" % npdir)

        if 'scipy' in self.package_name:
            import scipy
            print("SciPy version %s" % scipy.__version__)
            spdir = os.path.dirname(scipy.__file__)
            print("SciPy is installed in %s" % spdir)

        pyversion = sys.version.replace('\n', '')
        print("Python version %s" % pyversion)
        print("nose version %d.%d.%d" % nose.__versioninfo__)

    def _get_custom_doctester(self):
        """ Return instantiated plugin for doctests

        Allows subclassing of this class to override doctester

        A return value of None means use the nose builtin doctest plugin
        """
        from .noseclasses import NumpyDoctest
        return NumpyDoctest()

    def prepare_test_args(self, label='fast', verbose=1, extra_argv=None,
                          doctests=False, coverage=False, timer=False):
        """
        Run tests for module using nose.

        This method does the heavy lifting for the `test` method. It takes all
        the same arguments, for details see `test`.

        See Also
        --------
        test

        """
        # fail with nice error message if nose is not present
        import_nose()
        # compile argv
        argv = self._test_argv(label, verbose, extra_argv)
        # our way of doing coverage
        if coverage:
            argv += ['--cover-package=%s' % self.package_name, '--with-coverage',
                   '--cover-tests', '--cover-erase']

        if timer:
            if timer is True:
                argv += ['--with-timer']
            elif isinstance(timer, int):
                argv += ['--with-timer', '--timer-top-n', str(timer)]

        # construct list of plugins
        import nose.plugins.builtin
        from nose.plugins import EntryPointPluginManager
        from .noseclasses import (KnownFailurePlugin, Unplugger,
                                  FPUModeCheckPlugin)
        plugins = [KnownFailurePlugin()]
        plugins += [p() for p in nose.plugins.builtin.plugins]
        if self.check_fpu_mode:
            plugins += [FPUModeCheckPlugin()]
            argv += ["--with-fpumodecheckplugin"]
        try:
            # External plugins (like nose-timer)
            entrypoint_manager = EntryPointPluginManager()
            entrypoint_manager.loadPlugins()
            plugins += [p for p in entrypoint_manager.plugins]
        except ImportError:
            # Relies on pkg_resources, not a hard dependency
            pass

        # add doctesting if required
        doctest_argv = '--with-doctest' in argv
        if doctests == False and doctest_argv:
            doctests = True
        plug = self._get_custom_doctester()
        if plug is None:
            # use standard doctesting
            if doctests and not doctest_argv:
                argv += ['--with-doctest']
        else:  # custom doctesting
            if doctest_argv:  # in fact the unplugger would take care of this
                argv.remove('--with-doctest')
            plugins += [Unplugger('doctest'), plug]
            if doctests:
                argv += ['--with-' + plug.name]
        return argv, plugins

    def test(self, label='fast', verbose=1, extra_argv=None,
             doctests=False, coverage=False, raise_warnings=None,
             timer=False):
        """
        Run tests for module using nose.

        Parameters
        ----------
        label : {'fast', 'full', '', attribute identifier}, optional
            Identifies the tests to run. This can be a string to pass to
            the nosetests executable with the '-A' option, or one of several
            special values.  Special values are:

            * 'fast' - the default - which corresponds to the ``nosetests -A``
              option of 'not slow'.
            * 'full' - fast (as above) and slow tests as in the
              'no -A' option to nosetests - this is the same as ''.