server

internal/server/server.go

@@ -0,0 +1,110 @@
+// Package server implements the Monkey Lang Web Server that implements
+// a web-based Playground for testing out and trying Monkey on the Web.
+package server
+
+import (
+	"context"
+	"embed"
+	"errors"
+	"fmt"
+	"io/fs"
+	"net/http"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"go.mills.io/logger"
+	"go.mills.io/router"
+)
+
+const (
+	// DefaultBind is the default [<address>]:<port> to bind to
+	DefaultBind = ":8000"
+)
+
+//go:embed static/*
+var staticFS embed.FS
+
+// Option is a function type that configures the server
+type Option func(svr *Server) error
+
+// WithBind configures the server with a bind interface and port in the form of [<address>]:<port>
+// For example: WithBind(":8000")
+func WithBind(bind string) Option {
+	return func(svr *Server) error {
+		svr.bind = bind
+		return nil
+	}
+}
+
+type Server struct {
+	bind   string
+	routes *router.Router
+}
+
+func NewServer(opts ...Option) (*Server, error) {
+	routes := router.New()
+	routes.Use(router.Middleware(func(next router.Handle) router.Handle {
+		return func(w http.ResponseWriter, r *http.Request, p router.Params) {
+			w.Header().Set("Access-Control-Allow-Origin", "*")
+			w.Header().Set("Access-Control-Allow-Headers", "*")
+			next(w, r, p)
+		}
+	}))
+
+	svr := &Server{
+		bind:   DefaultBind,
+		routes: routes,
+	}
+
+	for _, opt := range opts {
+		if err := opt(svr); err != nil {
+			return nil, fmt.Errorf("error configuring server: %w", err)
+		}
+	}
+
+	svr.initRoutes()
+
+	return svr, nil
+}
+
+func (s *Server) initRoutes() {
+	fs, err := fs.Sub(staticFS, "static")
+	if err != nil {
+		log.Fatal(err)
+	}
+	s.routes.ServeFiles("/*filepath", http.FS(fs))
+
+	s.routes.POST("/api/run", s.runHandler())
+	s.routes.POST("/api/format", s.formatHandler())
+}
+
+// Run runs the server with the provided context and shuts down when the context is cancelled
+func (s *Server) Run(ctx context.Context) error {
+	svr := &http.Server{
+		Addr: s.bind,
+		Handler: logger.New(logger.Options{
+			Prefix:               "monkey",
+			RemoteAddressHeaders: []string{"X-Forwarded-For"},
+		}).Handler(s.routes),
+	}
+
+	go func() {
+		if err := svr.ListenAndServe(); err != nil {
+			if !errors.Is(err, http.ErrServerClosed) {
+				log.WithError(err).Error("svr.ListenAndServe error")
+			}
+		}
+	}()
+
+	select {
+	case <-ctx.Done():
+		ctx, cancel := context.WithTimeout(ctx, time.Second*3)
+		defer cancel()
+
+		if err := svr.Shutdown(ctx); err != nil {
+			return fmt.Errorf("error shutting down server: %w", err)
+		}
+
+		return nil
+	}
+}