"""Shared helpers for the root-cause diagnostic (docs/ROOT_CAUSE.md)."""
import sys
from pathlib import Path

import torch

ROOT = Path(__file__).resolve().parents[3]
sys.path.insert(0, str(ROOT)); sys.path.insert(0, str(ROOT / "tools"))
from chat_atom_native import load_model  # noqa: E402,F401
from src.io.atomizer import Atomizer  # noqa: E402,F401

CKPT = str(ROOT / "checkpoints/byte_tick_fieldsat/atom_native_step_4996000_d32_ms1M_lrd_b4828_fieldsat.pt")
PROMPTS = ["Bonjour, comment ça va ?", "Qui es-tu ?", "Il était une fois"]
OFFSETS = [("data/corpus_fr_medium.txt", o) for o in (50_000, 200_000, 400_000)] + [("data/corpus_fr_medium_s21.txt", 250_000)]
N = 512


def val_windows_bytes():
    """Exactly the 2048-transition val of docs/artifacts/field_leak_spectrum/eval_windows.py:
    4 windows, text=raw[off:off+2048] decoded ignore, first 513 bytes (byte-tick packets)."""
    out = []
    for p, off in OFFSETS:
        raw = (ROOT / p).read_bytes()
        text = raw[off: off + 4 * N].decode("utf-8", errors="ignore")
        b = text.encode("utf-8")[: N + 1]
        out.append(b)
    return out


def corpus_bytes():
    return b"".join((ROOT / f).read_bytes() for f in ("data/corpus_fr_medium.txt", "data/corpus_fr_medium_s21.txt"))