import { Client } from "@notionhq/client";
import type { ClientOptions } from "@notionhq/client/build/src/Client.js";

export type CapabilityContext = {
	/** Notion API SDK client for this execution. */
	notion: Client;
};

const LOCAL_FIX_STEPS =
	"\n\nFor local execution:\n" +
	"1. Create a personal access token at https://app.notion.com/developers/tokens\n" +
	"2. Add NOTION_API_TOKEN=<your-token> to your .env file\n\n" +
	"Deployed apps receive Notion API credentials automatically. Do not push NOTION_API_TOKEN.";

function missingTokenMessage(): string {
	if (process.env.NOTION_WORKFLOW_STEP_DIRECTORY) {
		return (
			"Notion API access is not configured for this deployed workflow. " +
			"In Notion, open Developer Tools → Workers, select this workflow, and grant access to the pages or databases it uses. " +
			"The runtime provides NOTION_API_TOKEN automatically after access is configured; do not set or push it yourself."
		);
	}

	return (
		"NOTION_API_TOKEN is not set. " +
		"context.notion requires an API token when an app capability runs locally." +
		LOCAL_FIX_STEPS
	);
}

function createUnauthenticatedNotionProxy(): Client {
	return new Proxy({} as Client, {
		get(_target, prop) {
			if (prop === "then" || typeof prop === "symbol") {
				return undefined;
			}
			throw new Error(missingTokenMessage());
		},
	});
}

export function createCapabilityContext(): CapabilityContext {
	const options: ClientOptions = {};

	if (process.env.NOTION_API_BASE_URL) {
		options.baseUrl = process.env.NOTION_API_BASE_URL;
	}

	if (!process.env.NOTION_API_TOKEN) {
		return { notion: createUnauthenticatedNotionProxy() };
	}

	options.auth = process.env.NOTION_API_TOKEN;
	const notion = new Client(options);

	return { notion };
}