import os
import logging
import subprocess

from theano.configparser import (
        AddConfigVar, BoolParam, ConfigParam, EnumStr, IntParam,
        TheanoConfigParser)
from theano.misc.cpucount import cpuCount

_logger = logging.getLogger('theano.configdefaults')

config = TheanoConfigParser()

AddConfigVar('floatX',
        "Default floating-point precision for python casts",
        EnumStr('float64', 'float32'),
        )

AddConfigVar('cast_policy',
        "Rules for implicit type casting",
        EnumStr('custom', 'numpy+floatX',
                # The 'numpy' policy was originally planned to provide a smooth
                # transition from numpy. It was meant to behave the same as
                # numpy+floatX, but keeping float64 when numpy would. However
                # the current implementation of some cast mechanisms makes it
                # a bit more complex to add than what was expected, so it is
                # currently not available.
                #numpy,
               ),
        )

# python 2.* define int / int to return int and int // int to return int.
# python 3* define int / int to return float and int // int to return int.
# numpy 1.6.1 behaves as python 2.*. I think we should not change it faster
# than numpy. When we will do the transition, we should create an int_warn
# and floatX_warn option.
AddConfigVar('int_division',
        "What to do when one computes x / y, where both x and y are of "
        "integer types",
        EnumStr('int', 'raise', 'floatX'),
        in_c_key=False)

# gpu means let the driver select the gpu. Needed in case of gpu in
# exclusive mode.
# gpuX mean use the gpu number X.
AddConfigVar('device',
        ("Default device for computations. If gpu*, change the default to try "
         "to move computation to it and to put shared variable of float32 "
         "on it. Do not use upper case letters, only lower case even if "
         "NVIDIA use capital letters."),
        EnumStr('cpu', 'gpu',
            'gpu0', 'gpu1', 'gpu2', 'gpu3',
            'gpu4', 'gpu5', 'gpu6', 'gpu7',
            'gpu8', 'gpu9', 'gpu10', 'gpu11',
            'gpu12', 'gpu13', 'gpu14', 'gpu15',
                allow_override=False),
        in_c_key=False,
        )

AddConfigVar('init_gpu_device',
        ("Initialize the gpu device to use, works only if device=cpu. "
         "Unlike 'device', setting this option will NOT move computations, "
         "nor shared variables, to the specified GPU. "
         "It can be used to run GPU-specific tests on a particular GPU."),
        EnumStr('', 'gpu',
            'gpu0', 'gpu1', 'gpu2', 'gpu3',
            'gpu4', 'gpu5', 'gpu6', 'gpu7',
            'gpu8', 'gpu9', 'gpu10', 'gpu11',
            'gpu12', 'gpu13', 'gpu14', 'gpu15',
                allow_override=False),
        in_c_key=False)

AddConfigVar('force_device',
        "Raise an error if we can't use the specified device",
        BoolParam(False, allow_override=False),
        in_c_key=False)

AddConfigVar('print_active_device',
        "Print active device at when the GPU device is initialized.",
        BoolParam(True, allow_override=False),
        in_c_key=False)

# Do not add FAST_RUN_NOGC to this list (nor any other ALL CAPS shortcut).
# The way to get FAST_RUN_NOGC is with the flag 'linker=c|py_nogc'.
# The old all capital letter way of working is deprecated as it is not
# scalable.
# Also, please be careful not to modify the first item in the enum when adding
# new modes, since it is the default mode.
AddConfigVar('mode',
        "Default compilation mode",
        EnumStr('Mode', 'ProfileMode', 'DebugMode', 'FAST_RUN',
                'FAST_COMPILE', 'PROFILE_MODE', 'DEBUG_MODE'),
        in_c_key=False)

enum = EnumStr("g++", "")

# Test whether or not g++ is present: disable C code if it is not.
# Using the dummy file descriptor below is a workaround for a crash experienced
# in an unusual Python 2.4.4 Windows environment with the default stdin=None.
dummy_stdin = open(os.devnull)
try:
    subprocess.Popen('g++', stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                     stdin=dummy_stdin.fileno())
    # Keep the default linker the same as the one for the mode FAST_RUN
    AddConfigVar('linker',
                 ("Default linker used if the theano flags mode is Mode "
                  "or ProfileMode"),
                 EnumStr('cvm', 'c|py', 'py', 'c', 'c|py_nogc', 'c&py',
                     'vm', 'vm_nogc', 'cvm_nogc'),
                 in_c_key=False)
except OSError:
    # g++ is not present, linker should default to python only
    AddConfigVar('linker',
                 ("Default linker used if the theano flags mode is Mode "
                  "or ProfileMode"),
                 EnumStr('py', 'vm', 'vm_nogc'),
                 in_c_key=False)
    _logger.warning('g++ not detected ! Theano will be unable to execute '
            'optimized C-implementations (for both CPU and GPU) and will '
            'default to Python implementations. Performance will be severely '
            'degraded.')
    enum = EnumStr("")

del dummy_stdin
AddConfigVar('cxx',
             "The c++ compiler to use. Currently only g++ is"
             " supported. But supporting more is easy if someone want this."
             "If it is empty, we don't compile c++ code.",
             enum,
             in_c_key=False)
del enum


#Keep the default value the same as the one for the mode FAST_RUN
AddConfigVar('allow_gc',
             "Do we default to delete intermediate results during Theano"
             " function calls? Doing so lowers the memory requirement, but"
             " asks that we reallocate memory at the next function call."
             " This is implemented for the default linker, but may not work"
             " for all linkers.",
             BoolParam(True),
             in_c_key=False)

#Keep the default optimizer the same as the one for the mode FAST_RUN
AddConfigVar('optimizer',
        ("Default optimizer. If not None, will use this linker with the Mode "
         "object (not ProfileMode or DebugMode)"),
        EnumStr('fast_run', 'merge', 'fast_compile', 'None'),
        in_c_key=False)

AddConfigVar('on_opt_error',
        ("What to do when an optimization crashes: warn and skip it, or raise "
         "the exception"),
        EnumStr('warn', 'raise'),
        in_c_key=False)


def safe_no_home(home):
    """
    Make sure the user is not attempting to use `config.home`.

    This config option was removed in Thenao 0.5 since it was redundant with
    `config.base_compiledir`. This filter function ensures people who were
    setting the location of their compilation directory through `config.home`
    switch to `config.basecompiledir` instead, by raising an error when
    `config.home` is used.
    """
    if home:
        raise RuntimeError(
                'The `config.home` option has been removed and should not be '
                'used anymore. Please set the `config.base_compiledir` option '
                'instead (for instance to: %s)' %
                os.path.join(home, '.theano'))
    return True


AddConfigVar('home',
        "This config option was removed in 0.5: do not use it!",
        ConfigParam('', allow_override=False, filter=safe_no_home),
        in_c_key=False)


AddConfigVar('nocleanup',
        "Suppress the deletion of code files that did not compile cleanly",
        BoolParam(False),
        in_c_key=False)

AddConfigVar('on_unused_input',
             "What to do if a variable in the 'inputs' list of "
             " theano.function() is not used in the graph.",
             EnumStr('raise', 'warn', 'ignore'),
             in_c_key=False)

# This flag is used when we import Theano to initialize global variables.
# So changing it after import will not modify these global variables.
# This could be done differently... but for now we simply prevent it from being
# changed at runtime.
AddConfigVar('tensor.cmp_sloppy',
        "Relax tensor._allclose (0) not at all, (1) a bit, (2) more",
        IntParam(0, lambda i: i in (0, 1, 2), allow_override=False),
        in_c_key=False)

AddConfigVar('tensor.local_elemwise_fusion',
        ("Enable or not in fast_run mode(fast_run optimization) the elemwise "
         "fusion optimization"),
        BoolParam(True),
        in_c_key=False)

AddConfigVar('gpu.local_elemwise_fusion',
        ("Enable or not in fast_run mode(fast_run optimization) the gpu "
         "elemwise fusion optimization"),
        BoolParam(True),
        in_c_key=False)

#http://developer.amd.com/CPU/LIBRARIES/LIBM/Pages/default.aspx
AddConfigVar('lib.amdlibm',
        "Use amd's amdlibm numerical library",
        BoolParam(False))

AddConfigVar('op.set_flops',
        ("currently used only in ConvOp. The profile mode will print the "
         "flops/s for the op."),
        BoolParam(False),
        in_c_key=False)

AddConfigVar('gpuelemwise.sync',
        "when true, wait that the gpu fct finished and check it error code.",
        BoolParam(True))

AddConfigVar('traceback.limit',
             "The number of stack to trace. -1 mean all.",
             IntParam(5),
             in_c_key=False)

AddConfigVar('experimental.mrg',
             "Another random number generator that work on the gpu",
             BoolParam(False))

AddConfigVar('numpy.seterr_all',
             ("Sets numpy's behaviour for floating-point errors, ",
              "see numpy.seterr. "
              "'None' means not to change numpy's default, which can be "
              "different for different numpy releases. "
              "This flag sets the default behaviour for all kinds of floating-"
              "point errors, its effect can be overriden for specific errors "
              "by the following flags: seterr_divide, seterr_over, "
              "seterr_under and seterr_invalid."),
             EnumStr('ignore', 'warn', 'raise', 'call', 'print', 'log', 'None',
                 allow_override=False),
             in_c_key=False)

AddConfigVar('numpy.seterr_divide',
             ("Sets numpy's behavior for division by zero, see numpy.seterr. "
              "'None' means using the default, defined by numpy.seterr_all."),
             EnumStr('None', 'ignore', 'warn', 'raise', 'call', 'print', 'log',
                 allow_override=False),
             in_c_key=False)

AddConfigVar('numpy.seterr_over',
             ("Sets numpy's behavior for floating-point overflow, "
              "see numpy.seterr. "
              "'None' means using the default, defined by numpy.seterr_all."),
             EnumStr('None', 'ignore', 'warn', 'raise', 'call', 'print', 'log',
                 allow_override=False),
             in_c_key=False)

AddConfigVar('numpy.seterr_under',
             ("Sets numpy's behavior for floating-point underflow, "
              "see numpy.seterr. "
              "'None' means using the default, defined by numpy.seterr_all."),
             EnumStr('None', 'ignore', 'warn', 'raise', 'call', 'print', 'log',
                 allow_override=False),
             in_c_key=False)

AddConfigVar('numpy.seterr_invalid',
             ("Sets numpy's behavior for invalid floating-point operation, "
              "see numpy.seterr. "
              "'None' means using the default, defined by numpy.seterr_all."),
             EnumStr('None', 'ignore', 'warn', 'raise', 'call', 'print', 'log',
                 allow_override=False),
             in_c_key=False)

###
### To disable some warning about old bug that are fixed now.
###
AddConfigVar('warn.ignore_bug_before',
             ("If 'None', we warn about all Theano bugs found by default. "
              "If 'all', we don't warn about Theano bugs found by default. "
              "If a version, we print only the warnings relative to Theano "
              "bugs found after that version. "
              "Warning for specific bugs can be configured with specific "
              "[warn] flags."),
             EnumStr('None', 'all', '0.3', '0.4', '0.4.1', '0.5', '0.6',
                     allow_override=False),
             in_c_key=False)


def warn_default(version):
    """
    Return True iff we should warn about bugs fixed after a given version.
    """
    if config.warn.ignore_bug_before == 'None':
        return True
    if config.warn.ignore_bug_before == 'all':
        return False
    if config.warn.ignore_bug_before >= version:
        return False
    return True


AddConfigVar('warn.argmax_pushdown_bug',
             ("Warn if in past version of Theano we generated a bug with the "
              "theano.tensor.nnet.nnet.local_argmax_pushdown optimization. "
              "Was fixed 27 may 2010"),
             BoolParam(warn_default('0.3')),
             in_c_key=False)

AddConfigVar('warn.gpusum_01_011_0111_bug',
             ("Warn if we are in a case where old version of Theano had a "
              "silent bug with GpuSum pattern 01,011 and 0111 when the first "
              "dimensions was bigger then 4096. Was fixed 31 may 2010"),
             BoolParam(warn_default('0.3')),
             in_c_key=False)

AddConfigVar('warn.sum_sum_bug',
             ("Warn if we are in a case where Theano version between version "
              "9923a40c7b7a and the 2 august 2010 (fixed date), generated an "
              "error in that case. This happens when there are 2 consecutive "
              "sums in the graph, bad code was generated. "
              "Was fixed 2 August 2010"),
             BoolParam(warn_default('0.3')),
             in_c_key=False)

AddConfigVar('warn.sum_div_dimshuffle_bug',
             ("Warn if previous versions of Theano (between rev. "
              "3bd9b789f5e8, 2010-06-16, and cfc6322e5ad4, 2010-08-03) "
              "would have given incorrect result. This bug was triggered by "
              "sum of division of dimshuffled tensors."),
             BoolParam(warn_default('0.3')),
             in_c_key=False)

AddConfigVar('warn.subtensor_merge_bug',
        "Warn if previous versions of Theano (before 0.5rc2) could have given "
        "incorrect results when indexing into a subtensor with negative "
        "stride (for instance, for instance, x[a:b:-1][c]).",
        BoolParam(warn_default('0.5')),
        in_c_key=False)

AddConfigVar('warn.gpu_set_subtensor1',
        "Warn if previous versions of Theano (before 0.6) could have given "
        "incorrect results when moving to the gpu "
        "set_subtensor(x[int vector], new_value)",
        BoolParam(warn_default('0.6')),
        in_c_key=False)

AddConfigVar('warn.vm_gc_bug',
        "There was a bug that existed in the default Theano configuration,"
        " only in the development version between July 5th 2012"
        " and July 30th 2012. This was not in a released version."
        " If your code was affected by this bug, a warning"
        " will be printed during the code execution if you use the"
        " `linker=vm,vm.lazy=True,warn.vm_gc_bug=True` Theano flags."
        " This warning is disabled by default as the bug was not released.",
        BoolParam(False),
        in_c_key=False)

AddConfigVar('compute_test_value',
        ("If 'True', Theano will run each op at graph build time, using "
         "Constants, SharedVariables and the tag 'test_value' as inputs "
         "to the function. This helps the user track down problems in the "
         "graph before it gets optimized."),
        EnumStr('off', 'ignore', 'warn', 'raise'),
        in_c_key=False)


"""Note to developers:
    Generally your exceptions should use an apply node's __str__
    method when exception_verbosity == 'low'. When exception_verbosity
    == 'high', you should include a call to printing.min_informative_str
    on all important apply nodes.
"""
AddConfigVar('exception_verbosity',
        "If 'low', the text of exceptions will generally refer " \
        + "to apply nodes with short names such as " \
        + "Elemwise{add_no_inplace}. If 'high', some exceptions " \
        + "will also refer to apply nodes with long descriptions " \
        + """ like:
        A. Elemwise{add_no_inplace}
                B. log_likelihood_v_given_h
                C. log_likelihood_h""",
        EnumStr('low', 'high'),
        in_c_key=False)

#Test if the env variable is set
var = os.getenv('OMP_NUM_THREADS', None)
if var:
    try:
        int(var)
    except ValueError:
        raise TypeError("The environment variable OMP_NUM_THREADS"
                        " should be a number, got '%s'." % var)
    else:
        default_openmp = not int(var) == 1
else:
    #Check the number of cores availables.
    count = cpuCount()
    if count == -1:
        _logger.warning("We are not able to detect the number of CPU cores."
                        " We disable openmp by default. To remove this"
                        " warning, set the environment variable"
                        " OMP_NUM_THREADS to the number of threads you"
                        " want theano to use.")
    default_openmp = count > 1

AddConfigVar('openmp',
             "Allow (or not) parallel computation on the CPU with OpenMP. "
             "This is the default value used when creating an Op that "
             "supports OpenMP parallelization. It is preferable to define it "
             "via the Theano configuration file ~/.theanorc or with the "
             "environment variable THEANO_FLAGS. Parallelization is only "
             "done for some operations that implement it, and even for "
             "operations that implement parallelism, each operation is free "
             "to respect this flag or not. You can control the number of "
             "threads used with the environment variable OMP_NUM_THREADS."
             " If it is set to 1, we disable openmp in Theano by default.",
             BoolParam(default_openmp),
             in_c_key=False,
         )
