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"
	"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()
	ctx := context.Background()

	msg := module.NewServerMessage(ctx, data)
	if err := m.bus.Publish(ctx, msg); 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")))
	}

	var ctx context.Context

	firstArg := call.Argument(0)

	sessionID, ok := firstArg.Export().(string)
	if ok {
		ctx = module.WithContext(context.Background(), map[module.ContextKey]any{
			edgeHTTP.ContextKeySessionID: sessionID,
		})
	} else {
		ctx = util.AssertContext(firstArg, rt)
	}

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

	msg := module.NewServerMessage(ctx, data)
	if err := m.bus.Publish(ctx, msg); err != nil {
		panic(rt.ToValue(errors.WithStack(err)))
	}

	return nil
}

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

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

	clientMessages, err := m.bus.Subscribe(ctx, module.MessageNamespaceClient)
	if err != nil {
		panic(errors.WithStack(err))
	}

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

		m.bus.Unsubscribe(ctx, module.MessageNamespaceClient, clientMessages)
	}()

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

			return

		case msg := <-clientMessages:
			clientMessage, ok := msg.(*module.ClientMessage)
			if !ok {
				logger.Warn(
					ctx,
					"unexpected message type",
					logger.F("message", msg),
				)

				continue
			}

			logger.Debug(
				ctx,
				"received client message",
				logger.F("message", clientMessage),
			)

			if _, err := m.server.ExecFuncByName(clientMessage.Context, "onClientMessage", clientMessage.Context, clientMessage.Data); 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.handleClientMessages()

		return module
	}
}