Convert Apache rewrites to Cloudflare worker JS 301s

apache2cloudflareworker.py

import re
import urllib.parse

def escape_regex(text):
    """Escapes special characters in regex."""
    escaped_text = re.escape(text)
    # Replace escaped spaces with \s
    escaped_text = escaped_text.replace(r'\ ', r'\s')
    #remove escaped \
    escaped_text = escaped_text.replace(r'\\', r'\')
    
    # Replace escaped + with \+
    escaped_text = escaped_text.replace(r'\+', r'\+')
    
    return escaped_text

def generate_worker_script(redirect_file):
    """Generates a Cloudflare Worker script from a redirect file."""
    worker_code = """
addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request));
});

async function handleRequest(request) {
  const url = new URL(request.url);
  const path = url.pathname;
  const queryString = url.search.slice(1);  // Remove the '?'

  const redirects = [
"""

    with open(redirect_file, 'r') as f:
        lines = f.readlines()

    i = 0
    while i < len(lines):
        line = lines[i].strip()
        if line.startswith("RewriteCond"):
            cond_line = line
            rule_line = lines[i + 1].strip() if i + 1 < len(lines) else None
            i+=2
            if not rule_line or not rule_line.startswith("RewriteRule"):
               continue
            
            match_cond = re.match(r'RewriteCond %{QUERY_STRING} \^(.*)$', cond_line)
            match_rule = re.match(r'RewriteRule \^(.*)\$\s+(.*?)\s+\[L,R=301,NC\]$', rule_line)


            if match_cond and match_rule:
                query_string_condition = match_cond.group(1)
                original_path = match_rule.group(1)
                redirect_url = match_rule.group(2)
                if redirect_url.endswith("?"):
                    redirect_url = redirect_url[:-1]
                escaped_query_string_condition = escape_regex(query_string_condition)
                
                worker_code += f"""
    {{
      test: () => {{
        const cond = new RegExp('^{escaped_query_string_condition}$');
        const path_rule = new RegExp('^{original_path}$', 'i');
        return cond.test(queryString) && path_rule.test(path);
      }},
      target: "{redirect_url}"
    }},
"""
        else:
            i += 1
    worker_code += """
  ];

  for (const rule of redirects) {
    if (rule.test()) {
      return Response.redirect(rule.target, 301);
    }
  }

  return fetch(request);
}
"""
    return worker_code



if __name__ == "__main__":
    redirect_file = "redirect.txt"
    worker_script = generate_worker_script(redirect_file)
    print(worker_script)

    with open("worker.js", "w") as outfile:
        outfile.write(worker_script)
    print("Worker script generated and saved as worker.js")