3 files changed, 137 insertions, 3 deletions

diff --git a/ui/src/stores/game.svelte.ts b/ui/src/stores/game.svelte.ts
index ca5dc2b..3efcf71 100644
--- a/ui/src/stores/game.svelte.ts
+++ b/ui/src/stores/game.svelte.ts
@@ -2,6 +2,7 @@ import { invoke } from "@tauri-apps/api/core";
 import type { Version } from "../types";
 import { uiState } from "./ui.svelte";
 import { authState } from "./auth.svelte";
+import { instancesState } from "./instances.svelte";
 
 export class GameState {
   versions = $state<Version[]>([]);
@@ -34,10 +35,19 @@ export class GameState {
       return;
     }
 
+    if (!instancesState.activeInstanceId) {
+      alert("Please select an instance first!");
+      uiState.setView("instances");
+      return;
+    }
+
     uiState.setStatus("Preparing to launch " + this.selectedVersion + "...");
-    console.log("Invoking start_game for version:", this.selectedVersion);
+    console.log("Invoking start_game for version:", this.selectedVersion, "instance:", instancesState.activeInstanceId);
     try {
-      const msg = await invoke<string>("start_game", { versionId: this.selectedVersion });
+      const msg = await invoke<string>("start_game", {
+        instanceId: instancesState.activeInstanceId,
+        versionId: this.selectedVersion,
+      });
       console.log("Response:", msg);
       uiState.setStatus(msg);
     } catch (e) {
diff --git a/ui/src/stores/instances.svelte.ts b/ui/src/stores/instances.svelte.ts
new file mode 100644
index 0000000..f4ac4e9
--- /dev/null
+++ b/ui/src/stores/instances.svelte.ts
@@ -0,0 +1,109 @@
+import { invoke } from "@tauri-apps/api/core";
+import type { Instance } from "../types";
+import { uiState } from "./ui.svelte";
+
+export class InstancesState {
+  instances = $state<Instance[]>([]);
+  activeInstanceId = $state<string | null>(null);
+  get activeInstance(): Instance | null {
+    if (!this.activeInstanceId) return null;
+    return this.instances.find((i) => i.id === this.activeInstanceId) || null;
+  }
+
+  async loadInstances() {
+    try {
+      this.instances = await invoke<Instance[]>("list_instances");
+      const active = await invoke<Instance | null>("get_active_instance");
+      if (active) {
+        this.activeInstanceId = active.id;
+      } else if (this.instances.length > 0) {
+        // If no active instance but instances exist, set the first one as active
+        await this.setActiveInstance(this.instances[0].id);
+      }
+    } catch (e) {
+      console.error("Failed to load instances:", e);
+      uiState.setStatus("Error loading instances: " + e);
+    }
+  }
+
+  async createInstance(name: string): Promise<Instance | null> {
+    try {
+      const instance = await invoke<Instance>("create_instance", { name });
+      await this.loadInstances();
+      uiState.setStatus(`Instance "${name}" created successfully`);
+      return instance;
+    } catch (e) {
+      console.error("Failed to create instance:", e);
+      uiState.setStatus("Error creating instance: " + e);
+      return null;
+    }
+  }
+
+  async deleteInstance(id: string) {
+    try {
+      await invoke("delete_instance", { instanceId: id });
+      await this.loadInstances();
+      // If deleted instance was active, set another as active
+      if (this.activeInstanceId === id) {
+        if (this.instances.length > 0) {
+          await this.setActiveInstance(this.instances[0].id);
+        } else {
+          this.activeInstanceId = null;
+        }
+      }
+      uiState.setStatus("Instance deleted successfully");
+    } catch (e) {
+      console.error("Failed to delete instance:", e);
+      uiState.setStatus("Error deleting instance: " + e);
+    }
+  }
+
+  async updateInstance(instance: Instance) {
+    try {
+      await invoke("update_instance", { instance });
+      await this.loadInstances();
+      uiState.setStatus("Instance updated successfully");
+    } catch (e) {
+      console.error("Failed to update instance:", e);
+      uiState.setStatus("Error updating instance: " + e);
+    }
+  }
+
+  async setActiveInstance(id: string) {
+    try {
+      await invoke("set_active_instance", { instanceId: id });
+      this.activeInstanceId = id;
+      uiState.setStatus("Active instance changed");
+    } catch (e) {
+      console.error("Failed to set active instance:", e);
+      uiState.setStatus("Error setting active instance: " + e);
+    }
+  }
+
+  async duplicateInstance(id: string, newName: string): Promise<Instance | null> {
+    try {
+      const instance = await invoke<Instance>("duplicate_instance", {
+        instanceId: id,
+        newName,
+      });
+      await this.loadInstances();
+      uiState.setStatus(`Instance duplicated as "${newName}"`);
+      return instance;
+    } catch (e) {
+      console.error("Failed to duplicate instance:", e);
+      uiState.setStatus("Error duplicating instance: " + e);
+      return null;
+    }
+  }
+
+  async getInstance(id: string): Promise<Instance | null> {
+    try {
+      return await invoke<Instance>("get_instance", { instanceId: id });
+    } catch (e) {
+      console.error("Failed to get instance:", e);
+      return null;
+    }
+  }
+}
+
+export const instancesState = new InstancesState();
diff --git a/ui/src/types/index.ts b/ui/src/types/index.ts
index 9a4da2b..a5b336e 100644
--- a/ui/src/types/index.ts
+++ b/ui/src/types/index.ts
@@ -1,4 +1,4 @@
-export type ViewType = "home" | "versions" | "settings" | "guide";
+export type ViewType = "home" | "versions" | "settings" | "guide" | "instances";
 
 export interface Version {
   id: string;
@@ -187,3 +187,18 @@ export interface InstalledForgeVersion {
 // ==================== Mod Loader Type ====================
 
 export type ModLoaderType = "vanilla" | "fabric" | "forge";
+
+// ==================== Instance Types ====================
+
+export interface Instance {
+  id: string;
+  name: string;
+  game_dir: string;
+  version_id?: string;
+  created_at: number;
+  last_played?: number;
+  icon_path?: string;
+  notes?: string;
+  mod_loader?: string;
+  mod_loader_version?: string;
+}