package module

import (
	"tunnel/pkg/server/queue"
	"fmt"
	"log"
)

var modules = map[string]M{}

type pipe func (rq, wq queue.Q) error

type M interface {
	Open() (pipe, pipe)
}

type reverse struct {
	M
}

func Reverse(m M) M {
	return &reverse{m}
}

func (r *reverse) Open() (pipe, pipe) {
	p1, p2 := r.M.Open()
	return p2, p1
}

func (p pipe) Open() (pipe, pipe) {
	return p, nil
}

func register(name string, m M) {
	if _, ok := modules[name]; ok {
		log.Panicf("duplicate module name '%s'", name)
	}

	modules[name] = m
}

func New(name string) (M, error) {
	if m, ok := modules[name]; ok {
		return m, nil
	}

	return nil, fmt.Errorf("unknown module '%s'", name)
}