#!/bin/bash
# Build the shared rules (core/) for the browser: a release WebAssembly module
# plus its wasm-bindgen ES module glue and TypeScript declarations.
#
# Usage: core/wasm/build.sh [OUT_DIR]      (default: core/wasm/pkg)
#
# Requires Rust 1.88+ with the wasm32-unknown-unknown target and
# wasm-bindgen-cli at exactly the version Cargo.lock pins for wasm-bindgen.
# Reads CARGO_HOME (default ~/.cargo) only to remap its paths; it replaces
# any RUSTFLAGS for this build. OUT_DIR is replaced only after both steps pass.
set -euo pipefail
[ $# -le 1 ] || { sed -n '2,/^set -e/p' "$0" | sed '$d;s/^# \{0,1\}//' >&2; exit 2; }
HERE=$(cd "$(dirname "$0")" && pwd)
OUT=$(realpath -m "${1:-$HERE/pkg}")
command -v cargo >/dev/null || { echo "core/wasm/build.sh: cargo is required (Rust 1.88+)" >&2; exit 2; }
command -v wasm-bindgen >/dev/null || {
  echo "core/wasm/build.sh: wasm-bindgen-cli is required: cargo install wasm-bindgen-cli --version VERSION --locked" >&2
  exit 2
}
want=$(sed -n '/^name = "wasm-bindgen"$/{n;s/^version = "\(.*\)"$/\1/p;}' "$HERE/Cargo.lock")
have=$(wasm-bindgen --version | cut -d' ' -f2)
[ "$want" = "$have" ] || {
  echo "core/wasm/build.sh: wasm-bindgen-cli $have does not match the locked crate $want" >&2
  exit 2
}
rustup target list --installed 2>/dev/null | grep -qx wasm32-unknown-unknown || [ ! -x "$(command -v rustup)" ] || {
  echo "core/wasm/build.sh: run: rustup target add wasm32-unknown-unknown" >&2
  exit 2
}
# Remap the checkout, Cargo registry and toolchain paths that panic locations
# would embed, so the same commit builds the same bytes on any machine and no
# build-machine path ships in the app. Symbols are stripped (Cargo.toml).
# Builds of one checkout run one at a time where flock(1) exists.
mkdir -p "$HERE/target" "$(dirname "$OUT")"
if command -v flock >/dev/null; then
  exec 9>"$HERE/target/.build.lock"
  flock 9
fi
ROOT=$(dirname "$(dirname "$HERE")")
REGISTRY=${CARGO_HOME:-$HOME/.cargo}/registry/src
SYSROOT=$(rustc --print sysroot)
FLAGS=()
for map in "$ROOT=/tokenling" "$(realpath -m "$ROOT")=/tokenling" "$REGISTRY=/cargo" \
  "$(realpath -m "$REGISTRY")=/cargo" "$SYSROOT=/rust" "$(realpath -m "$SYSROOT")=/rust"; do
  FLAGS+=("--remap-path-prefix=$map")
done
CARGO_ENCODED_RUSTFLAGS=$(IFS=$'\x1f'; echo "${FLAGS[*]}") \
  cargo build --release --locked --quiet --manifest-path "$HERE/Cargo.toml" --target wasm32-unknown-unknown
# Stage beside OUT, so the final swap is a rename on one filesystem.
STAGE=$(mktemp -d "$(dirname "$OUT")/.$(basename "$OUT").XXXXXX")
trap 'rm -rf "$STAGE"' EXIT
wasm-bindgen "$HERE/target/wasm32-unknown-unknown/release/tokenling_core.wasm" \
  --target web --out-dir "$STAGE"
chmod 755 "$STAGE"
rm -rf "$OUT"
mv "$STAGE" "$OUT"
trap - EXIT