<?php

namespace authkit2\Observers;
use authkit2\Authkit2;
use authkit2\Models\Token;

/**
 * Watch for user models being loaded or saved and handle installing an
 * `authkit` object on them to allow the main application to easily interact
 * with other services as the user or fetch data from the OIDC provider.
 */
class UserObserver
{
	/**
	 * When a user model is saved we have to remove the authkit property from it
	 * to avoid Eloquent or another ORM from trying to save it. When we do so,
	 * we cache it here so we can restore it when the save is complete.
	 *
	 * @var array<mixed,string>
	 */
	protected static $token_cache = [];

	/**
	 * Run in response to a user model being loaded, locating their token and
	 * creating a client to place on the model
	 *
	 * @param mixed $user
	 * @return void
	 */
	public function retrieved($user): void
	{
		// Find the token + refresh token for the user
		$token = Token::where('user_id', $user->{$user->getAuthIdentifierName()})->first();

		// Create a token object
		$user->authkit = Authkit2::get_token($token->access_token, $token->refresh_token);

		// Set a refresh callback on the token -- when it's been refreshed,
		// save the new tokens.
		$user->authkit->setRefreshCallback(
			/**
			 * When a token has been refreshed, save the updated values
			 * to the token model
			 * @param \authkit2\Oidc\Token $oidc_token
			 * @return void
			 */
			function(\authkit2\Oidc\Token $oidc_token) use ($token) : void {
				$token->access_token = $oidc_token->getAccessToken();
				$token->refresh_token = $oidc_token->getRefreshToken();
				$token->save();
			});
	}

	/**
	 * Before we save a user model, remove the token/client so the ORM doesn't
	 * try and write those out.
	 *
	 * @param mixed $user
	 * @return void
	 */
	public function saving($user): void
	{
		if (isset($user->authkit))
			static::$token_cache[$user->{$user->getAuthIdentifierName()}] = $user->authkit;
		unset($user->authkit);
	}

	/**
	 * After a user model is saved, restore the client and token
	 *
	 * @param mixed $user
	 * @return void
	 */
	public function saved($user): void
	{
		$user_id = $user->{$user->getAuthIdentifierName()};
		if (isset(static::$token_cache[$user_id]))
		{
			$user->authkit = static::$token_cache[$user_id];
			unset(static::$token_cache[$user_id]);
		}

	}
}