# --- STAGE 1: Build Frontend ---
FROM node:20-slim AS frontend-builder
WORKDIR /build
# Use --no-cache and clear npm cache to keep this layer small if needed, 
# although it's a build stage.
COPY frontend/package*.json ./
RUN npm install --no-audit --no-fund
COPY frontend/ ./
RUN npm run build

# --- STAGE 2: Backend Builder ---
FROM python:3.11-slim AS backend-builder
WORKDIR /app

# Install only the bare essentials for building Python wheels
RUN apt-get update && \
    apt-get install -y --no-install-recommends build-essential gcc && \
    rm -rf /var/lib/apt/lists/*

COPY requirements.txt .
# Install to /install to easily copy to final stage
RUN pip install --no-cache-dir --prefix=/install -r requirements.txt

# --- STAGE 3: Final Runtime ---
FROM python:3.11-slim
WORKDIR /app

# Set non-interactive to avoid prompts
ENV DEBIAN_FRONTEND=noninteractive

# Minimal runtime system dependencies (if any are ever needed)
# Currently none identified from requirements.txt that need system libs on slim
RUN apt-get update && \
    apt-get install -y --no-install-recommends curl && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

# Copy only the installed Python packages
COPY --from=backend-builder /install /usr/local
ENV PATH=/usr/local/bin:$PATH

# Copy Built Frontend
COPY --from=frontend-builder /build/dist /frontend_static

# Copy only necessary Backend Source
COPY backend ./backend

# Environment Variables
ENV PYTHONPATH=/app
ENV PYTHONUNBUFFERED=1

# Expose Port
EXPOSE 8000

# Start FastAPI (Production mode without --reload)
CMD ["uvicorn", "backend.app:app", "--host", "0.0.0.0", "--port", "8000"]