package websocket

import (
	"errors"
	"net/http"
	"net/textproto"

	"github.com/gorilla/websocket"
)

type Socket struct {
	*websocket.Conn
	Listeners map[string](chan<- []byte)
	done      chan struct{}
	errd      bool
	errsig    chan error
}

var client *Socket

func NewClient(remote string) (*Socket, error) {
	if remote == "" {
		return nil, errors.New("remote url is empty")
	}
	var err error

	headers := http.Header{}

	headers.Set(
		textproto.CanonicalMIMEHeaderKey("X-Auth-Key"),
		"rpi",
	)
	c, resp, err := websocket.DefaultDialer.Dial(remote, headers)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	client = &Socket{
		Conn:      c,
		Listeners: make(map[string](chan<- []byte)),
		done:      make(chan struct{}, 0),
		errd:      false,
		errsig:    make(chan error),
	}

	return client, nil
}

func (p *Socket) Listen() error {
	go func() {
		defer close(p.done)
		for {
			_, msg, err := p.ReadMessage()
			if err != nil {
				p.errsig <- err
			}

			for _, v := range p.Listeners {
				v <- msg
			}
		}
	}()

	select {
	case <-p.done:
		return nil
	case err := <-p.errsig:
		return err
	}
}

func (p *Socket) AddListener(alias string, c chan<- []byte) error {
	if _, ok := p.Listeners[alias]; ok {
		return errors.New("listener name exists")
	}
	p.Listeners[alias] = c

	return nil
}

func (p *Socket) RemoveListener(alias string) error {
	if v, ok := p.Listeners[alias]; !ok {
		return errors.New("listener not exists")
	} else {
		close(v)
		delete(p.Listeners, alias)
	}

	return nil
}