Backend: Auto load annotation (#1904)

Co-authored-by: Brady <thatgravyboat@gmail.com>

5 files changed, 112 insertions, 0 deletions

diff --git a/annotation-processors/build.gradle.kts b/annotation-processors/build.gradle.kts
new file mode 100644
index 000000000..c091ba6e3
--- /dev/null
+++ b/annotation-processors/build.gradle.kts
@@ -0,0 +1,27 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+plugins {
+    idea
+    kotlin("jvm")
+    java
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation(kotlin("stdlib-jdk8"))
+    implementation("com.google.devtools.ksp:symbol-processing-api:1.8.0-1.0.8")
+}
+
+tasks.withType<JavaCompile> {
+    if (JavaVersion.current().isJava9Compatible) {
+        options.release.set(8)
+    }
+}
+
+val compileKotlin: KotlinCompile by tasks
+compileKotlin.kotlinOptions {
+    jvmTarget = "1.8"
+}
diff --git a/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProcessor.kt b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProcessor.kt
new file mode 100644
index 000000000..bc7d262b4
--- /dev/null
+++ b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProcessor.kt
@@ -0,0 +1,68 @@
+package at.hannibal2.skyhanni.skyhannimodule
+
+import com.google.devtools.ksp.processing.CodeGenerator
+import com.google.devtools.ksp.processing.Dependencies
+import com.google.devtools.ksp.processing.KSPLogger
+import com.google.devtools.ksp.processing.Resolver
+import com.google.devtools.ksp.processing.SymbolProcessor
+import com.google.devtools.ksp.symbol.ClassKind
+import com.google.devtools.ksp.symbol.KSAnnotated
+import com.google.devtools.ksp.symbol.KSClassDeclaration
+import com.google.devtools.ksp.validate
+import java.io.OutputStreamWriter
+
+class ModuleProcessor(private val codeGenerator: CodeGenerator, private val logger: KSPLogger) : SymbolProcessor {
+
+    override fun process(resolver: Resolver): List<KSAnnotated> {
+
+        val symbols = resolver.getSymbolsWithAnnotation(SkyHanniModule::class.qualifiedName!!).toList()
+        val validSymbols = symbols.mapNotNull { validateSymbol(it) }
+
+        if (validSymbols.isNotEmpty()) {
+            generateFile(validSymbols)
+        }
+
+        return emptyList()
+    }
+
+    private fun validateSymbol(symbol: KSAnnotated): KSClassDeclaration? {
+        if (!symbol.validate()) {
+            logger.warn("Symbol is not valid: $symbol")
+            return null
+        }
+
+        if (symbol !is KSClassDeclaration) {
+            logger.error("@SkyHanniModule is only valid on class declarations", symbol)
+            return null
+        }
+
+        if (symbol.classKind != ClassKind.OBJECT) {
+            logger.error("@SkyHanniModule is only valid on kotlin objects", symbol)
+            return null
+        }
+
+        return symbol
+    }
+
+    private fun generateFile(symbols: List<KSClassDeclaration>) {
+        val dependencies = symbols.mapNotNull { it.containingFile }.toTypedArray()
+        val deps = Dependencies(true, *dependencies)
+
+        val file = codeGenerator.createNewFile(deps, "at.hannibal2.skyhanni.skyhannimodule", "LoadedModules")
+
+        OutputStreamWriter(file).use {
+            it.write("package at.hannibal2.skyhanni.skyhannimodule\n\n")
+            it.write("object LoadedModules {\n")
+            it.write("    val modules: List<Any> = listOf(\n")
+
+            symbols.forEach { symbol ->
+                it.write("        ${symbol.qualifiedName!!.asString()},\n")
+            }
+
+            it.write("    )\n")
+            it.write("}\n")
+        }
+
+        logger.warn("Generated LoadedModules file with ${symbols.size} modules")
+    }
+}
diff --git a/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProvider.kt b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProvider.kt
new file mode 100644
index 000000000..47d03655f
--- /dev/null
+++ b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/ModuleProvider.kt
@@ -0,0 +1,11 @@
+package at.hannibal2.skyhanni.skyhannimodule
+
+import com.google.devtools.ksp.processing.SymbolProcessor
+import com.google.devtools.ksp.processing.SymbolProcessorEnvironment
+import com.google.devtools.ksp.processing.SymbolProcessorProvider
+
+class ModuleProvider : SymbolProcessorProvider {
+    override fun create(environment: SymbolProcessorEnvironment): SymbolProcessor {
+        return ModuleProcessor(environment.codeGenerator, environment.logger)
+    }
+}
diff --git a/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/SkyHanniModule.kt b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/SkyHanniModule.kt
new file mode 100644
index 000000000..cb6b0eae4
--- /dev/null
+++ b/annotation-processors/src/main/kotlin/at/hannibal2/skyhanni/skyhannimodule/SkyHanniModule.kt
@@ -0,0 +1,5 @@
+package at.hannibal2.skyhanni.skyhannimodule
+
+@Target(AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.SOURCE)
+annotation class SkyHanniModule
diff --git a/annotation-processors/src/main/resources/META-INF/services/com.google.devtools.ksp.processing.SymbolProcessorProvider b/annotation-processors/src/main/resources/META-INF/services/com.google.devtools.ksp.processing.SymbolProcessorProvider
new file mode 100644
index 000000000..5f0d42dc4
--- /dev/null
+++ b/annotation-processors/src/main/resources/META-INF/services/com.google.devtools.ksp.processing.SymbolProcessorProvider
@@ -0,0 +1 @@
+at.hannibal2.skyhanni.skyhannimodule.ModuleProvider