Refactor O365 login to use server-side state and add account support

Co-authored-by: kristofer.john.nilsson <kristofer.john.nilsson@gmail.com>

plugins/login-o365/LoginOAuth2.js

@@ -1,38 +1,37 @@
 ((rl) => {
   const client_id = rl.pluginSettingsGet("login-o365", "client_id"),
-    // https://learn.microsoft.com/en-us/entra/identity-platform/reply-url#query-parameter-support-in-redirect-uris
-    tenant = rl.pluginSettingsGet("login-o365", "tenant"),
-    login = () => {
-      document.location = "https://login.microsoftonline.com/" +
-        tenant +
-        "/oauth2/v2.0/authorize?" +
-        new URLSearchParams({
-          response_type: "code",
-          client_id: client_id,
-          redirect_uri:
-            document.location.href.replace(/\/$/, "") + "/LoginO365",
-          scope: [
-            // Associate personal info
-            "openid",
-            "offline_access",
-            "email",
-            "profile",
-            // Access IMAP and SMTP through OAUTH
-            "https://outlook.office.com/IMAP.AccessAsUser.All",
-            "https://outlook.office.com/SMTP.Send",
-          ].join(" "),
-          state: "o365",
-          access_type: "offline_access"
-          // prompt: "consent",
-        });
+    allowAnyDomain = !!rl.pluginSettingsGet("login-o365", "allow_any_domain"),
+    isSupportedEmail = (email) => {
+      email = (email || "").toLowerCase();
+      if (!email.includes("@")) return false;
+      if (allowAnyDomain) return true;
+      return /@(outlook\.com|hotmail\.com|live\.com)$/.test(email);
+    },
+    startOAuth = (op, opts = {}) => {
+      const email = (opts.email || "").toLowerCase();
+      const name = opts.name || "";
+      const returnHash = opts.return || "";
+
+      // Server mints a signed state + correct redirect_uri and returns full authUrl.
+      rl.pluginRemoteRequest((iError, data) => {
+        const url = data?.Result?.authUrl;
+        if (!iError && url) {
+          document.location = url;
+        }
+      }, "LoginO365AuthUrl", {
+        op: op,
+        email: email,
+        name: name,
+        return: returnHash,
+      });
     };
 
   if (client_id) {
     addEventListener("sm-user-login", (e) => {
       const email = (e.detail.get("Email") || "").toLowerCase();
-      if (/@(outlook\.com|hotmail\.com|live\.com)$/.test(email)) {
+      if (isSupportedEmail(email)) {
         e.preventDefault();
-        login();
+        startOAuth("login", { email });
       }
     });
 
@@ -42,10 +41,51 @@
 		  container = e.detail.viewModelDom.querySelector("#plugin-Login-BottomControlGroup"),
           btn = Element.fromHTML('<button type="button">Outlook</button>'),
           div = Element.fromHTML('<div class="controls"></div>');
-        btn.onclick = login;
+        btn.onclick = () => {
+          // Best-effort: try to read the email field if present.
+          const input = e.detail.viewModelDom.querySelector('input[type="email"], input[name="Email"], input[name="email"], input');
+          const email = (input?.value || "").toLowerCase();
+          if (!email || isSupportedEmail(email)) {
+            startOAuth("login", { email });
+          }
+        };
         div.append(btn);
         container && container.append(div);
       }
+
+      // "Add account" popup (Settings → Accounts → Add account)
+      if ("Account" === e.detail.viewModelTemplateID) {
+        // Only for the "Add account" mode, not "Edit account".
+        if (typeof e.detail.isNew === "function" && !e.detail.isNew()) {
+          return;
+        }
+        const root = e.detail.viewModelDom;
+        if (!root) return;
+
+        const footer = root.querySelector("footer");
+        const form = root.querySelector("#accountform");
+        const addButton = root.querySelector("button.buttonAddAccount");
+        if (!footer || !form || !addButton) return;
+
+        // Avoid inserting duplicates when view model is re-rendered.
+        if (root.querySelector(".plugin-o365-add-account")) return;
+
+        const btn = Element.fromHTML(
+          '<button type="button" class="btn plugin-o365-add-account" style="margin-left: 6px;">Outlook</button>'
+        );
+
+        btn.onclick = () => {
+          const email = (form.querySelector('input[name="email"]')?.value || "").trim().toLowerCase();
+          const name = (form.querySelector('input[name="name"]')?.value || "").trim();
+          if (!email || !isSupportedEmail(email)) {
+            return;
+          }
+          startOAuth("add", { email, name, return: document.location.hash || "#/settings/accounts" });
+        };
+
+        // Put the button next to the default Add Account submit button.
+        footer.insertBefore(btn, addButton.nextSibling);
+      }
     });
   }
 })(window.rl);