import json
import os
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer


APP_NAME = os.environ.get("APP_NAME", "demo-app")
APP_VERSION = os.environ.get("APP_VERSION", "local")
PORT = int(os.environ.get("PORT", "8080"))


class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/health":
            self._send_json(200, {"status": "ok", "app": APP_NAME, "version": APP_VERSION})
            return

        if self.path == "/":
            body = f"{APP_NAME} is running\nversion={APP_VERSION}\n"
            self._send_text(200, body)
            return

        self._send_json(404, {"error": "not found"})

    def log_message(self, fmt, *args):
        print("%s - %s" % (self.address_string(), fmt % args))

    def _send_json(self, status, payload):
        body = json.dumps(payload, separators=(",", ":")).encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "application/json")
        self.send_header("Content-Length", str(len(body)))
        self.end_headers()
        self.wfile.write(body)

    def _send_text(self, status, body_text):
        body = body_text.encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "text/plain; charset=utf-8")
        self.send_header("Content-Length", str(len(body)))
        self.end_headers()
        self.wfile.write(body)


def main():
    server = ThreadingHTTPServer(("0.0.0.0", PORT), Handler)
    print(f"{APP_NAME} listening on 0.0.0.0:{PORT}")
    server.serve_forever()


if __name__ == "__main__":
    main()