package namecheck

import (
	"fmt"
	"sync"
)

var (
	usernames []string = []string{"foxdeveloper666", "jubobs"}
	sn        []SocialNetwork
)

type MyError interface {
	error
	Unwrap() error
}

type ErrUnknownAvailability struct {
	Username string
	Cause    error
}

func (e *ErrUnknownAvailability) Unwrap() error {
	return e.Cause
}

func (e *ErrUnknownAvailability) Error() string {
	return fmt.Sprintf("Unknown availability error for %s", e.Username)
}

type Validator interface {
	IsValid(username string) bool
}

type Provider interface {
	IsAvailable(username string) (bool, error)
}

type SocialNetwork interface {
	fmt.Stringer
	Validator
	Provider
}

func AddSn(social SocialNetwork) {
	sn = append(sn, social)
}

func SocialNetworks() []SocialNetwork {
	return sn
}

func Namecheck(sn SocialNetwork, username string, wg *sync.WaitGroup, ch chan string) {
	defer wg.Done()
	if ok := sn.IsValid(username); !ok {
		ch <- fmt.Sprintf("%s is not valid!", username)
	}

	ok, err := sn.IsAvailable(username)

	if err != nil {
		err, ok := err.(MyError)
		if ok {
			cause := err.Unwrap()
			ch <- fmt.Sprintf("%v\n", cause)
		}
		ch <- fmt.Sprintf("%s\n", err.Error())
	}

	ch <- fmt.Sprintf("On %s \"%v\" is Available : %v\n", sn.String(), username, ok)
}

func Run(sns []SocialNetwork, username string, ch chan string) {
	var wg sync.WaitGroup
	for _, sn := range sns {
		wg.Add(1)
		go Namecheck(sn, username, &wg, ch)
	}
	wg.Wait()
	close(ch)
}