import { Injectable } from '@nestjs/common'
import { isNil } from 'lodash'

import { BioimpedanceCreditService, CreditService, TeleconsultationsCreditService } from '../../../services/credits'
import { BusinessExceptionError } from '../../../errors/business_exception.error'
import { CreditAuthor, Patient, Products } from '../../../models'
import { PatientRepository } from '../../../repositories/patient.repository'

type AditionalData = {
  externalId?: string
}

@Injectable()
export class Credits {
  constructor(
    private readonly bioimpedanceCreditService: BioimpedanceCreditService,
    private readonly teleconsultationsCreditService: TeleconsultationsCreditService,
    private readonly patientRepository: PatientRepository,
  ) {}

  async add(
    identifier: Partial<Patient> & AditionalData,
    productCode: Products,
    author: CreditAuthor = { type: 'system' },
  ): Promise<void> {
    const patient = await this.getPatient(identifier)
    const service = this.getCreditServiceByProduct(productCode)

    await service.createTransaction({
      patientId: patient.id,
      reason: 'single_buy',
      value: 1,
      author,
      identifier: {
        documentNumber: patient.document_number,
        email: patient.email,
        externalId: identifier.externalId,
      },
    })
  }

  private async getPatient(patientData: Partial<Patient>): Promise<Patient> {
    const patient = Patient.toInstance(patientData)
    const result = await this.patientRepository.findByLogin(patient.login)

    if (!isNil(result)) return result

    return patient
  }

  private getCreditServiceByProduct(productCode: Products): CreditService {
    if (productCode === Products.BIOIMPEDANCE) return this.bioimpedanceCreditService
    if (productCode === Products.TELECONSULTATIONS) return this.teleconsultationsCreditService

    throw new BusinessExceptionError('Invalid product')
  }
}