package middleware

import (
	"context"
	"fmt"
	"net/http"
	"sync/atomic"
)

type ctxKeyRequestID int

const RequestIDKey ctxKeyRequestID = 0

func (m *Middleware) RequestID(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		ctx := r.Context()
		requestID := r.Header.Get(m.cfg.RequestIDHeader)
		if requestID == "" {
			myID := atomic.AddUint64(&m.reqID, 1)
			requestID = fmt.Sprintf("%06d", myID)
		}
		ctx = context.WithValue(ctx, RequestIDKey, requestID)
		r = r.WithContext(ctx)
		next(w, r)
	}
}