/**
 * Hugging Face Inference login flow.
 *
 * Hugging Face Inference Providers expose an OpenAI-compatible endpoint via
 * https://router.huggingface.co/v1.
 *
 * This is an API key flow:
 * 1. Open browser to Hugging Face token settings
 * 2. User creates/copies a token with Inference Providers permission
 * 3. User pastes the token into the CLI
 */

import { validateOpenAICompatibleApiKey } from "./api-key-validation";
import type { OAuthController } from "./types";

const AUTH_URL =
	"https://huggingface.co/settings/tokens/new?ownUserPermissions=inference.serverless.write&tokenType=fineGrained";
const API_BASE_URL = "https://router.huggingface.co/v1";
const VALIDATION_MODEL = "openai/gpt-oss-120b";

/**
 * Login to Hugging Face Inference Providers.
 *
 * Opens browser to token settings, prompts user to paste their API key.
 * Returns the API key directly (not OAuthCredentials - this isn't OAuth).
 */
export async function loginHuggingface(options: OAuthController): Promise<string> {
	if (!options.onPrompt) {
		throw new Error("Hugging Face login requires onPrompt callback");
	}

	options.onAuth?.({
		url: AUTH_URL,
		instructions:
			"Create/copy a token with Make calls to Inference Providers permission (usable as HUGGINGFACE_HUB_TOKEN or HF_TOKEN)",
	});

	const apiKey = await options.onPrompt({
		message: "Paste your Hugging Face token (HUGGINGFACE_HUB_TOKEN / HF_TOKEN)",
		placeholder: "hf_...",
	});

	if (options.signal?.aborted) {
		throw new Error("Login cancelled");
	}

	const trimmed = apiKey.trim();
	if (!trimmed) {
		throw new Error("API key is required");
	}

	options.onProgress?.("Validating API key...");
	await validateOpenAICompatibleApiKey({
		provider: "Hugging Face",
		apiKey: trimmed,
		baseUrl: API_BASE_URL,
		model: VALIDATION_MODEL,
		signal: options.signal,
	});

	return trimmed;
}