<?php
require("../include/appConfig.php");
session_start();

////
//
/// Functions
//
////

function generateRandomString($length = 10)
{
	$characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
	$charactersLength = strlen($characters);
	$randomString = '';
	for ($i = 0; $i < $length; $i++)
	{
		$randomString .= $characters[rand(0, $charactersLength - 1)];
	}
	return $randomString;
}

function checkInput()
{
	global $appConfig;
	$checkOK = true;

	if (isset($_GET['outputImageResolution']))
	{
		$found = false;
		foreach ($appConfig['outputImageResolution'] as $item)
		{
			if($item[0] == $_GET['outputImageResolution']) $found = true;
		}
		if(!$found) $checkOK = false;
	}
	else $checkOK = false;

	if (isset($_GET['outputImageColorDepth']))
	{
		$found = false;
		foreach ($appConfig['outputImageColorDepth'] as $item)
		{
			if($item[0] == $_GET['outputImageColorDepth']) $found = true;
		}
		if(!$found) $checkOK = false;
	}
	else $checkOK = false;

	if(isset($_GET['outputFileFormat']))
	{
		$found = false;
		foreach ($appConfig['outputImageFormats'] as $item)
		{
			if($item[0] == $_GET['outputFileFormat']) $found = true;
		}
		if(!$found) $checkOK = false;
	}
	else $checkOK = false;

	if (isset($_GET['inputPageSize']))
	{
		$found = false;
		foreach ($appConfig['inputPageSizes'] as $item)
		{
			if($item[0] == $_GET['inputPageSize']) $found = true;
		}
		if(!$found) $checkOK = false;
	}
	else $checkOK = false;

	if (isset($_GET['deviceID']))
	{
		$found = false;
		foreach ($_SESSION['ScannersList'] as $item)
		{
			if($item[0] == $_GET['deviceID']) $found = true;
		}
		if(!$found) $checkOK = false;
	}
	else $checkOK = false;

	return $checkOK;
}

function getNewFileName()
{
	return 'scan-'.date('Ymd').'-'.generateRandomString().'.'.$_GET['outputFileFormat'];
}


////
//
/// Logic
//
////

if(checkInput() !== true)
{
	echo "400 - Bad request";
	http_response_code(400);
	exit;
}
//Generate file name for scanned image
$filename = getNewFileName();

$scanCommand = "sudo scanimage --device-name ".$_GET['deviceID']." --format ".$_GET['outputFileFormat']." --resolution ".$_GET['outputImageResolution']." --mode ".$_GET['outputImageColorDepth']." > ".$appConfig['imagesLocation'].$filename;


////
//
/// Scanning start
//
////

//Prepare directory for scanned image
if(!is_dir($appConfig['imagesLocation'])) mkdir($appConfig['imagesLocation'], 777, true);

//Scan image
shell_exec($scanCommand);

//Output scanned image name indicating that scanning finished
echo $filename;

?>