package httpapi

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

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

// statusRecorder captures the response status for structured request logs.
type statusRecorder struct {
	http.ResponseWriter
	status int
	bytes  int
}

func (r *statusRecorder) WriteHeader(code int) {
	r.status = code
	r.ResponseWriter.WriteHeader(code)
}

func (r *statusRecorder) Write(b []byte) (int, error) {
	if r.status == 0 {
		r.status = http.StatusOK
	}
	n, err := r.ResponseWriter.Write(b)
	r.bytes += n
	return n, err
}

// RequestLogger emits one structured slog line per request with request_id.
// Pair with chi middleware.RequestID (already mounted in Router).
func RequestLogger(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		rec := &statusRecorder{ResponseWriter: w, status: http.StatusOK}
		next.ServeHTTP(rec, r)
		slog.Info("http_request",
			"request_id", chimw.GetReqID(r.Context()),
			"method", r.Method,
			"path", r.URL.Path,
			"status", rec.status,
			"bytes", rec.bytes,
			"duration_ms", time.Since(start).Milliseconds(),
			"remote_ip", r.RemoteAddr,
		)
	})
}