FROM node:18-alpine

# Build arguments for versioning
ARG GIT_COMMIT=unknown
ARG APP_VERSION=1.0.0

WORKDIR /app

# Install curl for healthcheck and git for commit info
RUN apk add --no-cache curl git

# Copy package files first for layer caching
COPY package*.json ./
RUN npm install --production

# Copy app code (changes more often — below the cached layer)
COPY . .

# Try to get git commit if not provided and .git exists
RUN if [ "$GIT_COMMIT" = "unknown" ] && [ -d .git ]; then \
      GIT_COMMIT=$(git rev-parse HEAD 2>/dev/null || echo "unknown"); \
    fi && \
    echo "export GIT_COMMIT=${GIT_COMMIT}" >> /etc/profile.d/git-version.sh

# Set environment variables for runtime
ENV GIT_COMMIT=${GIT_COMMIT} \
    APP_VERSION=${APP_VERSION}

EXPOSE 3000

HEALTHCHECK --interval=10s --timeout=3s --start-period=5s --retries=2 \
  CMD curl -f http://localhost:3000/health || exit 1

CMD ["node", "server.js"]