import os

from .builder import Builder, get_cuda_cc_flag


class ScaledSoftmaxBuilder(Builder):

    def __init__(self):
        self.base_dir = "colossalai/kernel/cuda_native/csrc"
        self.name = 'scaled_upper_triang_masked_softmax'
        super().__init__()

    def include_dirs(self):
        ret = []
        ret = [os.path.join(self.base_dir, "includes"), self.get_cuda_home_include()]
        ret.append(os.path.join(self.base_dir, "kernels", "include"))
        return [self.colossalai_src_path(path) for path in ret]

    def sources_files(self):
        ret = [
            os.path.join(self.base_dir, fname)
            for fname in ['scaled_upper_triang_masked_softmax.cpp', 'scaled_upper_triang_masked_softmax_cuda.cu']
        ]
        return [self.colossalai_src_path(path) for path in ret]

    def cxx_flags(self):
        return ['-O3']

    def nvcc_flags(self):
        extra_cuda_flags = [
            '-U__CUDA_NO_HALF_OPERATORS__', '-U__CUDA_NO_HALF_CONVERSIONS__', '--expt-relaxed-constexpr',
            '--expt-extended-lambda'
        ]
        extra_cuda_flags.extend(get_cuda_cc_flag())
        ret = ['-O3', '--use_fast_math'] + extra_cuda_flags
        return ret
