From 2c27cd1b56f9f26636fb69f8c53220da7c5c6abd Mon Sep 17 00:00:00 2001
From: AMelonInsideLemon <166175391+AMelonInsideLemon@users.noreply.github.com>
Date: Mon, 7 Apr 2025 10:43:17 +0200
Subject: [PATCH] set sortie timestamps using getSortieTime

Co-Authored-By: Sainan <63328889+Sainan@users.noreply.github.com>
---
 .../dynamic/worldStateController.ts           | 26 ++++++++++----
 src/helpers/worlstateHelper.ts                | 36 +++++++------------
 2 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/src/controllers/dynamic/worldStateController.ts b/src/controllers/dynamic/worldStateController.ts
index 70b29b36..2be65e3a 100644
--- a/src/controllers/dynamic/worldStateController.ts
+++ b/src/controllers/dynamic/worldStateController.ts
@@ -11,7 +11,8 @@ import { config } from "@/src/services/configService";
 import { CRng } from "@/src/services/rngService";
 import { ExportNightwave, ExportRegions } from "warframe-public-export-plus";
 import {
-    getTorontoTimeAtHour,
+    EPOCH,
+    getSortieTime,
     missionTags,
     sortieBosses,
     sortieBossNode,
@@ -20,8 +21,6 @@ import {
     sortieFactionToSystemIndexes
 } from "@/src/helpers/worlstateHelper";
 
-const EPOCH = 1734307200 * 1000; // Monday, Dec 16, 2024 @ 00:00 UTC+0; should logically be winter in 1999 iteration 0
-
 export const worldStateController: RequestHandler = (req, res) => {
     const day = Math.trunc((Date.now() - EPOCH) / 86400000);
     const week = Math.trunc(day / 7);
@@ -166,10 +165,23 @@ export const worldStateController: RequestHandler = (req, res) => {
 
     // Sortie cycling every day
     {
-        const dayStart = getTorontoTimeAtHour(EPOCH + day * 86400000, 12);
-        const dayEnd = getTorontoTimeAtHour(EPOCH + (day + 1) * 86400000, 12);
+        let genDay;
+        let dayStart;
+        let dayEnd;
+        const sortieRolloverToday = getSortieTime(day);
+        if (Date.now() < sortieRolloverToday) {
+            // Early in the day, generate sortie for `day - 1`, expiring at `sortieRolloverToday`.
+            genDay = day - 1;
+            dayStart = getSortieTime(genDay);
+            dayEnd = sortieRolloverToday;
+        } else {
+            // Late in the day, generate sortie for `day`, expiring at `getSortieTime(day + 1)`.
+            genDay = day;
+            dayStart = getSortieTime(genDay);
+            dayEnd = getSortieTime(day + 1);
+        }
 
-        const rng = new CRng(day);
+        const rng = new CRng(genDay);
 
         const boss = rng.randomElement(sortieBosses);
 
@@ -281,7 +293,7 @@ export const worldStateController: RequestHandler = (req, res) => {
             Activation: { $date: { $numberLong: dayStart.toString() } },
             Expiry: { $date: { $numberLong: dayEnd.toString() } },
             Reward: "/Lotus/Types/Game/MissionDecks/SortieRewards",
-            Seed: day,
+            Seed: genDay,
             Boss: boss,
             Variants: selectedNodes
         });
diff --git a/src/helpers/worlstateHelper.ts b/src/helpers/worlstateHelper.ts
index e6d83b74..4501d4d1 100644
--- a/src/helpers/worlstateHelper.ts
+++ b/src/helpers/worlstateHelper.ts
@@ -113,28 +113,18 @@ export const sortieBossNode: Record<string, string> = {
     SORTIE_BOSS_INFALAD: "SolNode705"
 };
 
-// ChatGPT generated that. And seems it works fine
-export const getTorontoTimeAtHour = (date: number, hour: number): number => {
-    const formatter = new Intl.DateTimeFormat("en-US", {
+export const EPOCH = 1734307200 * 1000; // Monday, Dec 16, 2024 @ 00:00 UTC+0; should logically be winter in 1999 iteration 0
+
+export const getSortieTime = (day: number): number => {
+    const dayStart = EPOCH + day * 86400000;
+    const date = new Date(dayStart);
+    date.setUTCHours(12);
+    const isDst = new Intl.DateTimeFormat("en-US", {
         timeZone: "America/Toronto",
-        year: "numeric",
-        month: "2-digit",
-        day: "2-digit"
-    });
-
-    const parts = formatter.formatToParts(date).reduce<Record<string, string>>((acc, { type, value }) => {
-        if (["year", "month", "day"].includes(type)) {
-            acc[type] = value;
-        }
-        return acc;
-    }, {});
-
-    const assumedLocalDate = new Date(
-        `${parts.year}-${parts.month}-${parts.day}T${hour.toString().padStart(2, "0")}:00:00`
-    );
-
-    const localDate = new Date(assumedLocalDate.toLocaleString("en-US", { timeZone: "America/Toronto" }));
-    const offsetMs = assumedLocalDate.getTime() - localDate.getTime();
-
-    return assumedLocalDate.getTime() + offsetMs;
+        timeZoneName: "short"
+    })
+        .formatToParts(date)
+        .find(part => part.type === "timeZoneName")!
+        .value.includes("DT");
+    return dayStart + (isDst ? 16 : 17) * 3600000;
 };