edge/pkg/module/net/module.go

package net

import (
	"context"

	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/bus"
	edgehttp "forge.cadoles.com/arcad/edge/pkg/http"
	"forge.cadoles.com/arcad/edge/pkg/module/util"
	"github.com/dop251/goja"
	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
)

type Module struct {
	server *app.Server
	bus    bus.Bus
}

func (m *Module) Name() string {
	return "net"
}

func (m *Module) Export(export *goja.Object) {
	if err := export.Set("broadcast", m.broadcast); err != nil {
		panic(errors.Wrap(err, "could not set 'broadcast' function"))
	}

	if err := export.Set("send", m.send); err != nil {
		panic(errors.Wrap(err, "could not set 'send' function"))
	}
}

func (m *Module) broadcast(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	if len(call.Arguments) < 1 {
		panic(rt.ToValue(errors.New("invalid number of argument")))
	}

	data := call.Argument(0).Export()

	env := edgehttp.NewOutgoingMessageEnvelope("", data)
	if err := m.bus.Publish(env); err != nil {
		panic(rt.ToValue(errors.WithStack(err)))
	}

	return nil
}

func (m *Module) send(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	if len(call.Arguments) < 2 {
		panic(rt.ToValue(errors.New("invalid number of argument")))
	}

	firstArg := call.Argument(0)

	sessionID, ok := firstArg.Export().(string)
	if !ok {
		ctx := util.AssertContext(firstArg, rt)
		sessionID, ok = edgehttp.ContextSessionID(ctx)
		if !ok {
			panic(rt.ToValue(errors.New("could not find session id in context")))
		}
	}

	data := call.Argument(1).Export()

	env := edgehttp.NewOutgoingMessageEnvelope(sessionID, data)
	if err := m.bus.Publish(env); err != nil {
		panic(rt.ToValue(errors.WithStack(err)))
	}

	return nil
}

func (m *Module) handleIncomingMessages() {
	ctx := context.Background()

	logger.Debug(
		ctx,
		"subscribing to bus envelopes",
	)

	envelopes, err := m.bus.Subscribe(ctx, edgehttp.AddressIncomingMessage)
	if err != nil {
		panic(errors.WithStack(err))
	}

	defer func() {
		logger.Debug(
			ctx,
			"unsubscribing from bus envelopes",
		)

		m.bus.Unsubscribe(edgehttp.AddressIncomingMessage, envelopes)
	}()

	for {
		logger.Debug(
			ctx,
			"waiting for next envelope",
		)
		select {
		case <-ctx.Done():
			logger.Debug(
				ctx,
				"context done",
			)

			return

		case env := <-envelopes:
			incomingMessage, ok := env.Message().(*edgehttp.IncomingMessage)
			if !ok {
				logger.Warn(
					ctx,
					"unexpected message type",
					logger.F("message", env.Message()),
				)

				continue
			}

			logger.Debug(
				ctx,
				"received incoming message",
				logger.F("message", incomingMessage),
			)

			if _, err := m.server.ExecFuncByName(incomingMessage.Context, "onClientMessage", incomingMessage.Context, incomingMessage.Payload); err != nil {
				if errors.Is(err, app.ErrFuncDoesNotExist) {
					continue
				}

				logger.Error(
					ctx,
					"on client message error",
					logger.CapturedE(errors.WithStack(err)),
				)
			}
		}
	}
}

func ModuleFactory(bus bus.Bus) app.ServerModuleFactory {
	return func(server *app.Server) app.ServerModule {
		module := &Module{
			server: server,
			bus:    bus,
		}

		go module.handleIncomingMessages()

		return module
	}
}