all: add "-dev" option for running lilin

The "-dev" flag enable running in development mode, where each refresh
will re-read, parse, and execute the template.

1 files changed, 59 insertions, 17 deletions

diff --git a/server.go b/server.go
index 7943b1b..1741c27 100644
--- a/server.go
+++ b/server.go
@@ -8,8 +8,10 @@ import (
 	"context"
 	"fmt"
 	"html/template"
+	"io/fs"
 	"log"
 	"net/http"
+	"os"
 	"sync"
 	"time"
 )
@@ -25,6 +27,8 @@ type Server struct {
 	httpd  *http.Server
 	worker *worker
 
+	fs fs.ReadFileFS
+
 	// updateq channel to receive notification when the new report coming
 	// from worker.
 	updateq chan struct{}
@@ -58,6 +62,48 @@ func NewServer(opts ServerOptions) (srv *Server, err error) {
 		return nil, fmt.Errorf(`%s: %w`, logp, err)
 	}
 
+	err = srv.initFS()
+	if err != nil {
+	}
+
+	err = srv.initTemplate()
+	if err != nil {
+		return nil, fmt.Errorf(`%s: %w`, logp, err)
+	}
+
+	var mux = http.NewServeMux()
+	mux.Handle(`GET /`, srv)
+
+	srv.httpd = &http.Server{
+		Addr:         srv.Options.Address,
+		Handler:      mux,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 5 * time.Second,
+	}
+	return srv, nil
+}
+
+func (srv *Server) initFS() (err error) {
+	if srv.Options.IsDevelopment {
+		var dirfs = os.DirFS(`_www`)
+		if err != nil {
+			return err
+		}
+		srv.fs = dirfs.(fs.ReadFileFS)
+	} else {
+		var subfs fs.FS
+		subfs, err = fs.Sub(wwwFS, `_www`)
+		if err != nil {
+			return err
+		}
+		srv.fs = subfs.(fs.ReadFileFS)
+	}
+	return nil
+}
+
+func (srv *Server) initTemplate() (err error) {
+	var logp = `initTemplate`
+
 	srv.pageIndexTmpl = template.New("index.html").Funcs(template.FuncMap{
 		`reverse`: func(rev []ScanReport) (ver []ScanReport) {
 			var size = len(rev)
@@ -68,30 +114,21 @@ func NewServer(opts ServerOptions) (srv *Server, err error) {
 			return ver
 		},
 	})
+
 	var tmplraw []byte
-	tmplraw, err = wwwFS.ReadFile(`_www/index.tmpl`)
+	tmplraw, err = srv.fs.ReadFile(`index.tmpl`)
 	if err != nil {
-		return nil, err
+		return fmt.Errorf(`%s: %w`, logp, err)
 	}
 	srv.pageIndexTmpl, err = srv.pageIndexTmpl.Parse(string(tmplraw))
 	if err != nil {
-		return nil, err
+		return fmt.Errorf(`%s: %w`, logp, err)
 	}
 	err = srv.pageIndexTmpl.Execute(&srv.pageIndexBody, &srv.worker.Reports)
 	if err != nil {
-		return nil, err
+		return fmt.Errorf(`%s: %w`, logp, err)
 	}
-
-	var mux = http.NewServeMux()
-	mux.Handle(`GET /`, srv)
-
-	srv.httpd = &http.Server{
-		Addr:         srv.Options.Address,
-		Handler:      mux,
-		ReadTimeout:  5 * time.Second,
-		WriteTimeout: 5 * time.Second,
-	}
-	return srv, nil
+	return nil
 }
 
 // ListenAndServe start handling request on incoming connections.
@@ -172,8 +209,13 @@ func (srv *Server) update() {
 			srv.worker.Reports.Lock()
 
 			srv.pageIndexBody.Reset()
-			err = srv.pageIndexTmpl.Execute(&srv.pageIndexBody,
-				&srv.worker.Reports)
+			if srv.Options.IsDevelopment {
+				err = srv.initTemplate()
+			} else {
+				err = srv.pageIndexTmpl.Execute(
+					&srv.pageIndexBody,
+					&srv.worker.Reports)
+			}
 			if err != nil {
 				log.Printf(`update: pageIndexTmpl: %s`, err)
 			}