Refactor select fields

web/src/aggregator/CityResult.tsx

@@ -0,0 +1,26 @@
+import { Component } from "solid-js";
+import { CityChart } from "./CityChart";
+
+export const CityResult: Component<{ city: string, value: any }> = ({ city, value }) => {
+    return (
+        <div class="result-item">
+            <h4>{ city }</h4>
+            {
+                isDateNumber(value)
+                ? <CityChart data={value}/>
+                : value
+            }
+        </div>
+    );
+}
+
+function isDateNumber(value: unknown): value is [string, number | null][] {
+    if (!Array.isArray(value)) return false;
+    for (let i = 0; i < value.length; i++) {
+        let item = value[i];
+        if (!Array.isArray(item) || item.length !== 2 || typeof item[0] !== 'string' || (typeof item[1] !== 'number' && item[1] !== null)) {
+            return false;
+        }
+    }
+    return true;
+}