<?php

namespace MwgAuth\Controllers;

use MwgAuth\Core\Controller;
use MwgAuth\Models\User;

class ControllerV1 extends Controller
{
    public static function login(): string
    {
        self::requireMethod('POST');
        $input = self::getPost();
        if (null === $input) {
            return self::error(self::ERROR_INVALID_INPUT);
        }
        $userName = $input[self::PARAMETER_USERNAME] ?? null;
        if (null === $userName) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_USERNAME);
        }
        $password = $input[self::PARAMETER_PASSWORD] ?? null;
        if (null === $password) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_PASSWORD);
        }
        $user = User::load($userName, $password, $_SERVER['REMOTE_ADDR']);
        if (null === $user) {
            return self::error(self::ERROR_INVALID_PASSWORD);
        }
        return self::response([self::PARAMETER_AUTH => $user->getAuth()]);
    }

    public static function getToken(): string
    {
        self::requireMethod('POST');
        $input = self::getPost();
        if (null === $input) {
            return self::error(self::ERROR_INVALID_INPUT);
        }
        $auth = $input[self::PARAMETER_AUTH] ?? null;
        if (null === $auth) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_AUTH);
        }
        $callback = $input[self::PARAMETER_CALLBACK_URL] ?? null;
        if (null === $callback) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_CALLBACK_URL);
        }
        $user = User::verifyAuth($auth);
        if (null === $user) {
            return self::error(self::ERROR_INVALID_AUTH);
        }
        $token = $user->getToken($callback);
        return self::response([self::PARAMETER_TOKEN => $token]);
    }

    public static function getUser(): string
    {
        self::requireMethod('POST');
        $input = self::getPost();
        if (null === $input) {
            return self::error(self::ERROR_INVALID_INPUT);
        }
        $auth = $input[self::PARAMETER_AUTH] ?? null;
        if (null === $auth) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_AUTH);
        }
        $user = User::verifyAuth($auth);
        if (null === $user) {
            return self::error(self::ERROR_INVALID_AUTH);
        }
        $token = $input[self::PARAMETER_TOKEN] ?? null;
        if (null === $token) {
            return self::error(self::ERROR_MISSING_PARAMETER, self::PARAMETER_TOKEN);
        }
        if (!$user->verifyToken($token)) {
            return self::error(self::ERROR_INVALID_TOKEN);
        }
        $userData = $user->getLoginData($token);
        if (null === $userData) {
            return self::error(self::ERROR_INVALID_LOGIN);
        }
        return self::response($userData);
    }

    private static function json(array $values): string
    {
        return json_encode($values, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
    }

    private static function response(array $values): string
    {
        $response = [
            self::LABEL_ERROR_CODE => self::ERROR_OK,
            self::LABEL_STATUS => self::STATUS_OK,
            self::LABEL_DESCRIPTION => self::ERROR_DESCRIPTIONS[self::ERROR_OK],
        ];
        $response += $values;
        return self::json($response);
    }

    private static function error(int $errorCode, ...$parameters): string
    {
        $status = $errorCode == self::ERROR_OK ? self::STATUS_OK : self::STATUS_ERROR;
        return self::json([
            self::LABEL_ERROR_CODE => $errorCode,
            self::LABEL_STATUS => $status,
            self::LABEL_DESCRIPTION => vsprintf(self::ERROR_DESCRIPTIONS[$errorCode], $parameters),
        ]);
    }

    protected const LABEL_ERROR_CODE = 'code';
    protected const LABEL_DESCRIPTION = 'description';
    protected const LABEL_STATUS = 'status';

    protected const ERROR_OK = 0;
    protected const ERROR_INVALID_AUTH = 1;
    protected const ERROR_INVALID_LOGIN = 2;
    protected const ERROR_INVALID_TOKEN = 3;
    protected const ERROR_INVALID_INPUT = 4;
    protected const ERROR_MISSING_PARAMETER = 5;
    protected const ERROR_INVALID_PASSWORD = 6;

    protected const STATUS_OK = 'success';
    protected const STATUS_ERROR = 'error';

    protected const ERROR_DESCRIPTIONS = [
        self::ERROR_OK => 'success',
        self::ERROR_INVALID_AUTH => 'invalid or expired authorization',
        self::ERROR_INVALID_LOGIN => 'no login associated with this token',
        self::ERROR_INVALID_TOKEN => 'invalid or expired token',
        self::ERROR_INVALID_INPUT => 'invalid input',
        self::ERROR_MISSING_PARAMETER => "parameter '%s' is missing",
        self::ERROR_INVALID_PASSWORD => 'invalid username or password',
    ];

    protected const PARAMETER_AUTH = 'auth';
    protected const PARAMETER_CALLBACK_URL = 'callback';
    protected const PARAMETER_REDIRECT = 'redirect';
    protected const PARAMETER_TOKEN = 'token';
    protected const PARAMETER_USERNAME = 'username';
    protected const PARAMETER_PASSWORD = 'password';
}