1 files changed, 85 insertions, 0 deletions
diff --git a/src/main/kotlin/util/net/HttpUtil.kt b/src/main/kotlin/util/net/HttpUtil.kt
new file mode 100644
index 0000000..50e0644
--- /dev/null
+++ b/src/main/kotlin/util/net/HttpUtil.kt
@@ -0,0 +1,85 @@
+package moe.nea.firmament.util.net
+
+import java.io.InputStream
+import java.net.URI
+import java.net.URL
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+import java.net.http.HttpResponse
+import java.nio.ByteBuffer
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.CompletionStage
+import java.util.concurrent.Flow
+import kotlinx.serialization.DeserializationStrategy
+import kotlinx.serialization.json.decodeFromStream
+import kotlinx.serialization.serializer
+import moe.nea.firmament.Firmament
+
+object HttpUtil {
+	val httpClient = HttpClient.newBuilder()
+		.build()
+
+	data class Request(val request: HttpRequest.Builder) {
+		fun <T> execute(bodyHandler: HttpResponse.BodyHandler<T>): CompletableFuture<HttpResponse<T>> {
+			return httpClient.sendAsync(request.build(), bodyHandler)
+		}
+
+		fun <T> forBody(bodyHandler: HttpResponse.BodyHandler<T>): CompletableFuture<T> {
+			return execute(bodyHandler).thenApply { it.body() }
+		}
+
+		fun forInputStream(): CompletableFuture<InputStream> {
+			return forBody(HttpResponse.BodyHandlers.ofInputStream())
+		}
+
+		inline fun <reified T> forJson(): CompletableFuture<T> {
+			return forJson(serializer())
+		}
+
+		fun <T> forJson(serializer: DeserializationStrategy<T>): CompletableFuture<T> {
+			return forBody(jsonBodyHandler(serializer))
+		}
+
+		fun header(key: String, value: String) {
+			request.header(key, value)
+		}
+	}
+
+	fun <T> jsonBodyHandler(serializer: DeserializationStrategy<T>): HttpResponse.BodyHandler<T> {
+		val inp = HttpResponse.BodyHandlers.ofInputStream()
+		return HttpResponse.BodyHandler {
+			val subscriber = inp.apply(it)
+			object : HttpResponse.BodySubscriber<T> {
+				override fun getBody(): CompletionStage<T> {
+					return subscriber.body.thenApply { Firmament.json.decodeFromStream(serializer, it) }
+				}
+
+				override fun onSubscribe(subscription: Flow.Subscription?) {
+					subscriber.onSubscribe(subscription)
+				}
+
+				override fun onNext(item: List<ByteBuffer?>?) {
+					subscriber.onNext(item)
+				}
+
+				override fun onError(throwable: Throwable?) {
+					subscriber.onError(throwable)
+				}
+
+				override fun onComplete() {
+					subscriber.onComplete()
+				}
+			}
+		}
+	}
+
+	fun request(url: String): Request = request(URI.create(url))
+	fun request(url: URL): Request = request(url.toURI())
+	fun request(url: URI): Request {
+		return Request(
+			HttpRequest.newBuilder(url)
+				.GET()
+				.header("user-agent", "Firmament/${Firmament.version}")
+		)
+	}
+}