<?php
// Script that generates image data for a requested part in fbsql_database
//
// possible GET valiables:
//      PartId    (required) - Id of part in databse
//      MaxWidth  (optional) - When given, image is scaled down to that maximum width
//      MaxHeight (optional) - When given, image is scaled down to that maximum height


//main include code
include ("./includes/globals.php");
include ("./includes/load_config.php");
include ("./includes/log.php");
include ("./includes/language.php");
include ("./includes/mysql.php");
include ("./includes/other_functions.php");


// get part Id
if (!isset($_GET['PartId'])) {
    exit("ERROR: PartId no given!");
}
$part_id = intval($_GET['PartId']);


// get picture path
$db_query = "SELECT PicturePath FROM `Parts` WHERE `Id` = $part_id;";
$db_result = mysqli_query($GlobalMysqlHandler, $db_query);
if ($db_result->num_rows == 0) {
    exit("ERROR: PartId not found!");
}
$source_path = $GlobalPictureDir . "/" . $db_result->fetch_array()['PicturePath'];


// get image info
list($source_width, $source_height) = getimagesize($source_path);
$mime_type = mime_content_type($source_path);


// calculate new With and Height
$output_width = $source_width;
$output_height = $source_height;
$max_width = 0;
if (isset($_GET['MaxWidth'])) {
    $max_width = intval($_GET['MaxWidth']);
    if ($output_width > $max_width) {
        $scale_factor = $max_width / $output_width;
        $output_width *= $scale_factor;
        $output_height *= $scale_factor;
    }
}
$max_height = 0;
if (isset($_GET['MaxHeight'])) {
    $max_height = intval($_GET['MaxHeight']);
    if ($output_height > $max_height) {
        $scale_factor = $max_height / $output_height;
        $output_width *= $scale_factor;
        $output_height *= $scale_factor;
    }
}


// load image
if ($mime_type == 'image/jpeg') {
    $source_image = imagecreatefromjpeg($source_path);
    $output_image = imagecreatetruecolor($output_width, $output_height);
} else if ($mime_type == 'image/png') {
    $source_image = imagecreatefrompng($source_path);
    imagealphablending($source_image, true);
    imagesavealpha($source_image, true);
    $output_image = imagecreate($output_width, $output_height);
} else {
    ErrorLog("Unkown mime type: " . $mime_type . "!");
    exit("Can't handle requested mime-type.");
}


// resize
$res = imagecopyresized($output_image, $source_image, 0, 0, 0, 0, $output_width, $output_height, $source_width, $source_height);
if ($res !== True) {
    $msg = "Cannot resize image: " . $source_path . "\n";
    $msg .= "source: " . $source_width . "x" . $source_height;
    $msg .= ", max: " . $max_width . "x" . $max_height;
    $msg .= ", output: " . $output_width . "x" . $output_height;
    ErrorLog($msg);
    exit("Cannot resize image!");
}


// output as png
header('Content-Type: image/png');
imagepng($output_image);
imagedestroy($output_image);
imagedestroy($source_width);
?>