class HomeController extends Controller
{
    private function getUserInformation(Request $request, $token) {
        $url = 'https://api.vk.com/method/users.get';
        $params = array(
            'uid'          => $request->session()->get('user_id'),
            'access_token' => $token,
            'fields'       => 'first_name,last_name'
        );
        $userInfo = json_decode(file_get_contents($url . '?' . urldecode(http_build_query($params))), true);
        return $userInfo;
    }

    private function getFriends(Request $request, $token) {
        $url = 'https://api.vk.com/method/friends.get';

        $params = array(
            'access_token' => $token,
            'order'        => 'random',
            'count'        => 5,
            'offset'       => 3,
            'fields'       => 'first_name,last_name'
        );
        $friends = json_decode(file_get_contents($url . '?' . urldecode(http_build_query($params))), true);
        return $friends;
    }

    public function index(Request $request) {
        $clientId = 0;
        $clientSecret = '0';
        $redirectUri = 'http://u3835.red.elastictech.org/';
        $display = 'page';
        $scope = 'friends';
        $responseType = 'code';

        if($request->session()->has('token')){
            $token = $request->session()->get('token');
            return view('auth',[
                'user_info' => $this->getUserInformation($request, $token),
                'friends'   => $this->getFriends($request, $token)
            ]);
        } else if ($request->has('code')) {
            $url = 'https://oauth.vk.com/access_token';
            $code = $request->input('code');

            $params = array(
                'client_id'     => $clientId,
                'redirect_uri'  => $redirectUri,
                'client_secret' => $clientSecret,
                'code'          => $code
            );

            $query = $url . '?' . urldecode(http_build_query($params));
            $response = json_decode(file_get_contents($query, true));
            $request->session()->put('token', $response['access_token']);
            $request->session()->put('user_id', $response['user_id']);
            return redirect('/');
        } else if ($request->has("error")){
            return view('welcome', [
                'error' => $request->input("error"),
                'error_description' => $request->input("error_description")
            ]);
        } else {
            $url = 'https://oauth.vk.com/authorize';

            $params = array(
                'client_id'     => $clientId,
                'redirect_uri'  => $redirectUri,
                'display'       => $display,
                'scope'         => $scope,
                'response_type' => $responseType
            );

            $query = $url . '?' . urldecode(http_build_query($params));

            return view('welcome', [
                'query' => $query
            ]);
        }
    }


    public function logout(Request $request){
        $request->session()->flush();
        return redirect('/');
    }
}