FROM python:3.12-slim AS builder

WORKDIR /app

# Install system dependencies needed for pymupdf and psycopg2
RUN apt-get update && apt-get install -y --no-install-recommends \
    libgl1 \
    libglib2.0-0 \
    gcc \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Copy and install Python dependencies
COPY backend/requirements.txt .
RUN pip install --no-cache-dir --upgrade pip && \
    pip install --no-cache-dir -r requirements.txt

# ─────────────────────────────────────────────────────────────────────
FROM python:3.12-slim

WORKDIR /app

# Copy only runtime system deps (pymupdf needs libgl, libglib) and curl for healthcheck
RUN apt-get update && apt-get install -y --no-install-recommends \
    libgl1 \
    libglib2.0-0 \
    libpq5 \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy 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

# Copy application code
COPY backend/ .

# Create directories for uploads and fastembed cache
RUN mkdir -p /app/uploads /app/fastembed_cache

# Expose the application port
EXPOSE 8000

# Run the FastAPI application with uvicorn
# Uses UVICORN_WORKERS environment variable (defaults to 4) for production concurrency
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--workers", "4"]