<?php

/*
 * SCROTT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * For more information, please refer to UNLICENSE
 */

require_once "class/obj.class.php";

/*
 * This file defines various functions which exist in the global namespace.
 * These are utility functions and constants for the Scrott application.
 */

define("__VERSION__", "v0.0");

/*
 * These global variables are arrays of strings logged by Scrott business
 * logic to report errors, warnings, or informational responses to the
 * user in cases where an exception doesn't need to be thrown.
 */
define("ERROR", "ERROR_LIST");
define("WARNING", "WARNING_LIST");
define("NOTICE", "NOTICE_LIST");

$_SCROTT[ERROR] = array();
$_SCROTT[WARNING] = array();
$_SCROTT[NOTICE] = array();

/*
 * The page object is the object our current request is primarily
 * interested in.  For example, when navigating to a pad web page by
 * its guid, that pad is the page object.  When viewing the dashboard,
 * the current logged-in user is the page object.
 */
$_SCROTT['PAGE_OBJECT'] = NULL;

/*
 * Get the application root path.  This is an absolute path on the server.
 */
function ar() : string
{
    return substr($_SERVER['SCRIPT_NAME'], 0, -10); // 10 = strlen of "/index.php"
}

/*
 * Get the current page's path.  This is an absolute path on the server.
 */
function ap() : string
{
    return ar() . $_SERVER['PATH_INFO'];
}

/*
 * Redirect to the given URL and die.
 */
function redirect(string $url) : void
{
    header("Location: " . $url);
    exit;
}

/*
 * Redirect to the given in-app URL and die.  The given URL should be a path
 * relative to the app root.  No argument reloads the current path.
 */
function location(?string $path = NULL) : void
{
    if ($path)
        redirect(ar() . $path);
    else
        redirect(ap());
}

/*
 * Assert that the current connection to the server is over HTTPS.  Redirect
 * if not.
 */
function require_https() : void
{
    if (!isset($_SERVER['HTTPS']))
        redirect("https://" . $_SERVER['SERVER_NAME'] . ap());
}

/*
 * Check whether an action string was submitted by the user agent
 */
function isAction(string $action) : bool
{
    if (!isset($_REQUEST['action']))
        return false;

    return $_REQUEST['action'] == $action;
}

/*
 * Get an array of submitted form input
 */
function input() : array
{
    if (!isset($_REQUEST['input']))
        throw new Exception("Requested form input, but no input data was supplied");

    return $_REQUEST['input'];
}

/*
 * Check for errors, warnings, or notices
 */
function isError(string $level) : bool
{
    global $_SCROTT;
    return count($_SCROTT[$level]) > 0;
}

/*
 * Log an error, warning, or notice
 */
function logError(string $level, string $error) : void
{
    global $_SCROTT;
    $_SCROTT[$level][] = $error;
}

/*
 * Get an array of all errors, warnings, or notices
 */
function getErrors(string $level) : array
{
    global $_SCROTT;
    return $_SCROTT[$level];
}

/*
 * Set the page object for the current request.  This can only
 * be called once per runtime.
 */
function setPageObj(obj $obj) : void
{
    global $_SCROTT;

    if ($_SCROTT['PAGE_OBJECT'] !== NULL)
        throw new Exception("Tried to establish page object context twice");

    $_SCROTT['PAGE_OBJECT'] = $obj;
}

/*
 * Get the page object for the current request.
 */
function getPageObj() : ?obj
{
    global $_SCROTT;
    return $_SCROTT['PAGE_OBJECT'];
}

/*
 * Save an uploaded file and impose some constraints on supplied
 * data.  Caller can optionally pass some strings by reference to
 * be given the supplied file's original name and mime-type.
 * Maxsize is in bytes.  If this function returns false, the
 * appropriate error will be logged.
 */
function saveFile(array $file, string $path, int $maxsize, ?array $allowedMime = NULL,
    ?string &$origName = NULL, ?string &$origMime = NULL) : bool
{
    if ($file['error'] > 0)
    {
        if ($file['error'] != UPLOAD_ERR_NO_FILE)
            logError(ERROR, "An unknown error occurred");

        return false;
    }

    if ($file['size'] > $maxsize)
    {
        logError(ERROR, "File must be no larger than " . $maxsize . " bytes");
        return false;
    }

    if (is_array($allowedMime) && array_search($file['type'], $allowedMime) === false)
    {
        logError(ERROR, "File type is not supported");
        return false;
    }

    if (!move_uploaded_file($file['tmp_name'], $path))
    {
        logError(ERROR, "Error saving uploaded file");
        return false;
    }

    $origName = $file['name'];
    $origMime = $file['type'];
    return true;
}

?>