feat: 重构配置管理，使用数据库替代环境变量，优化系统配置读取

server/utils/env.ts

@@ -1,80 +0,0 @@
-// server/utils/env.ts - 服务端环境变量读取与规范化
-
-/**
- * 允许 `.env` 里保留类似 Python 旧项目的写法：
- * `OPENAI_API_BASE=https://example.com/v1  # 注释`
- * Nuxt/Node 读到的是整行值，所以这里主动裁掉行尾注释
- */
-const stripInlineComment = (value: string) => {
-  return value.replace(/\s+#.*$/u, "").trim();
-};
-
-/**
- * 读取字符串环境变量
- *
- * - 空字符串视为未配置，回退到 fallback
- * - 返回值统一去掉行尾注释，避免 baseURL、model 之类配置带上注释文本
- */
-const readString = (key: string, fallback = "") => {
-  const value = process.env[key];
-  if (value === undefined || value === null || value.trim() === "") {
-    return fallback;
-  }
-
-  return stripInlineComment(value);
-};
-
-/** 读取可选字符串；空值统一转成 undefined，方便后续判断是否启用某能力 */
-const readOptionalString = (key: string) => {
-  const value = readString(key);
-  return value || undefined;
-};
-
-/** 兼容常见布尔写法，便于 Docker、面板和手写 `.env` 配置 */
-const readBoolean = (key: string, fallback: boolean) => {
-  const value = readString(key);
-  if (!value) return fallback;
-  return ["1", "true", "yes", "on"].includes(value.toLowerCase());
-};
-
-/** 读取整数配置；非法值不抛错，使用默认值保证服务能启动 */
-const readInteger = (key: string, fallback: number) => {
-  const value = Number.parseInt(readString(key), 10);
-  return Number.isFinite(value) ? value : fallback;
-};
-
-/** 读取小数配置，主要用于 OpenAI temperature */
-const readNumber = (key: string, fallback: number) => {
-  const value = Number.parseFloat(readString(key));
-  return Number.isFinite(value) ? value : fallback;
-};
-
-/** OpenAI 兼容接口 baseURL 统一不带结尾斜杠，后续再拼 `/chat/completions` */
-const normalizeBaseUrl = (url: string) => {
-  return url.replace(/\/+$/u, "");
-};
-
-/**
- * 服务端环境配置的唯一出口
- *
- * 业务代码不要直接读 `process.env`，这样可以把默认值、格式修正和安全边界
- * 都收敛在这里，后续迁移部署平台时也只需要检查这个文件
- */
-export const serverEnv = {
-  /** OpenAI 或兼容中转平台 API Key，仅服务端使用，不能返回给前端 */
-  openAiApiKey: readString("OPENAI_API_KEY"),
-  /** OpenAI 兼容 API base，例如 `https://api.openai.com/v1` */
-  openAiApiBase: normalizeBaseUrl(
-    readString("OPENAI_API_BASE", "https://api.openai.com/v1")
-  ),
-  /** Chat Completions 使用的模型名 */
-  openAiModel: readString("OPENAI_MODEL", "gpt-3.5-turbo"),
-  /** 单次回答最大 token 数，沿用旧 Python 服务的配置语义 */
-  maxTokens: readInteger("MAX_TOKENS", 500),
-  /** 模型采样温度，越低越稳定 */
-  temperature: readNumber("TEMPERATURE", 0.7),
-  /** 预留日志级别配置，目前日志工具只负责安全输出 */
-  logLevel: readString("LOG_LEVEL", "INFO"),
-  /** 单行 SSE data 的最大字节数，用于防止异常流无限堆内存 */
-  maxSseLineBytes: readInteger("OPENAI_STREAM_MAX_SSE_LINE_BYTES", 1_048_576)
-};

server/utils/openai.ts

@@ -1,8 +1,6 @@
 // server/utils/openai.ts - OpenAI Chat Completions 流式调用工具
-import { serverEnv } from "~~/server/utils/env";
+import { getSysConfig } from "~~/server/utils/sysConfig";
 
-/** 旧项目的 `OPENAI_API_BASE` 语义是完整 base，例如 `https://api.openai.com/v1` */
-const CHAT_COMPLETIONS_URL = `${serverEnv.openAiApiBase}/chat/completions`;
 /** 复用编码器计算 SSE data 字节长度，避免循环里频繁创建对象 */
 const textEncoder = new TextEncoder();
 
@@ -56,21 +54,25 @@ export const askAnswerStream = async ({
   prompt: string;
   systemPrompt: string;
 }): Promise<AskAnswerStreamResult> => {
-  if (!serverEnv.openAiApiKey) {
+  const cfg = await getSysConfig();
+
+  if (!cfg.openAiApiKey) {
     throw new Error("OPENAI_API_KEY is not set.");
   }
 
+  const chatCompletionsUrl = `${cfg.openAiApiBase}/chat/completions`;
+
   // 这里不要记录 request body：其中包含完整题目和可能的选项文本
-  const response = await fetch(CHAT_COMPLETIONS_URL, {
+  const response = await fetch(chatCompletionsUrl, {
     method: "POST",
     headers: {
-      Authorization: `Bearer ${serverEnv.openAiApiKey}`,
+      Authorization: `Bearer ${cfg.openAiApiKey}`,
       "Content-Type": "application/json"
     },
     body: JSON.stringify({
-      model: serverEnv.openAiModel,
-      temperature: serverEnv.temperature,
-      max_tokens: serverEnv.maxTokens,
+      model: cfg.openAiModel,
+      temperature: cfg.temperature,
+      max_tokens: cfg.maxTokens,
       stream: true,
       messages: [
         {
@@ -94,7 +96,10 @@ export const askAnswerStream = async ({
   }
 
   // 将 SSE delta 读完后再返回给 API handler，由 handler 统一做答案清洗和缓存
-  const upstreamResponse = await readChatCompletionStream(response.body);
+  const upstreamResponse = await readChatCompletionStream(
+    response.body,
+    cfg.maxSseLineBytes
+  );
 
   return {
     answer: upstreamResponse.content.trim(),
@@ -112,7 +117,8 @@ export const askAnswerStream = async ({
  * 网络 chunk 不一定按行对齐，所以用 buffer 保存尚未拼完整的一行
  */
 export const readChatCompletionStream = async (
-  stream: ReadableStream<Uint8Array>
+  stream: ReadableStream<Uint8Array>,
+  maxSseLineBytes: number
 ): Promise<ChatCompletionStreamResult> => {
   const reader = stream.getReader();
   const decoder = new TextDecoder();
@@ -146,14 +152,14 @@ export const readChatCompletionStream = async (
 
     // stream: true 可以正确处理跨 chunk 的多字节字符，例如中文
     buffer += decoder.decode(value, { stream: true });
-    assertSseBufferSize(buffer, serverEnv.maxSseLineBytes);
+    assertSseBufferSize(buffer, maxSseLineBytes);
 
     // 只处理已经遇到换行的完整 SSE 行，最后一段留到下次 chunk 再拼
     const lines = buffer.split(/\r?\n/u);
     buffer = lines.pop() ?? "";
 
     for (const line of lines) {
-      const chunk = parseSseDataLine(line, serverEnv.maxSseLineBytes);
+      const chunk = parseSseDataLine(line, maxSseLineBytes);
       if (chunk) collectChunk(chunk);
     }
   }
@@ -161,7 +167,7 @@ export const readChatCompletionStream = async (
   // 处理流结束时仍留在 buffer 中的最后一行
   const finalText = buffer + decoder.decode();
   for (const line of finalText.split(/\r?\n/u)) {
-    const chunk = parseSseDataLine(line, serverEnv.maxSseLineBytes);
+    const chunk = parseSseDataLine(line, maxSseLineBytes);
     if (chunk) collectChunk(chunk);
   }
 

server/utils/runtimeState.ts

@@ -1,6 +1,6 @@
 // server/utils/runtimeState.ts - 服务启动时间内存状态 + 问答记录 DB 读写
 import { prisma } from "~~/server/utils/db";
-import { serverEnv } from "~~/server/utils/env";
+import { getSysConfig } from "~~/server/utils/sysConfig";
 
 /** 进程启动时间，用于 `/api/stats` 返回 uptime */
 const startTime = Date.now();
@@ -100,10 +100,11 @@ export const getQaRecords = async (
   return { records, total };
 };
 /** 生成 `/api/stats` 的基础运行时信息，不包含用户相关数据 */
-export const getRuntimeStats = () => {
+export const getRuntimeStats = async () => {
+  const cfg = await getSysConfig();
   return {
     version: SERVICE_VERSION,
     uptime: (Date.now() - startTime) / 1000,
-    model: serverEnv.openAiModel
+    model: cfg.openAiModel
   };
 };

server/utils/sysConfig.ts

@@ -0,0 +1,96 @@
+// server/utils/sysConfig.ts - 从数据库读取系统配置，带 60 秒 TTL 内存缓存
+// 替代原 env.ts 中的 OpenAI 配置项，配置以 DB 为准，管理员可通过后台修改
+import { prisma } from "~~/server/utils/db";
+
+/** 系统配置字段，对应 system_config 表中的各 key */
+export interface SysConfig {
+  /** OpenAI 或兼容 API Key，仅服务端使用，不能返回给前端 */
+  openAiApiKey: string;
+  /** OpenAI 兼容 API base URL，不含结尾斜杠 */
+  openAiApiBase: string;
+  /** Chat Completions 使用的模型名 */
+  openAiModel: string;
+  /** 单次回答最大 token 数 */
+  maxTokens: number;
+  /** 模型采样温度，越低越稳定 */
+  temperature: number;
+  /** 单行 SSE data 最大字节数，防止异常流无限堆内存 */
+  maxSseLineBytes: number;
+}
+
+// system_config 表 key 字段的常量映射
+const CONFIG_KEYS = {
+  openAiApiKey: "openai_api_key",
+  openAiApiBase: "openai_api_base",
+  openAiModel: "openai_model",
+  maxTokens: "max_tokens",
+  temperature: "temperature",
+  maxSseLineBytes: "openai_stream_max_sse_line_bytes"
+} as const;
+
+// 硬编码默认值，与原 env.ts 的 fallback 保持一致
+const DEFAULTS: SysConfig = {
+  openAiApiKey: "",
+  openAiApiBase: "https://api.openai.com/v1",
+  openAiModel: "gpt-3.5-turbo",
+  maxTokens: 500,
+  temperature: 0.7,
+  maxSseLineBytes: 1_048_576
+};
+
+// 内存缓存：减少每请求查 DB 的开销
+let _cachedConfig: SysConfig | null = null;
+let _cacheExpiresAt = 0;
+const CACHE_TTL_MS = 60_000;
+
+/** baseURL 不能带结尾斜杠，后续拼 `/chat/completions` 时格式才正确 */
+const normalizeBaseUrl = (url: string) => url.replace(/\/+$/u, "");
+
+/**
+ * 读取系统配置
+ *
+ * 60 秒内命中内存缓存直接返回，过期后重新查 DB；
+ * 管理员更新配置后可调用 invalidateSysConfigCache() 主动失效
+ */
+export const getSysConfig = async (): Promise<SysConfig> => {
+  const now = Date.now();
+  if (_cachedConfig && now < _cacheExpiresAt) {
+    return _cachedConfig;
+  }
+
+  const rows = await prisma.systemConfig.findMany({
+    select: { key: true, value: true }
+  });
+  const map = new Map(rows.map((r) => [r.key, r.value]));
+
+  const str = (key: string, fallback: string) => map.get(key) ?? fallback;
+  const int = (key: string, fallback: number) => {
+    const v = Number.parseInt(map.get(key) ?? "", 10);
+    return Number.isNaN(v) ? fallback : v;
+  };
+  const float = (key: string, fallback: number) => {
+    const v = Number.parseFloat(map.get(key) ?? "");
+    return Number.isNaN(v) ? fallback : v;
+  };
+
+  const config: SysConfig = {
+    openAiApiKey: str(CONFIG_KEYS.openAiApiKey, DEFAULTS.openAiApiKey),
+    openAiApiBase: normalizeBaseUrl(
+      str(CONFIG_KEYS.openAiApiBase, DEFAULTS.openAiApiBase)
+    ),
+    openAiModel: str(CONFIG_KEYS.openAiModel, DEFAULTS.openAiModel),
+    maxTokens: int(CONFIG_KEYS.maxTokens, DEFAULTS.maxTokens),
+    temperature: float(CONFIG_KEYS.temperature, DEFAULTS.temperature),
+    maxSseLineBytes: int(CONFIG_KEYS.maxSseLineBytes, DEFAULTS.maxSseLineBytes)
+  };
+
+  _cachedConfig = config;
+  _cacheExpiresAt = now + CACHE_TTL_MS;
+  return config;
+};
+
+/** 主动使缓存失效，管理员更新系统配置后调用，下次请求将重新查 DB */
+export const invalidateSysConfigCache = () => {
+  _cachedConfig = null;
+  _cacheExpiresAt = 0;
+};