# ============================================
# Certificate Verification AI Service
# Multi-stage Production Dockerfile
# ============================================

# ------ Stage 1: Builder ------
FROM python:3.11-slim AS builder

WORKDIR /build

# Install build dependencies
RUN apt-get update && \
    apt-get install -y --no-install-recommends gcc g++ && \
    rm -rf /var/lib/apt/lists/*

COPY requirements.txt .

# Install CPU-only PyTorch first (saves ~1.5GB vs full CUDA bundle)
RUN pip install --no-cache-dir --prefix=/install \
    torch torchvision --index-url https://download.pytorch.org/whl/cpu

# Install remaining requirements
RUN pip install --no-cache-dir --prefix=/install -r requirements.txt


# ------ Stage 2: Runtime ------
FROM python:3.11-slim AS runtime

LABEL maintainer="AI Certificate Verification Service"
LABEL description="FastAPI-based certificate verification with YOLO & ViT models"

# Environment defaults
ENV PYTHONUNBUFFERED=1 \
    PYTHONDONTWRITEBYTECODE=1 \
    APP_HOME=/app \
    PORT=8080 \
    WORKERS=1 \
    LOG_LEVEL=info \
    SKIP_MODEL_LOADING=true \
    GUNICORN_TIMEOUT=300 \
    GUNICORN_KEEP_ALIVE=5 \
    GUNICORN_GRACEFUL_TIMEOUT=120 \
    # Disable HuggingFace telemetry & symlinks
    HF_HUB_DISABLE_TELEMETRY=1 \
    TRANSFORMERS_OFFLINE=0 \
    # Torch settings
    OMP_NUM_THREADS=2 \
    MKL_NUM_THREADS=2

WORKDIR $APP_HOME

# Install runtime system dependencies only
RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    libgl1 \
    libglib2.0-0 \
    libsm6 \
    libxext6 \
    libxrender1 \
    curl \
    tini && \
    rm -rf /var/lib/apt/lists/* && \
    # Create non-root user
    groupadd -r appuser && \
    useradd -r -g appuser -d $APP_HOME -s /sbin/nologin appuser

# Copy installed Python packages from builder
COPY --from=builder /install /usr/local

# Copy application code
COPY api.py ocr_client.py verifier_supabase.py verifier.py \
    yolo_seal_detector.py yolo_new.py vit_seal_classifier.py \
    image_annotator.py model_downloader.py \
    ./

# Keep image lean for Render free; models are downloaded at runtime when enabled

# Copy production configs
COPY gunicorn.conf.py ./
COPY entrypoint.sh ./

# Make entrypoint executable
RUN chmod +x entrypoint.sh

# Create writable directories for model downloads & temp files
RUN mkdir -p /app/models /app/tmp && \
    chown -R appuser:appuser /app

# Switch to non-root user
USER appuser

# Expose port
EXPOSE ${PORT}

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=120s --retries=3 \
    CMD curl -f http://localhost:${PORT}/health || exit 1

# Use tini for proper signal handling
ENTRYPOINT ["tini", "--"]

# Start service via entrypoint
CMD ["./entrypoint.sh"]