import { DateTime } from 'luxon';

import { IS_BILLING_ENABLED } from '@documenso/lib/constants/app';
import { prisma } from '@documenso/prisma';
import { SubscriptionStatus } from '@documenso/prisma/client';

import { getDocumentRelatedPrices } from '../stripe/get-document-related-prices.ts';
import { FREE_PLAN_LIMITS, SELFHOSTED_PLAN_LIMITS, TEAM_PLAN_LIMITS } from './constants';
import { ERROR_CODES } from './errors';
import { ZLimitsSchema } from './schema';

export type GetServerLimitsOptions = {
  email?: string | null;
  teamId?: number | null;
};

export const getServerLimits = async ({ email, teamId }: GetServerLimitsOptions) => {
  if (!IS_BILLING_ENABLED()) {
    return {
      quota: SELFHOSTED_PLAN_LIMITS,
      remaining: SELFHOSTED_PLAN_LIMITS,
    };
  }

  if (!email) {
    throw new Error(ERROR_CODES.UNAUTHORIZED);
  }

  return teamId ? handleTeamLimits({ email, teamId }) : handleUserLimits({ email });
};

type HandleUserLimitsOptions = {
  email: string;
};

const handleUserLimits = async ({ email }: HandleUserLimitsOptions) => {
  const user = await prisma.user.findFirst({
    where: {
      email,
    },
    include: {
      Subscription: true,
    },
  });

  if (!user) {
    throw new Error(ERROR_CODES.USER_FETCH_FAILED);
  }

  let quota = structuredClone(FREE_PLAN_LIMITS);
  let remaining = structuredClone(FREE_PLAN_LIMITS);

  const activeSubscriptions = user.Subscription.filter(
    ({ status }) => status === SubscriptionStatus.ACTIVE,
  );

  if (activeSubscriptions.length > 0) {
    const documentPlanPrices = await getDocumentRelatedPrices();

    for (const subscription of activeSubscriptions) {
      const price = documentPlanPrices.find((price) => price.id === subscription.priceId);

      if (!price || typeof price.product === 'string' || price.product.deleted) {
        continue;
      }

      const currentQuota = ZLimitsSchema.parse(
        'metadata' in price.product ? price.product.metadata : {},
      );

      // Use the subscription with the highest quota.
      if (currentQuota.documents > quota.documents && currentQuota.recipients > quota.recipients) {
        quota = currentQuota;
        remaining = structuredClone(quota);
      }
    }
  }

  const documents = await prisma.document.count({
    where: {
      userId: user.id,
      teamId: null,
      createdAt: {
        gte: DateTime.utc().startOf('month').toJSDate(),
      },
    },
  });

  remaining.documents = Math.max(remaining.documents - documents, 0);

  return {
    quota,
    remaining,
  };
};

type HandleTeamLimitsOptions = {
  email: string;
  teamId: number;
};

const handleTeamLimits = async ({ email, teamId }: HandleTeamLimitsOptions) => {
  const team = await prisma.team.findFirst({
    where: {
      id: teamId,
      members: {
        some: {
          user: {
            email,
          },
        },
      },
    },
    include: {
      subscription: true,
    },
  });

  if (!team) {
    throw new Error('Team not found');
  }

  const { subscription } = team;

  if (subscription && subscription.status === SubscriptionStatus.INACTIVE) {
    return {
      quota: {
        documents: 0,
        recipients: 0,
      },
      remaining: {
        documents: 0,
        recipients: 0,
      },
    };
  }

  return {
    quota: structuredClone(TEAM_PLAN_LIMITS),
    remaining: structuredClone(TEAM_PLAN_LIMITS),
  };
};