convex/settings.ts

import { v } from 'convex/values';
import { mutation, query } from './_generated/server';

export const get = query({
	args: { userId: v.string() },
	handler: async (ctx, { userId }) => {
		const doc = await ctx.db
			.query('userSettings')
			.withIndex('by_userId', (q) => q.eq('userId', userId))
			.first();
		return doc ?? null;
	}
});

export const save = mutation({
	args: {
		userId: v.string(),
		data: v.any()
	},
	handler: async (ctx, { userId, data }) => {
		const existing = await ctx.db
			.query('userSettings')
			.withIndex('by_userId', (q) => q.eq('userId', userId))
			.first();

		if (existing) {
			await ctx.db.patch(existing._id, { data, updatedAt: Date.now() });
		} else {
			await ctx.db.insert('userSettings', {
				userId,
				data,
				updatedAt: Date.now()
			});
		}
	}
});