Split skia download/unzipping task creation and invocation (#960)

This commit is first step in set of actions we need to take to build
skia-package via gradle in the skiko repository

However it makes sense on it's own as well.

skiko/build.gradle.kts

@@ -3,6 +3,8 @@ import org.gradle.crypto.checksum.Checksum
 import org.jetbrains.compose.internal.publishing.MavenCentralProperties
 import org.jetbrains.kotlin.gradle.targets.js.dsl.ExperimentalWasmDsl
 import tasks.configuration.*
+import kotlin.collections.HashMap
+import declareSkiaTasks
 
 plugins {
     kotlin("multiplatform")
@@ -46,6 +48,8 @@ repositories {
 }
 
 kotlin {
+    skikoProjectContext.declareSkiaTasks()
+
     if (supportAwt) {
         jvm("awt") {
             compilations.all {

skiko/buildSrc/src/main/kotlin/SkikoProjectContext.kt

@@ -5,6 +5,8 @@ import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.Copy
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.api.tasks.bundling.Jar
+import org.gradle.kotlin.dsl.register
+import org.gradle.kotlin.dsl.withType
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 import java.io.File
 
@@ -25,38 +27,70 @@ class SkikoProjectContext(
     val allJvmRuntimeJars = mutableMapOf<Pair<OS, Arch>, TaskProvider<Jar>>()
 }
 
+fun SkikoProjectContext.declareSkiaTasks() {
+    val basicConfigs = listOf("android", "ios", "iosSim", "linux", "macos", "tvos", "tvosSim", "wasm", "windows")
+
+    basicConfigs.forEach { config ->
+        (if (config == "wasm") listOf("wasm") else listOf("arm64", "x64")).forEach { arch ->
+            val taskNameSuffix = joinToTitleCamelCase(config, arch)
+            val target = "$config-$arch"
+            val skiaReleaseTag = project.property("dependencies.skia.$target") as String
+
+            val skiaBaseUrl = "https://github.com/JetBrains/skia-pack/releases/download/$skiaReleaseTag"
+
+            val artifactId = "Skia-${skiaReleaseTag}-${config}-$buildType-${arch}"
+
+            val downloadSkiaTask = project.tasks.register<Download>("downloadSkia$buildType$taskNameSuffix") {
+                group = "Skia Binaries"
+
+                val skiaUrl = "$skiaBaseUrl/$artifactId.zip"
+                description = "downloads $skiaUrl"
+
+                onlyIfModified(true)
+                src(skiaUrl)
+                dest(skiko.dependenciesDir.resolve(
+                    "skia/$skiaReleaseTag/Skia-$skiaReleaseTag-$config-Release-${arch}.zip")
+                )
+            }
+
+            project.tasks.register<Copy>("unzipSkia$buildType$taskNameSuffix") {
+                group = "Skia Binaries"
+
+                val outputDir = skiko.dependenciesDir.resolve("skia/$skiaReleaseTag/$artifactId")
+                description = "unzips to $outputDir"
+
+                dependsOn(downloadSkiaTask)
+                from(project.zipTree(downloadSkiaTask.get().dest))
+
+                into(outputDir)
+            }
+        }
+    }
+}
+
+
 /**
  * Do not call inside tasks.register or tasks.call callback
  * (tasks' registration during other task's registration is prohibited)
  */
 fun SkikoProjectContext.registerOrGetSkiaDirProvider(
     os: OS, arch: Arch, isUikitSim: Boolean = false
-): Provider<File> = with(this.project) {
+): Provider<File> {
     val taskNameSuffix = joinToTitleCamelCase(buildType.id, os.idWithSuffix(isUikitSim = isUikitSim), arch.id)
-    val skiaRelease = skiko.skiaReleaseFor(os, arch, buildType, isUikitSim)
-    val downloadSkia = tasks.registerOrGetTask<Download>("downloadSkia$taskNameSuffix") {
-        onlyIf { !dest.exists() }
-        onlyIfModified(true)
-        val skiaUrl = "https://github.com/JetBrains/skia-pack/releases/download/$skiaRelease.zip"
-        inputs.property("skia.url", skiaUrl)
-        src(skiaUrl)
-        dest(skiko.dependenciesDir.resolve("skia/$skiaRelease.zip"))
-    }.map { it.dest.absoluteFile }
 
-    return if (skiko.skiaDir != null) {
-        tasks.registerOrGetTask<DefaultTask>("skiaDir$taskNameSuffix") {
+    val skiaDir = skiko.skiaDir
+    return if (skiaDir != null) {
+        project.tasks.registerOrGetTask<DefaultTask>("skiaDir$taskNameSuffix") {
             // dummy task to simplify usage of the resulting provider (see `else` branch)
             // if a file provider is not created from a task provider,
             // then it cannot be used instead of a task in `dependsOn` clauses of other tasks.
             // e.g. the resulting `skiaDir` could not be used in `dependsOn` of CppCompile configuration
             enabled = false
-        }.map { skiko.skiaDir!!.absoluteFile }
+        }.map {
+            skiaDir.absoluteFile
+        }
     } else {
-        tasks.registerOrGetTask<Copy>("unzipSkia$taskNameSuffix") {
-            dependsOn(downloadSkia)
-            from(downloadSkia.map { zipTree(it) })
-            into(skiko.dependenciesDir.resolve("skia/$skiaRelease"))
-        }.map { it.destinationDir.absoluteFile }
+        project.tasks.withType<Copy>().named("unzipSkia$taskNameSuffix").map { it.destinationDir.absoluteFile }
     }
 }
 

skiko/buildSrc/src/main/kotlin/properties.kt

+import org.gradle.api.GradleException
 import org.gradle.api.Project
 import java.io.File
 
@@ -141,12 +142,6 @@ class SkikoProperties(private val myProject: Project) {
     val includeTestHelpers: Boolean
         get() = !isRelease
 
-    fun skiaReleaseFor(os: OS, arch: Arch, buildType: SkiaBuildType, isIosSim: Boolean = false): String {
-        val target = "${os.idWithSuffix(isUikitSim = isIosSim)}-${arch.id}"
-        val tag = myProject.property("dependencies.skia.$target") as String
-        return "${tag}/Skia-${tag}-${os.idWithSuffix(isUikitSim = isIosSim)}-${buildType.id}-${arch.id}"
-    }
-
     val releaseGithubVersion: String
         get() = (myProject.property("release.github.version") as String)
 
@@ -158,11 +153,12 @@ class SkikoProperties(private val myProject: Project) {
 
     // todo: make compatible with the configuration cache
     val skiaDir: File?
-        get() = (
-                System.getenv()["SKIA_DIR"]
-                ?: System.getProperty("skia.dir")
-                ?: myProject.findProperty("skia.dir")?.toString()
-            )?.let { File(it) }?.takeIf { it.isDirectory }
+        get() = (System.getenv()["SKIA_DIR"] ?: System.getProperty("skia.dir") ?: myProject.findProperty("skia.dir")
+            ?.toString())?.let { skiaDirProp ->
+                val file = File(skiaDirProp)
+                if (!file.isDirectory) throw (GradleException("\"skiko.skiaDir\" property was explicitly set to ${skiaDirProp} which is not resolved as a directory"))
+                file
+            }
 
     val composeRepoUrl: String
         get() = System.getenv("COMPOSE_REPO_URL") ?: "https://maven.pkg.jetbrains.space/public/p/compose/dev"