#!/usr/bin/env bash
#
# Build xmrblocks (the Onion Monero Blockchain Explorer) reproducibly.
#
# WHY THIS SCRIPT EXISTS
# ----------------------
# xmrblocks is not a client of monerod. It links 21 static libraries out of a
# compiled monero source tree and opens the LMDB directly, so building it means
# first compiling monero itself. Measured on Debian 13: a single cc1plus peaks
# at ~3.1 GB and a -j4 build peaks at ~5.5 GB. monerod-box has 2 GB, so it
# cannot build this at any level of parallelism - the binary has to be built
# elsewhere and shipped.
#
# Shipping a binary that only one machine can produce is how estates end up
# with artefacts nobody can rebuild. This script is the answer to that: it runs
# the whole build inside a debian:13 container, so any machine with Docker and
# ~6 GB of RAM produces the same binary. Nothing is installed on the host.
#
# WHAT IT GUARANTEES
#   - the monero source is the GPG-signed release tarball, verified against
#     binaryFate's key (the same chain roles/monero uses for the daemon)
#   - the explorer is pinned to an exact commit
#   - the one upstream patch is applied from an anchor, and the script FAILS
#     if the anchor is missing rather than silently skipping it
#
# WHAT IT IS NOT
#   Not bit-for-bit reproducible. Debian's toolchain, timestamps and build
#   paths all leak in. It is repeatable, not deterministic; the MANIFEST
#   records what went in so two builds can be compared.
#
# Usage:  scripts/build-xmrblocks.sh [output-dir]
# Needs:  docker, ~6 GB RAM available to it, ~2 GB disk
set -euo pipefail

# --- Pins. Change these together and rebuild. --------------------------------
MONERO_VERSION="0.18.5.1"
MONERO_SRC_TARBALL="monero-source-v${MONERO_VERSION}.tar.bz2"
MONERO_SRC_URL="https://downloads.getmonero.org/cli/${MONERO_SRC_TARBALL}"
# From the GPG-signed hashes.txt. Verified by the container, not trusted from here.
MONERO_SRC_SHA256="9ec6ed0fd37db9d81cf7738a5f0536cf9aec6ed8ef8fd48649a59a6aaf20de3d"
BINARYFATE_FPR="81AC591FE9C4B65C5806AFC3F0AF4D462A0BDF92"

EXPLORER_REPO="https://github.com/moneroexamples/onion-monero-blockchain-explorer.git"
EXPLORER_COMMIT="29593b709edeb23daba035009ccd134a5862543a"

BUILD_IMAGE="debian:13"   # must match the TARGET host's Debian release
JOBS="${JOBS:-4}"

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
SIGNING_KEY="${REPO_ROOT}/ansible/roles/monero/files/binaryfate.asc"
OUT_DIR="${1:-$HOME/personal_infra_artifacts/xmrblocks}"

command -v docker >/dev/null || { echo "docker is required" >&2; exit 1; }
[ -f "$SIGNING_KEY" ] || { echo "missing signing key: $SIGNING_KEY" >&2; exit 1; }

WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT
cp "$SIGNING_KEY" "$WORK/binaryfate.asc"
mkdir -p "$OUT_DIR"

echo "==> building xmrblocks"
echo "    monero    ${MONERO_VERSION} (signed source tarball)"
echo "    explorer  ${EXPLORER_COMMIT}"
echo "    image     ${BUILD_IMAGE}, -j${JOBS}"
echo "    output    ${OUT_DIR}"

cat > "$WORK/build.sh" <<INNER
#!/bin/bash
set -euo pipefail
export DEBIAN_FRONTEND=noninteractive
apt-get update -qq
# libasio-dev is NOT in upstream's dependency list. That list is Ubuntu-based
# and omits it; on Debian 13 Crow fails with "asio.hpp: No such file".
# libminiupnpc-dev is needed because monero stopped vendoring miniupnp as a
# submodule while the explorer's FindMonero.cmake still expects it in-tree.
apt-get install -y -qq --no-install-recommends \\
  build-essential cmake pkg-config git ca-certificates curl bzip2 gnupg \\
  libssl-dev libzmq3-dev libunbound-dev libsodium-dev libunwind-dev \\
  libreadline-dev libhidapi-dev libusb-1.0-0-dev libprotobuf-dev \\
  protobuf-compiler libboost-all-dev libcurl4-openssl-dev \\
  libasio-dev libminiupnpc-dev >/dev/null

cd /build

echo "--> verifying the monero source tarball"
export GNUPGHOME=/build/gnupg; mkdir -p \$GNUPGHOME; chmod 700 \$GNUPGHOME
gpg --batch --import /build/binaryfate.asc 2>/dev/null
gpg --batch --with-colons --fingerprint | awk -F: '/^fpr:/{print \$10}' \\
  | grep -qx "${BINARYFATE_FPR}" || { echo "signing key is not binaryFate's"; exit 1; }
curl -sSL -o hashes.txt https://www.getmonero.org/downloads/hashes.txt
gpg --batch --status-fd 2 --output hashes-verified.txt --decrypt hashes.txt 2>gpg.err
grep -q "VALIDSIG.*${BINARYFATE_FPR}" gpg.err || { echo "hashes.txt did not verify"; exit 1; }
curl -sSL -o "${MONERO_SRC_TARBALL}" "${MONERO_SRC_URL}"
ACTUAL=\$(sha256sum "${MONERO_SRC_TARBALL}" | cut -d' ' -f1)
[ "\$ACTUAL" = "${MONERO_SRC_SHA256}" ] || { echo "tarball sha mismatch"; exit 1; }
grep -Fxq "\$ACTUAL  ${MONERO_SRC_TARBALL}" hashes-verified.txt \\
  || { echo "tarball is not the one binaryFate signed"; exit 1; }
echo "    source verified against the signed hashes"

tar xjf "${MONERO_SRC_TARBALL}"
SRC=/build/monero-source-v${MONERO_VERSION}

echo "--> building the monero libraries xmrblocks links against"
# Only the libraries. Upstream's Dockerfile runs a full \`make\`, which also
# builds monerod, both wallets and the test suite - none of which are linked
# into xmrblocks. USE_DEVICE_TREZOR=OFF drops the generated protobuf units too;
# an explorer has no use for hardware wallets.
mkdir -p \$SRC/build/release && cd \$SRC/build/release
cmake -D CMAKE_BUILD_TYPE=Release -D BUILD_TESTS=OFF -D USE_DEVICE_TREZOR=OFF ../.. >/dev/null
cmake --build . -j${JOBS} --target \\
  common blocks cryptonote_basic cryptonote_core multisig cryptonote_protocol \\
  daemonizer mnemonics epee lmdb device wallet-crypto blockchain_db ringct \\
  wallet cncrypto easylogging version checkpoints randomx hardforks >/dev/null

echo "--> fetching the explorer at ${EXPLORER_COMMIT}"
cd /build
git clone -q "${EXPLORER_REPO}" explorer
cd explorer && git checkout -q "${EXPLORER_COMMIT}"

# monero v0.18.5.0 changed get_pruned_transaction_hash from returning the hash
# to returning bool with an out-param. The explorer still calls the old form,
# so it does not compile against the daemon we actually run. Anchored on the
# exact line: if upstream fixes this, the anchor vanishes and we stop loudly
# rather than building something unexpected.
OLD='        txd.hash = get_pruned_transaction_hash(tx, tx.prunable_hash);'
NEW='        get_pruned_transaction_hash(tx, tx.prunable_hash, txd.hash);'
if grep -qF "\$OLD" src/page.h; then
  sed -i "s|\$OLD|\$NEW|" src/page.h
  echo "    applied get_pruned_transaction_hash patch"
elif grep -qF "\$NEW" src/page.h; then
  echo "    upstream already uses the new signature - patch not needed"
else
  echo "PATCH ANCHOR NOT FOUND in src/page.h - upstream changed; review before building" >&2
  exit 1
fi

echo "--> building xmrblocks"
mkdir -p build && cd build
# Xmr_MINIUPNPC_LIBRARY: FindMonero.cmake searches for miniupnpc *inside* the
# monero build tree with NO_DEFAULT_PATH, but monero no longer vendors it.
# Point it at the system library instead of patching their cmake.
cmake -D MONERO_DIR=\$SRC \\
      -D Xmr_MINIUPNPC_LIBRARY=/usr/lib/x86_64-linux-gnu/libminiupnpc.a .. >/dev/null
cmake --build . -j${JOBS} >/dev/null
[ -x xmrblocks ] || { echo "no xmrblocks produced"; exit 1; }
./xmrblocks --help >/dev/null 2>&1 || true

echo "--> collecting"
install -m 0755 xmrblocks /out/xmrblocks
rm -rf /out/templates && cp -r templates /out/templates
chmod -R a+rX /out/templates

{
  echo "artifact:        xmrblocks"
  echo "built:           \$(date -u +%Y-%m-%dT%H:%M:%SZ)"
  echo "build-image:     ${BUILD_IMAGE}"
  echo "monero-version:  ${MONERO_VERSION}"
  echo "monero-src-sha:  ${MONERO_SRC_SHA256}"
  echo "explorer-commit: ${EXPLORER_COMMIT}"
  echo "cmake-flags:     USE_DEVICE_TREZOR=OFF BUILD_TESTS=OFF CMAKE_BUILD_TYPE=Release"
  echo "patches:         get_pruned_transaction_hash -> out-param form (monero >= 0.18.5.0)"
  echo "xmrblocks-sha256: \$(sha256sum /out/xmrblocks | cut -d' ' -f1)"
  echo "templates-sha256: \$(find /out/templates -type f | sort | xargs sha256sum | sha256sum | cut -d' ' -f1)"
  echo "needed-libs:"
  objdump -p /out/xmrblocks 2>/dev/null | awk '/NEEDED/{print "  " \$2}' | sort
} > /out/MANIFEST
INNER
chmod +x "$WORK/build.sh"

docker run --rm \
  -v "$WORK":/build \
  -v "$OUT_DIR":/out \
  "$BUILD_IMAGE" bash /build/build.sh

echo
echo "==> done"
sed -n '1,12p' "$OUT_DIR/MANIFEST"
echo
echo "    pin xmrblocks_sha256 in ansible/roles/xmrblocks/defaults/main.yml to:"
grep '^xmrblocks-sha256:' "$OUT_DIR/MANIFEST" | awk '{print "    " $2}'