"""
Brian 2
"""


def _check_dependencies():
    """Check basic dependencies"""
    import sys
    missing = []
    try:
        import numpy
    except ImportError as ex:
        sys.stderr.write(f"Importing numpy failed: '{ex}'\n")
        missing.append('numpy')
    try:
        import sympy
    except ImportError as ex:
        sys.stderr.write(f"Importing sympy failed: '{ex}'\n")
        missing.append('sympy')
    try:
        import pyparsing
    except ImportError as ex:
        sys.stderr.write(f"Importing pyparsing failed: '{ex}'\n")
        missing.append('pyparsing')
    try:
        import jinja2
    except ImportError as ex:
        sys.stderr.write(f"Importing Jinja2 failed: '{ex}'\n")
        missing.append('jinja2')

    if len(missing):
        raise ImportError(f"Some required dependencies are missing:\n{', '.join(missing)}")

_check_dependencies()

try:
    from pylab import *
except ImportError:
    # Do the non-matplotlib pylab imports manually
    from numpy import *
    from numpy.fft import *
    from numpy.random import *
    from numpy.linalg import *
    import numpy.ma as ma
    # don't let numpy's datetime hide stdlib
    import datetime

from ._version import get_versions as _get_versions
__version__ = _get_versions()['version']
__release_date__ = _get_versions()['date']

if __release_date__ is not None:
    __release_date__ = __release_date__[:10]  #only use date part
__git_revision__ = _get_versions()['full-revisionid']

# Make sure that Brian's unit-aware functions are used, even when directly
# using names prefixed with numpy or np
import brian2.numpy_ as numpy
import brian2.numpy_ as np

# delete some annoying names from the namespace
if 'x' in globals():
    del x
if 'f' in globals():
    del f
if 'rate' in globals():
    del rate

__docformat__ = "restructuredtext en"

from brian2.only import *
from brian2.only import test

# Check for outdated dependency versions
def _check_dependency_version(name, version):
    from distutils.version import LooseVersion
    from .core.preferences import prefs
    from .utils.logger import get_logger
    import sys
    logger = get_logger(__name__)

    module = sys.modules[name]
    if not isinstance(module.__version__, str):  # mocked module
        return
    if not LooseVersion(module.__version__) >= LooseVersion(version):
        message = f'{name} is outdated (got version {module.__version__}, need version {version})'
        if prefs.core.outdated_dependency_error:
            raise ImportError(message)
        else:

            logger.warn(message, 'outdated_dependency')


def _check_dependency_versions():
    for name, version in [('numpy',  '1.10'),
                          ('sympy',  '1.2'),
                          ('jinja2', '2.7')]:
        _check_dependency_version(name, version)

_check_dependency_versions()

# Initialize the logging system
BrianLogger.initialize()
logger = get_logger(__name__)


# Check the caches
def _get_size_recursively(dirname):
    import os
    total_size = 0
    for dirpath, _, filenames in os.walk(dirname):
        for fname in filenames:
            # When other simulations are running, files may disappear while
            # we walk through the directory (in particular with Cython, where
            # we delete the source files after compilation by default)
            try:
                size = os.path.getsize(os.path.join(dirpath, fname))
                total_size += size
            except (OSError, IOError):
                pass  # ignore the file
    return total_size

#: Stores the cache directory for code generation targets
_cache_dirs_and_extensions = {}

def check_cache(target):
    cache_dir, _ = _cache_dirs_and_extensions.get(target, (None, None))
    if cache_dir is None:
        return
    size = _get_size_recursively(cache_dir)
    size_in_mb = int(round(size/1024./1024.))
    if size_in_mb > prefs.codegen.max_cache_dir_size:
        logger.info(f"Cache size for target '{target}': {size} MB.\n"
                    f"You can call clear_cache('{target}') to delete all "
                    f"files from the cache or manually delete files in the "
                    f"'{cache_dir}' directory.")
    else:
        logger.debug(f"Cache size for target '{target}': {size_in_mb} MB")


def clear_cache(target):
    """
    Clears the on-disk cache with the compiled files for a given code generation
    target.

    Parameters
    ----------
    target : str
        The code generation target (e.g. ``'cython'``)

    Raises
    ------
    ValueError
        If the given code generation target does not have an on-disk cache
    IOError
        If the cache directory contains unexpected files, suggesting that
        deleting it would also delete files unrelated to the cache.
    """
    import os
    import shutil
    cache_dir, extensions = _cache_dirs_and_extensions.get(target, (None, None))
    if cache_dir is None:
        raise ValueError(f'No cache directory registered for target "{target}".')
    cache_dir = os.path.abspath(cache_dir)  # just to make sure...
    for folder, _, files in os.walk(cache_dir):
        for f in files:
            for ext in extensions:
                if f.endswith(ext):
                    break
            else:
                raise IOError(f"The cache directory for target '{target}' contains "
                              f"the file '{os.path.join(folder, f)}' of an unexpected type and "
                              f"will therefore not be removed. Delete files in "
                              f"'{cache_dir}' manually")

    logger.debug(f"Clearing cache for target '{target}' (directory '{cache_dir}').")
    shutil.rmtree(cache_dir)


def _check_caches():
    from brian2.codegen.runtime.cython_rt.extension_manager import get_cython_cache_dir
    from brian2.codegen.runtime.cython_rt.extension_manager import get_cython_extensions

    for target, (dirname, extensions) in [('cython', (get_cython_cache_dir(), get_cython_extensions()))]:
        _cache_dirs_and_extensions[target] = (dirname, extensions)
        if prefs.codegen.max_cache_dir_size > 0:
            check_cache(target)

_check_caches()
