#!/usr/bin/env python3
"""
Simple reverse proxy: port 7860 -> Neo4j on port 7474
Strips X-Frame-Options so Neo4j Browser can be embedded in HuggingFace iframe.
"""
import http.server
import urllib.request
import urllib.error
import sys

TARGET = "http://127.0.0.1:7474"
STRIP_HEADERS = {'x-frame-options', 'content-security-policy', 'transfer-encoding'}

class ProxyHandler(http.server.BaseHTTPRequestHandler):
    def log_message(self, fmt, *args):
        print(f"[proxy] {self.command} {self.path} -> {args[1] if len(args)>1 else ''}", flush=True)

    def do_request(self):
        url = TARGET + self.path
        length = int(self.headers.get('Content-Length', 0))
        body = self.rfile.read(length) if length > 0 else None

        fwd_headers = {}
        for k, v in self.headers.items():
            if k.lower() not in ('host', 'connection', 'transfer-encoding'):
                fwd_headers[k] = v

        req = urllib.request.Request(url, data=body, headers=fwd_headers, method=self.command)
        try:
            with urllib.request.urlopen(req, timeout=60) as resp:
                data = resp.read()
                self.send_response(resp.status)
                for k, v in resp.headers.items():
                    if k.lower() not in STRIP_HEADERS:
                        self.send_header(k, v)
                self.send_header('X-Frame-Options', 'ALLOWALL')
                self.send_header('Access-Control-Allow-Origin', '*')
                self.send_header('Content-Length', str(len(data)))
                self.end_headers()
                self.wfile.write(data)
        except urllib.error.HTTPError as e:
            data = e.read()
            self.send_response(e.code)
            for k, v in e.headers.items():
                if k.lower() not in STRIP_HEADERS:
                    self.send_header(k, v)
            self.send_header('Content-Length', str(len(data)))
            self.end_headers()
            self.wfile.write(data)
        except Exception as e:
            msg = str(e).encode()
            self.send_response(502)
            self.send_header('Content-Length', str(len(msg)))
            self.end_headers()
            self.wfile.write(msg)

    def do_GET(self):     self.do_request()
    def do_POST(self):    self.do_request()
    def do_PUT(self):     self.do_request()
    def do_DELETE(self):  self.do_request()
    def do_OPTIONS(self): self.do_request()
    def do_HEAD(self):    self.do_request()

if __name__ == '__main__':
    server = http.server.HTTPServer(('0.0.0.0', 7860), ProxyHandler)
    print(">>> Python proxy listening on 0.0.0.0:7860 -> Neo4j 127.0.0.1:7474", flush=True)
    sys.stdout.flush()
    server.serve_forever()