import { Application } from '@feathersjs/express';
import { HookContext } from '@feathersjs/feathers';
import service from 'feathers-mongoose';
import { populate, alterItems } from 'feathers-hooks-common';
import Bluebird from 'bluebird';
import _ from 'lodash';
import Model from '../models/waybill/waybill.model';
import { WaybillSchema } from '../models/waybill/waybill.schema';
import Contractor from '../models/contractor/contractor.model';
import Product from '../models/product/product.model';

const waybills = service({ Model });

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

const performWaybillOperation = async (id: string, cancel = false) => {
  const waybill = await Model.findById(id);
  if (!waybill) return;
  waybill.status = cancel ? 'cancelled' : 'executed';

  const signMultiplier = (waybill.operation === 'in' ? 1 : -1) * (cancel ? -1 : 1);
  const total = waybill.records.reduce((sum, record) => sum + record.price * record.quantity, 0);

  await Bluebird.map(waybill.records, record => Product.updateOne(
    { _id: record.productId },
    {
      $inc: {
        quantity: record.quantity * signMultiplier
      }
    }
  ));

  await Contractor.updateOne(
    { _id: waybill.contractorId },
    {
      $inc: {
        debt: total * signMultiplier * (-1)
      }
    }
  );

  return waybill.save();
};


const addFields = (item: WaybillSchema) => {
  const { operation, records } = item;
  const total = item.records.reduce((sum, record) => sum + record.price * record.quantity, 0);
  const op = operation === 'in' ? 'приход' : 'расход';
  const name = `Накладная: ${op} $${total}`;
  return { name, total, ...item };
};

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

  app.post('/waybills/:id/execute', async (req, res) => {
    const result = await performWaybillOperation(req.params.id);
    res.send(result);
  });

  app.post('/waybills/:id/cancel', async (req, res) => {
    const result = await performWaybillOperation(req.params.id, true);
    res.send(result);
  });

  app.service('waybills').hooks({
    after: {
      all: [
        populate({ schema: populateSchema }),
        alterItems(addFields)
      ],
    },
  })
};