add login page to webserver

webserver/login_page.go

@@ -0,0 +1,27 @@
+package webserver
+
+import (
+	"net/http"
+	"strings"
+	"text/template"
+)
+
+type LoginPageData struct {
+	IsHiddenClassList string
+}
+
+func loginHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	tmpl := template.Must(template.ParseFiles("webserver/pages/login_page.html"))
+	if r.Method == http.MethodGet {
+		tmpl.Execute(w, LoginPageData{IsHiddenClassList: "hidden"})
+		return
+	}
+
+	if r.Method == http.MethodPost {
+		username := r.FormValue("username")
+		if strings.Contains(username, "/") {
+			tmpl.Execute(w, LoginPageData{IsHiddenClassList: ""})
+		}
+	}
+}