edge/pkg/http/handler.go

package http

import (
	"context"
	"io"
	"net/http"
	"sync"

	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/bundle"
	"forge.cadoles.com/arcad/edge/pkg/bus"
	"github.com/go-chi/chi/v5"
	"github.com/igm/sockjs-go/v3/sockjs"
	"github.com/pkg/errors"
)

const (
	sockJSPathPrefix = "/edge/sock"
	serverMainScript = "server/main.js"
)

type Handler struct {
	bundle bundle.Bundle
	public http.Handler
	router chi.Router

	sockjs     http.Handler
	bus        bus.Bus
	sockjsOpts sockjs.Options

	server                *app.Server
	serverModuleFactories []app.ServerModuleFactory

	httpClient *http.Client

	mutex sync.RWMutex
}

func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	h.router.ServeHTTP(w, r)
}

func (h *Handler) Load(ctx context.Context, bdle bundle.Bundle) error {
	h.mutex.Lock()
	defer h.mutex.Unlock()

	file, _, err := bdle.File(serverMainScript)
	if err != nil {
		return errors.Wrap(err, "could not open server main script")
	}

	mainScript, err := io.ReadAll(file)
	if err != nil {
		return errors.Wrap(err, "could not read server main script")
	}

	server := app.NewServer(h.serverModuleFactories...)

	fs := bundle.NewFileSystem("public", bdle)
	public := HTML5Fileserver(fs)
	sockjs := sockjs.NewHandler(sockJSPathPrefix, h.sockjsOpts, h.handleSockJSSession)

	if h.server != nil {
		h.server.Stop()
	}

	if err := server.Start(ctx, serverMainScript, string(mainScript)); err != nil {
		return errors.WithStack(err)
	}

	h.bundle = bdle
	h.server = server
	h.public = public
	h.sockjs = sockjs

	return nil
}

func NewHandler(funcs ...HandlerOptionFunc) *Handler {
	opts := defaultHandlerOptions()
	for _, fn := range funcs {
		fn(opts)
	}

	router := chi.NewRouter()

	handler := &Handler{
		sockjsOpts:            opts.SockJS,
		router:                router,
		serverModuleFactories: opts.ServerModuleFactories,
		httpClient:            opts.HTTPClient,
		bus:                   opts.Bus,
	}

	for _, middleware := range opts.HTTPMiddlewares {
		router.Use(middleware)
	}

	router.Route("/edge", func(r chi.Router) {
		r.Route("/sdk", func(r chi.Router) {
			r.Get("/client.js", handler.handleSDKClient)
			r.Get("/client.js.map", handler.handleSDKClientMap)
		})

		for _, fn := range opts.HTTPMounts {
			r.Group(func(r chi.Router) {
				r.Use(handler.contextMiddleware)
				fn(r)
			})
		}

		r.HandleFunc("/sock/*", handler.handleSockJS)
	})

	router.Get("/*", handler.handleAppFiles)

	return handler
}