From 80c2e809251cdb04d2dd3b3bfdbb8844bdfa31fa Mon Sep 17 00:00:00 2001
From: Sculas <contact@sculas.xyz>
Date: Wed, 7 Sep 2022 22:31:15 +0200
Subject: [PATCH] feat: deprecation for patches

---
 .../kotlin/app/revanced/patcher/Patcher.kt    |  5 +++++
 .../revanced/patcher/annotation/Deprecated.kt | 20 +++++++++++++++++++
 .../extensions/AnnotationExtensions.kt        | 18 ++++++++++-------
 3 files changed, 36 insertions(+), 7 deletions(-)
 create mode 100644 src/main/kotlin/app/revanced/patcher/annotation/Deprecated.kt

diff --git a/src/main/kotlin/app/revanced/patcher/Patcher.kt b/src/main/kotlin/app/revanced/patcher/Patcher.kt
index c202dc6f..eb83ec65 100644
--- a/src/main/kotlin/app/revanced/patcher/Patcher.kt
+++ b/src/main/kotlin/app/revanced/patcher/Patcher.kt
@@ -4,6 +4,7 @@ import app.revanced.patcher.data.Data
 import app.revanced.patcher.data.PackageMetadata
 import app.revanced.patcher.data.impl.findIndexed
 import app.revanced.patcher.extensions.PatchExtensions.dependencies
+import app.revanced.patcher.extensions.PatchExtensions.deprecated
 import app.revanced.patcher.extensions.PatchExtensions.patchName
 import app.revanced.patcher.extensions.nullOutputStream
 import app.revanced.patcher.fingerprint.method.utils.MethodFingerprintUtils.resolve
@@ -289,6 +290,10 @@ class Patcher(private val options: PatcherOptions) {
             return PatchResultError("'$patchName' is a resource patch, but resource patching is disabled")
         }
 
+        patch.deprecated?.let { (reason, replacement) ->
+            logger.warn("'$patchName' is deprecated: '$reason'" + if (replacement != null) ". Use '$replacement' instead." else "")
+        }
+
         // TODO: find a solution for this
         val data = if (isResourcePatch) {
             data.resourceData
diff --git a/src/main/kotlin/app/revanced/patcher/annotation/Deprecated.kt b/src/main/kotlin/app/revanced/patcher/annotation/Deprecated.kt
new file mode 100644
index 00000000..a6e3021e
--- /dev/null
+++ b/src/main/kotlin/app/revanced/patcher/annotation/Deprecated.kt
@@ -0,0 +1,20 @@
+package app.revanced.patcher.annotation
+
+import app.revanced.patcher.data.Data
+import app.revanced.patcher.patch.Patch
+import kotlin.reflect.KClass
+
+/**
+ * Declares a [Patch] deprecated for removal.
+ * @param reason The reason why the patch is deprecated.
+ * @param replacement The replacement for the deprecated patch, if any.
+ */
+@Target(AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+@Repeatable
+annotation class PatchDeprecated(
+    val reason: String,
+    val replacement: KClass<out Patch<Data>> = Patch::class
+    // Values cannot be nullable in annotations, so this will have to do.
+)
\ No newline at end of file
diff --git a/src/main/kotlin/app/revanced/patcher/extensions/AnnotationExtensions.kt b/src/main/kotlin/app/revanced/patcher/extensions/AnnotationExtensions.kt
index cf5ecf4c..c01945fa 100644
--- a/src/main/kotlin/app/revanced/patcher/extensions/AnnotationExtensions.kt
+++ b/src/main/kotlin/app/revanced/patcher/extensions/AnnotationExtensions.kt
@@ -1,9 +1,6 @@
 package app.revanced.patcher.extensions
 
-import app.revanced.patcher.annotation.Compatibility
-import app.revanced.patcher.annotation.Description
-import app.revanced.patcher.annotation.Name
-import app.revanced.patcher.annotation.Version
+import app.revanced.patcher.annotation.*
 import app.revanced.patcher.data.Data
 import app.revanced.patcher.fingerprint.method.impl.MethodFingerprint
 import app.revanced.patcher.patch.OptionsContainer
@@ -45,9 +42,16 @@ object PatchExtensions {
     val Class<out Patch<Data>>.description get() = recursiveAnnotation(Description::class)?.description
     val Class<out Patch<Data>>.dependencies get() = recursiveAnnotation(app.revanced.patcher.patch.annotations.DependsOn::class)?.dependencies
     val Class<out Patch<Data>>.compatiblePackages get() = recursiveAnnotation(Compatibility::class)?.compatiblePackages
-    val Class<out Patch<Data>>.options get() = kotlin.companionObjectInstance?.let {
-        (it as? OptionsContainer)?.options
-    }
+    val Class<out Patch<Data>>.options
+        get() = kotlin.companionObjectInstance?.let {
+            (it as? OptionsContainer)?.options
+        }
+    val Class<out Patch<Data>>.deprecated: Pair<String, KClass<out Patch<Data>>?>?
+        get() = recursiveAnnotation(PatchDeprecated::class)?.let {
+            it.reason to it.replacement.let { cl ->
+                if (cl == Patch::class) null else cl
+            }
+        }
 
     @JvmStatic
     fun Class<out Patch<Data>>.dependsOn(patch: Class<out Patch<Data>>): Boolean {