# 分层构建：依赖与代码分离，仅代码变更时只重建最后一层，加快迭代
FROM tiangolo/uvicorn-gunicorn-fastapi:python3.11-slim

ENV MODULE_NAME=backend.app.main
ENV VARIABLE_NAME=app
ENV PORT=8000
ENV HOST=0.0.0.0
# SQLite 对并发写不友好，单 worker 避免多进程竞争
ENV WEB_CONCURRENCY=1

WORKDIR /app

# 依赖层：只有 requirements 变更时才重建
COPY requirements.txt /app/requirements.txt
RUN pip install --no-cache-dir -r /app/requirements.txt

# 代码层：仅此层会随业务代码变更而重建
COPY backend /app/backend