main.go

package main

import (
	"log"
	_ "net/http/pprof"
	"os"
	"os/signal"
	"runtime"
	"syscall"

	"github.com/ProjectLighthouseCAU/beacon/auth"
	"github.com/ProjectLighthouseCAU/beacon/auth/hardcoded"
	"github.com/ProjectLighthouseCAU/beacon/auth/heimdall"
	"github.com/ProjectLighthouseCAU/beacon/auth/legacy"
	"github.com/ProjectLighthouseCAU/beacon/cli"
	"github.com/ProjectLighthouseCAU/beacon/directory/tree"
	"github.com/ProjectLighthouseCAU/beacon/handler"
	"github.com/ProjectLighthouseCAU/beacon/network"
	"github.com/ProjectLighthouseCAU/beacon/network/websocket"
	"github.com/ProjectLighthouseCAU/beacon/resource"
	"github.com/ProjectLighthouseCAU/beacon/snapshot"
	"github.com/ProjectLighthouseCAU/beacon/static"

	"github.com/ProjectLighthouseCAU/beacon/config"
)

// The main function sets up the webserver routes for websocket connections
// and for the testing site.
func main() {
	// ### PROFILING ###
	// var f *os.File
	// var e error
	// f, e = os.Create("cpuprofile.pprof")
	// if e != nil {
	// 	log.Fatal(e)
	// }
	// pprof.StartCPUProfile(f)
	// defer pprof.StopCPUProfile()

	// f, e = os.Create("memprofile.pprof")
	// if e != nil {
	// 	log.Fatal(e)
	// }
	// defer pprof.WriteHeapProfile(f)

	// ### STARTUP ###
	log.Println("Starting server...")

	log.Printf("GOMAXPROCS: %d\n", runtime.GOMAXPROCS(0))

	// TODO: maybe make createResourceFunc configurable again via dependency injection
	// var createResourceFunc func(path []string, initialValue resource.Content) resource.Resource[resource.Content]
	// switch config.ResourceImplementation {
	// case "brokerless":
	// 	createResourceFunc = brokerless.Create[resource.Content]
	// case "broker":
	// 	createResourceFunc = broker.Create
	// default:
	// 	log.Println("RESOURCE_IMPL environment variable not specified, using \"brokerless\" as default")
	// 	createResourceFunc = brokerless.Create
	// }

	directory := tree.NewTree[resource.Resource[resource.Content]]()

	err := snapshot.Restore(config.SnapshotPath, directory)
	if err != nil {
		panic(err)
	}

	var authImpl auth.Auth
	switch config.Auth {
	case "hardcoded":
		authImpl = hardcoded.New()
	case "legacy":
		authImpl = legacy.New(directory)
	case "allow_all":
		authImpl = auth.AllowAll()
	case "allow_none":
		authImpl = auth.AllowNone()
	case "heimdall":
		authImpl = heimdall.New(directory)
	}

	handler := handler.New(directory)

	websocketEndpoint := websocket.CreateEndpoint(config.WebsocketHost, config.WebsocketPort, authImpl, handler)
	endpoints := []network.Endpoint{websocketEndpoint}

	static.StartFileserver()

	log.Println("Server started")

	// wait for interrupt
	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt, syscall.SIGINT, syscall.SIGTERM) // SIGINT: Ctrl + C, SIGTERM: used by docker

	stop := make(chan struct{})
	go cli.RunCLI(stop, directory)

	snapshotter := snapshot.CreateSnapshotter(directory)
	snapshotter.Start(directory)
	log.Printf("Started automatic snapshotting to %s every %s\n", config.SnapshotPath, config.SnapshotInterval)

	// Wait for either interrupt or stop command
	select {
	case <-interrupt:
	case <-stop:
	}

	log.Println("Stopping server...")

	for _, ep := range endpoints {
		ep.Close()
	}

	handler.Close()

	log.Println("Closed all endpoints and handlers")
	snapshotter.StopAndWait()
	log.Println("Server stopped")
}