From 86c328b33f3d6494036bfc9fcc789739b825c604 Mon Sep 17 00:00:00 2001
From: Lorenz Stechauner <lorenz.stechauner@necronda.net>
Date: Sun, 9 May 2021 21:24:42 +0200
Subject: [PATCH] Add usimp.chooseDomainServer

---
 www/res/js/locutus.js | 28 ++++++++++++++++++----------
 www/res/js/usimp.js   | 28 ++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/www/res/js/locutus.js b/www/res/js/locutus.js
index 0146880..8e0cb01 100644
--- a/www/res/js/locutus.js
+++ b/www/res/js/locutus.js
@@ -37,26 +37,34 @@ function createLoginWindow() {
             form.removeChild(d);
         }
 
+        function formError(msg) {
+            let div = document.createElement("div");
+            div.classList.add("error");
+            div.innerText = msg;
+            form.appendChild(div);
+        }
+
         usimp.lookup(form.domain.value)
             .then(res => {
                 if (res.ok) {
                     res.json()
-                        .then(data => console.log(data))
-                        .catch(reason => console.error(reason))
+                        .then(data => {
+                            console.log(data["domain"]);
+                            let domainServer = usimp.chooseDomainServer(data["domain_servers"]);
+                            console.log(domainServer);
+                        })
+                        .catch(reason => {
+                            console.error(reason);
+                            formError("Could not communicate with USIMP domain");
+                        })
                 } else {
                     document.getElementsByName("domain")[0].setAttribute("invalid", "invalid");
-                    let div = document.createElement("div");
-                    div.classList.add("error");
-                    div.innerText = "Invalid USIMP domain";
-                    form.appendChild(div);
+                    formError("Invalid USIMP domain");
                 }
             })
             .catch(reason => {
                 document.getElementsByName("domain")[0].setAttribute("invalid", "invalid");
-                let div = document.createElement("div");
-                div.classList.add("error");
-                div.innerText = "Invalid USIMP domain";
-                form.appendChild(div);
+                formError("Invalid USIMP domain");
             })
             .finally(() => {
                 for (let e of form) e.disabled = false;
diff --git a/www/res/js/usimp.js b/www/res/js/usimp.js
index 079c6ef..960e787 100644
--- a/www/res/js/usimp.js
+++ b/www/res/js/usimp.js
@@ -7,3 +7,31 @@ usimp.lookup = function (domain_name) {
         redirect: "manual",
     });
 }
+
+usimp.chooseDomainServer = function (domainServers, invalidDomainServers = []) {
+    if (domainServers.length === 0) throw Error("No domain servers specified");
+
+    domainServers.filter(srv => invalidDomainServers.map(srv => srv.host).includes(srv));
+    if (domainServers.length === 0) throw Error("No domain servers reachable");
+    if (domainServers.length === 1) return domainServers[0];
+
+    let priority = domainServers.reduce((min, srv) => Math.min(min, srv.priority), Infinity);
+    domainServers = domainServers.filter(srv => srv.priority === priority);
+    if (domainServers.length === 1) return domainServers[0];
+
+    let totalWeight = domainServers.reduce((total, srv) => total + srv.weight, 0);
+    let w = Math.floor(Math.random() * totalWeight);
+
+    let accumulator = 0;
+    for (let srv of domainServers) {
+        accumulator += srv.weight;
+        if (w < accumulator) return srv;
+    }
+
+    console.warn("Domain server selection not worked correctly");
+    return domainServers[0];
+}
+
+usimp.login = function (domainServer, accountName, password) {
+    return fetch(``)
+}