Mirgate project to go

internal/server/server.go

@@ -0,0 +1,170 @@
+package server
+
+import (
+	"errors"
+	"fmt"
+	"html"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"sync"
+	"time"
+)
+
+const (
+	address          = ":5000"
+	htmlContentType  = "text/html; charset=utf-8"
+	notFoundTemplate = `
+		<div class="tui-window">
+			<fieldset class="tui-fieldset">
+				<legend>Error</legend>
+				<p>Route %s not found.</p>
+			</fieldset>
+		</div>
+		`
+)
+
+// Server hosts the Luxtools HTTP handlers.
+type Server struct {
+	mux        *http.ServeMux
+	indexPage  []byte
+	staticRoot string
+	assetsRoot string
+
+	counterMu  sync.Mutex
+	clickCount int
+}
+
+// New constructs a configured Server ready to serve requests.
+func New() (*Server, error) {
+	projectRoot, err := goProjectRoot()
+	if err != nil {
+		return nil, err
+	}
+
+	indexPath := filepath.Join(projectRoot, "web", "templates", "index.html")
+	staticDir := filepath.Join(projectRoot, "web", "static")
+	assetsDir := filepath.Join(projectRoot, "assets")
+
+	indexPage, err := os.ReadFile(indexPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read index template: %w", err)
+	}
+
+	if _, err := os.Stat(staticDir); err != nil {
+		return nil, fmt.Errorf("static directory check failed: %w", err)
+	}
+	if _, err := os.Stat(assetsDir); err != nil {
+		return nil, fmt.Errorf("assets directory check failed: %w", err)
+	}
+
+	s := &Server{
+		mux:        http.NewServeMux(),
+		indexPage:  indexPage,
+		staticRoot: staticDir,
+		assetsRoot: assetsDir,
+	}
+
+	s.registerRoutes()
+	return s, nil
+}
+
+// Router exposes the configured http.Handler for the server.
+func (s *Server) Router() http.Handler {
+	return s.mux
+}
+
+// Address returns the default listen address for the server.
+func (s *Server) Address() string {
+	return address
+}
+
+func (s *Server) registerRoutes() {
+	s.mux.Handle("/static/", http.StripPrefix("/static/", allowGetHead(http.FileServer(http.Dir(s.staticRoot)))))
+	s.mux.Handle("/assets/", http.StripPrefix("/assets/", allowGetHead(http.FileServer(http.Dir(s.assetsRoot)))))
+	s.mux.HandleFunc("/", s.handleRequest)
+}
+
+func (s *Server) handleRequest(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/":
+		s.sendHTML(w, http.StatusOK, s.indexPage)
+	case "/counter":
+		s.handleCounter(w, r)
+	case "/time":
+		s.sendHTMLString(w, http.StatusOK, renderTime(time.Now()))
+	default:
+		s.sendHTMLString(w, http.StatusNotFound, fmt.Sprintf(notFoundTemplate, html.EscapeString(r.URL.Path)))
+	}
+}
+
+func (s *Server) handleCounter(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodPost || r.Method == http.MethodPut {
+		s.counterMu.Lock()
+		s.clickCount++
+		s.counterMu.Unlock()
+	}
+
+	s.counterMu.Lock()
+	count := s.clickCount
+	s.counterMu.Unlock()
+
+	s.sendHTMLString(w, http.StatusOK, renderCounter(count))
+}
+
+func (s *Server) sendHTML(w http.ResponseWriter, status int, body []byte) {
+	w.Header().Set("Content-Type", htmlContentType)
+	w.WriteHeader(status)
+	if len(body) > 0 {
+		if _, err := w.Write(body); err != nil {
+			log.Printf("write response failed: %v", err)
+		}
+	}
+}
+
+func (s *Server) sendHTMLString(w http.ResponseWriter, status int, body string) {
+	s.sendHTML(w, status, []byte(body))
+}
+
+func renderCounter(count int) string {
+	return fmt.Sprintf(`
+  <div id="counter" class="tui-panel tui-panel-inline">
+    <p><strong>Clicks:</strong> %d</p>
+    <button class="tui-button" hx-post="/counter" hx-target="#counter" hx-swap="outerHTML">
+      Increment
+    </button>
+  </div>
+  `, count)
+}
+
+func renderTime(now time.Time) string {
+	return fmt.Sprintf(`
+  <div id="server-time" class="tui-panel tui-panel-inline">
+    <p><strong>Server time:</strong> %s</p>
+  </div>
+  `, now.Format("2006-01-02 15:04:05"))
+}
+
+func allowGetHead(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet, http.MethodHead:
+			next.ServeHTTP(w, r)
+		default:
+			http.NotFound(w, r)
+		}
+	})
+}
+
+func goProjectRoot() (string, error) {
+	_, currentFile, _, ok := runtime.Caller(0)
+	if !ok {
+		return "", errors.New("unable to determine caller information")
+	}
+
+	dir := filepath.Dir(currentFile)
+	projectRoot := filepath.Clean(filepath.Join(dir, "..", ".."))
+	return projectRoot, nil
+}