Implement user authentication and registration; enhance error handling and database interaction in API

api/setup/save.php

@@ -2,4 +2,39 @@
 // Load Main Libary
 require "../api.php";
 
-bin2hex(random_bytes(32))
+$api = new gbAPI(true);
+
+// Check Request body
+if ($_SERVER["REQUEST_METHOD"] !== "POST") {
+    $api->answer(400, [
+        "error" => "false_request_method",
+        "error_text" => "Only POST allowed"
+    ]);
+}
+
+if (!isset($_POST["username"]) || !isset($_POST["password"]) || !isset($_POST["password_repeat"])) {
+    $api->answer(400, [
+        "error" => "missing_fields",
+        "error_text" => "Some fields are missing"
+    ]);
+}
+
+$username = $_POST["username"];
+$password = $_POST["password"];
+$password_repeat = $_POST["password_repeat"];
+
+// Check Passwords
+if ($password !== $password_repeat) {
+    $api->answer(400, [
+        "error" => "passwords_dont_match",
+        "error_text" => "The passwords does not match."
+    ]);
+}
+
+// Hash Password
+$hash = hash("sha256", $password);
+
+
+
+// CREATE DATABASE STRUCTURE
+file_get_contents(APP_PATH . "db_structure.sql");