api url with redirect to discord invite

src/main/java/me/youhavetrouble/inviter/Main.java

@@ -98,4 +98,8 @@ public class Main {
         LOGGER.info("Welcome to the Inviter Application!");
     }
 
+    public static Storage getStorage() {
+        return storage;
+    }
+
 }

src/main/java/me/youhavetrouble/inviter/http/ApiServer.java

@@ -2,6 +2,7 @@ package me.youhavetrouble.inviter.http;
 
 import com.sun.net.httpserver.HttpServer;
 import me.youhavetrouble.inviter.Main;
+import me.youhavetrouble.inviter.http.endpoints.HandlerKernel;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
@@ -14,6 +15,7 @@ public class ApiServer {
     public ApiServer(String hostname, int port) throws IllegalArgumentException, IOException {
         server = HttpServer.create(new InetSocketAddress(hostname, port), 0);
         server.setExecutor(Executors.newVirtualThreadPerTaskExecutor());
+        server.createContext("/", new HandlerKernel());
         server.start();
         Main.LOGGER.info("Http API server started on {}:{}", hostname, port);
     }

src/main/java/me/youhavetrouble/inviter/http/endpoints/EndpointHandler.java

@@ -0,0 +1,15 @@
+package me.youhavetrouble.inviter.http.endpoints;
+
+import com.sun.net.httpserver.HttpExchange;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.IOException;
+import java.util.regex.Pattern;
+
+public interface EndpointHandler {
+
+    @NotNull Pattern pathPattern();
+
+    void handle(@NotNull HttpExchange exchange) throws IOException;
+
+}

src/main/java/me/youhavetrouble/inviter/http/endpoints/GetDiscordInviteByGuildId.java

@@ -0,0 +1,74 @@
+package me.youhavetrouble.inviter.http.endpoints;
+
+import com.sun.net.httpserver.HttpExchange;
+import me.youhavetrouble.inviter.DiscordInvite;
+import me.youhavetrouble.inviter.Main;
+import me.youhavetrouble.inviter.storage.Storage;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.IOException;
+import java.util.regex.Pattern;
+
+public class GetDiscordInviteByGuildId implements EndpointHandler {
+
+    private final Pattern pathPattern = Pattern.compile("^/api/v1/discord/\\d{10,18}$");
+
+    @NotNull
+    @Override
+    public Pattern pathPattern() {
+        return pathPattern;
+    }
+
+    @Override
+    public void handle(@NotNull HttpExchange exchange) throws IOException {
+        if (!exchange.getRequestMethod().equals("GET")) {
+            exchange.sendResponseHeaders(405, -1); // Method Not Allowed
+            return;
+        }
+
+        String path = exchange.getRequestURI().getPath();
+
+        String[] parts = path.split("/");
+        String guildId = parts[parts.length - 1];
+        long guildIdLong;
+        try {
+            guildIdLong = Long.parseLong(guildId);
+        } catch (NumberFormatException e) {
+            exchange.sendResponseHeaders(400, -1); // Bad Request
+            return;
+        }
+
+        Storage storage = Main.getStorage();
+        DiscordInvite invite = storage.getInvite(guildIdLong);
+
+        if (invite == null) {
+            exchange.sendResponseHeaders(404, -1); // Not Found
+            return;
+        }
+
+        String inviteUrl = "https://discord.gg/" + invite.code();
+
+        switch (exchange.getRequestHeaders().getFirst("Accept")) {
+            case "text/plain" -> {
+                exchange.getResponseHeaders().set("Content-Type", "text/plain");
+                exchange.sendResponseHeaders(200, inviteUrl.length());
+                exchange.getResponseBody().write(inviteUrl.getBytes());
+            }
+            case "application/json" -> {
+                exchange.getResponseHeaders().set("Content-Type", "application/json");
+                String jsonResponse = "{\"url\": \"" + inviteUrl + "\"}";
+                exchange.sendResponseHeaders(200, jsonResponse.length());
+                exchange.getResponseBody().write(jsonResponse.getBytes());
+            }
+            default -> {
+                exchange.getResponseHeaders().set("Location", inviteUrl);
+                exchange.sendResponseHeaders(307, -1);
+            }
+        }
+
+
+
+    }
+
+
+}

src/main/java/me/youhavetrouble/inviter/http/endpoints/HandlerKernel.java

@@ -0,0 +1,43 @@
+package me.youhavetrouble.inviter.http.endpoints;
+
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import me.youhavetrouble.inviter.Main;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+public class HandlerKernel implements HttpHandler {
+
+    private final Set<EndpointHandler> handlers = new HashSet<>();
+
+    public HandlerKernel() {
+        handlers.add(new GetDiscordInviteByGuildId());
+    }
+
+    @Override
+    public void handle(HttpExchange exchange) throws IOException {
+
+        String path = exchange.getRequestURI().getPath();
+        if (path.endsWith("/")) path = path.substring(0, path.length() - 1);
+        exchange.getResponseHeaders().set("Access-Control-Allow-Origin", "*");
+        exchange.getResponseHeaders().set("Access-Control-Allow-Methods", "*");
+        exchange.getResponseHeaders().set("Access-Control-Allow-Headers", "Content-Type");
+
+        for (EndpointHandler handler : handlers) {
+            if (handler.pathPattern().matcher(path).matches()) {
+                handler.handle(exchange);
+                return;
+            }
+        }
+
+        try {
+            exchange.sendResponseHeaders(404, -1);
+            exchange.getResponseBody().close();
+        } catch (Exception e) {
+            Main.LOGGER.error("Error handling request for {}: {}", path, e.getMessage());
+        }
+
+    }
+}