#!/usr/bin/env bash
#
# Build the pinned toolchain and prove the committed oracle still reproduces.
#
#   ./tools/reference-toolchain/verify.sh          # verify the hash only
#   ./tools/reference-toolchain/verify.sh --full   # regenerate and compare
#
# --full runs all 123 cases through OpenSCAD. On the staging host that takes a
# while: the solvers are single-threaded and the CPU is old. That is expected.

set -euo pipefail

REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
IMAGE="mechcomp/reference-toolchain:8.0.0"
EXPECTED="ddd0f1548379205dd0c652ec07285b0dae331e52ff0a0437005dfc6cddcc2cb2"

echo "==> building ${IMAGE}"
docker build -t "${IMAGE}" "${REPO}/tools/reference-toolchain"

echo
echo "==> toolchain versions"
docker run --rm "${IMAGE}" openscad --version
docker run --rm "${IMAGE}" git -C /BOSL2 rev-parse HEAD 2>/dev/null \
    || echo "(BOSL2 .git removed at build time; commit is pinned by ARG)"

echo
echo "==> verifying the committed oracle"
python3 "${REPO}/fixtures/strap-beam-8.0.0/make_fixtures.py" --verify

if [[ "${1:-}" == "--full" ]]; then
    echo
    echo "==> regenerating all 123 cases inside the pinned toolchain"
    tmp="$(mktemp -d)"
    trap 'rm -rf "${tmp}"' EXIT
    cp "${REPO}/fixtures/strap-beam-8.0.0/strap-beam-fixtures-8.0.0.json" "${tmp}/before.json"

    docker run --rm -v "${REPO}:/repo" "${IMAGE}" \
        python3 /repo/fixtures/strap-beam-8.0.0/make_fixtures.py --regenerate

    echo
    echo "==> comparing against the committed oracle"
    if diff -q "${tmp}/before.json" \
            "${REPO}/fixtures/strap-beam-8.0.0/strap-beam-fixtures-8.0.0.json" >/dev/null; then
        echo "OK - byte-identical."
    else
        echo "DIFFERS from the committed oracle." >&2
        echo "The 'frozen' date changes on every regeneration, so a one-line" >&2
        echo "diff there is expected. Any other difference means the toolchain" >&2
        echo "has drifted; investigate before proceeding." >&2
        diff "${tmp}/before.json" \
             "${REPO}/fixtures/strap-beam-8.0.0/strap-beam-fixtures-8.0.0.json" | head -40 >&2 || true
        cp "${tmp}/before.json" \
           "${REPO}/fixtures/strap-beam-8.0.0/strap-beam-fixtures-8.0.0.json"
        echo >&2
        echo "The committed oracle has been restored. Nothing was overwritten." >&2
        exit 1
    fi
fi

echo
echo "expected sha256: ${EXPECTED}"