import { FREE_PLAN } from "./constants";
import { prisma } from "./db";

function getNextQuotaReset(from: Date = new Date()): Date {
  return new Date(from.getFullYear(), from.getMonth() + 1, 1);
}

export async function ensureQuotaReset(userId: string) {
  const user = await prisma.user.findUniqueOrThrow({ where: { id: userId } });
  if (new Date() >= user.quotaResetAt) {
    return prisma.user.update({
      where: { id: userId },
      data: {
        videosUsed: 0,
        quotaResetAt: getNextQuotaReset(),
      },
    });
  }
  return user;
}

export async function getQuotaInfo(userId: string) {
  const user = await ensureQuotaReset(userId);
  const remaining = Math.max(0, FREE_PLAN.monthlyQuota - user.videosUsed);
  return {
    used: user.videosUsed,
    limit: FREE_PLAN.monthlyQuota,
    remaining,
    resetsAt: user.quotaResetAt.toISOString(),
  };
}

export async function checkQuota(userId: string, requestedCount: number) {
  const info = await getQuotaInfo(userId);
  if (requestedCount > info.remaining) {
    return {
      ok: false as const,
      error: `Quota exceeded. You have ${info.remaining} videos remaining this month.`,
      ...info,
    };
  }
  return { ok: true as const, ...info };
}

export async function incrementQuota(userId: string, count: number) {
  await ensureQuotaReset(userId);
  await prisma.user.update({
    where: { id: userId },
    data: { videosUsed: { increment: count } },
  });
}

export function getInitialQuotaResetAt(): Date {
  return getNextQuotaReset();
}