Native jni build (#5)

* Each native library is in its own jar. Got rid of cross compilation. The project is `secp256k1` and not `secp256k1-kmp`.

* Updated CI to use all 3 OS VMs

Co-authored-by: Salomon BRYS <salomon@kodein.net>

jni/jvm/build.gradle.kts

@@ -3,8 +3,27 @@ plugins {
     `maven-publish`
 }
 
-kotlin {
-    explicitApi()
+val currentOs = org.gradle.internal.os.OperatingSystem.current()
+val bash = if (currentOs.isWindows) "bash.exe" else "bash"
+
+val buildNativeHost by tasks.creating(Exec::class) {
+    group = "build"
+    dependsOn(":jni:generateHeaders")
+    dependsOn(":native:buildSecp256k1Host")
+
+    val target = when {
+        currentOs.isLinux -> "linux"
+        currentOs.isMacOsX -> "darwin"
+        currentOs.isWindows -> "mingw"
+        else -> error("Unsupported OS $currentOs")
+    }
+
+    inputs.files(projectDir.resolve("build.sh"))
+    outputs.dir(buildDir.resolve(target))
+
+    workingDir = projectDir
+    environment("TARGET", target)
+    commandLine(bash, "build.sh")
 }
 
 dependencies {
@@ -12,26 +31,17 @@ dependencies {
     implementation(kotlin("stdlib-jdk8"))
 }
 
-val copyJni by tasks.creating(Sync::class) {
-    dependsOn(":jni:buildNativeJni")
-    from(rootDir.resolve("jni/build/jni/linux/libsecp256k1-jni.so")) { rename { "libsecp256k1-jni-linux-x86_64.so" } }
-    from(rootDir.resolve("jni/build/jni/darwin/libsecp256k1-jni.dylib")) { rename { "libsecp256k1-jni-darwin-x86_64.dylib" } }
-    from(rootDir.resolve("jni/build/jni/mingw/secp256k1-jni.dll")) { rename { "secp256k1-jni-mingw-x86_64.dll" } }
-    into(buildDir.resolve("jniResources/fr/acinq/secp256k1/jni/native"))
-}
-
-(tasks["processResources"] as ProcessResources).apply {
-    dependsOn("copyJni")
-    from(buildDir.resolve("jniResources"))
-}
-
-java.withSourcesJar()
-
 publishing {
     publications {
         create<MavenPublication>("jvm") {
-            artifactId = "secp256k1-jni-jvm"
+            artifactId = "secp256k1-jni-jvm-extract"
             from(components["java"])
         }
     }
 }
+
+afterEvaluate {
+    tasks["clean"].doLast {
+        delete("$buildDir/build/cmake")
+    }
+}