<?php

namespace App\Lib\CafelApi\Transport;

use App\Enums\ApiStatus;
use App\Exceptions\CafelApiException;
use App\Lib\CafelApi\Models\CafelClientModel;

/**
 * @ignore
 *
 * This class contains static api credentials
 * It handles a request to get a response
 *
 * @package LDCCrmClient
 * @subpackage transport
 */
class ApiInterface
{
    /**
     * The api endpoint url
     *
     * @var string
     */
    protected static $endpoint;

    /**
     * The api user
     *
     * @var string
     */
    protected static $user;

    /**
     * The api user password
     *
     * @var string
     */
    protected static $password;

    /**
     * The api token
     * ! For the service that should be stateless
     *
     * @var string
     */
    protected static $token;

    /**
     * CafelApi
     *
     * @param string|null $endpoint The api endpoint url.
     * @param string|null $user     The api user.
     * @param string|null $password The api password.
     * @throws \App\Exceptions\CafelApiException If cafel.user, cafel.password or
     * cafel.endpoint is missing on .env file or in laravel config. Or
     * if authentification to the service failed.
     */
    public function __construct(string $endpoint = null, string $user = null, string $password = null)
    {
        self::$endpoint = self::$endpoint ?: $endpoint;
        self::$user     = self::$user ?: $user;
        self::$password = self::$password ?: $password;

        static::$user     = static::$user ?: config('cafel.user');
        static::$password = static::$password ?: config('cafel.password');
        static::$endpoint = static::$endpoint ?: config('cafel.endpoint');

        if (!self::$user or !self::$password or !self::$endpoint) {
            throw new CafelApiException(
                'Either config or .env file need to have the token var set (cafel.user, cafel.password, cafel.endpoint)'
            );
        }
        $this->authenticate();
    }

    /**
     * Login to the api
     * !That should be stateless !!!!!
     *
     * @return void
     * @throws CafelApiException If Authentification failed.
     */
    private function authenticate()
    {
        $request  = CafelClientModel::getResquest(
            'cafel.users.connect',
            [],
            [
                'Login' => static::$user,
                'Password' => static::$password
            ]
        );
        $response = $this->call($request);

        if (!isset($response->body['token'])) {
            throw new CafelApiException('Missing api token after authentification');
        }

        self::$token = $response->body['token'];
    }

    /**
     * Make a crm http call to get a reponse
     *
     * @param \App\Lib\CafelApi\Transport\Request $request
     * @return \App\Lib\CafelApi\Transport\Response
     * @throws \App\Exceptions\CafelApiException If reponse status is KO or not Json.
     */
    public function call(Request $request): Response
    {
        $response = $this->processRequest($request);

        // * Handle response Status.
        if ($response->status->equals(ApiStatus::KO())) {
            throw new CafelApiException($response->message, $response->httpCode);
        }

        return $response;
    }

    /**
     * Process request
     *
     * @param \App\Lib\CafelApi\Transport\Request $request
     * @return \App\Lib\CafelApi\Transport\Response
     * @throws \App\Exceptions\CafelApiException If HTTP response body in not JSON.
     */
    private function processRequest(Request $request): Response
    {
        $this->setCredentials($request);
        $this->setHeaders($request);
        $request->setEndpoint(self::$endpoint);

        /** @var \Psr\Http\Message\ResponseInterface $response */
        $response = $request->call();
        $status   = in_array($response->getStatusCode(), [200, 201]) ?
            ApiStatus::OK() : ApiStatus::KO();

        return new Response($status, $response, $request);
    }

    /**
     * Add spécific headers to the request
     *
     * @param \App\Lib\CafelApi\Transport\Request $request
     * @return void
     */
    private function setHeaders(Request &$request): void
    {
        $headers = [
            'User-Agent' => sprintf('BOGT CAFEL API client version %s', config('cafel.client_version')),
            'Accept'     => 'application/json',
            'Content-Type' => 'application/json'
        ];
        $request->addHeaders($headers);
    }

    /**
     * Inject bearer credentials into the request
     *
     * @param \LDC\LDCCRM\Transport\Request $request
     * @return void
     */
    protected function setCredentials(Request $request)
    {
        if (self::$token) {
            $request->addHeaders([
                'Authorization' => implode(',', [
                    sprintf('Bearer %s', self::$token)
                ])
            ]);
        }
    }
}