package apis

import (
	"log/slog"
	"net"
	"net/http"
	"strings"
	"time"

	"github.com/go-chi/chi/v5/middleware"
)

// ClientIP getIP returns the ip address from the http request
func ClientIP(r *http.Request) string {
	xForwardedFor := r.Header.Get("X-Forwarded-For")
	ip := strings.TrimSpace(strings.Split(xForwardedFor, ",")[0])
	if ip != "" {
		return ip
	}

	ip = strings.TrimSpace(r.Header.Get("X-Real-Ip"))
	if ip != "" {
		return ip
	}

	if ip, _, err := net.SplitHostPort(strings.TrimSpace(r.RemoteAddr)); err == nil {
		return ip
	}

	return ""
}

// Logger returns a `func(http.Handler) http.Handler` (middleware) that logs requests using slog.
func Logger(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		st := time.Now()
		ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)

		defer func() {
			msg := r.Method + " " + r.RequestURI + " " + r.Proto

			ip := ClientIP(r)
			status := ww.Status()
			if status == 0 {
				status = http.StatusOK
			}

			attrs := []slog.Attr{
				slog.String("ip", ip),
				slog.String("id", middleware.GetReqID(r.Context())),
				slog.Int("status", status),
				slog.Duration("latency", time.Since(st)),
				slog.Int("length", ww.BytesWritten()),
			}
			slog.LogAttrs(r.Context(), slog.LevelInfo, msg, attrs...)
		}()

		next.ServeHTTP(ww, r)
	}

	return http.HandlerFunc(fn)
}