import { Application } from '@feathersjs/express';
import { HookContext } from '@feathersjs/feathers';
import service from 'feathers-mongoose';
import { populate, alterItems, getItems } from 'feathers-hooks-common';
import Model from '../models/transfer/transfer.model';
import formatDate from '../hooks/formatDate';

const transfers = service({ Model });

const populateSchema = {
  include: [
    {
      service: 'contractors',
      nameAs: 'contractor',
      parentField: 'contractorId',
      childField: '_id'
    }
  ]
};

const addFields = (item: any) => {
  const { operation, contractor, amount } = item;
  const op = operation === 'in' ? 'приход' : 'расход';
  const name = `Перевод: ${op} $${amount} от ${contractor.name}`;
  return { ...item, name };
};

const applyTransfer = async (context: HookContext): Promise<HookContext> => {
  const { contractorId, amount, operation, _id } = getItems(context);

  let inc;

  // After Create / Delete
  if (context.method === 'create') inc = amount;
  if (context.method === 'remove') inc = -amount;

  // Before Patch / Update
  else if (['patch', 'update'].includes(context.method)) {
    const oldTransfer = await context.service.get(_id);
    inc = amount ? (amount - oldTransfer.amount) : 0;
  };

  if (inc) await context.app.service('contractors').patch(contractorId, {
    $inc: {
      debt: inc * (operation === 'in' ? -1 : 1)
    }
  });

  return context;
};

export default (app: Application): void => {
  app.use('/transfers', transfers);

  app.service('transfers').hooks({
    after: {
      all: [
        populate({ schema: populateSchema }),
        alterItems(addFields),
        formatDate(),
      ],
      create: applyTransfer,
      remove: applyTransfer,
    },
    before: {
      patch: applyTransfer,
      update: applyTransfer,
    }
  })
};