feat: Use old-style server.dir value as a fallback

Author: osipxd

src/main/kotlin/server/DeprecatedServerProperties.kt

@@ -0,0 +1,77 @@
+package ru.endlesscode.bukkitgradle.server
+
+import org.gradle.api.provider.Provider
+import org.gradle.api.provider.ProviderFactory
+import org.slf4j.LoggerFactory
+import java.io.File
+import java.util.*
+
+internal class DeprecatedServerProperties(rootDir: File, private val providers: ProviderFactory) {
+
+    val devServerDir: File?
+
+    private val logger = LoggerFactory.getLogger("DeprecatedServerProperties")
+    private val properties = Properties()
+
+    private val propertiesFile = File(rootDir, NAME)
+
+    init {
+        if (propertiesFile.exists()) {
+            properties.load(propertiesFile.reader())
+        }
+
+        // Read properties eagerly to show deprecation warning
+        devServerDir = getDir(DEV_SERVER_DIR)
+        getDir(BUILD_TOOLS_DIR)
+    }
+
+    private fun getDir(property: Property): File? {
+        val path = get(property) ?: return null
+
+        showDeprecationWarning(property)
+        return File(path)
+            .absoluteFile
+            .also { it.mkdirs() }
+    }
+
+    private fun get(property: Property): String? {
+        val localProp = properties.getProperty(property.name)
+        val globalEnv = getEnvProvider(property.envVariable)
+        return localProp ?: globalEnv.orNull
+    }
+
+    private fun getEnvProvider(name: String): Provider<String> {
+        return providers.environmentVariable(name)
+    }
+
+    private fun showDeprecationWarning(property: Property) {
+        logger.warn(
+            """
+            Property '${property.name}' is Deprecated.
+            ${property.replacementNote}
+            Please, remove the property from $NAME and unset '${property.envVariable}' environment variable.
+            """.trimIndent()
+        )
+    }
+
+    private data class Property(
+        val name: String,
+        val envVariable: String,
+        val replacementNote: String,
+    )
+
+    private companion object {
+        private const val NAME: String = "local.properties"
+
+        private val BUILD_TOOLS_DIR: Property = Property(
+            name = "buildtools.dir",
+            envVariable = "BUKKIT_BUILDTOOLS_HOME",
+            replacementNote = "Building and running Spigot server is not supported anymore.",
+        )
+        private val DEV_SERVER_DIR: Property = Property(
+            name = "server.dir",
+            envVariable = "BUKKIT_DEV_SERVER_HOME",
+            replacementNote = "Set Gradle property 'bukkitgradle.server.dir' in \$HOME/.gradle/gradle.properties instead.",
+        )
+    }
+}

src/main/kotlin/server/DevServerPlugin.kt

@@ -59,7 +59,11 @@ public class DevServerPlugin : Plugin<Project> {
     }
 
     private fun Project.resolveConfiguredServerDir(): Provider<Directory>? {
-        val serverDirProperty = providers.gradleProperty("bukkitgradle.server.dir").orNull ?: return null
+        val deprecated = DeprecatedServerProperties(rootDir, providers)
+
+        val serverDirProperty = providers.gradleProperty("bukkitgradle.server.dir")
+            .orElse(provider { deprecated.devServerDir?.absolutePath })
+            .orNull ?: return null
         val serverDirFile = provider { File(serverDirProperty).absoluteFile }
         return layout.dir(serverDirFile)
     }