// src/shared/types.ts
import type { ChromeUserMeta, ChromePlatformMeta } from "@nexus/chrome-adapter";

// Define your application-specific user metadata by extending ChromeUserMeta
// For example, if your content script adds a specific 'feature'
export interface MyUserMeta extends ChromeUserMeta {
  hasFeatureX?: boolean;
}

// You can use or extend ChromePlatformMeta directly
export type MyPlatformMeta = ChromePlatformMeta;

// src/shared/api.ts
import { TokenSpace } from "@nexus/core";
import type { MyUserMeta, MyPlatformMeta } from "./types";

// 1. Define the interface for your service
export interface IMyContentScriptAPI {
  getMessage(): Promise<string>;
}

// 2. Create a TokenSpace for structured token management
// This allows for hierarchical token IDs and default target inheritance.
const appSpace = new TokenSpace<MyUserMeta, MyPlatformMeta>({
  name: "my-extension",
});

// 3. Create a sub-space for content script services
// Define a default target for all tokens within this space
const contentScriptSpace = appSpace.tokenSpace("content-script-services", {
  defaultTarget: {
    matcher: (identity) => identity.context === "content-script",
    expects: "first", // Default to 'first' for content script calls
  },
});

// 4. Create a unique Token for the service within the defined space.
// The full ID will be "my-extension:content-script-services:my-service"
export const MyContentScriptAPI =
  contentScriptSpace.token<IMyContentScriptAPI>("my-service");

// src/content-script.ts
// IMPORTANT: This file MUST be imported at the very top of your content script entry file
import { Expose } from "@nexus/core";
import { usingContentScript } from "@nexus/chrome-adapter"; // Import the factory
import { MyContentScriptAPI, IMyContentScriptAPI } from "./shared/api";
import { MyUserMeta, MyPlatformMeta } from "./shared/types"; // Import your custom types

// 1. Initialize Nexus for the content script context.
// This sets up the endpoint, default meta, and connectTo background.
// Chain .configure() to add your custom user metadata.
usingContentScript<MyUserMeta, MyPlatformMeta>().configure({
  endpoint: {
    meta: {
      url: window.location.href, // Dynamic metadata for the content script
      // You can also add your custom `hasFeatureX: true` here
    },
  },
});

// 2. Expose the service implementation using the Token
@Expose(MyContentScriptAPI)
class ContentScriptService implements IMyContentScriptAPI {
  async getMessage(): Promise<string> {
    console.log("Content Script received request for message.");
    return "Hello from Content Script!";
  }
}

// Ensure the service is instantiated (if not using a factory in ExposeOptions)
new ContentScriptService();

// src/background.ts
// IMPORTANT: This file MUST be imported at the very top of your background script entry file
import { nexus } from "@nexus/core";
import { usingBackgroundScript } from "@nexus/chrome-adapter"; // Import the factory
import { MyContentScriptAPI } from "./shared/api";
import { MyUserMeta, MyPlatformMeta } from "./shared/types"; // Import your custom types

// 1. Initialize Nexus for the background script context.
// This sets up the endpoint and default meta for the background script.
usingBackgroundScript<MyUserMeta, MyPlatformMeta>();

// Example function to call the remote service
async function callContentScript() {
  try {
    // 2. Create a proxy for the remote service.
    // Leverage the default target defined in TokenSpace, or explicitly define it here.
    // The 'any-content-script' matcher is provided by usingBackgroundScript().
    const remoteContentScript = await nexus.create(MyContentScriptAPI, {
      target: {
        matcher: "any-content-script", // Use the named matcher provided by the Chrome adapter
      },
      // 'expects: "first"' is already the default for this TokenSpace, so it can be omitted
    });

    if (remoteContentScript) {
      // 3. Call the remote method as if it were local
      const message = await remoteContentScript.getMessage();
      console.log("Received message from content script:", message);
    } else {
      console.log("No content script found to connect to.");
    }
  } catch (error) {
    console.error("Failed to call content script:", error);
  }
}

// In a real Chrome Extension, you would trigger this call
// based on an event, e.g., chrome.action.onClicked, or chrome.tabs.onUpdated.
// For demonstration, let's call it after a short delay:
// Ensure the content script has time to connect.
setTimeout(() => {
  console.log("Attempting to call content script...");
  callContentScript();
}, 3000); // Adjust delay as needed