Refactor domain check endpoint to accept JSON input and enhance domain validation

app.py

@@ -2,7 +2,7 @@ import json5
 import os
 import random
 from typing import Callable, Literal
-from flask import Flask, send_from_directory
+from flask import Flask, send_from_directory, request
 from urllib.parse import urlparse
 import dns.resolver
 import socket
@@ -10,6 +10,7 @@ import requests
 import platform
 import subprocess
 from shutil import which
+import re
 
 app = Flask(__name__)
 
@@ -20,16 +21,16 @@ def index():
         return send_from_directory('.', 'index.html')
     except Exception as e:
         return str(e)
+    
+@app.route('/check', methods=['POST'])
+def check():
+    return check_domain(request.get_json().get('domain', ''))
 
-@app.route('/check/<domain>', methods=['POST'])
 def check_domain(domain: str):
     """Check domain availability"""
     logs: list[str] = []
     try:
-        domain = domain.lower().strip('/').strip()
-        if '://' in domain:
-            domain = urlparse(domain).netloc
-
+        domain = validate_and_correct_domain(domain)
         result = check_domain_availability(domain, logs.append)
         if result:
             return { 
@@ -43,6 +44,19 @@ def check_domain(domain: str):
         logs.append(f"{check_domain.__name__}:Exception:{str(e)}")
     return default_error(domain, logs)
 
+def validate_and_correct_domain(domain: str):
+    # remove leding and trailing "/"
+    domain = domain.lower().strip('/').strip()
+    # extract domain 
+    domain = urlparse(domain).netloc.strip() if '://' in domain else domain
+    # remove www.
+    domain = domain.lstrip("www.").strip()
+    # remove inner spaces
+    domain = re.sub(r'[\n\s]+', '', domain).strip()
+    # replace unwanted characters with hyphens
+    domain = re.sub(r'[^a-zA-Z0-9\.]', '-', domain).strip('-').strip('.').strip()
+    return domain
+
 def default_error(domain: str, logs: list[str]):
     cannot_confirm = "Cannot confirm if doimain is available"
     try:

index.html

@@ -21,7 +21,7 @@
                         </p>
                         <form id="searchForm" class="mb-3 mt-4">
                             <div class="input-group">
-                                <input type="text" id="domain" class="form-control" placeholder="Enter domain name... eg: example.com">
+                                <input type="text" id="domain" class="form-control" placeholder="Enter domain name... eg: example.com" required/>
                                 <button class="btn btn-primary" type="submit">Check</button>
                             </div>
                         </form>
@@ -46,6 +46,10 @@
         document.getElementById('searchForm').onsubmit = async (e) => {
             e.preventDefault();
             const domain = document.getElementById('domain').value;
+            if ((domain || '').trim().length == 0){
+                return;
+            }
+
             const result = document.getElementById('result');
             const spinner = document.getElementById('spinner');
             const resultText = document.getElementById('resultText');
@@ -55,7 +59,13 @@
             resultText.innerHTML = '';
 
             try {
-                const response = await fetch(`/check/${domain}`, { method: 'POST' });
+                const response = await fetch(`/check`, { 
+                    method: 'POST', 
+                    headers: {
+                        'Content-Type': 'application/json'
+                    },
+                    body: JSON.stringify({ domain })
+                 });
                 const data = await response.json();
 
                 resultText.innerHTML = `