Exposing Signal CLI as HTTP Server (#1078)

[signal-cli] / src / main / java / org / asamk / signal / http / HttpServerHandler.java

diff --git a/src/main/java/org/asamk/signal/http/HttpServerHandler.java b/src/main/java/org/asamk/signal/http/HttpServerHandler.java
new file mode 100644 (file)
index 0000000..b2544b2
--- /dev/null
+++ b/src/main/java/org/asamk/signal/http/HttpServerHandler.java
@@ -0,0 +1,110 @@
+package org.asamk.signal.http;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpServer;
+
+import org.asamk.signal.commands.Commands;
+import org.asamk.signal.jsonrpc.JsonRpcReader;
+import org.asamk.signal.jsonrpc.JsonRpcResponse;
+import org.asamk.signal.jsonrpc.JsonRpcSender;
+import org.asamk.signal.jsonrpc.SignalJsonRpcCommandHandler;
+import org.asamk.signal.manager.Manager;
+import org.asamk.signal.manager.MultiAccountManager;
+import org.asamk.signal.util.Util;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.concurrent.Executors;
+
+public class HttpServerHandler {
+
+    private final static Logger logger = LoggerFactory.getLogger(HttpServerHandler.class);
+
+    private final ObjectMapper objectMapper = Util.createJsonObjectMapper();
+
+    private final InetSocketAddress address;
+
+    private final SignalJsonRpcCommandHandler commandHandler;
+
+    public HttpServerHandler(final InetSocketAddress address, final Manager m) {
+        this.address = address;
+        commandHandler = new SignalJsonRpcCommandHandler(m, Commands::getCommand);
+    }
+
+    public HttpServerHandler(final InetSocketAddress address, final MultiAccountManager c) {
+        this.address = address;
+        commandHandler = new SignalJsonRpcCommandHandler(c, Commands::getCommand);
+    }
+
+    public void init() throws IOException {
+
+            logger.info("Starting server on " + address.toString());
+
+            final var server = HttpServer.create(address, 0);
+            server.setExecutor(Executors.newFixedThreadPool(10));
+
+            server.createContext("/api/v1/rpc", httpExchange -> {
+
+                if (!"POST".equals(httpExchange.getRequestMethod())) {
+                    sendResponse(405, null, httpExchange);
+                    return;
+                }
+
+                if (!"application/json".equals(httpExchange.getRequestHeaders().getFirst("Content-Type"))) {
+                    sendResponse(415, null, httpExchange);
+                    return;
+                }
+
+                try {
+
+                    final Object[] result = {null};
+                    final var jsonRpcSender = new JsonRpcSender(s -> {
+                        if (result[0] != null) {
+                            throw new AssertionError("There should only be a single JSON-RPC response");
+                        }
+
+                        result[0] = s;
+                    });
+
+                    final var jsonRpcReader = new JsonRpcReader(jsonRpcSender, httpExchange.getRequestBody());
+                    jsonRpcReader.readMessages((method, params) -> commandHandler.handleRequest(objectMapper, method, params),
+                            response -> logger.debug("Received unexpected response for id {}", response.getId()));
+
+                    if (result[0] !=null) {
+                        sendResponse(200, result[0], httpExchange);
+                    } else {
+                        sendResponse(201, null, httpExchange);
+                    }
+
+                }
+                catch (Throwable aEx) {
+                    logger.error("Failed to process request.", aEx);
+                    sendResponse(200, JsonRpcResponse.forError(
+                            new JsonRpcResponse.Error(JsonRpcResponse.Error.INTERNAL_ERROR,
+                            "An internal server error has occurred.", null), null), httpExchange);
+                }
+            });
+
+            server.start();
+
+    }
+
+    private void sendResponse(int status, Object response, HttpExchange httpExchange) throws IOException {
+        if (response != null) {
+            final var byteResponse = objectMapper.writeValueAsBytes(response);
+
+            httpExchange.getResponseHeaders().add("Content-Type", "application/json");
+            httpExchange.sendResponseHeaders(status, byteResponse.length);
+
+            httpExchange.getResponseBody().write(byteResponse);
+        } else {
+            httpExchange.sendResponseHeaders(status, 0);
+        }
+
+        httpExchange.getResponseBody().close();
+    }
+
+}