package hws

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

func startTimer(next http.Handler) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			start := time.Now()
			ctx := setStart(r.Context(), start)
			newReq := r.WithContext(ctx)
			next.ServeHTTP(w, newReq)
		},
	)
}

type contextKey string

func (c contextKey) String() string {
	return "hws context key " + string(c)
}

var requestTimerCtxKey = contextKey("request-timer")

// Set the start time of the request
func setStart(ctx context.Context, time time.Time) context.Context {
	return context.WithValue(ctx, requestTimerCtxKey, time)
}

// Get the start time of the request
func getStartTime(ctx context.Context) (time.Time, error) {
	start, ok := ctx.Value(requestTimerCtxKey).(time.Time)
	if !ok {
		return time.Time{}, errors.New("failed to get start time of request")
	}
	return start, nil
}