#!/bin/bash
# bleach_zuse_img.sh - Reset disk/zuse.img back to pristine/unminted state.
#
# disk/zuse.img simulates the physical Zuse superuser thumbdrive for QEMU
# testing (FABRIC-3.md, Phase 8 kickoff). "Bleaching" it means restoring the
# all-zero blank state homeblocks_sig_check() reads as HOMEBLOCKS_SIG_BLANK
# -- i.e. simulating a genuine first boot, so the one-time mint-Zuse flow can
# be exercised repeatedly during development without hand-regenerating the
# whole image each time.
#
# Deliberately a flat/raw image, not GPT-partitioned, matching the same
# simplifying assumption homeblocks_sig_check()'s current call site in
# repl.c uses (sig_start_fblock=0) -- both will need to move to a real
# GPT-partition-relative offset together, once a GPT parser exists. Not
# invented ahead of that work here.
#
# Usage: scripts/bleach_zuse_img.sh [path]
#   path  Optional override; defaults to disk/zuse.img relative to repo root.

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
IMG="${1:-$REPO_ROOT/disk/zuse.img}"
SIZE_MB=64

if [ -e "$IMG" ] && [ ! -f "$IMG" ]; then
    echo "bleach_zuse_img: refusing to overwrite non-regular-file '$IMG'" >&2
    exit 1
fi

dd if=/dev/zero of="$IMG" bs=1M count="$SIZE_MB" status=none
echo "bleach_zuse_img: $IMG reset to ${SIZE_MB}MB blank (pristine/unminted)"