my-portfolio/dist/api/project/projectRoutes.php

<?php
namespace api\project;
require_once __DIR__ . "/../utils/routesInterface.php";
require_once "projectData.php";

use api\utils\routesInterface;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\App;

class projectRoutes implements routesInterface
{
    private projectData $projectData;

    /**
     * constructor used to instantiate a base project routes, to be used in the index.php file.
     * @param App $app - the slim app used to create the routes
     */
    public function __construct(App $app)
    {
        $this->projectData = new projectData();
        $this->createRoutes($app);
    }

    /**
     * creates the routes for the project
     * @param App $app - the slim app used to create the routes
     * @return void - returns nothing
     */
    public function createRoutes(App $app): void
    {
        $app->get("/projectData", function (Request $request, Response $response)
        {
            $result = $this->projectData->getProjectData();

            $json = json_encode($result);

            $response->getBody()->write($json);

            if(array_key_exists("errorMessage", $result))
            {
                $response = $response->withStatus(404);
            }

            //use content type json to indicate json data on frontend.
            return $response;
        });

        $app->patch("/projectData/{id}", function (Request $request, Response $response, array $args)
        {
            $data = $request->getParsedBody();
            if ($args["id"] != "undefined")
            {
                if (empty($data["title"]) || empty($data["isMainProject"]) || empty($data["information"]) || empty($data["gitLink"]))
                {
                    // uh oh sent some empty data
                    $response->getBody()->write(json_encode(array("error" => "Only some of the data was sent")));
                    return $response->withStatus(400);
                }

                $update = $this->projectData->updateProjectData($args["id"], $data["title"], $data["isMainProject"], $data["information"], $data["projectLink"], $data["gitLink"]);

                if ($update === "unset main project")
                {
                    // uh oh something went wrong
                    $response->getBody()->write(json_encode(array("error" => "Can't unset project as main project, try updating another project as the main project")));
                    return $response->withStatus(400);
                }

                if (!$update)
                {
                    // uh oh something went wrong
                    $response->getBody()->write(json_encode(array("error" => "Something went wrong")));
                    return $response->withStatus(500);
                }
                return $response;
            }

            $response->getBody()->write(json_encode(array("error" => "Please provide an ID")));
            return $response->withStatus(400);
        });

        $app->delete("/projectData/{id}", function (Request $request, Response $response, array $args)
        {
            if ($args["id"] != null)
            {
                $message = $this->projectData->deleteProjectData($args["id"]);
                if ($message === "error")
                {
                    // uh oh something went wrong
                    $response->getBody()->write(json_encode(array("error" => "Something went wrong or the project with ID ".$args["id"]."does not exist")));
                    return $response->withStatus(500);
                }

                if ($message === "cannot delete")
                {
                    //uh oh cannot delete the main project
                    $response->getBody()->write(json_encode(array("error" => "Cannot delete the main project")));
                    return $response->withStatus(409);
                }

                return $response;
            }

            $response->getBody()->write(json_encode(array("error" => "Please provide an ID")));
            return $response->withStatus(400);
        });

        $app->post("/projectData", function (Request $request, Response $response)
        {
            $data = $request->getParsedBody();
            if (empty($data["title"]) || empty($data["isMainProject"]) || empty($data["information"]) || empty($data["gitLink"]))
            {
                // uh oh sent some empty data
                $response->getBody()->write(json_encode(array("error" => "Only some of the data was sent")));
                return $response->withStatus(400);
            }

            $insertedID = $this->projectData->addProjectData($data["title"], $data["isMainProject"], $data["information"], $data["projectLink"], $data["gitLink"]);
            if (!is_int($insertedID))
            {
                // uh oh something went wrong
                $response->getBody()->write(json_encode(array("error" => "Something went wrong", "message" => $insertedID)));
                return $response->withStatus(500);
            }

            $response->getBody()->write(json_encode(array("ID" => $insertedID)));
            return $response;
        });

        $app->post("/projectImage/{id}", function (Request $request, Response $response, array $args)
        {
            $files = $request->getUploadedFiles();
            if (empty($args["id"]) || empty($files))
            {
                // uh oh only some of the data was sent
                $response->getBody()->write(json_encode(array("error" => "Only some of the data was sent")));
                return $response->withStatus(400);
            }

            $message = $this->projectData->uploadImage($args["id"], $files["img"]);
            if (!is_array($message))
            {
                // uh oh something went wrong
                $response->getBody()->write(json_encode(array("error" => $message)));
                return $response->withStatus(500);
            }

            $response->getBody()->write(json_encode($message));
            return $response;
        });
    }
}