<?php
// Upload image
// proccess is called via url:
// upload.php ? id = X [&sec = 1] [&del = Y]
// X : item ID
// Y : old image file
// &sec=1 : declares the image as "2nd" image of the item
// --- -- -- - - -
// Workline:
// 1. Validate input
// 2. Check common errors
// -- If everything is ok:
// 3. Upload image
// 4. Make a thumbnail of the image
// 5. Update database record
// ---
// last update: 2020-06-21
////////////////////////////////////////////////////////////////////////////////


include("config/parametres.php");

  // #1.  VALIDATE input and init paremetres of the script
  // --- -- -- - - -
  // valid record id exist
  // validate delete image (if exist)
  // calculate filenames, file-extensions, paths etc.
  //////////////////////////////////////////////////////////////////////////////

  // validate 'id'
  // ---------------------------------------------------------------------------
  if (isset($_GET['id']) && is_numeric($_GET['id']) && (($_GET['id'] != '0'))) {
      $id  = $_GET['id'];                 // id of photo to upload
      $sub_dir = intdiv($id, FOLDER_CPC) .'/';    // subdirectory to put the image
          // each subdir hosts up to 256 items and 1024 images
          // 256 items x (2 imgs + 2 thumbs) = 1024
  }
  else {
      echo '{"success": false, "err" : "ID ERROR"}'; die();
  }

  // validate 'sec' parameter (if this is the SECOND image of the item)
  // ---------------------------------------------------------------------------
  if (isset($_GET['sec']) && is_numeric($_GET['sec']) && (($_GET['sec'] == '1'))) {
      define("IS_2ND_IMG", true);  // is second image of item
  }
  else {
      define("IS_2ND_IMG", false);
  }

  // validate 'del' imagefile
  // ---------------------------------------------------------------------------
  if ( isset($_GET['del'])
      && ( preg_match('/^(\d+)_([A-Fa-f0-9]{5})\.jpg/',$_GET['del']) )   // match filename format: ID_HEX{5}.jpg
      && ( explode( "_", $_GET['del'] )[0] == $id )                // ID part of file is same as $id
      && file_exists( UPLOAD_DIR. $sub_dir . $_GET['del'] ) ) {   // file exists (on the right folder)
          $delete_old = true;
          $del = strtolower($_GET['del']);    // old image-file to delete (format: int _ HEX{5} . jpg)
  }
  else {
      $delete_old = false;
  }

  // Calculate file-names, file-extensions, paths etc.
  // ---------------------------------------------------------------------------
  $rnd = substr(strtolower(md5(time())),0,5) .".";
  $ext = strtolower(end(explode(".", $_FILES["fileToUpload"]["name"])));

  $localFN = $id ."_". $rnd.$ext;       // local filename (new uploaded image)
  $thumbFN = "pi". $localFN;            // thumbnail (pico image)
  $path_file  = UPLOAD_DIR . $sub_dir . $localFN;   // target path + filename
  $path_thumb = UPLOAD_DIR . $sub_dir . $thumbFN;   // thumbnail path + filename

  $uploadOk = 1;                        // flag to catch uploading errors


  // TODO:
  // If is 'second' image, check that 1st image exists
  // --- Depricated:
  // Can be handled in presentation;
  // if 1st image is absend, then the second is used instead


  // Check common errors; then upload image if everything is ok
  //////////////////////////////////////////////////////////////////////////////

  // Check if image file is a actual image or fake image
  // ---------------------------------------------------------------------------
  $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
  if ($check !== false) {
      // File is an image
      $uploadOk = 1;
  }
  else {
      // File is not an image
      $uploadOk = -1;
      echo '{"success": false, "err" : "MIME ERROR"}'; die();
  }

  // Check if file already exists
  // if (file_exists($path_file)) {
  //    unlink($path_file);    // delete it if exists
  // }

  // Check file size
  // ---------------------------------------------------------------------------
  if ($_FILES["fileToUpload"]["size"] > 1048576) {    // limit filesize to 1MB
      $uploadOk = -2;
      echo '{"success": false, "err" : "SIZE ERROR"}'; die();
  }

  // Allow certain file formats (only jpeg)
  // ---------------------------------------------------------------------------
  if ($ext != "jpg" && $ext != "jpeg" ) {    // file extension shall be [ jpg | jpeg ]
      $uploadOk = -3;
      echo '{"success": false, "err" : "JPEG ERROR"}'; die();
  }
  // Check if $uploadOk is set to 0 by an error
  // (though this would have ended the script already) -------------------------
  if ($uploadOk < 0) {
      echo '{"success": false, "err" : "IMG-ERR:'. (-$uploadOk) .'"}'; die();

  }
  // if everything is ok, try to upload the file info folder
  // ---------------------------------------------------------------------------
  else {

      if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $path_file)) {
          // image uploaded;

          // delete old image + old thumbnail
          //////////////////////////////////////////////////////////////////////
          if ($delete_old) {
              unlink(UPLOAD_DIR. $sub_dir . $del);        // delete old image
              unlink(UPLOAD_DIR. $sub_dir .'pi'. $del);   // delete old thumbnail
          }

          // Create thumbnail
          //////////////////////////////////////////////////////////////////////

          // load image and get image size
          $img = imagecreatefromjpeg( $path_file );
          $width = imagesx( $img );
          $height = imagesy( $img );

          // calculate thumbnail size
          $new_width = THUMBWIDTH;
          $new_height = floor( $height * ( THUMBWIDTH / $width ) );

          // create a new temporary image
          $tmp_img = imagecreatetruecolor( $new_width, $new_height );

          // copy and resize old image into new image
          imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

          // save thumbnail into a file
          imagejpeg( $tmp_img, $path_thumb );


          // Update item record on database
          //////////////////////////////////////////////////////////////////////

          // init database connection
          $_dbc = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_DBMS);
          if ($_dbc->connect_errno) {
            echo "Database connection failed; Please try in a few minutes.";
            if (TESTING) echo $_dbc->connect_error;
            $_dbc->close(); die();
          }
          $_dbc->set_charset("utf8");

          if (IS_2ND_IMG)
            $_upd = $_dbc->prepare("UPDATE items SET img2 = ? WHERE id = ?");
          else
            $_upd = $_dbc->prepare("UPDATE items SET img = ? WHERE id = ?");
          $_upd->bind_param("sd", $localFN, $id);
          $_upd->execute();
          $_upd->close();
          $_dbc->close();


          // send image thumbnail for preview
          // -------------------------------------------------------------------

          echo '{ "success" : true, "img" : "'. $localFN .'", "sec" : "'. (IS_2ND_IMG ? 'true' : 'false') .'", "thumbnail" : "'. $path_thumb .'" }';
          die();    // everything done!

      }
      else {
          echo '{"success": false, "err" : "UPLOAD ERR"}'; die();
      }
  }