#!/usr/bin/env bash
# Builds the reference modules (extensions/quantum-wasmq.md §8) for wasm32-unknown-unknown
# and writes the modules of record, with what decided their bytes, into
# wai/quantum-conformance/wasmq/modules/.
#
#   build.sh             build and write the modules of record and modules.json
#   build.sh --check     build, and fail unless the build equals the modules of record
#   build.sh --sources   build nothing; fail unless every source modules.json pins has
#                        its digest (any host: python3 alone)
#
# rustc's wasm32 output depends on the host it runs on, so the modules of record are
# built on x86_64 Linux, the CI image's host; `--check` is run there. Every other host
# reads the committed modules, and modules.json pins the sources that made them.
set -euo pipefail
here=$(cd "$(dirname "$0")" && pwd)
root=$(cd "$here/../../.." && pwd)
out="$root/wai/quantum-conformance/wasmq/modules"
check=0
mkdir -p "$out"
[ "${1:-}" = "--check" ] && check=1
if [ "${1:-}" = "--sources" ]; then
  python3 -I - "$root" <<'PY'
import hashlib, json, os, sys
root = sys.argv[1]
doc = json.load(open(os.path.join(root, "wai/quantum-conformance/wasmq/modules/modules.json")))
bad = [p for p, h in doc["sources_sha256"].items() if hashlib.sha256(open(os.path.join(root, p), "rb").read()).hexdigest() != h]
for n, m in doc["modules"].items():
    b = open(os.path.join(root, "wai/quantum-conformance/wasmq/modules", m["file"]), "rb").read()
    if hashlib.sha256(b).hexdigest() != m["sha256"]:
        bad.append(m["file"])
for p in bad:
    print(f"::error::{p} is not what the modules of record were built from: rebuild them with wai/wai-wasmq/modules/build.sh on x86_64 Linux")
print(f"modules of record: {len(doc['sources_sha256'])} sources and {len(doc['modules'])} modules as pinned" if not bad else "")
sys.exit(1 if bad else 0)
PY
  exit $?
fi
cd "$here"
export CARGO_TARGET_DIR="${CARGO_TARGET_DIR:-$here/target}"
sysroot=$(rustc --print sysroot)
commit=$(rustc -vV | sed -n 's/^commit-hash: //p')
# The paths a build records: the same on every host.
export RUSTFLAGS="-C target-cpu=lime1 -C link-arg=--max-memory=67108864 --remap-path-prefix=$root=/src --remap-path-prefix=${CARGO_HOME:-$HOME/.cargo}=/cargo --remap-path-prefix=$sysroot/lib/rustlib/src/rust=/rustc/$commit"
cargo build --locked --release --target wasm32-unknown-unknown
built="$CARGO_TARGET_DIR/wasm32-unknown-unknown/release"
status=0
for name in qldpc_decoder atom_planner; do
  f="$built/wasmq_$name.wasm"
  if [ "$check" = 1 ]; then
    if cmp -s "$f" "$out/$name.wasm"; then
      echo "$name: the build equals the module of record"
    else
      echo "::error::$name: the build differs from the module of record ($(wc -c <"$f") bytes against $(wc -c <"$out/$name.wasm"))"
      status=1
    fi
  else
    cp "$f" "$out/$name.wasm"
  fi
done
if [ "$check" = 0 ]; then
  python3 - "$root" "$(rustc -V)" <<'PY'
import hashlib, json, sys, os
root, rustc = sys.argv[1], sys.argv[2]
def b3(p):
    # blake3 is not in the standard library; sha256 pins the sources, the crate pins the modules by blake3.
    return hashlib.sha256(open(os.path.join(root, p), 'rb').read()).hexdigest()
sources = ["wai/wai-wasmq/modules/Cargo.toml", "wai/wai-wasmq/modules/Cargo.lock", "wai/wai-wasmq/modules/.cargo/config.toml",
           "wai/wai-wasmq/modules/qldpc-decoder/Cargo.toml", "wai/wai-wasmq/modules/qldpc-decoder/src/lib.rs",
           "wai/wai-wasmq/modules/atom-planner/Cargo.toml", "wai/wai-wasmq/modules/atom-planner/src/lib.rs",
           "wai/wai-quantum/src/quantum_qec.rs", "wai/wai-quantum/src/quantum_atom.rs", "wai/wai-quantum/src/quantum_ops.rs", "rust-toolchain.toml"]
mods = {}
for n in ["qldpc_decoder", "atom_planner"]:
    b = open(os.path.join(root, "wai/quantum-conformance/wasmq/modules", n + ".wasm"), 'rb').read()
    mods[n] = {"file": n + ".wasm", "bytes": len(b), "sha256": hashlib.sha256(b).hexdigest()}
doc = {"built_with": rustc, "target": "wasm32-unknown-unknown", "host": "x86_64-unknown-linux-gnu", "modules": mods, "sources_sha256": {s: b3(s) for s in sources}}
open(os.path.join(root, "wai/quantum-conformance/wasmq/modules/modules.json"), "w").write(json.dumps(doc, indent=2, sort_keys=True) + "\n")
PY
  echo "wrote the modules of record and modules.json"
fi
exit $status