fairnesscoop / permacoop

import { CommandHandler } from '@nestjs/cqrs';

import { Inject } from '@nestjs/common';

import { GenerateInvoiceCommand } from './GenerateInvoiceCommand';

import { IEventRepository } from 'src/Domain/FairCalendar/Repository/IEventRepository';

import { Invoice } from 'src/Domain/Accounting/Invoice.entity';

import { InvoiceItem } from 'src/Domain/Accounting/InvoiceItem.entity';

import { IInvoiceRepository } from 'src/Domain/Accounting/Repository/IInvoiceRepository';

import { IInvoiceItemRepository } from 'src/Domain/Accounting/Repository/IInvoiceItemRepository';

import { InvoiceIdGenerator } from 'src/Domain/Accounting/Generators/InvoiceIdGenerator';

import { NoBillableEventsFoundException } from 'src/Domain/Accounting/Exception/NoBillableEventsFoundException';

import { IDateUtils } from 'src/Application/IDateUtils';

import { IProjectRepository } from 'src/Domain/Project/Repository/IProjectRepository';

import { ProjectNotFoundException } from 'src/Domain/Project/Exception/ProjectNotFoundException';

@CommandHandler(GenerateInvoiceCommand)

export class GenerateInvoiceCommandHandler {

  constructor(

    @Inject('IProjectRepository')

    private readonly projectRepository: IProjectRepository,

    @Inject('IEventRepository')

    private readonly eventRepository: IEventRepository,

    @Inject('IInvoiceRepository')

    private readonly invoiceRepository: IInvoiceRepository,

    @Inject('IInvoiceItemRepository')

    private readonly invoiceItemRepository: IInvoiceItemRepository,

    @Inject('IDateUtils')

    private readonly dateUtils: IDateUtils,

    private readonly invoiceIdGenerator: InvoiceIdGenerator

  ) {}

  public async execute(command: GenerateInvoiceCommand): Promise<string> {

    const { projectId, status, user, expireInDays } = command;

    const project = await this.projectRepository.findOneById(projectId);

    if (!project) {

      throw new ProjectNotFoundException();

    }

    const currentDate = this.dateUtils.getCurrentDate();

    const [ invoiceId, events ] = await Promise.all([

      this.invoiceIdGenerator.generate(),

      this.eventRepository.findBillableEventsByMonthAndProject(currentDate, project)

    ]);

    if (0 === events.length) {

      throw new NoBillableEventsFoundException();

    }

    const expiryDate = this.dateUtils.addDaysToDate(currentDate, expireInDays);

    const invoiceItems: InvoiceItem[] = [];

    const invoice = new Invoice(

      invoiceId,

      status,

      expiryDate.toISOString(),

      user,

      project

    );

    for (const event of events) {

      invoiceItems.push(this.buildInvoiceItem(invoice, event));

    }

    const savedInvoice = await this.invoiceRepository.save(invoice);

    await this.invoiceItemRepository.save(invoiceItems);

    return savedInvoice.getId();

  }

  private buildInvoiceItem(invoice: Invoice, {

    time_spent,

    billable,

    task_name,

    first_name,

    last_name,

    amount

  }): InvoiceItem {

    return new InvoiceItem(

      invoice,

      `${task_name} - ${first_name} ${last_name}`,

      Number(time_spent),

      amount ? Number(amount) : 0,

      billable ? 0 : 100

    );

  }

}