Market quartils

src/market/market.ts

@@ -0,0 +1,59 @@
+import { esiAxiosInstance } from "@/service";
+
+export const jitaId = 10000002;
+
+export type MarketOrderHistory = {
+    average: number;
+    date: string;
+    highest: number;
+    lowest: number;
+    order_count: number;
+    volume: number;
+}
+
+export const getHistory = async (regionId: number, tyeId: number): Promise<MarketOrderHistory[]> =>  (await esiAxiosInstance.get(`/markets/${regionId}/history/`, { params: { type_id: tyeId } })).data;
+
+export const getHistoryQuartils = async (regionId: number, tyeId: number): Promise<[number, number, number]> => {
+    const history = await getHistory(regionId, tyeId);
+    const volumes = history
+        .flatMap(h => {
+            const volume = h.volume;
+
+            if (volume === 0) {
+                return [];
+            }
+
+            const e = estimateVolume(h);
+
+            return [[h.highest, e], [h.lowest, volume - e]];
+        })
+        .filter(h => h[1] > 0)
+        .sort((a, b) => a[0] - b[0]);
+
+    const totalVolume = volumes.reduce((acc, [_, v]) => acc + v, 0);
+    const quartilVolume = totalVolume / 4;
+    const quartils: [number, number, number] = [0, 0, 0];
+
+    let currentVolume = 0;
+    let quartil = 0;
+
+    for (const [price, volume] of volumes) {
+        currentVolume += volume;
+
+        if (currentVolume >= quartilVolume * (quartil + 1)) {
+            quartils[quartil] = price;
+            if (quartil === 2) {
+                break;
+            }
+            quartil++;
+        }
+    }
+    return quartils;
+}
+
+const estimateVolume = (history: MarketOrderHistory): number => {
+    if (history.volume === 0) {
+        return 0;
+    }
+    return Math.max(1, Math.round(history.volume * ((history.average - history.lowest) / (history.highest - history.lowest))));
+}