From 405f139c1b8f8e2937f53480411d6a66ab0c34ae Mon Sep 17 00:00:00 2001
From: Arjun Komath <arjun@hey.com>
Date: Thu, 9 Jan 2025 21:58:07 +1100
Subject: [PATCH] Add user timezone handling to calendar events

---
 .../calendar/[ownerId]/[projectId]/route.ts   | 50 +++++++++++++++----
 lib/ops/auth.ts                               | 24 +++++++++
 2 files changed, 65 insertions(+), 9 deletions(-)

diff --git a/app/(api)/api/calendar/[ownerId]/[projectId]/route.ts b/app/(api)/api/calendar/[ownerId]/[projectId]/route.ts
index b609293..82b72bd 100644
--- a/app/(api)/api/calendar/[ownerId]/[projectId]/route.ts
+++ b/app/(api)/api/calendar/[ownerId]/[projectId]/route.ts
@@ -1,19 +1,39 @@
 import { calendarEvent, project, task, taskList } from "@/drizzle/schema";
+import { getUser } from "@/lib/ops/auth";
 import { getDatabaseForOwner } from "@/lib/utils/useDatabase";
 import { getVtimezoneComponent } from "@touch4it/ical-timezones";
+import dayjs from "dayjs";
+import tz from "dayjs/plugin/timezone";
+import utc from "dayjs/plugin/utc";
 import { and, desc, eq, lte } from "drizzle-orm";
 import ical, { ICalCalendarMethod } from "ical-generator";
+import type { NextRequest } from "next/server";
+
+dayjs.extend(utc);
+dayjs.extend(tz);
 
 export const revalidate = 0;
 export const dynamic = "force-dynamic";
 
 export async function GET(
-	_: Request,
-	props: { params: Promise<{ projectId: string; ownerId: string }> },
+	request: NextRequest,
+	props: {
+		params: Promise<{ projectId: string; ownerId: string }>;
+	},
 ) {
 	const params = await props.params;
+	const searchParams = request.nextUrl.searchParams;
 	const { projectId, ownerId } = params;
 
+	let timezone: string | null = null;
+	const userId = searchParams.get("userId");
+	if (userId) {
+		const user = await getUser(userId);
+		if (user.customData?.timezone) {
+			timezone = user.customData.timezone;
+		}
+	}
+
 	const db = await getDatabaseForOwner(ownerId);
 
 	const projectDetails = await db.query.project
@@ -47,21 +67,29 @@ export async function GET(
 	const calendar = ical({
 		name: projectDetails.name,
 		method: ICalCalendarMethod.PUBLISH,
-		timezone: { name: "Australia/Sydney", generator: getVtimezoneComponent },
+		timezone: timezone
+			? { name: timezone, generator: getVtimezoneComponent }
+			: null,
 	});
 
 	for (const event of events) {
 		calendar.createEvent({
 			id: event.id,
-			start: event.start,
-			end: event.end ?? null,
+			start: timezone
+				? dayjs.utc(event.start).tz(timezone).format("YYYY-MM-DDTHH:mm:ssZ")
+				: event.start,
+			end: event.end
+				? timezone
+					? dayjs.utc(event.end).tz(timezone).format("YYYY-MM-DDTHH:mm:ssZ")
+					: event.end
+				: null,
 			summary: event.name,
 			description: event.description,
 			allDay: event.allDay,
 			created: event.createdAt,
 			lastModified: event.updatedAt,
 			repeating: event.repeatRule,
-			timezone: "Australia/Sydney",
+			timezone,
 		});
 	}
 
@@ -76,14 +104,18 @@ export async function GET(
 
 			calendar.createEvent({
 				id: task.id,
-				start: task.dueDate,
-				end: task.dueDate,
+				start: timezone
+					? dayjs.utc(task.dueDate).tz(timezone).format("YYYY-MM-DDTHH:mm:ssZ")
+					: task.dueDate,
+				end: timezone
+					? dayjs.utc(task.dueDate).tz(timezone).format("YYYY-MM-DDTHH:mm:ssZ")
+					: task.dueDate,
 				summary: `[${tasklist.name}] ${task.name}`,
 				description: task.description,
 				allDay: true,
 				created: task.createdAt,
 				lastModified: task.updatedAt,
-				timezone: "Australia/Sydney",
+				timezone,
 			});
 		}
 	}
diff --git a/lib/ops/auth.ts b/lib/ops/auth.ts
index 17efc2d..2c5324e 100644
--- a/lib/ops/auth.ts
+++ b/lib/ops/auth.ts
@@ -46,6 +46,30 @@ export const fetchAccessToken = async () => {
 		}).toString(),
 	});
 };
+
+export const getUser = async (userId: string) => {
+	const { access_token } = await fetchAccessToken().then((res) => res.json());
+	if (!access_token) {
+		throw new Error("Access token not found");
+	}
+
+	const { endpoint } = logtoConfig;
+	const response = await fetch(`${endpoint}api/users/${userId}`, {
+		method: "GET",
+		headers: {
+			Authorization: `Bearer ${access_token}`,
+			"Content-Type": "application/json",
+		},
+	});
+
+	if (!response.ok) {
+		console.error("Failed to fetch user", response.status);
+		throw new Error("Failed to fetch user");
+	}
+
+	return await response.json();
+};
+
 export const updateUser = async (
 	userId: string,
 	data: {