import { createOrganisationClaimUpsertData } from '@documenso/lib/server-only/organisation/create-organisation';
import { type Stripe, stripe } from '@documenso/lib/server-only/stripe';
import { getSubscriptionClaim } from '@documenso/lib/server-only/subscription/get-subscription-claim';
import { INTERNAL_CLAIM_ID } from '@documenso/lib/types/subscription';
import { prisma } from '@documenso/prisma';
import { OrganisationType, type Prisma, SubscriptionStatus } from '@prisma/client';
import { match } from 'ts-pattern';
import { reconcileSeatBasedPlans } from './update-subscription-item-quantity';

const LIVE_SUBSCRIPTION_STATUSES: Stripe.Subscription.Status[] = ['active', 'trialing', 'past_due'];

export type SyncStripeCustomerSubscriptionOptions = {
  customerId: string;

  /**
   * When true, the organisationClaim will not be synced.
   *
   * Used by the admin sync route to update only the Subscription
   * row while leaving claim entitlements untouched.
   */
  bypassClaimUpdate?: boolean;
};

/**
 * Idempotent, convergent sync of a Stripe customer's subscription state into the local database.
 *
 * Fetches the current truth from Stripe and writes it locally, regardless of which
 * webhook event (or manual trigger) initiated the sync. Safe to run at any time,
 * any number of times.
 *
 * This function never creates organisations.
 */
export const syncStripeCustomerSubscription = async ({
  customerId,
  bypassClaimUpdate = false,
}: SyncStripeCustomerSubscriptionOptions) => {
  // Note: `data.items.data.price.product` would exceed Stripe's 4-level expansion
  // limit on list endpoints, so the product is fetched separately when needed.
  const stripeSubscriptions = await stripe.subscriptions.list({
    customer: customerId,
    status: 'all',
    limit: 100,
  });

  const liveSubscriptions = stripeSubscriptions.data.filter((subscription) =>
    LIVE_SUBSCRIPTION_STATUSES.includes(subscription.status),
  );

  if (liveSubscriptions.length > 1) {
    console.error(`Customer ${customerId} has ${liveSubscriptions.length} live subscriptions, expected at most 1`);

    throw new Error(`Customer ${customerId} has multiple live subscriptions`);
  }

  const organisation = await prisma.organisation.findFirst({
    where: {
      customerId,
    },
    include: {
      organisationClaim: true,
      subscription: true,
    },
  });

  if (!organisation) {
    console.error(`Organisation not found for customer ${customerId}, nothing to sync`);

    return;
  }

  const liveSubscription = liveSubscriptions[0];

  if (!liveSubscription) {
    await handleNoLiveSubscription({ organisation });

    return;
  }

  await handleLiveSubscription({
    organisation,
    subscription: liveSubscription,
    customerId,
    bypassClaimUpdate,
  });
};

type OrganisationWithClaimAndSubscription = Prisma.OrganisationGetPayload<{
  include: { organisationClaim: true; subscription: true };
}>;

type HandleNoLiveSubscriptionOptions = {
  organisation: OrganisationWithClaimAndSubscription;
};

const handleNoLiveSubscription = async ({ organisation }: HandleNoLiveSubscriptionOptions) => {
  // Individuals get their subscription deleted so they can return to the free plan.
  if (organisation.organisationClaim.originalSubscriptionClaimId === INTERNAL_CLAIM_ID.INDIVIDUAL) {
    const freeSubscriptionClaim = await getSubscriptionClaim(INTERNAL_CLAIM_ID.FREE);

    await prisma.$transaction(async (tx) => {
      if (organisation.subscription) {
        await tx.subscription.delete({
          where: {
            id: organisation.subscription.id,
          },
        });
      }

      await tx.organisationClaim.update({
        where: {
          id: organisation.organisationClaim.id,
        },
        data: {
          originalSubscriptionClaimId: INTERNAL_CLAIM_ID.FREE,
          ...createOrganisationClaimUpsertData(freeSubscriptionClaim),
        },
      });
    });

    return;
  }

  // For all other cases, mark the subscription as inactive if a row exists.
  if (organisation.subscription) {
    await prisma.subscription.update({
      where: {
        id: organisation.subscription.id,
      },
      data: {
        status: SubscriptionStatus.INACTIVE,
      },
    });
  }
};

type HandleLiveSubscriptionOptions = {
  organisation: OrganisationWithClaimAndSubscription;
  subscription: Stripe.Subscription;
  customerId: string;
  bypassClaimUpdate: boolean;
};

const handleLiveSubscription = async ({
  organisation,
  subscription,
  customerId,
  bypassClaimUpdate,
}: HandleLiveSubscriptionOptions) => {
  if (subscription.items.data.length !== 1) {
    console.error(`No support for multiple subscription items on subscription ${subscription.id}`);

    throw new Error(`No support for multiple subscription items on subscription ${subscription.id}`);
  }

  const subscriptionItem = subscription.items.data[0];

  const claim = await extractStripeClaim(subscriptionItem.price);

  if (!claim) {
    console.error(`Subscription claim on ${subscriptionItem.price.id} not found`);

    throw new Error(`Subscription claim on ${subscriptionItem.price.id} not found`);
  }

  const status = match(subscription.status)
    .with('active', () => SubscriptionStatus.ACTIVE)
    .with('trialing', () => SubscriptionStatus.ACTIVE)
    .with('past_due', () => SubscriptionStatus.PAST_DUE)
    .otherwise(() => SubscriptionStatus.INACTIVE);

  const periodEnd =
    subscription.status === 'trialing' && subscription.trial_end
      ? new Date(subscription.trial_end * 1000)
      : new Date(subscription.current_period_end * 1000);

  const shouldUpdateClaim =
    !bypassClaimUpdate && organisation.organisationClaim.originalSubscriptionClaimId !== claim.id;

  // Migrate the organisation type if it is no longer an individual/free plan.
  // Never demote an ORGANISATION back to PERSONAL.
  const shouldMigrateOrganisationType =
    organisation.type === OrganisationType.PERSONAL &&
    claim.id !== INTERNAL_CLAIM_ID.INDIVIDUAL &&
    claim.id !== INTERNAL_CLAIM_ID.FREE;

  await prisma.$transaction(async (tx) => {
    await tx.subscription.upsert({
      where: {
        organisationId: organisation.id,
      },
      create: {
        organisationId: organisation.id,
        status,
        customerId,
        planId: subscription.id,
        priceId: subscriptionItem.price.id,
        periodEnd,
        cancelAtPeriodEnd: subscription.cancel_at_period_end,
      },
      update: {
        status,
        customerId,
        planId: subscription.id,
        priceId: subscriptionItem.price.id,
        periodEnd,
        cancelAtPeriodEnd: subscription.cancel_at_period_end,
      },
    });

    if (shouldUpdateClaim) {
      await tx.organisationClaim.update({
        where: {
          id: organisation.organisationClaim.id,
        },
        data: {
          originalSubscriptionClaimId: claim.id,
          ...createOrganisationClaimUpsertData(claim),
        },
      });
    }

    if (shouldMigrateOrganisationType) {
      await tx.organisation.update({
        where: {
          id: organisation.id,
        },
        data: {
          type: OrganisationType.ORGANISATION,
        },
      });
    }
  });

  // Detect a billing-period roll by comparing the persisted period end with
  // the freshly-fetched one — the convergent equivalent of the old
  // `previous_attributes.current_period_start` signal. On renewal, reconcile
  // the seat quantity and claim down to the actual member count. The reconcile
  // itself no-ops for non-seat/unlimited plans and non-ACTIVE subscriptions.
  const previousPeriodEnd = organisation.subscription?.periodEnd ?? null;

  const hasPeriodAdvanced = previousPeriodEnd !== null && periodEnd.getTime() > previousPeriodEnd.getTime();

  if (hasPeriodAdvanced && !bypassClaimUpdate) {
    await reconcileSeatBasedPlans(organisation.id);
  }
};

/**
 * Checks the price metadata for a claimId, if it is missing it will fetch
 * and check the product metadata for a claimId.
 *
 * The order of priority is:
 * 1. Price metadata
 * 2. Product metadata
 *
 * @returns The claimId or null if no claimId is found.
 */
export const extractStripeClaimId = async (priceId: Stripe.Price) => {
  if (priceId.metadata.claimId) {
    return priceId.metadata.claimId;
  }

  // Use the expanded product when available to avoid an extra API call.
  if (typeof priceId.product !== 'string' && 'metadata' in priceId.product) {
    return priceId.product.metadata.claimId || null;
  }

  const productId = typeof priceId.product === 'string' ? priceId.product : priceId.product.id;

  const product = await stripe.products.retrieve(productId);

  return product.metadata.claimId || null;
};

/**
 * Checks the price metadata for a claimId, if it is missing it will fetch
 * and check the product metadata for a claimId.
 *
 */
export const extractStripeClaim = async (priceId: Stripe.Price) => {
  const claimId = await extractStripeClaimId(priceId);

  if (!claimId) {
    return null;
  }

  const subscriptionClaim = await prisma.subscriptionClaim.findFirst({
    where: { id: claimId },
  });

  if (!subscriptionClaim) {
    console.error(`Subscription claim ${claimId} not found`);
    return null;
  }

  return subscriptionClaim;
};