import torch


class DeviceManager(object):
    _instance = None

    @classmethod
    def get_instance(cls):
        if cls._instance is None:
            cls._instance = cls()
        return cls._instance

    def __init__(self):
        self.gpu_num = torch.cuda.device_count()
        self.mps_enabled: bool = (
            getattr(torch.backends, "mps", None) is not None
            and torch.backends.mps.is_available()
        )

    def getDevice(self, id: int):
        if id < 0 or (self.gpu_num == 0 and self.mps_enabled is False):
            dev = torch.device("cpu")
        elif self.mps_enabled:
            dev = torch.device("mps")
        else:
            dev = torch.device("cuda", index=id)
        return dev

    def halfPrecisionAvailable(self, id: int):
        if self.gpu_num == 0:
            return False
        if id < 0:
            return False

        gpuName = torch.cuda.get_device_name(id).upper()

        # original: https://github.com/RVC-Project/Retrieval-based-Voice-Conversion-WebUI/blob/main/config.py
        if (
            ("16" in gpuName and "V100" not in gpuName)
            or "P40" in gpuName.upper()
            or "1070" in gpuName
            or "1080" in gpuName
        ):
            return False

        return True