zod-backend/src/allowance/entities/allowance.entity.ts

import moment from 'moment';
import {
  Column,
  CreateDateColumn,
  DeleteDateColumn,
  Entity,
  JoinColumn,
  ManyToOne,
  OneToMany,
  PrimaryGeneratedColumn,
  UpdateDateColumn,
} from 'typeorm';
import { Guardian } from '~/guardian/entities/guradian.entity';
import { Junior } from '~/junior/entities';
import { AllowanceFrequency, AllowanceType } from '../enums';
import { AllowanceChangeRequest } from './allowance-change-request.entity';
@Entity('allowances')
export class Allowance {
  @PrimaryGeneratedColumn('uuid')
  id!: string;

  @Column({ type: 'varchar', length: 255, name: 'name' })
  name!: string;

  @Column({
    type: 'decimal',
    precision: 10,
    scale: 2,
    name: 'amount',
    transformer: { to: (value: number) => value, from: (value: string) => parseFloat(value) },
  })
  amount!: number;

  @Column({ type: 'varchar', length: 255, name: 'frequency' })
  frequency!: AllowanceFrequency;

  @Column({ type: 'varchar', length: 255, name: 'type' })
  type!: AllowanceType;

  @Column({ type: 'timestamp with time zone', name: 'start_date' })
  startDate!: Date;

  @Column({ type: 'timestamp with time zone', name: 'end_date', nullable: true })
  endDate?: Date;

  @Column({ type: 'int', name: 'number_of_transactions', nullable: true })
  numberOfTransactions?: number;

  @Column({ type: 'uuid', name: 'guardian_id' })
  guardianId!: string;

  @Column({ type: 'uuid', name: 'junior_id' })
  juniorId!: string;

  @ManyToOne(() => Guardian, (guardian) => guardian.allowances)
  @JoinColumn({ name: 'guardian_id' })
  guardian!: Guardian;

  @ManyToOne(() => Junior, (junior) => junior.allowances)
  @JoinColumn({ name: 'junior_id' })
  junior!: Junior;

  @OneToMany(() => AllowanceChangeRequest, (changeRequest) => changeRequest.allowance)
  changeRequests!: AllowanceChangeRequest[];

  @CreateDateColumn({ name: 'created_at', type: 'timestamp with time zone', default: () => 'CURRENT_TIMESTAMP' })
  createdAt!: Date;

  @UpdateDateColumn({ name: 'updated_at', type: 'timestamp with time zone', default: () => 'CURRENT_TIMESTAMP' })
  updatedAt!: Date;

  @DeleteDateColumn({ name: 'deleted_at', type: 'timestamp with time zone', nullable: true })
  deletedAt?: Date;

  get nextPaymentDate(): Date | null {
    const startDate = moment(this.startDate).clone().startOf('day');
    const endDate = this.endDate ? moment(this.endDate).endOf('day') : null;
    const now = moment().startOf('day');

    if (endDate && moment().isAfter(endDate)) {
      return null;
    }

    const calculateNextDate = (unit: moment.unitOfTime.Diff) => {
      const diff = now.diff(startDate, unit);
      const nextDate = startDate.clone().add(diff, unit);
      const adjustedDate = nextDate.isSameOrAfter(now) ? nextDate : nextDate.add('1', unit);

      if (endDate && adjustedDate.isAfter(endDate)) {
        return null;
      }

      return adjustedDate.toDate();
    };

    switch (this.frequency) {
      case AllowanceFrequency.DAILY:
        return calculateNextDate('days');
      case AllowanceFrequency.WEEKLY:
        return calculateNextDate('weeks');
      case AllowanceFrequency.MONTHLY:
        return calculateNextDate('months');
      default:
        return null;
    }
  }
}