feat: 班级小助手 阶段1-3（monorepo + 后端 REST/Socket.IO + Web 管理端）

packages/server/src/config/env.ts

@@ -0,0 +1,77 @@
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { config as loadEnv } from 'dotenv';
+import { z } from 'zod';
+
+const currentDir = path.dirname(fileURLToPath(import.meta.url));
+/**
+ * packages/server 根目录。
+ * 源码运行时为 src/config -> ../..；编译后为 dist/config -> ../..，两者一致。
+ */
+export const serverRoot = path.resolve(currentDir, '..', '..');
+
+// 显式按包根目录加载 .env，避免受启动时 cwd 影响
+loadEnv({ path: path.join(serverRoot, '.env') });
+
+const envSchema = z.object({
+  NODE_ENV: z.enum(['development', 'test', 'production']).default('development'),
+  PORT: z.coerce.number().int().min(1).max(65535).default(4000),
+  DATABASE_PROVIDER: z.enum(['sqlite', 'mysql']).default('sqlite'),
+  DATABASE_URL: z.string().min(1).default('file:./prisma/dev.db'),
+  JWT_SECRET: z.string().min(16),
+  JWT_EXPIRES_IN: z.string().default('7d'),
+  CORS_ORIGIN: z.string().default('*'),
+  BCRYPT_ROUNDS: z.coerce.number().int().min(4).max(15).default(10),
+  DEFAULT_STUDENT_PASSWORD: z.string().min(6).default('123456'),
+  TERM_START_DATE: z.string().default(''),
+  LOG_LEVEL: z.enum(['debug', 'info', 'warn', 'error']).default('info'),
+});
+
+const parsed = envSchema.safeParse(process.env);
+
+if (!parsed.success) {
+  const issues = parsed.error.issues
+    .map((issue) => `  - ${issue.path.join('.') || '(root)'}: ${issue.message}`)
+    .join('\n');
+  throw new Error(`环境变量校验失败，请检查 packages/server/.env（可从 .env.example 复制）：\n${issues}`);
+}
+
+const raw = parsed.data;
+
+/** 把 file:./prisma/dev.db 解析为绝对路径，保证任何 cwd 下都指向同一个数据库文件 */
+function resolveSqliteUrl(url: string): string {
+  if (!url.startsWith('file:')) return url;
+  const filePath = url.slice('file:'.length);
+  const absolute = path.isAbsolute(filePath) ? filePath : path.resolve(serverRoot, filePath);
+  return `file:${absolute.replace(/\\/g, '/')}`;
+}
+
+const isSqlite = raw.DATABASE_PROVIDER === 'sqlite';
+
+export const env = {
+  nodeEnv: raw.NODE_ENV,
+  isProduction: raw.NODE_ENV === 'production',
+  isDevelopment: raw.NODE_ENV === 'development',
+  port: raw.PORT,
+  databaseProvider: raw.DATABASE_PROVIDER,
+  /** 已规范化为绝对路径（SQLite）/ 原始连接串（MySQL） */
+  databaseUrl: isSqlite ? resolveSqliteUrl(raw.DATABASE_URL) : raw.DATABASE_URL,
+  rawDatabaseUrl: raw.DATABASE_URL,
+  jwtSecret: raw.JWT_SECRET,
+  jwtExpiresIn: raw.JWT_EXPIRES_IN,
+  /** true 表示允许所有来源，否则为白名单数组 */
+  corsOrigins:
+    raw.CORS_ORIGIN === '*'
+      ? true
+      : raw.CORS_ORIGIN.split(',')
+          .map((item) => item.trim())
+          .filter(Boolean),
+  bcryptRounds: raw.BCRYPT_ROUNDS,
+  /** 新增学生时未指定密码时的初始密码 */
+  defaultStudentPassword: raw.DEFAULT_STUDENT_PASSWORD,
+  termStartDate: raw.TERM_START_DATE,
+  logLevel: raw.LOG_LEVEL,
+  serverRoot,
+} as const;
+
+export type AppEnv = typeof env;