package overflow_gateway_websocket

import (
	"net/http"
	"sync"

	"git.loafle.net/overflow/overflow_gateway_websocket/websocket"
	"github.com/valyala/fasthttp"
)

type ()

type Server interface {
	ListenAndServe(addr string) error
	HandleSocket(pattern string, o *SocketOptions)
}

type server struct {
	_option   *ServerOptions
	_upgrader *websocket.Upgrader
	_handlers map[string]*SocketOptions
	_sockets  map[string]Socket
	_cMtx     sync.Mutex
}

func NewServer(o *ServerOptions) Server {
	s := &server{
		_option:   o.Validate(),
		_handlers: make(map[string]*SocketOptions, 1),
		_sockets:  make(map[string]Socket, 100),
	}

	s._upgrader = &websocket.Upgrader{
		HandshakeTimeout:  s._option.HandshakeTimeout,
		ReadBufferSize:    s._option.ReadBufferSize,
		WriteBufferSize:   s._option.WriteBufferSize,
		CheckOrigin:       s._option.OnCheckOrigin,
		Error:             s.onError,
		EnableCompression: s._option.EnableCompression,
	}

	return s
}

func (s *server) onError(ctx *fasthttp.RequestCtx, status int, reason error) {
	ctx.Response.Header.Set("Sec-Websocket-Version", "13")
	ctx.Error(http.StatusText(status), status)

	s._option.OnError(ctx, status, reason)
}

func (s *server) onDisconnected(soc Socket) {
	delete(s._sockets, soc.ID())

	s._option.OnDisconnected(soc)
}

func (s *server) onConnection(ctx *fasthttp.RequestCtx) {
	path := string(ctx.Path())
	co, ok := s._handlers[path]
	if !ok {
		s.onError(ctx, fasthttp.StatusNotFound, nil)
		return
	}

	s._upgrader.Upgrade(ctx, nil, func(conn *websocket.Conn, err error) {
		if err != nil {
			s.onError(ctx, fasthttp.StatusInternalServerError, err)
			return
		}
		s._cMtx.Lock()
		id := s._option.IDGenerator(ctx)
		soc := NewSocket(id, path, co, conn)
		s._sockets[id] = soc
		s._cMtx.Unlock()

		s._option.OnConnection(soc)

		soc.run()
	})
}

func (s *server) HandleSocket(pattern string, o *SocketOptions) {
	o.onDisconnected = s.onDisconnected

	s._handlers[pattern] = o.Validate()
}

func (s *server) ListenAndServe(addr string) error {
	return fasthttp.ListenAndServe(addr, s.onConnection)
}