#!/usr/bin/env bash
# download-frank-large-halogen.sh — fetch frank-large's halogen payload:
# the qwen3.8-27b .hgn checkpoint and the export tokenizer, from the
# PUBLIC peonist-ai/halogen-qwen3.8-27b repo (no token — and per the fleet
# secret law, none would ever touch argv).
#
# The fetch law, same as every sibling script: curl -f (an access error
# must not become a "successful" 153-byte artifact), exact byte count from
# the model card, LFS sha256 verification, --verify-only to re-check an
# existing payload without downloading.
set -euo pipefail

DEST="${FRANK_LARGE_MODEL_DIR:-$HOME/models/halogen-qwen3.8-27b}"
BASE="https://huggingface.co/peonist-ai/halogen-qwen3.8-27b/resolve/main"

FILES=(qwen3.8-27b-p1w4d-d2.hgn frank-large.tokenizer.gguf)
# Byte sizes and sha256 (LFS oid) as published by the Hub on 2026-10-05 —
# re-check with: curl -s "https://huggingface.co/api/models/peonist-ai/halogen-qwen3.8-27b/tree/main?recursive=true"
SIZES=(35880329102 1293343)
SHAS=(40874e7a5c27efcf1c83c44374db85726fa4086355b3c8aae1b363644d7e6234
      4c1ab3a19932f7d16eefc2c7fa60715c91133fe99c6dce683a3a7f11d463e7e9)

VERIFY_ONLY=0
[ "${1:-}" = "--verify-only" ] && VERIFY_ONLY=1

mkdir -p "$DEST"

for i in "${!FILES[@]}"; do
    f="${FILES[$i]}"; want="${SIZES[$i]}"; sha="${SHAS[$i]}"
    path="$DEST/$f"
    if [ "$VERIFY_ONLY" -eq 0 ]; then
        echo "FETCH $f -> $path"
        # -C - resumes a partial file; -f keeps HTTP errors fatal.
        curl -fL --retry 5 -C - -o "$path" "$BASE/$f"
    fi
    [ -f "$path" ] || { echo "MISSING $path (run without --verify-only)" >&2; exit 1; }
    got="$(stat -c %s "$path")"
    [ "$got" = "$want" ] || { echo "SIZE $path: $got != $want" >&2; exit 1; }
    echo "OK   $f ($got bytes)"
done

echo "byte counts match; verifying sha256 (one pass over 33.4 GiB)..."
for i in "${!FILES[@]}"; do
    f="${FILES[$i]}"; sha="${SHAS[$i]}"
    got="$(sha256sum "$DEST/$f" | cut -d' ' -f1)"
    [ "$got" = "$sha" ] || { echo "SHA256 $f: $got != $sha" >&2; exit 1; }
    echo "OK   $f sha256"
done
echo "DOWNLOAD_DONE $DEST"