package gateway

import (
    "bufio"
    "encoding/json"
    "fmt"
    "net"
    "net/http"
)

type statusResponseWriter struct {
	http.ResponseWriter
	status int
	bytes  int
}

func (w *statusResponseWriter) WriteHeader(code int) {
	w.status = code
	w.ResponseWriter.WriteHeader(code)
}

func (w *statusResponseWriter) Write(b []byte) (int, error) {
	n, err := w.ResponseWriter.Write(b)
	w.bytes += n
	return n, err
}

// Ensure websocket upgrades work by preserving Hijacker/Flusher/Pusher
// interfaces when the underlying ResponseWriter supports them.
func (w *statusResponseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
    if h, ok := w.ResponseWriter.(http.Hijacker); ok {
        return h.Hijack()
    }
    return nil, nil, fmt.Errorf("hijacker not supported")
}

func (w *statusResponseWriter) Flush() {
    if f, ok := w.ResponseWriter.(http.Flusher); ok {
        f.Flush()
    }
}

func (w *statusResponseWriter) Push(target string, opts *http.PushOptions) error {
    if p, ok := w.ResponseWriter.(http.Pusher); ok {
        return p.Push(target, opts)
    }
    return http.ErrNotSupported
}

// writeJSON writes JSON with status code
func writeJSON(w http.ResponseWriter, code int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(code)
	_ = json.NewEncoder(w).Encode(v)
}

// writeError writes a standardized JSON error
func writeError(w http.ResponseWriter, code int, msg string) {
	writeJSON(w, code, map[string]any{"error": msg})
}