#!/bin/bash

# Wrapper script for rust-backend that ensures rebuild on startup

# This is used by supervisord in development mode

set -e

# Set Docker environment variable to ensure PTX compilation at runtime

export DOCKER_ENV=1

log() {

echo "[RUST-WRAPPER][$(date '+%Y-%m-%d %H:%M:%S')] $1"

}

# Auto-detect GPU compute capability at runtime (GPU is accessible in container).

# ALWAYS prefer runtime detection over .env/compose values — the .env may contain

# a stale arch from a different GPU (e.g. sm_89 when the actual GPU is sm_86).

DETECTED_ARCH=$(nvidia-smi --query-gpu=compute_cap --format=csv,noheader --id=0 2>/dev/null | head -1 | tr -d '.' | tr -d '[:space:]')

if [ -n "$DETECTED_ARCH" ] && [ "$DETECTED_ARCH" != "" ]; then

if [ -n "${CUDA_ARCH:-}" ] && [ "$CUDA_ARCH" != "$DETECTED_ARCH" ]; then

log "WARNING: .env CUDA_ARCH=${CUDA_ARCH} does not match GPU (sm_${DETECTED_ARCH}). Overriding to sm_${DETECTED_ARCH}"

fi

export CUDA_ARCH="$DETECTED_ARCH"

log "GPU compute capability: sm_${CUDA_ARCH} (runtime-detected)"

else

if [ -n "${CUDA_ARCH:-}" ]; then

log "WARNING: nvidia-smi failed, using .env CUDA_ARCH=${CUDA_ARCH}"

else

export CUDA_ARCH="75"

log "WARNING: nvidia-smi failed, no .env CUDA_ARCH, falling back to sm_75"

fi

fi

# Truncate stale error log from previous runs

> /app/logs/rust-error.log

# Always rebuild in dev mode unless explicitly skipped

if [ "${SKIP_RUST_REBUILD:-false}" != "true" ]; then

log "Rebuilding Rust backend with GPU support to apply code changes..."

cd /app

# Detect bind-mounted source changes using content hash (not mtime).

# Docker image build bakes source + compiles a binary. At runtime, bind mounts

# overlay /app/src with host files. Cargo's fingerprints use mtime which may

# match the image build. Content hashing catches actual code changes.

# In dev mode, ALWAYS recompile the webxr crate on container start.

# Docker image build compiles a binary from COPY'd source, but the bind mount

# overlays /app/src with host files that may differ. Cargo's fingerprints can't

# detect this because the target volume persists across container restarts.

# Removing webxr artifacts is cheap (~2 min rebuild), deps stay cached.

HASH_FILE="/app/target/release/.webxr_source_hash"

CURRENT_HASH=$(find /app/src -name '*.rs' -o -name '*.cu' 2>/dev/null | sort | xargs cat 2>/dev/null | md5sum | cut -d' ' -f1)

CACHED_HASH=$(cat "$HASH_FILE" 2>/dev/null || echo "none")

if [ "$CURRENT_HASH" != "$CACHED_HASH" ]; then

log "Source content changed (hash $CACHED_HASH → $CURRENT_HASH) — invalidating webxr artifacts"

rm -rf /app/target/release/.fingerprint/webxr-* 2>/dev/null || true

rm -rf /app/target/release/deps/libwebxr* 2>/dev/null || true

rm -rf /app/target/release/deps/webxr-* 2>/dev/null || true

rm -f /app/target/release/webxr 2>/dev/null || true

rm -rf /app/target/release/build/webxr-* 2>/dev/null || true

mkdir -p /app/target/release

echo "$CURRENT_HASH" > "$HASH_FILE"

else

log "Source hash matches cached build — skipping recompilation"

fi

# Clean stale incremental cache if fingerprints look corrupt

if [ -d "/app/target/release/.fingerprint" ]; then

FINGERPRINT_AGE=$(find /app/target/release/.fingerprint -maxdepth 1 -type d -mmin +1440 2>/dev/null | head -1)

if [ -n "$FINGERPRINT_AGE" ]; then

log "Stale fingerprints detected (>24h old), cleaning incremental cache..."

cargo clean 2>/dev/null || true

fi

fi

# Build release with GPU features (matches dev-entrypoint.sh)

if cargo build --release --features gpu 2>&1; then

log "✓ Rust backend rebuilt successfully (release build with GPU)"

else

log "ERROR: Failed to rebuild Rust backend"

log "Attempting clean build..."

cargo clean 2>/dev/null || true

if cargo build --release --features gpu 2>&1; then

log "✓ Clean rebuild succeeded"

else

log "FATAL: Clean rebuild also failed"

exit 1

fi

fi

RUST_BINARY="/app/target/release/webxr"

else

log "Skipping Rust rebuild (SKIP_RUST_REBUILD=true)"

RUST_BINARY="/app/webxr"

fi

# Verify binary exists

if [ ! -f "${RUST_BINARY}" ]; then

log "ERROR: Rust binary not found at ${RUST_BINARY}"

exit 1

fi

log "Starting Rust backend from ${RUST_BINARY}..."

exec ${RUST_BINARY}