# Multi-stage production Dockerfile for SentinelAI-RAG
# Configured for Hugging Face Spaces (Docker SDK, 2 vCPU, 16GB RAM, Port 7860, UID 1000) & Render

# Stage 1: Build C++17 SIMD extension & Python dependencies
FROM python:3.12-slim AS builder

WORKDIR /build

# Install C++17 build tools & SIMD support
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    g++ \
    cmake \
    git \
    && rm -rf /var/lib/apt/lists/*

# Install slim CPU-only PyTorch first (avoids pulling 2GB CUDA binaries)
RUN pip install --no-cache-dir torch --index-url https://download.pytorch.org/whl/cpu

# Install remaining Python build dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Compile C++17 AVX2 SIMD engine
COPY cpp_engine/ ./cpp_engine/
WORKDIR /build/cpp_engine
RUN python setup.py build_ext --inplace

# Stage 2: Production runtime stage
FROM python:3.12-slim AS runtime

# Install runtime system packages
RUN apt-get update && apt-get install -y --no-install-recommends \
    libgomp1 \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy installed Python packages from builder
COPY --from=builder /usr/local/lib/python3.12/site-packages /usr/local/lib/python3.12/site-packages
COPY --from=builder /usr/local/bin /usr/local/bin

# Create non-root user with UID 1000 (Mandatory for Hugging Face Spaces)
RUN useradd -m -u 1000 user

# Configure environment for Hugging Face Spaces & Render
ENV HOME=/home/user \
    PATH=/home/user/.local/bin:$PATH \
    HF_HOME=/home/user/.cache/huggingface \
    PYTHONUNBUFFERED=1 \
    PYTHONPATH=/app:/app/cpp_engine \
    SERVER_HOST=0.0.0.0 \
    SERVER_PORT=7860 \
    USE_LOCAL_SIMULATOR=true

# Prepare home and app directories with proper ownership for UID 1000
WORKDIR /app
RUN mkdir -p /home/user/.cache/huggingface /app && \
    chown -R user:user /home/user /app

# Switch to non-root user (Hugging Face Spaces requirement)
USER user

# Pre-download all-MiniLM-L6-v2 model so it is baked into /home/user/.cache/huggingface
RUN python -c "from sentence_transformers import SentenceTransformer; SentenceTransformer('sentence-transformers/all-MiniLM-L6-v2', device='cpu')"

# Copy compiled SIMD extension with correct ownership
COPY --chown=user:user --from=builder /build/cpp_engine/simd_engine*.so /app/
COPY --chown=user:user --from=builder /build/cpp_engine/simd_engine*.so /app/cpp_engine/

# Copy application source code & data
COPY --chown=user:user app/ /app/app/
COPY --chown=user:user data/ /app/data/
COPY --chown=user:user benchmarks/ /app/benchmarks/
COPY --chown=user:user tests/ /app/tests/

EXPOSE 7860

HEALTHCHECK --interval=20s --timeout=5s --start-period=30s --retries=3 \
    CMD curl -f http://localhost:${PORT:-7860}/v1/health || exit 1

CMD ["sh", "-c", "uvicorn app.main:app --host 0.0.0.0 --port ${PORT:-7860} --workers 1"]