refactor: improve OptionsLoader a lot

src/main/kotlin/app/revanced/utils/OptionsLoader.kt

@@ -1,20 +1,19 @@
 package app.revanced.utils
 
 import app.revanced.cli.command.MainCommand.logger
+import app.revanced.patcher.Patcher
 import app.revanced.patcher.data.Data
 import app.revanced.patcher.extensions.PatchExtensions.options
 import app.revanced.patcher.extensions.PatchExtensions.patchName
 import app.revanced.patcher.patch.Patch
-import cc.ekblad.toml.encodeTo
+import cc.ekblad.toml.encodeToString
 import cc.ekblad.toml.model.TomlValue
 import cc.ekblad.toml.serialization.from
 import cc.ekblad.toml.tomlMapper
 import java.io.File
 
 private typealias PatchList = List<Class<out Patch<Data>>>
-private typealias OptionsMap = Map<String, Map<String, Any>>
+private typealias OptionsMap = MutableMap<String, MutableMap<String, Any>>
-
-private const val NULL = "null"
 
 object OptionsLoader {
     @JvmStatic
@@ -23,12 +22,9 @@ object OptionsLoader {
     @JvmStatic
     fun init(file: File, patches: PatchList) {
         if (!file.exists()) file.createNewFile()
-        val path = file.toPath()
+        val map = mapper.decodeWithDefaults(generateDefaults(patches), TomlValue.from(file.toPath()))
-        val map = mapper.decodeWithDefaults(
-            generateDefaults(patches),
-            TomlValue.from(path)
-        ).also { mapper.encodeTo(path, it) }
         readAndSet(map, patches)
+        save(map, file)
     }
 
     private fun readAndSet(map: OptionsMap, patches: PatchList) {
@@ -36,27 +32,46 @@ object OptionsLoader {
             val patch = patches.find { it.patchName == patchName } ?: continue
             val patchOptions = patch.options ?: continue
             for ((key, value) in options) {
+                if (value == "null") { // backwards compatibility, subject to removal
+                    options.remove(key)
+                    continue
+                }
                 try {
-                    patchOptions[key] = value.let {
+                    patchOptions[key] = value
-                        if (it == NULL) null else it
-                    }
                 } catch (e: Exception) {
-                    logger.warn("Error while setting option $key for patch $patchName: ${e.message}")
+                    logger.error("Error while setting option $key for patch $patchName: ${e.message}")
                     e.printStackTrace()
                 }
             }
         }
     }
 
+    private fun save(map: OptionsMap, file: File) {
+        val toml = mapper.encodeToString(map)
+        file.writeText(
+            """
+                # A list of options for each patch.
+                # This file does not contain all options by default.
+                # Run the CLI with the "--list --with-options" flags to see all available options.
+                # You can also run the CLI with the aforementioned flags and a patch name to see all available options for that patch.
+                # To set an option, add a line with the format "option = value".
+                # To remove or reset an option to its default value, delete the line.
+                # To reset all options to their default values, delete this file.
+                # 
+                # This file was generated by ReVanced Patcher version ${Patcher.version}.
+            """.trimIndent() + "\n\n$toml"
+        )
+    }
+
     private fun generateDefaults(patches: PatchList) = buildMap {
         for (patch in patches) {
             val options = patch.options ?: continue
             if (!options.iterator().hasNext()) continue
             put(patch.patchName, buildMap {
                 for (option in options) {
-                    put(option.key, option.value ?: NULL)
+                    put(option.key, option.value ?: continue)
                 }
-            })
+            } as MutableMap)
         }
-    }
+    } as MutableMap
 }