"""Shared config and paths for DecoyFace."""
from pathlib import Path

import torch

CKPT = Path(__file__).resolve().parent / "checkpoints"
ADAFACE_CKPT = CKPT / "adaface_ir50_ms1mv2.backbone.pth"

# DecoyFace hyper-parameters (paper Sec. V-B "Implementation Details").
CFG = {
    "C": 64,
    "r": 32,          # RSS rank
    "G": 16,          # groups
    "K": 3,           # preserved true-sample groups
    "M": 5000,        # auxiliary complementary bank size
    "sc_lo": 8, "sc_hi": 12,   # coherent subset size s_c ~ U[8,12]
    "L_lo": 2, "L_hi": 4,      # shared source count L ~ U[2,4]
    "t": 3,           # random scale exponent k ~ U[-3,3]
    "q": 0.95,        # quantile
    "tau_s": 0.8,     # server target magnitude
    "eps": 1e-6,
}

DEVICE = "cuda:0"


def fixed_perm(C=64, seed=1234):
    g = torch.Generator().manual_seed(seed)
    return torch.randperm(C, generator=g)