<?php
$mainSiteURL = "http://bonpharma.orionit.tech";

const DB_SERVER = "localhost";
const DB_USER = "PUMovMk1Kjb69i7";
const DB_PASSWORD = "SkD8tCxJPpagiQv";
const DB = "bonpharma";

/*
 * Database connection
 */
function connectDb()
{
    $db = new mysqli(DB_SERVER, DB_USER, DB_PASSWORD, DB);

    if ($db->connect_errno)
        echo "Failed to connect to MySQL: (" . $db->connect_errno . ") " . $db->connect_error;
    else
        $db->set_charset('utf8');

    return $db;
}

function performLogin($db, $user, $hash)
{
    if(!($saltQuery = $db->prepare("SELECT Salt FROM Users WHERE Username = ? LIMIT 1;")))
        $this->internal_error_with_msg("Prepare failed: (" . $db->errno . ") " . $db->error);

    if (!$saltQuery->bind_param("s", $user))
        $this->internal_error_with_msg("Binding parameters failed: (" . $saltQuery->errno . ") " . $saltQuery->error);

    $saltQuery->execute();

    $saltQuery->bind_result($salt);
    $saltQuery->store_result();

    if($saltQuery->num_rows() > 0)
    {
        $saltQuery->fetch();
        $saltQuery->close();

        $hash = strtolower($hash);
        $userHash = hash('sha512', $salt . $hash);

        if(!($userCheckQuery = $db->prepare("SELECT ID FROM Users WHERE Username = ? AND Hash = ? LIMIT 1;")))
            $this->internal_error_with_msg("Prepare failed: (" . $db->errno . ") " . $db->error);

        if (!$userCheckQuery->bind_param("ss", $user, $userHash))
            $this->internal_error_with_msg("Binding parameters failed: (" . $userCheckQuery->errno . ") " . $userCheckQuery->error);

        $userCheckQuery->execute();

        $userCheckQuery->bind_result($UID);
        $userCheckQuery->store_result();

        if($userCheckQuery->num_rows() > 0)
        {
            $userCheckQuery->fetch();
            $userCheckQuery->close();

            if(!($tokenQuery = $db->prepare("SELECT Token FROM UserTokens WHERE UserID = ? LIMIT 1;")))
                $this->internal_error_with_msg("Prepare failed: (" . $db->errno . ") " . $db->error);

            if (!$tokenQuery->bind_param("i", $UID))
                $this->internal_error_with_msg("Binding parameters failed: (" . $tokenQuery->errno . ") " . $tokenQuery->error);

            $tokenQuery->execute();

            $tokenQuery->bind_result($Token);
            $tokenQuery->store_result();

            if ($tokenQuery->num_rows > 0)
            {
                $tokenQuery->fetch();
                $tokenQuery->close();
                return $Token;
            }
            else
            {
                $tokenQuery->close();

                // Generate token for UID
                $Token = bin2hex(random_bytes(50));

                // Insert token
                if(!($insertTokenQuery = $db->prepare("INSERT INTO UserTokens (UserID, Token) VALUES (?, ?);")))
                    $this->internal_error_with_msg("Prepare failed: (" . $db->errno . ") " . $db->error);

                if (!$insertTokenQuery->bind_param("is", $UID, $Token))
                    $this->internal_error_with_msg("Binding parameters failed: (" . $insertTokenQuery->errno . ") " . $insertTokenQuery->error);

                $insertTokenQuery->execute();
                $insertTokenQuery->close();
                return $Token;
            }
        }
        else
            $userCheckQuery->close();
    }
    else
        $saltQuery->close();

    return "";
}

$db = connectDb();
?>