package middleware

import (
	"context"
	"net/http"
	"time"
)

// O11yRecorder matches api.Deps.O11y but lets this package avoid an
// import cycle.
type O11yRecorder interface {
	RecordRequest(ctx context.Context, route string, status int, durationMs int64)
}

// Telemetry records every request through deps.O11y. Safe with a nil
// recorder — the middleware becomes a no-op pass-through.
func Telemetry(rec O11yRecorder) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		if rec == nil {
			return next
		}
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			start := time.Now()
			sw := &statusWriter{ResponseWriter: w, status: http.StatusOK}
			next.ServeHTTP(sw, r)
			rec.RecordRequest(r.Context(), r.URL.Path, sw.status, time.Since(start).Milliseconds())
		})
	}
}

type statusWriter struct {
	http.ResponseWriter
	status int
}

func (s *statusWriter) WriteHeader(code int) {
	s.status = code
	s.ResponseWriter.WriteHeader(code)
}