slate/pages/api/subscribe.js

import * as Environment from "~/node_common/environment";
import * as Data from "~/node_common/data";
import * as Utilities from "~/node_common/utilities";
import * as Serializers from "~/node_common/serializers";
import * as Validations from "~/common/validations";

export default async (req, res) => {
  const id = Utilities.getIdFromCookie(req);
  if (!id) {
    return res.status(500).send({ decorator: "SERVER_SUBSCRIBE", error: true });
  }

  const user = await Data.getUserById({
    id,
  });

  if (!user) {
    return res
      .status(404)
      .send({ decorator: "SERVER_SUBSCRIBE_USER_NOT_FOUND", error: true });
  }

  if (user.error) {
    return res
      .status(500)
      .send({ decorator: "SERVER_SUBSCRIBE_USER_NOT_FOUND", error: true });
  }

  if (!req.body.data || (!req.body.data.userId && !req.body.data.slateId)) {
    return res.status(500).send({
      decorator: "SERVER_SUBSCRIBE_MUST_PROVIDE_SLATE_OR_USER",
      error: true,
    });
  }

  if (user.id === req.body.data.userId) {
    return res.status(500).send({
      decorator: "SERVER_SUBSCRIBE_CAN_NOT_SUBSCRIBE_TO_YOURSELF",
      error: true,
    });
  }

  let targetUser;
  if (req.body.data.userId) {
    targetUser = await Data.getUserById({
      id: req.body.data.userId,
    });

    if (!targetUser) {
      return res.status(404).send({
        decorator: "SERVER_SUBSCRIBE_TARGET_USER_NOT_FOUND",
        error: true,
      });
    }

    if (targetUser.error) {
      return res.status(500).send({
        decorator: "SERVER_SUBSCRIBE_TARGET_USER_NOT_FOUND",
        error: true,
      });
    }
  }

  let targetSlate;
  if (req.body.data.slateId) {
    targetSlate = await Data.getSlateById({ id: req.body.data.slateId });

    if (!targetSlate) {
      return res.status(404).send({
        decorator: "SERVER_SUBSCRIBE_TARGET_SLATE_NOT_FOUND",
        error: true,
      });
    }

    if (targetSlate.error) {
      return res.status(500).send({
        decorator: "SERVER_SUBSCRIBE_TARGET_SLATE_NOT_FOUND",
        error: true,
      });
    }
  }

  const existingResponse = await Data.getSubscriptionById({
    subscriberUserId: user.id,
    slateId: targetSlate ? targetSlate.id : null,
    userId: targetUser ? targetUser.id : null,
  });

  if (existingResponse && existingResponse.error) {
    return res.status(500).send({
      decorator: "SERVER_SUBSCRIBE_SUBSCRIPTION_CHECK_ERROR",
      error: true,
    });
  }

  // NOTE(jim): If it exists, we unsubscribe instead.
  if (existingResponse) {
    const unsubscribeResponse = await Data.deleteSubscriptionById({
      id: existingResponse.id,
    });

    if (!unsubscribeResponse) {
      return res
        .status(404)
        .send({ decorator: "SERVER_UNSUBSCRIBE_NOT_FOUND", error: true });
    }

    if (unsubscribeResponse.error) {
      return res
        .status(500)
        .send({ decorator: "SERVER_UNSUBSCRIBE_ERROR", error: true });
    }

    return res
      .status(200)
      .send({ decorator: "SERVER_UNSUBSCRIBE", data: unsubscribeResponse });
  }

  const subscribeResponse = await Data.createSubscription({
    subscriberUserId: user.id,
    slateId: targetSlate ? targetSlate.id : null,
    userId: targetUser ? targetUser.id : null,
  });

  if (!subscribeResponse) {
    return res
      .status(404)
      .send({ decorator: "SERVER_SUBSCRIBE_NOT_FOUND", error: true });
  }

  if (subscribeResponse.error) {
    return res
      .status(500)
      .send({ decorator: "SERVER_SUBSCRIBE_ERROR", error: true });
  }

  return res.status(200).send({
    decorator: "SERVER_SUBSCRIBE",
    data: {
      ...subscribeResponse,
      owner: Serializers.user(user),
      slate: targetSlate ? Serializers.slate(targetSlate) : null,
      user: targetUser ? Serializers.user(targetUser) : null,
    },
  });
};