"use server";

import { auth } from "@/lib/auth";
import { logger } from "@/lib/logger";
import { prisma } from "@/lib/prisma";

export async function linkDiscordId(discordId: string): Promise<string | null> {
	const session = await auth();
	if (!session?.user?.id) return "Not logged in";

	const userId = Number(session.user.id);
	if (!discordId || !/^\d{17,20}$/.test(discordId.trim())) {
		return "Invalid Discord ID format";
	}

	const discordIdClean = discordId.trim();

	try {
		const existing = await prisma.socialAccounts.findUnique({
			where: {
				provider_providerId: {
					provider: "discord",
					providerId: discordIdClean,
				},
			},
			select: { userId: true },
		});
		if (existing && Number(existing.userId) !== userId) {
			return "This Discord ID is already linked to another account";
		}
	} catch {
		return "Failed to check Discord ID";
	}

	try {
		await prisma.socialAccounts.upsert({
			where: {
				provider_providerId: {
					provider: "discord",
					providerId: discordIdClean,
				},
			},
			create: {
				userId: BigInt(userId),
				provider: "discord",
				providerId: discordIdClean,
				createdAt: new Date(),
				updatedAt: new Date(),
			},
			update: { userId: BigInt(userId), updatedAt: new Date() },
		});

		await prisma.user.update({
			where: { id: userId },
			data: { mailVerified: "1" },
		});

		return null;
	} catch (e) {
		logger.error("Failed to link Discord account", {
			module: "link-discord",
			error: (e as Error).message,
		});
		return "Failed to link Discord account";
	}
}