#!/usr/bin/env bash
# Build the WebAssembly target (openra3.js/.wasm + worker + page) with the
# Emscripten image.
#
# The engine runs inside a plain Web Worker and renders into an OffscreenCanvas
# with no SDL, so assets load on demand: point OPENRA3_WEB_ASSETS at the
# extracted asset tree and the build generates an assets manifest, embeds it, and
# registers every file as an Emscripten lazy file at startup. The browser then
# fetches each asset only when the engine opens it.
#
#   OPENRA3_WEB_ASSETS=/path/to/assets scripts/build-wasm.sh
#
# open http://localhost:8199/index.html
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
IMAGE="${OPENRA3_WASM_IMAGE:-openra3-wasm:local}"
BUILD_DIR="${1:-build/wasm}"

docker build --target dev -f "$ROOT/Dockerfile.wasm" -t "$IMAGE" "$ROOT"

mounts=(-v "$ROOT:/work")
configure=(-DCMAKE_TOOLCHAIN_FILE=cmake/toolchains/emscripten-wasm.cmake -DCMAKE_BUILD_TYPE=Release)
serve_assets=()
if [ -n "${OPENRA3_WEB_ASSETS:-}" ]; then
    mounts+=(-v "$OPENRA3_WEB_ASSETS:/assets:ro")
    manifest="$ROOT/$BUILD_DIR/assets.manifest.json"
    mkdir -p "$(dirname "$manifest")"
    python3 "$ROOT/scripts/make_web_manifest.py" --root "$OPENRA3_WEB_ASSETS" --out "$manifest"
    configure+=(-DOPENRA3_WEB_MANIFEST="/work/$BUILD_DIR/assets.manifest.json")
    serve_assets=(--assets "$OPENRA3_WEB_ASSETS")
fi

docker run --rm "${mounts[@]}" -w /work "$IMAGE" cmake -S . -B "$BUILD_DIR" -G Ninja "${configure[@]}"
docker run --rm "${mounts[@]}" -w /work "$IMAGE" cmake --build "$BUILD_DIR" -j

echo "WebAssembly: $ROOT/$BUILD_DIR/bin/index.html (+ openra3.js/.wasm, openra3.worker.js)"
echo "serve:  python3 \"$ROOT/apps/web/serve.py\" --root \"$ROOT/$BUILD_DIR/bin\" ${serve_assets[*]:-}"