Add auto create administrator when first startup

src/main/kotlin/top/fatweb/api/config/InitConfig.kt

@@ -0,0 +1,52 @@
+package top.fatweb.api.config
+
+import com.baomidou.mybatisplus.extension.kotlin.KtQueryWrapper
+import jakarta.annotation.PostConstruct
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import org.springframework.security.crypto.password.PasswordEncoder
+import org.springframework.stereotype.Component
+import top.fatweb.api.entity.permission.User
+import top.fatweb.api.service.IUserService
+import kotlin.random.Random
+
+@Component
+class InitConfig(
+    private val userService: IUserService, private val passwordEncoder: PasswordEncoder
+) {
+    private val logger: Logger = LoggerFactory.getLogger(this::class.java)
+
+    @PostConstruct
+    fun init() {
+        if (!userService.exists(KtQueryWrapper(User()).eq(User::id, 0))) {
+            val rawPassword = getRandPassword(10)
+            val encodedPassword = passwordEncoder.encode(rawPassword)
+            val user = User().apply {
+                id = 0
+                username = "admin"
+                password = encodedPassword
+                locking = 0
+                enable = 1
+            }
+            if (userService.save(user)) {
+                logger.warn("First startup, create administrator - username: admin, password: $rawPassword")
+                logger.warn("This information will only be shown once. Please change your password promptly after logging in.")
+            }
+        }
+
+    }
+
+    private fun getRandPassword(length: Int): String {
+        val characterSet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+        val random = Random(System.nanoTime())
+        val password = StringBuilder()
+
+        for (i in 0 until length) {
+            val rIndex = random.nextInt(characterSet.length)
+            password.append(characterSet[rIndex])
+        }
+
+        return password.toString()
+    }
+}