#!/usr/bin/env bash
# Build the npm package @transaction-science/wai-quantum: the quantum job service's
# engine for WebAssembly (wai/wai-web with its quantum_engine feature), its JavaScript
# bindings, and this folder's package.json and README, packed as one tarball:
#
#   bash wai/wai-quantum-js/build.sh OUT_DIR
#
# Writes OUT_DIR/package/ (the package's files) and OUT_DIR/<name>-<version>.tgz, and
# prints the tarball's SHA-256. It needs Rust with the wasm32-unknown-unknown target,
# wasm-bindgen 0.2.127 (the version wai-web's lock file pins) and npm. Paths are
# remapped out of the binary, and the build is refused if a local path is left in the
# files it ships.
set -euo pipefail
if [ $# -ne 1 ]; then
  echo "usage: bash wai/wai-quantum-js/build.sh OUT_DIR" >&2
  exit 2
fi
here=$(cd "$(dirname "$0")" && pwd)
root=$(cd "$here/../.." && pwd)
web="$root/wai/wai-web"
mkdir -p "$1"
out=$(cd "$1" && pwd)
sha256() { if command -v sha256sum >/dev/null 2>&1; then sha256sum "$1"; else shasum -a 256 "$1"; fi; }

want=$(sed -n '/^name = "wasm-bindgen"$/{n;s/^version = "\(.*\)"$/\1/p;}' "$web/Cargo.lock")
have=$(wasm-bindgen --version | cut -d' ' -f2)
[ "$have" = "$want" ] || { echo "build.sh: wasm-bindgen is $have; wai-web's lock file pins $want" >&2; exit 1; }

target=${CARGO_TARGET_DIR:-"$web/target"}
sysroot=$(cd "$web" && rustc --print sysroot)
commit=$(cd "$web" && rustc -vV | sed -n 's/^commit-hash: //p')
export RUSTFLAGS="--remap-path-prefix=$root=/open-standards --remap-path-prefix=${CARGO_HOME:-$HOME/.cargo}=/cargo --remap-path-prefix=$sysroot/lib/rustlib/src/rust=/rustc/$commit"
(cd "$web" && cargo build --locked --release --target wasm32-unknown-unknown --features quantum_engine)

pkg="$out/package"
rm -rf "$pkg"
mkdir -p "$pkg"
wasm-bindgen --target web --out-dir "$pkg" --out-name wai_quantum "$target/wasm32-unknown-unknown/release/wai_web.wasm"
cp "$here/package.json" "$here/README.md" "$pkg/"
cp "$root/wai/LICENSE" "$pkg/LICENSE"

# Nothing the package ships names the machine that built it.
for leak in "$HOME" /Users/ /home/ /Volumes/ /private/; do
  if grep -r -q -a -F "$leak" "$pkg"/wai_quantum*; then
    echo "build.sh: '$leak' is in the package's bindings or binary" >&2
    exit 1
  fi
done

rm -f "$out"/*.tgz
npm pack "$pkg" --pack-destination "$out" --silent > /dev/null
tgz=$(ls "$out"/*.tgz)
echo "wasm: $(wc -c < "$pkg/wai_quantum_bg.wasm" | tr -d ' ') bytes"
sha256 "$tgz"