import logging
import random
from datetime import datetime

import numpy as np
import torch


def get_safe_torch_device(cfg_device: str, log: bool = False) -> torch.device:
    match cfg_device:
        case "cuda":
            assert torch.cuda.is_available()
            device = torch.device("cuda")
        case "mps":
            assert torch.backends.mps.is_available()
            device = torch.device("mps")
        case "cpu":
            device = torch.device("cpu")
            if log:
                logging.warning("Using CPU, this will be slow.")
        case _:
            device = torch.device(cfg_device)
            if log:
                logging.warning(f"Using custom {cfg_device} device.")

    return device


def set_global_seed(seed):
    """Set seed for reproducibility."""
    random.seed(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)


def init_logging():
    def custom_format(record):
        dt = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        fnameline = f"{record.pathname}:{record.lineno}"
        message = f"{record.levelname} {dt} {fnameline[-15:]:>15} {record.msg}"
        return message

    logging.basicConfig(level=logging.INFO)

    for handler in logging.root.handlers[:]:
        logging.root.removeHandler(handler)

    formatter = logging.Formatter()
    formatter.format = custom_format
    console_handler = logging.StreamHandler()
    console_handler.setFormatter(formatter)
    logging.getLogger().addHandler(console_handler)


def format_big_number(num):
    suffixes = ["", "K", "M", "B", "T", "Q"]
    divisor = 1000.0

    for suffix in suffixes:
        if abs(num) < divisor:
            return f"{num:.0f}{suffix}"
        num /= divisor

    return num