#!/usr/bin/env python3
"""Simple HTTP server that serves frontend dist and proxies /api to backend."""

import http.server
import os
import socketserver
import urllib.request

PORT = 5173
BACKEND_URL = "http://localhost:8000"
DIST_DIR = "/home/lukas/Volume/repo/BanGUI/frontend/dist"


class ProxyHandler(http.server.SimpleHTTPRequestHandler):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, directory=DIST_DIR, **kwargs)

    def do_GET(self):
        if self.path.startswith("/api/"):
            self.proxy_request("GET")
        else:
            super().do_GET()

    def do_POST(self):
        if self.path.startswith("/api/"):
            self.proxy_request("POST")
        else:
            self.send_error(405)

    def do_PUT(self):
        if self.path.startswith("/api/"):
            self.proxy_request("PUT")
        else:
            self.send_error(405)

    def do_DELETE(self):
        if self.path.startswith("/api/"):
            self.proxy_request("DELETE")
        else:
            self.send_error(405)

    def do_PATCH(self):
        if self.path.startswith("/api/"):
            self.proxy_request("PATCH")
        else:
            self.send_error(405)

    def proxy_request(self, method):
        url = BACKEND_URL + self.path
        content_length = self.headers.get("Content-Length")
        data = None
        if content_length:
            data = self.rfile.read(int(content_length))

        req = urllib.request.Request(url, method=method, data=data)
        for key, value in self.headers.items():
            if key.lower() not in ("host", "content-length"):
                req.add_header(key, value)

        try:
            with urllib.request.urlopen(req) as resp:
                self.send_response(resp.status)
                for key, value in resp.headers.items():
                    if key.lower() not in ("transfer-encoding", "content-encoding"):
                        self.send_header(key, value)
                self.end_headers()
                self.wfile.write(resp.read())
        except urllib.error.HTTPError as e:
            self.send_response(e.code)
            for key, value in e.headers.items():
                self.send_header(key, value)
            self.end_headers()
            self.wfile.write(e.read())
        except Exception as e:
            self.send_error(502, str(e))

    def end_headers(self):
        self.send_header("Access-Control-Allow-Origin", "*")
        self.send_header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, PATCH, OPTIONS")
        self.send_header("Access-Control-Allow-Headers", "*")
        super().end_headers()

    def do_OPTIONS(self):
        self.send_response(204)
        self.end_headers()


if __name__ == "__main__":
    os.chdir(DIST_DIR)
    with socketserver.TCPServer(("", PORT), ProxyHandler) as httpd:
        print(f"Serving frontend at http://localhost:{PORT}")
        print(f"Proxying /api to {BACKEND_URL}")
        httpd.serve_forever()