import { Plan } from "@prisma/client";
import { prisma } from "./db";
import { getNextMonthlyQuotaReset, getPlanLimits } from "./plans";

/**
 * OSS / self-hosted quota: never blocks on credits or plan limits.
 * Batch size still enforced via SELFHOSTED_LIMITS.maxBatchSize.
 * videosUsed is incremented for display only.
 */

export function formatQuotaResetCountdown(_resetsAt: Date | string): string {
  return "never";
}

export function formatQuotaResetDisplay(_plan: Plan, _resetsAt: Date | string): string {
  return "never (self-hosted)";
}

export async function ensureQuotaReset(userId: string) {
  return prisma.user.findUniqueOrThrow({ where: { id: userId } });
}

export async function getQuotaInfo(userId: string) {
  const user = await ensureQuotaReset(userId);
  const limits = getPlanLimits(user.plan);
  return {
    used: user.videosUsed,
    limit: limits.monthlyQuota,
    baseLimit: limits.monthlyQuota,
    bonusQuota: 0,
    remaining: limits.monthlyQuota,
    videoCredits: 0,
    extraCredits: 0,
    creditBalanceMax: 0,
    totalAvailable: limits.monthlyQuota,
    resetsAt: user.quotaResetAt.toISOString(),
    resetsIn: formatQuotaResetDisplay(user.plan, user.quotaResetAt),
    plan: user.plan,
    maxBatchSize: limits.maxBatchSize,
    watermarkOptional: limits.watermarkOptional,
    customWatermark: limits.customWatermark,
    perItemImages: limits.perItemImages,
    artTrackLayouts: limits.artTrackLayouts,
    maxResolutionHeight: limits.maxResolutionHeight,
    selfHosted: true,
  };
}

export type ReservationSplit = {
  fromQuota: number;
  fromCredits: number;
};

/** Always succeed (except empty). Credits are never used in OSS. */
export function planReservation(
  _plan: Plan,
  _remainingQuota: number,
  _videoCredits: number,
  count: number,
): ReservationSplit | null {
  if (count <= 0) return { fromQuota: 0, fromCredits: 0 };
  return { fromQuota: count, fromCredits: 0 };
}

export async function checkQuota(userId: string, requestedCount: number) {
  const info = await getQuotaInfo(userId);
  if (requestedCount > info.maxBatchSize) {
    return {
      ok: false as const,
      error: `Batch limit exceeded. Max ${info.maxBatchSize} files per batch.`,
      used: info.used,
      limit: info.limit,
      remaining: info.remaining,
      videoCredits: 0,
      resetsAt: info.resetsAt,
    };
  }
  return {
    ok: true as const,
    ...info,
    reservation: { fromQuota: requestedCount, fromCredits: 0 },
  };
}

/** Track usage for display; never deduct credits or block. */
export async function reserveQuota(userId: string, count: number): Promise<ReservationSplit> {
  if (count <= 0) return { fromQuota: 0, fromCredits: 0 };

  const limits = getPlanLimits();
  if (count > limits.maxBatchSize) {
    throw new Error(`Batch limit exceeded. Max ${limits.maxBatchSize} files per batch.`);
  }

  await prisma.user.update({
    where: { id: userId },
    data: { videosUsed: { increment: count } },
  });
  return { fromQuota: count, fromCredits: 0 };
}

export async function releaseQuota(userId: string, count: number) {
  if (count <= 0) return;
  await prisma.$executeRaw`
    UPDATE "User"
    SET "videosUsed" = GREATEST(0, "videosUsed" - ${count})
    WHERE id = ${userId}
  `;
}

/** No-op in OSS (no prepaid credits). */
export async function releaseCredits(_userId: string, _count: number) {
  return;
}

export async function releaseReservation(
  userId: string,
  _billingSource: "QUOTA" | "CREDIT",
  count = 1,
) {
  await releaseQuota(userId, count);
}

export async function releaseReservationSplit(userId: string, split: ReservationSplit) {
  if (split.fromQuota > 0) await releaseQuota(userId, split.fromQuota);
}

export async function incrementQuota(userId: string, count: number) {
  await reserveQuota(userId, count);
}

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