Config migration and also more atomic config saves (#420)

Config migration and also more atomic config saves #420

5 files changed, 114 insertions, 10 deletions

diff --git a/src/main/java/at/hannibal2/skyhanni/config/ConfigManager.kt b/src/main/java/at/hannibal2/skyhanni/config/ConfigManager.kt
index a882af5d4..23e9b6261 100644
--- a/src/main/java/at/hannibal2/skyhanni/config/ConfigManager.kt
+++ b/src/main/java/at/hannibal2/skyhanni/config/ConfigManager.kt
@@ -10,6 +10,7 @@ import at.hannibal2.skyhanni.utils.NEUInternalName
 import at.hannibal2.skyhanni.utils.NEUInternalName.Companion.asInternalName
 import at.hannibal2.skyhanni.utils.NEUItems
 import com.google.gson.GsonBuilder
+import com.google.gson.JsonObject
 import com.google.gson.TypeAdapter
 import com.google.gson.stream.JsonReader
 import com.google.gson.stream.JsonWriter
@@ -100,10 +101,6 @@ class ConfigManager {
         configFile = File(configDirectory, "config.json")
         sackFile = File(configDirectory, "sacks.json")
 
-        fixedRateTimer(name = "skyhanni-config-auto-save", period = 60_000L, initialDelay = 60_000L) {
-            saveConfig("auto-save-60s")
-        }
-
         logger.log("Trying to load config from $configFile")
 
         if (configFile!!.exists()) {
@@ -119,8 +116,10 @@ class ConfigManager {
 
 
                 logger.log("load-config-now")
+                val jsonObject = gson.fromJson(builder.toString(), JsonObject::class.java)
+                val newJsonObject = ConfigUpdaterMigrator.fixConfig(jsonObject)
                 features = gson.fromJson(
-                    builder.toString(),
+                    newJsonObject,
                     Features::class.java
                 )
                 logger.log("Loaded config from file")
@@ -166,6 +165,10 @@ class ConfigManager {
             saveConfig("blank config")
         }
 
+        fixedRateTimer(name = "skyhanni-config-auto-save", period = 60_000L, initialDelay = 60_000L) {
+            saveConfig("auto-save-60s")
+        }
+
         if (!::sackData.isInitialized) {
             logger.log("Creating blank sack data and saving")
             sackData = SackData()
@@ -201,11 +204,14 @@ class ConfigManager {
         try {
             logger.log("Saving config file")
             file.parentFile.mkdirs()
-            file.createNewFile()
-            BufferedWriter(OutputStreamWriter(FileOutputStream(file), StandardCharsets.UTF_8)).use { writer ->
+            val unit = file.parentFile.resolve("config.json.write")
+            unit.createNewFile()
+            BufferedWriter(OutputStreamWriter(FileOutputStream(unit), StandardCharsets.UTF_8)).use { writer ->
                 // TODO remove old "hidden" area
                 writer.write(gson.toJson(SkyHanniMod.feature))
             }
+            // Perform move — which is atomic, unlike writing — after writing is done.
+            unit.renameTo(file)
         } catch (e: IOException) {
             logger.log("Could not save config file to $file")
             e.printStackTrace()
diff --git a/src/main/java/at/hannibal2/skyhanni/config/ConfigUpdaterMigrator.kt b/src/main/java/at/hannibal2/skyhanni/config/ConfigUpdaterMigrator.kt
new file mode 100644
index 000000000..6b590a389
--- /dev/null
+++ b/src/main/java/at/hannibal2/skyhanni/config/ConfigUpdaterMigrator.kt
@@ -0,0 +1,85 @@
+package at.hannibal2.skyhanni.config
+
+import at.hannibal2.skyhanni.events.LorenzEvent
+import at.hannibal2.skyhanni.utils.LorenzLogger
+import com.google.gson.JsonElement
+import com.google.gson.JsonObject
+import com.google.gson.JsonPrimitive
+
+object ConfigUpdaterMigrator {
+    val logger = LorenzLogger("ConfigMigration")
+    val configVersion = 0
+    fun JsonElement.at(chain: List<String>, init: Boolean): JsonElement? {
+        if (chain.isEmpty()) return this
+        if (this !is JsonObject) return null
+        var obj = this.get(chain.first())
+        if (obj == null && init) {
+            obj = JsonObject()
+            this.add(chain.first(), obj)
+        }
+        return obj?.at(chain.drop(1), init)
+    }
+
+
+    data class ConfigFixEvent(
+        val old: JsonObject,
+        val new: JsonObject,
+        val oldVersion: Int,
+        var movesPerformed: Int,
+    ) : LorenzEvent() {
+        fun move(since: Int, oldPath: String, newPath: String, transform: (JsonElement) -> JsonElement = { it }) {
+            if (since <= oldVersion) {
+                logger.log("Skipping move from $oldPath to $newPath ($since <= $oldVersion)")
+                return
+            }
+            val op = oldPath.split(".")
+            val np = newPath.split(".")
+            val oldElem = old.at(op, false)
+            if (oldElem == null) {
+                logger.log("Skipping move from $oldPath to $newPath ($oldPath not present)")
+                return
+            }
+            val x = new.at(np.dropLast(1), true)
+            if (x !is JsonObject) {
+                logger.log("Catastrophic: element at path $old could not be relocated to $new, since another element already inhabits that path")
+                return
+            }
+            movesPerformed++
+            x.add(np.last(), transform(oldElem))
+            logger.log("Moved element from $oldPath to $newPath")
+        }
+    }
+
+    fun merge(a: JsonObject, b: JsonObject): Int {
+        var c = 0
+        b.entrySet().forEach {
+            val e = a.get(it.key)
+            val n = it.value
+            if (e is JsonObject && n is JsonObject) {
+                c += merge(e, n)
+            } else {
+                if (e != null) {
+                    logger.log("Encountered destructive merge. Erasing $e in favour of $n.")
+                    c++
+                }
+                a.add(it.key, n)
+            }
+        }
+        return c
+    }
+
+    fun fixConfig(config: JsonObject): JsonObject {
+        val lV = (config.get("lastVersion") as? JsonPrimitive)
+            ?.takeIf { it.isNumber }?.asInt ?: -1
+        if (lV == configVersion) return config
+        logger.log("Starting config transformation from $lV to $configVersion")
+        val migration = ConfigFixEvent(config, JsonObject().also {
+            it.add("lastVersion", JsonPrimitive(configVersion))
+        }, lV, 0).also { it.postAndCatch() }
+        logger.log("Transformations scheduled: ${migration.new}")
+        val mergesPerformed = merge(migration.old, migration.new)
+        logger.log("Migration done with $mergesPerformed merges and ${migration.movesPerformed} moves performed")
+        return migration.old
+    }
+
+}
\ No newline at end of file
diff --git a/src/main/java/at/hannibal2/skyhanni/config/Features.java b/src/main/java/at/hannibal2/skyhanni/config/Features.java
index 541b6e72b..149f66020 100644
--- a/src/main/java/at/hannibal2/skyhanni/config/Features.java
+++ b/src/main/java/at/hannibal2/skyhanni/config/Features.java
@@ -136,4 +136,8 @@ public class Features extends Config {
 
     @Expose
     public Storage storage = new Storage();
+
+    @Expose
+    public int lastVersion = ConfigUpdaterMigrator.INSTANCE.getConfigVersion();
+
 }
diff --git a/src/main/java/at/hannibal2/skyhanni/config/features/AshfangConfig.java b/src/main/java/at/hannibal2/skyhanni/config/features/AshfangConfig.java
index 575a1987d..9cffc4ed8 100644
--- a/src/main/java/at/hannibal2/skyhanni/config/features/AshfangConfig.java
+++ b/src/main/java/at/hannibal2/skyhanni/config/features/AshfangConfig.java
@@ -13,7 +13,7 @@ public class AshfangConfig {
     @ConfigOption(name = "Freeze", desc = "Show the cooldown for how long Ashfang blocks your abilities.")
     @ConfigEditorBoolean
     @FeatureToggle
-    public boolean freezeCooldown = false;
+    public boolean brrrrItsSoColdCooldownCooldown = false;
 
     @Expose
     public Position freezeCooldownPos = new Position(10, 10, false, true);
diff --git a/src/main/java/at/hannibal2/skyhanni/features/nether/ashfang/AshfangFreezeCooldown.kt b/src/main/java/at/hannibal2/skyhanni/features/nether/ashfang/AshfangFreezeCooldown.kt
index 0bccfe254..264b443eb 100644
--- a/src/main/java/at/hannibal2/skyhanni/features/nether/ashfang/AshfangFreezeCooldown.kt
+++ b/src/main/java/at/hannibal2/skyhanni/features/nether/ashfang/AshfangFreezeCooldown.kt
@@ -1,6 +1,7 @@
 package at.hannibal2.skyhanni.features.nether.ashfang
 
 import at.hannibal2.skyhanni.SkyHanniMod
+import at.hannibal2.skyhanni.config.ConfigUpdaterMigrator
 import at.hannibal2.skyhanni.events.GuiRenderEvent
 import at.hannibal2.skyhanni.events.LorenzChatEvent
 import at.hannibal2.skyhanni.features.damageindicator.BossType
@@ -34,12 +35,20 @@ class AshfangFreezeCooldown {
         val remainingLong = maxDuration - duration
         if (remainingLong > 0) {
             var format = TimeUtils.formatDuration(remainingLong, showMilliSeconds = true)
-            SkyHanniMod.feature.ashfang.freezeCooldownPos.renderString("§cAshfang Freeze: §a$format", posLabel = "Ashfang Freeze Cooldown")
+            SkyHanniMod.feature.ashfang.freezeCooldownPos.renderString(
+                "§cAshfang Freeze: §a$format",
+                posLabel = "Ashfang Freeze Cooldown"
+            )
         }
     }
 
+    @SubscribeEvent
+    fun onConfigFix(event: ConfigUpdaterMigrator.ConfigFixEvent) {
+        event.move(0, "ashfang.freezeCooldown", "ashfang.brrrrItsSoColdCooldownCooldown")
+    }
+
     private fun isEnabled(): Boolean {
-        return LorenzUtils.inSkyBlock && SkyHanniMod.feature.ashfang.freezeCooldown &&
+        return LorenzUtils.inSkyBlock && SkyHanniMod.feature.ashfang.brrrrItsSoColdCooldownCooldown &&
                 DamageIndicatorManager.isBossSpawned(BossType.NETHER_ASHFANG)
     }
 }
\ No newline at end of file