add ApiHost option for ConfigGenerator (#705)

easytier-web/frontend/src/modules/api-host.ts

@@ -0,0 +1,64 @@
+const defaultApiHost = 'https://config-server.easytier.cn';
+
+interface ApiHost {
+    value: string;
+    usedAt: number;
+}
+
+const isValidHttpUrl = (s: string): boolean => {
+    let url;
+
+    try {
+        url = new URL(s);
+    } catch (_) {
+        return false;
+    }
+
+    return url.protocol === "http:" || url.protocol === "https:";
+};
+
+const cleanAndLoadApiHosts = (): Array<ApiHost> => {
+    const maxHosts = 10;
+    const apiHosts = localStorage.getItem('apiHosts');
+    if (apiHosts) {
+        const hosts: Array<ApiHost> = JSON.parse(apiHosts);
+        // sort by usedAt
+        hosts.sort((a, b) => b.usedAt - a.usedAt);
+
+        // only keep the first 10
+        if (hosts.length > maxHosts) {
+            hosts.splice(maxHosts);
+        }
+
+        localStorage.setItem('apiHosts', JSON.stringify(hosts));
+        return hosts;
+    } else {
+        return [];
+    }
+};
+
+const saveApiHost = (host: string) => {
+    console.log('Save API Host:', host);
+    if (!isValidHttpUrl(host)) {
+        console.error('Invalid API Host:', host);
+        return;
+    }
+
+    let hosts = cleanAndLoadApiHosts();
+    const newHost: ApiHost = {value: host, usedAt: Date.now()};
+    hosts = hosts.filter((h) => h.value !== host);
+    hosts.push(newHost);
+    localStorage.setItem('apiHosts', JSON.stringify(hosts));
+};
+
+const getInitialApiHost = (): string => {
+    const hosts = cleanAndLoadApiHosts();
+    if (hosts.length > 0) {
+        return hosts[0].value;
+    } else {
+        saveApiHost(defaultApiHost)
+        return defaultApiHost;
+    }
+};
+
+export {getInitialApiHost, cleanAndLoadApiHosts, saveApiHost}