split RMS login email into callsign and domain select

public/app.js

@@ -81,7 +81,8 @@ const state = {
 
 const els = {
   authForm: document.getElementById("authForm"),
-  email: document.getElementById("email"),
+  callsignInput: document.getElementById("callsignInput"),
+  emailDomainSelect: document.getElementById("emailDomainSelect"),
   loginBtn: document.getElementById("loginBtn"),
   authMethodSelect: document.getElementById("authMethodSelect"),
   otpWrap: document.getElementById("otpWrap"),
@@ -910,7 +911,7 @@ async function refreshFrontendOnResume() {
 
 async function requestAccess() {
   clearMessages("auth");
-  const email = els.email.value.trim();
+  const email = composeLoginEmail();
   if (!isLoginEmailAllowed(email)) {
     renderMessage(els.authMessage, `Nur Club-Mailadressen (${formatAllowedDomainsHint()}) sind zum Anmelden moeglich.`, true);
     return;
@@ -950,11 +951,12 @@ async function requestAccess() {
 
 async function verifyOtpCode() {
   clearMessages("auth");
+  const email = composeLoginEmail();
   try {
     const result = await api("/v1/auth/verify-email", {
       method: "POST",
       body: {
-        email: els.email.value.trim(),
+        email,
         code: els.otpCode.value.trim()
       },
       authRequired: false
@@ -997,6 +999,41 @@ function isLoginEmailAllowed(email) {
   return getAllowedLoginDomains().includes(domain);
 }
 
+function composeLoginEmail() {
+  const callsign = String(els.callsignInput && els.callsignInput.value ? els.callsignInput.value : "")
+    .trim()
+    .toLowerCase();
+  const selectedDomain = String(
+    els.emailDomainSelect && els.emailDomainSelect.value
+      ? els.emailDomainSelect.value
+      : getAllowedLoginDomains()[0] || ""
+  )
+    .trim()
+    .toLowerCase();
+  if (!callsign || !selectedDomain) {
+    return "";
+  }
+  if (callsign.includes("@")) {
+    return callsign;
+  }
+  return `${callsign}@${selectedDomain}`;
+}
+
+function splitEmailParts(email) {
+  const normalized = String(email || "").trim().toLowerCase();
+  const atIndex = normalized.lastIndexOf("@");
+  if (atIndex < 0) {
+    return {
+      callsign: normalized,
+      domain: ""
+    };
+  }
+  return {
+    callsign: normalized.slice(0, atIndex),
+    domain: normalized.slice(atIndex + 1)
+  };
+}
+
 function getAllowedLoginDomains() {
   const list = state && state.system && Array.isArray(state.system.allowedLoginDomains)
     ? state.system.allowedLoginDomains
@@ -1008,12 +1045,32 @@ function formatAllowedDomainsHint() {
   return getAllowedLoginDomains().map((domain) => `@${domain}`).join(" oder ");
 }
 
+function renderLoginDomainSelect() {
+  if (!els.emailDomainSelect) {
+    return;
+  }
+  const domains = getAllowedLoginDomains();
+  const previous = String(els.emailDomainSelect.value || "").toLowerCase();
+  els.emailDomainSelect.innerHTML = "";
+  for (const domain of domains) {
+    const option = document.createElement("option");
+    option.value = domain;
+    option.textContent = domain;
+    els.emailDomainSelect.appendChild(option);
+  }
+  if (previous && domains.includes(previous)) {
+    els.emailDomainSelect.value = previous;
+  } else if (domains.length > 0) {
+    els.emailDomainSelect.value = domains[0];
+  }
+}
+
 async function handleEmailTokenFromUrl() {
   const url = new URL(window.location.href);
   if (url.searchParams.get("requestApproval") === "1") {
     const email = (url.searchParams.get("email") || "").trim();
     if (email) {
-      els.email.value = email;
+      setLoginEmail(email);
       try {
         const result = await api("/v1/auth/request-approval", {
           method: "POST",
@@ -1066,6 +1123,19 @@ async function handleEmailTokenFromUrl() {
   }
 }
 
+function setLoginEmail(email) {
+  const parts = splitEmailParts(email);
+  if (els.callsignInput) {
+    els.callsignInput.value = parts.callsign || "";
+  }
+  if (els.emailDomainSelect) {
+    renderLoginDomainSelect();
+    if (parts.domain && getAllowedLoginDomains().includes(parts.domain)) {
+      els.emailDomainSelect.value = parts.domain;
+    }
+  }
+}
+
 async function refreshPublicSystemStatus() {
   try {
     const result = await api("/v1/public/system", { authRequired: false });
@@ -1085,6 +1155,7 @@ async function refreshPublicSystemStatus() {
       allowedLoginDomains: DEFAULT_ALLOWED_LOGIN_DOMAINS.slice()
     };
   }
+  renderLoginDomainSelect();
   renderMaintenanceBanner();
   renderBranding();
 }
@@ -4225,7 +4296,8 @@ function updateUserUi() {
   setDisabled(els.logoutBtn, !loggedIn);
   setDisabled(els.settingsLogoutTopBtn, !loggedIn);
   setDisabled(els.userMenuButton, !loggedIn);
-  setDisabled(els.email, loggedIn);
+  setDisabled(els.callsignInput, loggedIn);
+  setDisabled(els.emailDomainSelect, loggedIn);
   if (els.userMenuButton) {
     els.userMenuButton.textContent = "☰";
     els.userMenuButton.setAttribute("aria-label", loggedIn ? `Menue (${state.user.email})` : "Menue");