# ═══════════════════════════════════════════════════════════════════════════
#  PragatiVeer Backend – Python 3.11 slim
#  Optimised for fast re-builds:
#    • requirements.txt copied FIRST → pip cache layer is only invalidated
#      when dependencies change, not on every source-code edit.
#    • BuildKit pip cache mount keeps wheel cache on host between builds.
# ═══════════════════════════════════════════════════════════════════════════
FROM python:3.11-slim

# Install system deps in a single RUN layer, clean apt cache immediately
RUN apt-get update && apt-get install -y --no-install-recommends \
        build-essential \
        libpq-dev \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# ── Dependencies first (most stable layer) ──────────────────────────────────
COPY requirements.txt .
# Use BuildKit pip cache so wheels are reused across builds
RUN --mount=type=cache,target=/root/.cache/pip \
    pip install --no-cache-dir -r requirements.txt

# ── Source code (changes frequently; comes last) ─────────────────────────────
COPY . .

EXPOSE 8000

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]