From 763718716d1fc9a600cb0907f0c2a67bc067fd73 Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Sun, 4 Sep 2022 15:07:30 +0600
Subject: [PATCH] improve reconnect feature

---
 .../inmo/plagubot/config/DBConnectOptions.kt  |  9 +++++
 .../inmo/plagubot/config/DatabaseConfig.kt    | 40 +++++++++----------
 template.config.json                          |  5 ++-
 3 files changed, 31 insertions(+), 23 deletions(-)
 create mode 100644 bot/src/main/kotlin/dev/inmo/plagubot/config/DBConnectOptions.kt

diff --git a/bot/src/main/kotlin/dev/inmo/plagubot/config/DBConnectOptions.kt b/bot/src/main/kotlin/dev/inmo/plagubot/config/DBConnectOptions.kt
new file mode 100644
index 0000000..d072b3f
--- /dev/null
+++ b/bot/src/main/kotlin/dev/inmo/plagubot/config/DBConnectOptions.kt
@@ -0,0 +1,9 @@
+package dev.inmo.plagubot.config
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class DBConnectOptions(
+    val attempts: Int = 3,
+    val delay: Long = 1000L
+)
diff --git a/bot/src/main/kotlin/dev/inmo/plagubot/config/DatabaseConfig.kt b/bot/src/main/kotlin/dev/inmo/plagubot/config/DatabaseConfig.kt
index 0291200..6b864b8 100644
--- a/bot/src/main/kotlin/dev/inmo/plagubot/config/DatabaseConfig.kt
+++ b/bot/src/main/kotlin/dev/inmo/plagubot/config/DatabaseConfig.kt
@@ -1,5 +1,8 @@
 package dev.inmo.plagubot.config
 
+import dev.inmo.kslog.common.e
+import dev.inmo.kslog.common.logger
+import kotlinx.coroutines.delay
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.Transient
 import org.jetbrains.exposed.sql.Database
@@ -18,29 +21,22 @@ data class DatabaseConfig(
     val driver: String = JDBC::class.qualifiedName!!,
     val username: String = "",
     val password: String = "",
-    val waitForConnection: Boolean = true
+    val reconnectOptions: DBConnectOptions? = DBConnectOptions()
 ) {
     @Transient
-    val database: Database by lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
-        while (true) {
-            return@lazy try {
-                Database.connect(
-                    url,
-                    driver,
-                    username,
-                    password
-                ).also {
-                    it.transactionManager.defaultIsolationLevel = Connection.TRANSACTION_SERIALIZABLE // Or Connection.TRANSACTION_READ_UNCOMMITTED
-                }
-            } catch (e: Throwable) {
-                if (waitForConnection) {
-                    Thread.sleep(1000L)
-                    continue
-                } else {
-                    throw e
-                }
+    val database: Database = (0 until (reconnectOptions ?.attempts ?: 1)).firstNotNullOfOrNull {
+        runCatching {
+            Database.connect(
+                url,
+                driver,
+                username,
+                password
+            ).also {
+                it.transactionManager.defaultIsolationLevel = Connection.TRANSACTION_SERIALIZABLE // Or Connection.TRANSACTION_READ_UNCOMMITTED
             }
-        }
-        error("Unable to get database by some reason")
-    }
+        }.onFailure {
+            logger.e(it)
+            Thread.sleep(reconnectOptions ?.delay ?: return@onFailure)
+        }.getOrNull()
+    } ?: error("Unable to create database")
 }
diff --git a/template.config.json b/template.config.json
index ad6d9c5..4d7245f 100644
--- a/template.config.json
+++ b/template.config.json
@@ -4,7 +4,10 @@
     "driver": "org.sqlite.JDBC",
     "username": "OPTIONAL username",
     "password": "OPTIONAL password",
-    "waitForConnection": true
+    "reconnectOptions": {
+      "attempts": 3,
+      "delay": 1000
+    }
   },
   "botToken": "1234567890:ABCDEFGHIJKLMNOP_qrstuvwxyz12345678",
   "plugins": [