import argparse
import os
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path


DEFAULT_HOST = "127.0.0.1"
DEFAULT_PORT = 8787
CALLBACK_PATH = "/vk/callback"
HEALTH_PATH = "/health"


def _read_callback_html():
    html_path = Path(__file__).resolve().parent / "vk-callback" / "index.html"
    return html_path.read_bytes()


class VkCallbackHandler(BaseHTTPRequestHandler):
    server_version = "AnabasisVkCallback/1.0"

    def do_GET(self):
        path = self.path.split("?", 1)[0]
        if path == HEALTH_PATH:
            self._send_text(200, "ok\n")
            return
        if path in ("/", CALLBACK_PATH):
            self._send_html(200, _read_callback_html())
            return
        self._send_text(404, "not found\n")

    def log_message(self, fmt, *args):
        if getattr(self.server, "quiet", False):
            return
        super().log_message(fmt, *args)

    def _send_html(self, status, body):
        self.send_response(status)
        self.send_header("Content-Type", "text/html; charset=utf-8")
        self.send_header("Cache-Control", "no-store")
        self.send_header("Content-Length", str(len(body)))
        self.end_headers()
        self.wfile.write(body)

    def _send_text(self, status, text):
        body = text.encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "text/plain; charset=utf-8")
        self.send_header("Cache-Control", "no-store")
        self.send_header("Content-Length", str(len(body)))
        self.end_headers()
        self.wfile.write(body)


def parse_args():
    parser = argparse.ArgumentParser(description="Anabasis VK OAuth callback host")
    parser.add_argument("--host", default=os.getenv("ANABASIS_VK_CALLBACK_HOST", DEFAULT_HOST))
    parser.add_argument("--port", type=int, default=int(os.getenv("ANABASIS_VK_CALLBACK_PORT", DEFAULT_PORT)))
    parser.add_argument("--quiet", action="store_true")
    return parser.parse_args()


def main():
    args = parse_args()
    server = ThreadingHTTPServer((args.host, args.port), VkCallbackHandler)
    server.quiet = args.quiet
    print(f"VK callback server listening on http://{args.host}:{args.port}{CALLBACK_PATH}")
    print(f"Health check: http://{args.host}:{args.port}{HEALTH_PATH}")
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        pass
    finally:
        server.server_close()
    return 0


if __name__ == "__main__":
    raise SystemExit(main())