# ==========================================================
# Dockerfile for ChatBot Workshop
# LangGraph StateGraph + Guardrails Edition
# ==========================================================
# Multi-stage build for optimized image size
FROM python:3.13-slim AS builder

# Metadata
LABEL maintainer="CTW Team"
LABEL description="LangChain + LangGraph + Ollama ChatBot Workshop with Guardrails"
LABEL version="2.1"

# Environment variables
ENV PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1 \
    PIP_NO_CACHE_DIR=1 \
    PIP_DISABLE_PIP_VERSION_CHECK=1 \
    TRANSFORMERS_CACHE=/app/.cache/huggingface \
    SENTENCE_TRANSFORMERS_HOME=/app/.cache/sentence-transformers

# Install system dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    curl \
    git \
    && rm -rf /var/lib/apt/lists/*

# Create working directory
WORKDIR /app

# Copy requirements
COPY requirements.txt .

# Install dependencies
RUN pip install --upgrade pip && \
    pip install -r requirements.txt

# Pre-download the sentence-transformers model
RUN python3 -c "from sentence_transformers import SentenceTransformer; SentenceTransformer('all-MiniLM-L6-v2')"

# Final stage
FROM python:3.13-slim

# Environment variables
ENV PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1 \
    TRANSFORMERS_CACHE=/app/.cache/huggingface \
    SENTENCE_TRANSFORMERS_HOME=/app/.cache/sentence-transformers

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

# Create non-root user for security
RUN useradd -m -u 1000 -s /bin/bash chatbot && \
    mkdir -p /app/.cache && \
    chown -R chatbot:chatbot /app

# Set working directory
WORKDIR /app

# Copy Python packages from builder
COPY --from=builder /usr/local/lib/python3.13/site-packages /usr/local/lib/python3.13/site-packages
COPY --from=builder /usr/local/bin /usr/local/bin

# Copy pre-downloaded models from builder
COPY --from=builder --chown=chatbot:chatbot /app/.cache /app/.cache

# Copy application code
COPY --chown=chatbot:chatbot . .

# Switch to non-root user
USER chatbot

# Expose port for Streamlit (optional future use)
EXPOSE 8501

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
    CMD python3 -c "import langchain; import faiss; print('OK')" || exit 1

# Default entrypoint - can be overridden when running specific scripts
ENTRYPOINT ["python3"]
CMD ["--version"]
