UI: Show hints of Gang mechanic in pre-endgame (#2723)

src/Gang/helpers.ts

@@ -0,0 +1,26 @@
+import { Result } from "@nsdefs";
+import { Player } from "@player";
+import { FactionName } from "../Enums";
+import { GangConstants } from "./data/Constants";
+
+export function canCreateGang(faction: FactionName): Result {
+  if (Player.gang) {
+    return { success: false, message: "You already have a gang." };
+  }
+  const checkResult = Player.canAccessGang();
+  if (!checkResult.success) {
+    return { success: false, message: checkResult.message };
+  }
+  if (!GangConstants.Names.includes(faction)) {
+    return {
+      success: false,
+      message: `${faction} does not allow creating a gang. You can only do that with ${GangConstants.Names.join(
+        ", ",
+      )}.`,
+    };
+  }
+  if (!Player.factions.includes(faction)) {
+    return { success: false, message: `You are not a member of ${faction}.` };
+  }
+  return { success: true };
+}