#!/usr/bin/env bash
# Launch FastAPI (internal :8000) and Next.js (public :7860) together.
# HF Spaces sends SIGTERM on shutdown; we trap it and forward to children.
set -euo pipefail

BACKEND_PORT="${BACKEND_PORT:-8000}"
FRONTEND_PORT="${FRONTEND_PORT:-7860}"
BACKEND_INTERNAL_URL="${BACKEND_INTERNAL_URL:-http://127.0.0.1:${BACKEND_PORT}}"
export BACKEND_PORT FRONTEND_PORT BACKEND_INTERNAL_URL

cleanup() {
    echo "[start.sh] caught signal, shutting down…"
    [[ -n "${BACKEND_PID:-}" ]] && kill -TERM "$BACKEND_PID" 2>/dev/null || true
    [[ -n "${FRONTEND_PID:-}" ]] && kill -TERM "$FRONTEND_PID" 2>/dev/null || true
    wait || true
    exit 0
}
trap cleanup SIGINT SIGTERM

echo "[start.sh] launching FastAPI on :$BACKEND_PORT"
cd /app/backend
uv run uvicorn main:app --host 127.0.0.1 --port "$BACKEND_PORT" --workers 1 &
BACKEND_PID=$!

echo "[start.sh] waiting for FastAPI health check at $BACKEND_INTERNAL_URL/health"
for _ in $(seq 1 120); do
    if curl -fsS "$BACKEND_INTERNAL_URL/health" >/dev/null 2>&1; then
        echo "[start.sh] FastAPI is ready"
        break
    fi
    if ! kill -0 "$BACKEND_PID" 2>/dev/null; then
        wait "$BACKEND_PID" || true
        echo "[start.sh] FastAPI exited before becoming ready"
        cleanup
    fi
    sleep 1
done
if ! curl -fsS "$BACKEND_INTERNAL_URL/health" >/dev/null 2>&1; then
    echo "[start.sh] FastAPI did not become ready in time"
    cleanup
fi

echo "[start.sh] launching Next.js on :$FRONTEND_PORT"
cd /app/frontend
HOSTNAME=0.0.0.0 PORT="$FRONTEND_PORT" npx next start -p "$FRONTEND_PORT" -H 0.0.0.0 &
FRONTEND_PID=$!

# If either process dies, exit so HF restarts the Space.
wait -n "$BACKEND_PID" "$FRONTEND_PID"
EXIT_CODE=$?
echo "[start.sh] a child exited (code=$EXIT_CODE), shutting down sibling"
cleanup