apps/api/dependencies/auth.py

from fastapi import Security, HTTPException, status, Depends
from fastapi.security import APIKeyHeader
from typing import Optional

API_KEY_NAME = "X-API-Key"
api_key_header = APIKeyHeader(name=API_KEY_NAME, auto_error=False)

# 模拟数据库中存储的 API Key 列表与权限配置
# 实际应存在数据库如 users, api_keys 表中
VALID_API_KEYS = {
    "test_trial_key_123": {"tier": "trial", "rate_limit": 10},
    "test_standard_key_456": {"tier": "standard", "rate_limit": 100},
    "test_enterprise_key_789": {"tier": "enterprise", "rate_limit": 1000},
}

async def get_api_key(api_key_header: str = Security(api_key_header)) -> str:
    """
    鉴权依赖项，验证请求头中的 API Key。
    """
    if not api_key_header:
        # 在 MVP 阶段，为了方便调试，如果没有传 key，则默认给一个 trial 权限
        # 真实环境应该抛出 403
        return "test_trial_key_123"
        
    if api_key_header not in VALID_API_KEYS:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN, detail="Could not validate credentials"
        )
        
    return api_key_header

def get_current_user_tier(api_key: str = Depends(get_api_key)) -> str:
    """获取当前用户的产品层级"""
    return VALID_API_KEYS.get(api_key, {}).get("tier", "trial")