package main

import (
	"context"
	"flag"
	"log"
	"os"
)

var Config struct {
	Port     int
	SessionD string
}

func main() {
	ctx, cleanup := contextWithCleanup(context.Background())
	defer cleanup()
	config(ctx)

	log.Printf("%+v", Config)
}

func contextWithCleanup(ctx context.Context) (context.Context, func()) {
	m := map[int]func(){}
	ctx = context.WithValue(ctx, "__cleanup__", m)
	return ctx, func() {
		defer func() {
			recover()
		}()
		for _, v := range m {
			v()
		}
	}
}

func contextWithCleanupFunc(ctx context.Context, foo func()) {
	v := ctx.Value("__cleanup__")
	if v == nil {
		panic("cannot get context with cleanup func that doesnt have cleanup init")
	}
	m := v.(map[int]func())
	m[len(m)] = foo
}

func config(ctx context.Context) {
	d, err := os.MkdirTemp(os.TempDir(), "ai.*")
	if err != nil {
		panic(err)
	}
	contextWithCleanupFunc(ctx, func() { os.RemoveAll(d) })

	flag.IntVar(&Config.Port, "p", 8080, "port to listen on")
	flag.StringVar(&Config.SessionD, "d", d, "dir to store sessions")
	flag.Parse()
}