feat(nestjs): migrate to NestJS

packages/server/src/modules/BillPayments/BillPayments.controller.ts

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+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  Param,
+  Post,
+  Put,
+} from '@nestjs/common';
+import { BillPaymentsApplication } from './BillPaymentsApplication.service';
+import { ApiOperation, ApiParam, ApiTags } from '@nestjs/swagger';
+import {
+  CreateBillPaymentDto,
+  EditBillPaymentDto,
+} from './dtos/BillPayment.dto';
+
+@Controller('bill-payments')
+@ApiTags('bill-payments')
+export class BillPaymentsController {
+  constructor(private billPaymentsApplication: BillPaymentsApplication) {}
+
+  @Post()
+  @ApiOperation({ summary: 'Create a new bill payment.' })
+  public createBillPayment(@Body() billPaymentDTO: CreateBillPaymentDto) {
+    return this.billPaymentsApplication.createBillPayment(billPaymentDTO);
+  }
+
+  @Delete(':billPaymentId')
+  @ApiOperation({ summary: 'Delete the given bill payment.' })
+  @ApiParam({
+    name: 'billPaymentId',
+    required: true,
+    type: Number,
+    description: 'The bill payment id',
+  })
+  public deleteBillPayment(@Param('billPaymentId') billPaymentId: string) {
+    return this.billPaymentsApplication.deleteBillPayment(
+      Number(billPaymentId),
+    );
+  }
+
+  @Put(':billPaymentId')
+  @ApiOperation({ summary: 'Edit the given bill payment.' })
+  @ApiParam({
+    name: 'billPaymentId',
+    required: true,
+    type: Number,
+    description: 'The bill payment id',
+  })
+  public editBillPayment(
+    @Param('billPaymentId') billPaymentId: string,
+    @Body() billPaymentDTO: EditBillPaymentDto,
+  ) {
+    return this.billPaymentsApplication.editBillPayment(
+      Number(billPaymentId),
+      billPaymentDTO,
+    );
+  }
+
+  @Get(':billPaymentId')
+  @ApiOperation({ summary: 'Retrieves the bill payment details.' })
+  @ApiParam({
+    name: 'billPaymentId',
+    required: true,
+    type: Number,
+    description: 'The bill payment id',
+  })
+  public getBillPayment(@Param('billPaymentId') billPaymentId: string) {
+    return this.billPaymentsApplication.getBillPayment(Number(billPaymentId));
+  }
+
+  @Get(':billPaymentId/bills')
+  @ApiOperation({ summary: 'Retrieves the bills of the given bill payment.' })
+  @ApiParam({
+    name: 'billPaymentId',
+    required: true,
+    type: Number,
+    description: 'The bill payment id',
+  })
+  public getPaymentBills(@Param('billPaymentId') billPaymentId: string) {
+    return this.billPaymentsApplication.getPaymentBills(Number(billPaymentId));
+  }
+}

packages/server/src/modules/BillPayments/BillPayments.module.ts

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+import { Module } from '@nestjs/common';
+import { BillPaymentsApplication } from './BillPaymentsApplication.service';
+import { CreateBillPaymentService } from './commands/CreateBillPayment.service';
+import { EditBillPayment } from './commands/EditBillPayment.service';
+import { GetBillPayment } from './queries/GetBillPayment.service';
+import { DeleteBillPayment } from './commands/DeleteBillPayment.service';
+import { BillPaymentBillSync } from './commands/BillPaymentBillSync.service';
+import { GetPaymentBills } from './queries/GetPaymentBills.service';
+import { BillPaymentValidators } from './commands/BillPaymentValidators.service';
+import { CommandBillPaymentDTOTransformer } from './commands/CommandBillPaymentDTOTransformer.service';
+import { TenancyContext } from '../Tenancy/TenancyContext.service';
+import { BranchTransactionDTOTransformer } from '../Branches/integrations/BranchTransactionDTOTransform';
+import { BranchesSettingsService } from '../Branches/BranchesSettings';
+import { BillPaymentsController } from './BillPayments.controller';
+import { BillPaymentGLEntries } from './commands/BillPaymentGLEntries';
+import { BillPaymentGLEntriesSubscriber } from './subscribers/BillPaymentGLEntriesSubscriber';
+import { LedgerModule } from '../Ledger/Ledger.module';
+import { AccountsModule } from '../Accounts/Accounts.module';
+
+@Module({
+  imports: [LedgerModule, AccountsModule],
+  providers: [
+    BillPaymentsApplication,
+    CreateBillPaymentService,
+    EditBillPayment,
+    GetBillPayment,
+    DeleteBillPayment,
+    BillPaymentBillSync,
+    GetPaymentBills,
+    BillPaymentValidators,
+    CommandBillPaymentDTOTransformer,
+    BranchTransactionDTOTransformer,
+    BranchesSettingsService,
+    TenancyContext,
+    BillPaymentGLEntries,
+    BillPaymentGLEntriesSubscriber,
+  ],
+  exports: [BillPaymentValidators, CreateBillPaymentService],
+  controllers: [BillPaymentsController],
+})
+export class BillPaymentsModule {}

packages/server/src/modules/BillPayments/BillPaymentsApplication.service.ts

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+import { Injectable } from '@nestjs/common';
+import { CreateBillPaymentService } from './commands/CreateBillPayment.service';
+import { DeleteBillPayment } from './commands/DeleteBillPayment.service';
+import { EditBillPayment } from './commands/EditBillPayment.service';
+// import { GetBillPayments } from './GetBillPayments';
+import { GetBillPayment } from './queries/GetBillPayment.service';
+import { GetPaymentBills } from './queries/GetPaymentBills.service';
+import { GetBillPayments } from '../Bills/queries/GetBillPayments';
+import { CreateBillPaymentDto, EditBillPaymentDto } from './dtos/BillPayment.dto';
+
+/**
+ * Bill payments application.
+ * @service
+ */
+@Injectable()
+export class BillPaymentsApplication {
+  constructor(
+    private createBillPaymentService: CreateBillPaymentService,
+    private editBillPaymentService: EditBillPayment,
+    private deleteBillPaymentService: DeleteBillPayment,
+    private getBillPaymentService: GetBillPayment,
+    private getPaymentBillsService: GetPaymentBills,
+    // private getBillPaymentsService: GetBillPayments,
+  ) {}
+
+  /**
+   * Creates a bill payment with associated GL entries.
+   * @param {IBillPaymentDTO} billPaymentDTO
+   * @returns {Promise<IBillPayment>}
+   */
+  public createBillPayment(billPaymentDTO: CreateBillPaymentDto) {
+    return this.createBillPaymentService.createBillPayment(billPaymentDTO);
+  }
+
+  /**
+   * Delets the given bill payment with associated GL entries.
+   * @param {number} billPaymentId
+   */
+  public deleteBillPayment(billPaymentId: number) {
+    return this.deleteBillPaymentService.deleteBillPayment(billPaymentId);
+  }
+
+  /**
+   * Edits the given bill payment with associated GL entries.
+   * @param {number} billPaymentId - The given bill payment id.
+   * @param {IBillPaymentDTO} billPaymentDTO - The given bill payment DTO.
+   * @returns {Promise<IBillPayment>}
+   */
+  public editBillPayment(
+    billPaymentId: number,
+    billPaymentDTO: EditBillPaymentDto,
+  ) {
+    return this.editBillPaymentService.editBillPayment(
+      billPaymentId,
+      billPaymentDTO,
+    );
+  }
+
+  /**
+   * Retrieves bill payments list.
+   * @param {number} tenantId
+   * @param filterDTO
+   * @returns
+   */
+  // public getBillPayments(filterDTO: IBillPaymentsFilter) {
+  // return this.getBillPaymentsService.getBillPayments(filterDTO);
+  // }
+
+  /**
+   * Retrieve specific bill payment.
+   * @param {number} billPyamentId - The given bill payment id.
+   */
+  public getBillPayment(billPyamentId: number) {
+    return this.getBillPaymentService.getBillPayment(billPyamentId);
+  }
+
+  /**
+   * Retrieve payment made associated bills.
+   * @param {number} billPaymentId - The given bill payment id.
+   */
+  public getPaymentBills(billPaymentId: number) {
+    return this.getPaymentBillsService.getPaymentBills(billPaymentId);
+  }
+}

packages/server/src/modules/BillPayments/GetBillPayments.ts

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+// import { Inject, Service } from 'typedi';
+// import * as R from 'ramda';
+// import {
+//   IBillPayment,
+//   IBillPaymentsFilter,
+//   IPaginationMeta,
+//   IFilterMeta,
+// } from '@/interfaces';
+// import { BillPaymentTransformer } from './queries/BillPaymentTransformer';
+// import DynamicListingService from '@/services/DynamicListing/DynamicListService';
+// import HasTenancyService from '@/services/Tenancy/TenancyService';
+// import { TransformerInjectable } from '@/lib/Transformer/TransformerInjectable';
+
+// @Service()
+// export class GetBillPayments {
+//   @Inject()
+//   private tenancy: HasTenancyService;
+
+//   @Inject()
+//   private dynamicListService: DynamicListingService;
+
+//   @Inject()
+//   private transformer: TransformerInjectable;
+
+//   /**
+//    * Retrieve bill payment paginted and filterable list.
+//    * @param {number} tenantId
+//    * @param {IBillPaymentsFilter} billPaymentsFilter
+//    */
+//   public async getBillPayments(
+//     tenantId: number,
+//     filterDTO: IBillPaymentsFilter
+//   ): Promise<{
+//     billPayments: IBillPayment[];
+//     pagination: IPaginationMeta;
+//     filterMeta: IFilterMeta;
+//   }> {
+//     const { BillPayment } = this.tenancy.models(tenantId);
+
+//     // Parses filter DTO.
+//     const filter = this.parseListFilterDTO(filterDTO);
+
+//     // Dynamic list service.
+//     const dynamicList = await this.dynamicListService.dynamicList(
+//       tenantId,
+//       BillPayment,
+//       filter
+//     );
+//     const { results, pagination } = await BillPayment.query()
+//       .onBuild((builder) => {
+//         builder.withGraphFetched('vendor');
+//         builder.withGraphFetched('paymentAccount');
+
+//         dynamicList.buildQuery()(builder);
+//         filter?.filterQuery && filter?.filterQuery(builder);
+//       })
+//       .pagination(filter.page - 1, filter.pageSize);
+
+//     // Transformes the bill payments models to POJO.
+//     const billPayments = await this.transformer.transform(
+//       tenantId,
+//       results,
+//       new BillPaymentTransformer()
+//     );
+//     return {
+//       billPayments,
+//       pagination,
+//       filterMeta: dynamicList.getResponseMeta(),
+//     };
+//   }
+
+//   private parseListFilterDTO(filterDTO) {
+//     return R.compose(this.dynamicListService.parseStringifiedFilter)(filterDTO);
+//   }
+// }

packages/server/src/modules/BillPayments/commands/BillPaymentBillSync.service.ts

@@ -0,0 +1,51 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import { Bill } from '../../Bills/models/Bill';
+import { entriesAmountDiff } from '@/utils/entries-amount-diff';
+import Objection, { ModelObject } from 'objection';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { BillPaymentEntryDto } from '../dtos/BillPayment.dto';
+import { BillPaymentEntry } from '../models/BillPaymentEntry';
+
+@Injectable()
+export class BillPaymentBillSync {
+  constructor(
+    @Inject(Bill.name)
+    private readonly bill: TenantModelProxy<typeof Bill>,
+  ) {}
+
+  /**
+   * Saves bills payment amount changes different.
+   * @param {number} tenantId -
+   * @param {IBillPaymentEntryDTO[]} paymentMadeEntries -
+   * @param {IBillPaymentEntryDTO[]} oldPaymentMadeEntries -
+   */
+  public async saveChangeBillsPaymentAmount(
+    paymentMadeEntries: BillPaymentEntryDto[],
+    oldPaymentMadeEntries?: ModelObject<BillPaymentEntry>[],
+    trx?: Knex.Transaction,
+  ): Promise<void> {
+    const opers: Objection.QueryBuilder<Bill, Bill[]>[] = [];
+
+    const diffEntries = entriesAmountDiff(
+      paymentMadeEntries,
+      oldPaymentMadeEntries,
+      'paymentAmount',
+      'billId',
+    );
+    diffEntries.forEach(
+      (diffEntry: { paymentAmount: number; billId: number }) => {
+        if (diffEntry.paymentAmount === 0) {
+          return;
+        }
+        const oper = this.bill().changePaymentAmount(
+          diffEntry.billId,
+          diffEntry.paymentAmount,
+          trx,
+        );
+        opers.push(oper);
+      },
+    );
+    await Promise.all(opers);
+  }
+}

packages/server/src/modules/BillPayments/commands/BillPaymentExportable.ts

@@ -0,0 +1,34 @@
+// import { Inject, Service } from 'typedi';
+// import { Exportable } from '@/services/Export/Exportable';
+// import { BillPaymentsApplication } from './BillPaymentsApplication';
+// import { EXPORT_SIZE_LIMIT } from '@/services/Export/constants';
+
+// @Service()
+// export class BillPaymentExportable extends Exportable {
+//   @Inject()
+//   private billPaymentsApplication: BillPaymentsApplication;
+
+//   /**
+//    * Retrieves the accounts data to exportable sheet.
+//    * @param {number} tenantId
+//    * @returns
+//    */
+//   public exportable(tenantId: number, query: any) {
+//     const filterQuery = (builder) => {
+//       builder.withGraphFetched('entries.bill');
+//       builder.withGraphFetched('branch');
+//     };
+//     const parsedQuery = {
+//       sortOrder: 'desc',
+//       columnSortBy: 'created_at',
+//       ...query,
+//       page: 1,
+//       pageSize: EXPORT_SIZE_LIMIT,
+//       filterQuery
+//     } as any;
+
+//     return this.billPaymentsApplication
+//       .getBillPayments(tenantId, parsedQuery)
+//       .then((output) => output.billPayments);
+//   }
+// }

packages/server/src/modules/BillPayments/commands/BillPaymentGL.ts

@@ -0,0 +1,191 @@
+import { sumBy } from 'lodash';
+import { BillPayment } from '../models/BillPayment';
+import { AccountNormal } from '@/interfaces/Account';
+import { ILedgerEntry } from '@/modules/Ledger/types/Ledger.types';
+import { Ledger } from '@/modules/Ledger/Ledger';
+
+export class BillPaymentGL {
+  private billPayment: BillPayment;
+  private APAccountId: number;
+  private gainLossAccountId: number;
+  private baseCurrency: string;
+
+  constructor(billPayment: BillPayment) {
+    this.billPayment = billPayment;
+  }
+
+  /**
+   * Sets the A/P account ID.
+   * @param {number} APAccountId -
+   * @returns {BillPaymentGL}
+   */
+  setAPAccountId(APAccountId: number) {
+    this.APAccountId = APAccountId;
+    return this;
+  }
+
+  /**
+   * Sets the gain/loss account ID.
+   * @param {number} gainLossAccountId -
+   * @returns {BillPaymentGL}
+   */
+  setGainLossAccountId(gainLossAccountId: number) {
+    this.gainLossAccountId = gainLossAccountId;
+    return this;
+  }
+
+  /**
+   * Sets the base currency.
+   * @param {string} baseCurrency -
+   * @returns {BillPaymentGL}
+   */
+  setBaseCurrency(baseCurrency: string) {
+    this.baseCurrency = baseCurrency;
+    return this;
+  }
+
+  /**
+   * Retrieves the payment common entry.
+   */
+  private get paymentCommonEntry() {
+    const formattedDate = moment(this.billPayment.paymentDate).format(
+      'YYYY-MM-DD',
+    );
+
+    return {
+      debit: 0,
+      credit: 0,
+
+      exchangeRate: this.billPayment.exchangeRate,
+      currencyCode: this.billPayment.currencyCode,
+
+      transactionId: this.billPayment.id,
+      transactionType: 'BillPayment',
+
+      transactionNumber: this.billPayment.paymentNumber,
+      referenceNumber: this.billPayment.reference,
+
+      date: formattedDate,
+      createdAt: this.billPayment.createdAt,
+
+      branchId: this.billPayment.branchId,
+    };
+  }
+
+  /**
+   * Calculates the payment total exchange gain/loss.
+   * @param   {IBillPayment} paymentReceive - Payment receive with entries.
+   * @returns {number}
+   */
+  private get paymentExGainOrLoss(): number {
+    return sumBy(this.billPayment.entries, (entry) => {
+      const paymentLocalAmount =
+        entry.paymentAmount * this.billPayment.exchangeRate;
+      const invoicePayment = entry.paymentAmount * entry.bill.exchangeRate;
+
+      return invoicePayment - paymentLocalAmount;
+    });
+  }
+
+  /**
+   * Retrieves the payment exchange gain/loss entries.
+   * @returns {ILedgerEntry[]}
+   */
+  private get paymentExGainOrLossEntries(): ILedgerEntry[] {
+    const commonEntry = this.paymentCommonEntry;
+    const totalExGainOrLoss = this.paymentExGainOrLoss;
+    const absExGainOrLoss = Math.abs(totalExGainOrLoss);
+
+    return totalExGainOrLoss
+      ? [
+          {
+            ...commonEntry,
+            currencyCode: this.baseCurrency,
+            exchangeRate: 1,
+            credit: totalExGainOrLoss > 0 ? absExGainOrLoss : 0,
+            debit: totalExGainOrLoss < 0 ? absExGainOrLoss : 0,
+            accountId: this.gainLossAccountId,
+            index: 2,
+            indexGroup: 20,
+            accountNormal: AccountNormal.DEBIT,
+          },
+          {
+            ...commonEntry,
+            currencyCode: this.baseCurrency,
+            exchangeRate: 1,
+            debit: totalExGainOrLoss > 0 ? absExGainOrLoss : 0,
+            credit: totalExGainOrLoss < 0 ? absExGainOrLoss : 0,
+            accountId: this.APAccountId,
+            index: 3,
+            accountNormal: AccountNormal.DEBIT,
+          },
+        ]
+      : [];
+  }
+
+  /**
+   * Retrieves the payment deposit GL entry.
+   * @param   {IBillPayment} billPayment
+   * @returns {ILedgerEntry}
+   */
+  private get paymentGLEntry(): ILedgerEntry {
+    const commonEntry = this.paymentCommonEntry;
+
+    return {
+      ...commonEntry,
+      credit: this.billPayment.localAmount,
+      accountId: this.billPayment.paymentAccountId,
+      accountNormal: AccountNormal.DEBIT,
+      index: 2,
+    };
+  }
+
+  /**
+   * Retrieves the payment GL payable entry.
+   * @returns {ILedgerEntry}
+   */
+  private get paymentGLPayableEntry(): ILedgerEntry {
+    const commonEntry = this.paymentCommonEntry;
+
+    return {
+      ...commonEntry,
+      exchangeRate: this.billPayment.exchangeRate,
+      debit: this.billPayment.localAmount,
+      contactId: this.billPayment.vendorId,
+      accountId: this.APAccountId,
+      accountNormal: AccountNormal.CREDIT,
+      index: 1,
+    };
+  }
+
+  /**
+   * Retrieves the payment GL entries.
+   * @param   {IBillPayment} billPayment
+   * @param   {number} APAccountId
+   * @returns {ILedgerEntry[]}
+   */
+  private get paymentGLEntries(): ILedgerEntry[] {
+    // Retrieves the payment deposit entry.
+    const paymentEntry = this.paymentGLEntry;
+
+    // Retrieves the payment debit A/R entry.
+    const payableEntry = this.paymentGLPayableEntry;
+
+    // Retrieves the exchange gain/loss entries.
+    const exGainLossEntries = this.paymentExGainOrLossEntries;
+
+    return [paymentEntry, payableEntry, ...exGainLossEntries];
+  };
+
+  /**
+   * Retrieves the bill payment ledger.
+   * @param   {IBillPayment} billPayment
+   * @param   {number} APAccountId
+   * @returns {Ledger}
+   */
+  public getBillPaymentLedger(): Ledger {
+    const entries = this.paymentGLEntries;
+
+    return new Ledger(entries);
+  }
+}

packages/server/src/modules/BillPayments/commands/BillPaymentGLEntries.ts

@@ -0,0 +1,99 @@
+import { Knex } from 'knex';
+import { BillPaymentGL } from './BillPaymentGL';
+import { Inject, Injectable } from '@nestjs/common';
+import { LedgerStorageService } from '@/modules/Ledger/LedgerStorage.service';
+import { Account } from '@/modules/Accounts/models/Account.model';
+import { BillPayment } from '../models/BillPayment';
+import { AccountRepository } from '@/modules/Accounts/repositories/Account.repository';
+import { TenancyContext } from '@/modules/Tenancy/TenancyContext.service';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class BillPaymentGLEntries {
+  constructor(
+    private readonly ledgerStorage: LedgerStorageService,
+    private readonly accountRepository: AccountRepository,
+    private readonly tenancyContext: TenancyContext,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+
+    @Inject(Account.name)
+    private readonly accountModel: TenantModelProxy<typeof Account>,
+  ) {}
+
+  /**
+   * Creates a bill payment GL entries.
+   * @param {number} billPaymentId - Bill payment id.
+   * @param {Knex.Transaction} trx - Knex transaction.
+   */
+  public writePaymentGLEntries = async (
+    billPaymentId: number,
+    trx?: Knex.Transaction,
+  ): Promise<void> => {
+    // Retrieves the bill payment details with associated entries.
+    const payment = await this.billPaymentModel()
+      .query(trx)
+      .findById(billPaymentId)
+      .withGraphFetched('entries.bill');
+
+    // Retrieves the given tenant metadata.
+    const tenantMeta = await this.tenancyContext.getTenantMetadata();
+
+    // Finds or creates a new A/P account of the given currency.
+    const APAccount = await this.accountRepository.findOrCreateAccountsPayable(
+      payment.currencyCode,
+      {},
+      trx,
+    );
+    // Exchange gain or loss account.
+    const EXGainLossAccount = await this.accountModel()
+      .query(trx)
+      .modify('findBySlug', 'exchange-grain-loss')
+      .first();
+
+    // Retrieves the bill payment ledger.
+    const ledger = new BillPaymentGL(payment)
+      .setAPAccountId(APAccount.id)
+      .setGainLossAccountId(EXGainLossAccount.id)
+      .setBaseCurrency(tenantMeta.baseCurrency)
+      .getBillPaymentLedger();
+
+    // Commits the ledger on the storage.
+    await this.ledgerStorage.commit(ledger, trx);
+  };
+
+  /**
+   * Rewrites the bill payment GL entries.
+   * @param {number} tenantId
+   * @param {number} billPaymentId
+   * @param {Knex.Transaction} trx
+   */
+  public rewritePaymentGLEntries = async (
+    billPaymentId: number,
+    trx?: Knex.Transaction,
+  ): Promise<void> => {
+    // Revert payment GL entries.
+    await this.revertPaymentGLEntries(billPaymentId, trx);
+
+    // Write payment GL entries.
+    await this.writePaymentGLEntries(billPaymentId, trx);
+  };
+
+  /**
+   * Reverts the bill payment GL entries.
+   * @param {number} tenantId
+   * @param {number} billPaymentId
+   * @param {Knex.Transaction} trx
+   */
+  public revertPaymentGLEntries = async (
+    billPaymentId: number,
+    trx?: Knex.Transaction,
+  ): Promise<void> => {
+    await this.ledgerStorage.deleteByReference(
+      billPaymentId,
+      'BillPayment',
+      trx,
+    );
+  };
+}

packages/server/src/modules/BillPayments/commands/BillPaymentValidators.service.ts

@@ -0,0 +1,258 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { sumBy, difference } from 'lodash';
+import { ERRORS } from '../constants';
+import { Bill } from '../../Bills/models/Bill';
+import { BillPayment } from '../models/BillPayment';
+import { BillPaymentEntry } from '../models/BillPaymentEntry';
+import { ServiceError } from '../../Items/ServiceError';
+import { ACCOUNT_TYPE } from '@/constants/accounts';
+import { Account } from '../../Accounts/models/Account.model';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import {
+  BillPaymentEntryDto,
+  EditBillPaymentDto,
+} from '../dtos/BillPayment.dto';
+
+@Injectable()
+export class BillPaymentValidators {
+  constructor(
+    @Inject(Bill.name)
+    private readonly billModel: TenantModelProxy<typeof Bill>,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+
+    @Inject(BillPaymentEntry.name)
+    private readonly billPaymentEntryModel: TenantModelProxy<
+      typeof BillPaymentEntry
+    >,
+
+    @Inject(Account.name)
+    private readonly accountModel: TenantModelProxy<typeof Account>,
+  ) {}
+
+  /**
+   * Validates the bill payment existance.
+   * @param {Request} req
+   * @param {Response} res
+   * @param {Function} next
+   */
+  public async getPaymentMadeOrThrowError(paymentMadeId: number) {
+    const billPayment = await this.billPaymentModel()
+      .query()
+      .withGraphFetched('entries')
+      .findById(paymentMadeId);
+
+    if (!billPayment) {
+      throw new ServiceError(ERRORS.PAYMENT_MADE_NOT_FOUND);
+    }
+    return billPayment;
+  }
+
+  /**
+   * Validates the payment account.
+   * @param {number} tenantId -
+   * @param {number} paymentAccountId
+   * @return {Promise<IAccountType>}
+   */
+  public async getPaymentAccountOrThrowError(paymentAccountId: number) {
+    const paymentAccount = await this.accountModel()
+      .query()
+      .findById(paymentAccountId);
+
+    if (!paymentAccount) {
+      throw new ServiceError(ERRORS.PAYMENT_ACCOUNT_NOT_FOUND);
+    }
+    // Validate the payment account type.
+    if (
+      !paymentAccount.isAccountType([
+        ACCOUNT_TYPE.BANK,
+        ACCOUNT_TYPE.CASH,
+        ACCOUNT_TYPE.OTHER_CURRENT_ASSET,
+      ])
+    ) {
+      throw new ServiceError(ERRORS.PAYMENT_ACCOUNT_NOT_CURRENT_ASSET_TYPE);
+    }
+    return paymentAccount;
+  }
+
+  /**
+   * Validates the payment number uniqness.
+   * @param {number} tenantId -
+   * @param {string} paymentMadeNumber -
+   * @return {Promise<IBillPayment>}
+   */
+  public async validatePaymentNumber(
+    paymentMadeNumber: string,
+    notPaymentMadeId?: number,
+  ) {
+    const foundBillPayment = await this.billPaymentModel()
+      .query()
+      .onBuild((builder: any) => {
+        builder.findOne('payment_number', paymentMadeNumber);
+
+        if (notPaymentMadeId) {
+          builder.whereNot('id', notPaymentMadeId);
+        }
+      });
+
+    if (foundBillPayment) {
+      throw new ServiceError(ERRORS.BILL_PAYMENT_NUMBER_NOT_UNQIUE);
+    }
+    return foundBillPayment;
+  }
+
+  /**
+   * Validate whether the entries bills ids exist on the storage.
+   */
+  public async validateBillsExistance(
+    billPaymentEntries: { billId: number }[],
+    vendorId: number,
+  ) {
+    const entriesBillsIds = billPaymentEntries.map((e: any) => e.billId);
+
+    const storedBills = await this.billModel()
+      .query()
+      .whereIn('id', entriesBillsIds)
+      .where('vendor_id', vendorId);
+
+    const storedBillsIds = storedBills.map((t: Bill) => t.id);
+    const notFoundBillsIds = difference(entriesBillsIds, storedBillsIds);
+
+    if (notFoundBillsIds.length > 0) {
+      throw new ServiceError(ERRORS.BILL_ENTRIES_IDS_NOT_FOUND);
+    }
+    // Validate the not opened bills.
+    const notOpenedBills = storedBills.filter((bill) => !bill.openedAt);
+
+    if (notOpenedBills.length > 0) {
+      throw new ServiceError(ERRORS.BILLS_NOT_OPENED_YET, null, {
+        notOpenedBills,
+      });
+    }
+    return storedBills;
+  }
+
+  /**
+   * Validate wether the payment amount bigger than the payable amount.
+   * @param {Request} req
+   * @param {Response} res
+   * @param {NextFunction} next
+   * @return {void}
+   */
+  public async validateBillsDueAmount(
+    billPaymentEntries: BillPaymentEntryDto[],
+    oldPaymentEntries: BillPaymentEntry[] = [],
+  ) {
+    const billsIds = billPaymentEntries.map(
+      (entry: BillPaymentEntryDto) => entry.billId,
+    );
+
+    const storedBills = await this.billModel().query().whereIn('id', billsIds);
+    const storedBillsMap = new Map(
+      storedBills.map((bill) => {
+        const oldEntries = oldPaymentEntries.filter(
+          (entry) => entry.billId === bill.id,
+        );
+        const oldPaymentAmount = sumBy(oldEntries, 'paymentAmount') || 0;
+
+        return [
+          bill.id,
+          { ...bill, dueAmount: bill.dueAmount + oldPaymentAmount },
+        ];
+      }),
+    );
+    interface invalidPaymentAmountError {
+      index: number;
+      due_amount: number;
+    }
+    const hasWrongPaymentAmount: invalidPaymentAmountError[] = [];
+
+    billPaymentEntries.forEach((entry: BillPaymentEntryDto, index: number) => {
+      const entryBill = storedBillsMap.get(entry.billId);
+      const { dueAmount } = entryBill;
+
+      if (dueAmount < entry.paymentAmount) {
+        hasWrongPaymentAmount.push({ index, due_amount: dueAmount });
+      }
+    });
+    if (hasWrongPaymentAmount.length > 0) {
+      throw new ServiceError(ERRORS.INVALID_BILL_PAYMENT_AMOUNT);
+    }
+  }
+
+  /**
+   * Validate the payment receive entries IDs existance.
+   * @param {Request} req
+   * @param {Response} res
+   * @return {Response}
+   */
+  public async validateEntriesIdsExistance(
+    billPaymentId: number,
+    billPaymentEntries: BillPaymentEntry[],
+  ) {
+    const entriesIds = billPaymentEntries
+      .filter((entry: any) => entry.id)
+      .map((entry: any) => entry.id);
+
+    const storedEntries = await this.billPaymentEntryModel()
+      .query()
+      .where('bill_payment_id', billPaymentId);
+
+    const storedEntriesIds = storedEntries.map((entry: any) => entry.id);
+    const notFoundEntriesIds = difference(entriesIds, storedEntriesIds);
+
+    if (notFoundEntriesIds.length > 0) {
+      throw new ServiceError(ERRORS.BILL_PAYMENT_ENTRIES_NOT_FOUND);
+    }
+  }
+
+  /**
+   * * Validate the payment vendor whether modified.
+   * @param {string} billPaymentNo
+   */
+  public validateVendorNotModified(
+    billPaymentDTO: EditBillPaymentDto,
+    oldBillPayment: BillPayment,
+  ) {
+    if (billPaymentDTO.vendorId !== oldBillPayment.vendorId) {
+      throw new ServiceError(ERRORS.PAYMENT_NUMBER_SHOULD_NOT_MODIFY);
+    }
+  }
+
+  /**
+   * Validates the payment account currency code. The deposit account curreny
+   * should be equals the customer currency code or the base currency.
+   * @param  {string} paymentAccountCurrency
+   * @param  {string} customerCurrency
+   * @param  {string} baseCurrency
+   * @throws {ServiceError(ERRORS.WITHDRAWAL_ACCOUNT_CURRENCY_INVALID)}
+   */
+  public validateWithdrawalAccountCurrency = (
+    paymentAccountCurrency: string,
+    customerCurrency: string,
+    baseCurrency: string,
+  ) => {
+    if (
+      paymentAccountCurrency !== customerCurrency &&
+      paymentAccountCurrency !== baseCurrency
+    ) {
+      throw new ServiceError(ERRORS.WITHDRAWAL_ACCOUNT_CURRENCY_INVALID);
+    }
+  };
+
+  /**
+   * Validates the given vendor has no associated payments.
+   * @param {number} tenantId
+   * @param {number} vendorId
+   */
+  public async validateVendorHasNoPayments(vendorId: number) {
+    const payments = await this.billPaymentModel()
+      .query()
+      .where('vendor_id', vendorId);
+
+    if (payments.length > 0) {
+      throw new ServiceError(ERRORS.VENDOR_HAS_PAYMENTS);
+    }
+  }
+}

packages/server/src/modules/BillPayments/commands/BillPaymentsImportable.ts

@@ -0,0 +1,45 @@
+// import { Inject, Service } from 'typedi';
+// import { Knex } from 'knex';
+// import { IBillPaymentDTO } from '@/interfaces';
+// import { CreateBillPayment } from './CreateBillPayment';
+// import { Importable } from '@/services/Import/Importable';
+// import { BillsPaymentsSampleData } from './constants';
+
+// @Service()
+// export class BillPaymentsImportable extends Importable {
+//   @Inject()
+//   private createBillPaymentService: CreateBillPayment;
+
+//   /**
+//    * Importing to account service.
+//    * @param {number} tenantId
+//    * @param {IAccountCreateDTO} createAccountDTO
+//    * @returns
+//    */
+//   public importable(
+//     tenantId: number,
+//     billPaymentDTO: IBillPaymentDTO,
+//     trx?: Knex.Transaction
+//   ) {
+//     return this.createBillPaymentService.createBillPayment(
+//       tenantId,
+//       billPaymentDTO,
+//       trx
+//     );
+//   }
+
+//   /**
+//    * Concurrrency controlling of the importing process.
+//    * @returns {number}
+//    */
+//   public get concurrency() {
+//     return 1;
+//   }
+
+//   /**
+//    * Retrieves the sample data that used to download accounts sample sheet.
+//    */
+//   public sampleData(): any[] {
+//     return BillsPaymentsSampleData;
+//   }
+// }

packages/server/src/modules/BillPayments/commands/BillPaymentsPages.service.ts

@@ -0,0 +1,106 @@
+import { omit } from 'lodash';
+import { ERRORS } from '../constants';
+import { Inject, Injectable } from '@nestjs/common';
+import { Bill } from '../../Bills/models/Bill';
+import { BillPayment } from '../models/BillPayment';
+import { IBillReceivePageEntry } from '../types/BillPayments.types';
+import { ServiceError } from '../../Items/ServiceError';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export default class BillPaymentsPages {
+  /**
+   * @param {TenantModelProxy<typeof Bill>} billModel - Bill model.
+   * @param {TenantModelProxy<typeof BillPayment>} billPaymentModel - Bill payment model.
+   */
+  constructor(
+    @Inject(Bill.name)
+    private readonly billModel: TenantModelProxy<typeof Bill>,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+  ) {}
+
+  /**
+   * Retrieve bill payment with associated metadata.
+   * @param {number} billPaymentId - The bill payment id.
+   * @return {object}
+   */
+  public async getBillPaymentEditPage(billPaymentId: number): Promise<{
+    billPayment: Omit<BillPayment, 'entries'>;
+    entries: IBillReceivePageEntry[];
+  }> {
+    const billPayment = await this.billPaymentModel()
+      .query()
+      .findById(billPaymentId)
+      .withGraphFetched('entries.bill')
+      .withGraphFetched('attachments');
+
+    // Throw not found the bill payment.
+    if (!billPayment) {
+      throw new ServiceError(ERRORS.PAYMENT_MADE_NOT_FOUND);
+    }
+    const paymentEntries = billPayment.entries.map((entry) => ({
+      ...this.mapBillToPageEntry(entry.bill),
+      dueAmount: entry.bill.dueAmount + entry.paymentAmount,
+      paymentAmount: entry.paymentAmount,
+    }));
+
+    const resPayableBills = await Bill.query()
+      .modify('opened')
+      .modify('dueBills')
+      .where('vendor_id', billPayment.vendorId)
+      .whereNotIn(
+        'id',
+        billPayment.entries.map((e) => e.billId),
+      )
+      .orderBy('bill_date', 'ASC');
+
+    // Mapping the payable bills to entries.
+    const restPayableEntries = resPayableBills.map(this.mapBillToPageEntry);
+    const entries = [...paymentEntries, ...restPayableEntries];
+
+    return {
+      billPayment: omit(billPayment, ['entries']),
+      entries,
+    };
+  }
+
+  /**
+   * Retrieve the payable entries of the new page once vendor be selected.
+   * @param {number} tenantId
+   * @param {number} vendorId
+   */
+  public async getNewPageEntries(
+    vendorId: number,
+  ): Promise<IBillReceivePageEntry[]> {
+    // Retrieve all payable bills that associated to the payment made transaction.
+    const payableBills = await this.billModel()
+      .query()
+      .modify('opened')
+      .modify('dueBills')
+      .where('vendor_id', vendorId)
+      .orderBy('bill_date', 'ASC');
+
+    return payableBills.map(this.mapBillToPageEntry);
+  }
+
+  /**
+   * Retrive edit page invoices entries from the given sale invoices models.
+   * @param {Bill} bill - Bill.
+   * @return {IBillReceivePageEntry}
+   */
+  private mapBillToPageEntry(bill: Bill): IBillReceivePageEntry {
+    return {
+      entryType: 'invoice',
+      billId: bill.id,
+      billNo: bill.billNumber,
+      amount: bill.amount,
+      dueAmount: bill.dueAmount,
+      totalPaymentAmount: bill.paymentAmount,
+      paymentAmount: bill.paymentAmount,
+      currencyCode: bill.currencyCode,
+      date: bill.billDate,
+    };
+  }
+}

packages/server/src/modules/BillPayments/commands/CommandBillPaymentDTOTransformer.service.ts

@@ -0,0 +1,54 @@
+import { Injectable } from '@nestjs/common';
+import * as R from 'ramda';
+import { omit, sumBy } from 'lodash';
+import { formatDateFields } from '@/utils/format-date-fields';
+import { assocItemEntriesDefaultIndex } from '@/utils/associate-item-entries-index';
+import { BranchTransactionDTOTransformer } from '@/modules/Branches/integrations/BranchTransactionDTOTransform';
+import { Vendor } from '@/modules/Vendors/models/Vendor';
+import { BillPayment } from '../models/BillPayment';
+import {
+  CreateBillPaymentDto,
+  EditBillPaymentDto,
+} from '../dtos/BillPayment.dto';
+
+@Injectable()
+export class CommandBillPaymentDTOTransformer {
+  constructor(
+    private readonly branchDTOTransform: BranchTransactionDTOTransformer,
+  ) {}
+
+  /**
+   * Transforms create/edit DTO to model.
+   * @param {number} tenantId
+   * @param {IBillPaymentDTO} billPaymentDTO - Bill payment.
+   * @param {IBillPayment} oldBillPayment - Old bill payment.
+   * @return {Promise<IBillPayment>}
+   */
+  public async transformDTOToModel(
+    billPaymentDTO: CreateBillPaymentDto | EditBillPaymentDto,
+    vendor: Vendor,
+    oldBillPayment?: BillPayment,
+  ): Promise<BillPayment> {
+    const amount =
+      billPaymentDTO.amount ?? sumBy(billPaymentDTO.entries, 'paymentAmount');
+
+    // Associate the default index to each item entry.
+    const entries = R.compose(
+      // Associate the default index to payment entries.
+      assocItemEntriesDefaultIndex,
+    )(billPaymentDTO.entries);
+
+    const initialDTO = {
+      ...formatDateFields(omit(billPaymentDTO, ['attachments']), [
+        'paymentDate',
+      ]),
+      amount,
+      currencyCode: vendor.currencyCode,
+      exchangeRate: billPaymentDTO.exchangeRate || 1,
+      entries,
+    };
+    return R.compose(this.branchDTOTransform.transformDTO<BillPayment>)(
+      initialDTO,
+    );
+  }
+}

packages/server/src/modules/BillPayments/commands/CreateBillPayment.service.ts

@@ -0,0 +1,122 @@
+import { Knex } from 'knex';
+import {
+  IBillPaymentEventCreatedPayload,
+  IBillPaymentCreatingPayload,
+} from '../types/BillPayments.types';
+import { Inject, Injectable } from '@nestjs/common';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { UnitOfWork } from '../../Tenancy/TenancyDB/UnitOfWork.service';
+import { BillPaymentValidators } from './BillPaymentValidators.service';
+import { CommandBillPaymentDTOTransformer } from './CommandBillPaymentDTOTransformer.service';
+import { events } from '@/common/events/events';
+import { TenancyContext } from '../../Tenancy/TenancyContext.service';
+import { BillPayment } from '../models/BillPayment';
+import { Vendor } from '../../Vendors/models/Vendor';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { CreateBillPaymentDto } from '../dtos/BillPayment.dto';
+
+@Injectable()
+export class CreateBillPaymentService {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {BillPaymentValidators} validators - Bill payment validators service.
+   * @param {CommandBillPaymentDTOTransformer} commandTransformerDTO - Command bill payment DTO transformer service.
+   * @param {TenancyContext} tenancyContext - Tenancy context service.
+   * @param {TenantModelProxy<typeof Vendor>} vendorModel - Vendor model.
+   * @param {TenantModelProxy<typeof BillPayment>} billPaymentModel - Bill payment model.
+   */
+  constructor(
+    private uow: UnitOfWork,
+    private eventPublisher: EventEmitter2,
+    private validators: BillPaymentValidators,
+    private commandTransformerDTO: CommandBillPaymentDTOTransformer,
+    private tenancyContext: TenancyContext,
+
+    @Inject(Vendor.name)
+    private readonly vendorModel: TenantModelProxy<typeof Vendor>,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+  ) {}
+
+  /**
+   * Creates a new bill payment transcations and store it to the storage
+   * with associated bills entries and journal transactions.
+   * ------
+   * Precedures:-
+   * ------
+   * - Records the bill payment transaction.
+   * - Records the bill payment associated entries.
+   * - Increment the payment amount of the given vendor bills.
+   * - Decrement the vendor balance.
+   * - Records payment journal entries.
+   * ------
+   * @param {number} tenantId - Tenant id.
+   * @param {BillPaymentDTO} billPayment - Bill payment object.
+   */
+  public async createBillPayment(
+    billPaymentDTO: CreateBillPaymentDto,
+    trx?: Knex.Transaction,
+  ): Promise<BillPayment> {
+    const tenantMeta = await this.tenancyContext.getTenant(true);
+
+    // Retrieves the payment vendor or throw not found error.
+    const vendor = await this.vendorModel()
+      .query()
+      .findById(billPaymentDTO.vendorId)
+      .throwIfNotFound();
+
+    // Transform create DTO to model object.
+    const billPaymentObj = await this.commandTransformerDTO.transformDTOToModel(
+      billPaymentDTO,
+      vendor,
+    );
+    // Validate the payment account existance and type.
+    const paymentAccount = await this.validators.getPaymentAccountOrThrowError(
+      billPaymentObj.paymentAccountId,
+    );
+    // Validate the payment number uniquiness.
+    if (billPaymentObj.paymentNumber) {
+      await this.validators.validatePaymentNumber(billPaymentObj.paymentNumber);
+    }
+    // Validates the bills existance and associated to the given vendor.
+    await this.validators.validateBillsExistance(
+      billPaymentObj.entries,
+      billPaymentDTO.vendorId,
+    );
+    // Validates the bills due payment amount.
+    await this.validators.validateBillsDueAmount(billPaymentObj.entries);
+    // Validates the withdrawal account currency code.
+    this.validators.validateWithdrawalAccountCurrency(
+      paymentAccount.currencyCode,
+      vendor.currencyCode,
+      tenantMeta.metadata.baseCurrency,
+    );
+    // Writes bill payment transacation with associated transactions
+    // under unit-of-work envirement.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onBillPaymentCreating` event.
+      await this.eventPublisher.emitAsync(events.billPayment.onCreating, {
+        billPaymentDTO,
+        trx,
+      } as IBillPaymentCreatingPayload);
+
+      // Writes the bill payment graph to the storage.
+      const billPayment = await this.billPaymentModel()
+        .query(trx)
+        .insertGraphAndFetch({
+          ...billPaymentObj,
+        });
+      // Triggers `onBillPaymentCreated` event.
+      await this.eventPublisher.emitAsync(events.billPayment.onCreated, {
+        billPayment,
+        billPaymentId: billPayment.id,
+        billPaymentDTO,
+        trx,
+      } as IBillPaymentEventCreatedPayload);
+
+      return billPayment;
+    }, trx);
+  }
+}

packages/server/src/modules/BillPayments/commands/DeleteBillPayment.service.ts

@@ -0,0 +1,77 @@
+import { Knex } from 'knex';
+import { Inject, Injectable } from '@nestjs/common';
+import {
+  IBillPaymentDeletingPayload,
+  IBillPaymentEventDeletedPayload,
+} from '../types/BillPayments.types';
+import { BillPayment } from '../models/BillPayment';
+import { BillPaymentEntry } from '../models/BillPaymentEntry';
+import { UnitOfWork } from '../../Tenancy/TenancyDB/UnitOfWork.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { events } from '@/common/events/events';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class DeleteBillPayment {
+  /**
+   * @param {EventPublisher} eventPublisher - Event publisher.
+   * @param {UnitOfWork} uow - Unit of work.
+   * @param {typeof BillPayment} billPaymentModel - Bill payment model.
+   * @param {typeof BillPaymentEntry} billPaymentEntryModel - Bill payment entry model.
+   */
+  constructor(
+    private readonly eventEmitter: EventEmitter2,
+    private readonly uow: UnitOfWork,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+
+    @Inject(BillPaymentEntry.name)
+    private readonly billPaymentEntryModel: TenantModelProxy<
+      typeof BillPaymentEntry
+    >,
+  ) {}
+
+  /**
+   * Deletes the bill payment and associated transactions.
+   * @param {Integer} billPaymentId - The given bill payment id.
+   * @return {Promise}
+   */
+  public async deleteBillPayment(billPaymentId: number) {
+    // Retrieve the bill payment or throw not found service error.
+    const oldBillPayment = await this.billPaymentModel()
+      .query()
+      .withGraphFetched('entries')
+      .findById(billPaymentId)
+      .throwIfNotFound();
+
+    // Deletes the bill transactions with associated transactions under
+    // unit-of-work environment.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onBillPaymentDeleting` payload.
+      await this.eventEmitter.emitAsync(events.billPayment.onDeleting, {
+        oldBillPayment,
+        trx,
+      } as IBillPaymentDeletingPayload);
+
+      // Deletes the bill payment associated entries.
+      await this.billPaymentEntryModel()
+        .query(trx)
+        .where('bill_payment_id', billPaymentId)
+        .delete();
+
+      // Deletes the bill payment transaction.
+      await this.billPaymentModel()
+        .query(trx)
+        .where('id', billPaymentId)
+        .delete();
+
+      // Triggers `onBillPaymentDeleted` event.
+      await this.eventEmitter.emitAsync(events.billPayment.onDeleted, {
+        billPaymentId,
+        oldBillPayment,
+        trx,
+      } as IBillPaymentEventDeletedPayload);
+    });
+  }
+}

packages/server/src/modules/BillPayments/commands/EditBillPayment.service.ts

@@ -0,0 +1,137 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { BillPaymentValidators } from './BillPaymentValidators.service';
+import {
+  IBillPaymentEditingPayload,
+  IBillPaymentEventEditedPayload,
+} from '../types/BillPayments.types';
+import { Knex } from 'knex';
+import { BillPayment } from '../models/BillPayment';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { CommandBillPaymentDTOTransformer } from './CommandBillPaymentDTOTransformer.service';
+import { Vendor } from '@/modules/Vendors/models/Vendor';
+import { events } from '@/common/events/events';
+import { TenancyContext } from '@/modules/Tenancy/TenancyContext.service';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { EditBillPaymentDto } from '../dtos/BillPayment.dto';
+
+@Injectable()
+export class EditBillPayment {
+  constructor(
+    private readonly validators: BillPaymentValidators,
+    private readonly eventPublisher: EventEmitter2,
+    private readonly uow: UnitOfWork,
+    private readonly transformer: CommandBillPaymentDTOTransformer,
+    private readonly tenancyContext: TenancyContext,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+
+    @Inject(Vendor.name)
+    private readonly vendorModel: TenantModelProxy<typeof Vendor>,
+  ) {}
+
+  /**
+   * Edits the details of the given bill payment.
+   *
+   * Preceducres:
+   * ------
+   * - Update the bill payment transaction.
+   * - Insert the new bill payment entries that have no ids.
+   * - Update the bill paymeny entries that have ids.
+   * - Delete the bill payment entries that not presented.
+   * - Re-insert the journal transactions and update the diff accounts balance.
+   * - Update the diff vendor balance.
+   * - Update the diff bill payment amount.
+   * ------
+   * @param {Integer} billPaymentId
+   * @param {EditBillPaymentDto} billPayment
+   * @param {BillPayment} oldBillPayment
+   */
+  public async editBillPayment(
+    billPaymentId: number,
+    billPaymentDTO: EditBillPaymentDto,
+  ): Promise<BillPayment> {
+    const tenantMeta = await this.tenancyContext.getTenant(true);
+
+    const oldBillPayment = await this.billPaymentModel()
+      .query()
+      .findById(billPaymentId)
+      .withGraphFetched('entries')
+      .throwIfNotFound();
+
+    const vendor = await this.vendorModel()
+      .query()
+      .findById(billPaymentDTO.vendorId)
+      .throwIfNotFound();
+
+    const billPaymentObj = await this.transformer.transformDTOToModel(
+      billPaymentDTO,
+      vendor,
+      oldBillPayment,
+    );
+    // Validate vendor not modified.
+    this.validators.validateVendorNotModified(billPaymentDTO, oldBillPayment);
+
+    // Validate the payment account existance and type.
+    const paymentAccount = await this.validators.getPaymentAccountOrThrowError(
+      billPaymentObj.paymentAccountId,
+    );
+    // Validate the items entries IDs existance on the storage.
+    await this.validators.validateEntriesIdsExistance(
+      billPaymentId,
+      billPaymentObj.entries,
+    );
+    // Validate the bills existance and associated to the given vendor.
+    await this.validators.validateBillsExistance(
+      billPaymentObj.entries,
+      billPaymentDTO.vendorId,
+    );
+    // Validates the bills due payment amount.
+    await this.validators.validateBillsDueAmount(
+      billPaymentObj.entries,
+      oldBillPayment.entries,
+    );
+    // Validate the payment number uniquiness.
+    if (billPaymentObj.paymentNumber) {
+      await this.validators.validatePaymentNumber(
+        billPaymentObj.paymentNumber,
+        billPaymentId,
+      );
+    }
+    // Validates the withdrawal account currency code.
+    this.validators.validateWithdrawalAccountCurrency(
+      paymentAccount.currencyCode,
+      vendor.currencyCode,
+      tenantMeta.metadata.baseCurrency,
+    );
+    // Edits the bill transactions with associated transactions
+    // under unit-of-work envirement.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onBillPaymentEditing` event.
+      await this.eventPublisher.emitAsync(events.billPayment.onEditing, {
+        oldBillPayment,
+        billPaymentDTO,
+        trx,
+      } as IBillPaymentEditingPayload);
+
+      // Edits the bill payment transaction graph on the storage.
+      const billPayment = await this.billPaymentModel()
+        .query(trx)
+        .upsertGraphAndFetch({
+          id: billPaymentId,
+          ...billPaymentObj,
+        });
+      // Triggers `onBillPaymentEdited` event.
+      await this.eventPublisher.emitAsync(events.billPayment.onEdited, {
+        billPaymentId,
+        billPayment,
+        oldBillPayment,
+        billPaymentDTO,
+        trx,
+      } as IBillPaymentEventEditedPayload);
+
+      return billPayment;
+    });
+  }
+}

packages/server/src/modules/BillPayments/constants.ts

@@ -0,0 +1,50 @@
+export const ERRORS = {
+  BILL_VENDOR_NOT_FOUND: 'VENDOR_NOT_FOUND',
+  PAYMENT_MADE_NOT_FOUND: 'PAYMENT_MADE_NOT_FOUND',
+  BILL_PAYMENT_NUMBER_NOT_UNQIUE: 'BILL_PAYMENT_NUMBER_NOT_UNQIUE',
+  PAYMENT_ACCOUNT_NOT_FOUND: 'PAYMENT_ACCOUNT_NOT_FOUND',
+  PAYMENT_ACCOUNT_NOT_CURRENT_ASSET_TYPE:
+    'PAYMENT_ACCOUNT_NOT_CURRENT_ASSET_TYPE',
+  BILL_ENTRIES_IDS_NOT_FOUND: 'BILL_ENTRIES_IDS_NOT_FOUND',
+  BILL_PAYMENT_ENTRIES_NOT_FOUND: 'BILL_PAYMENT_ENTRIES_NOT_FOUND',
+  INVALID_BILL_PAYMENT_AMOUNT: 'INVALID_BILL_PAYMENT_AMOUNT',
+  PAYMENT_NUMBER_SHOULD_NOT_MODIFY: 'PAYMENT_NUMBER_SHOULD_NOT_MODIFY',
+  BILLS_NOT_OPENED_YET: 'BILLS_NOT_OPENED_YET',
+  VENDOR_HAS_PAYMENTS: 'VENDOR_HAS_PAYMENTS',
+  WITHDRAWAL_ACCOUNT_CURRENCY_INVALID: 'WITHDRAWAL_ACCOUNT_CURRENCY_INVALID',
+};
+
+export const DEFAULT_VIEWS = [];
+
+export const BillsPaymentsSampleData = [
+  {
+    'Payment Date': '2024-03-01',
+    Vendor: 'Gabriel Kovacek',
+    'Payment No.': 'P-10001',
+    'Reference No.': 'REF-1',
+    'Payment Account': 'Petty Cash',
+    Statement: 'Vel et dolorem architecto veniam.',
+    'Bill No': 'B-120',
+    'Payment Amount': 100,
+  },
+  {
+    'Payment Date': '2024-03-02',
+    Vendor: 'Gabriel Kovacek',
+    'Payment No.': 'P-10002',
+    'Reference No.': 'REF-2',
+    'Payment Account': 'Petty Cash',
+    Statement: 'Id est molestias.',
+    'Bill No': 'B-121',
+    'Payment Amount': 100,
+  },
+  {
+    'Payment Date': '2024-03-03',
+    Vendor: 'Gabriel Kovacek',
+    'Payment No.': 'P-10003',
+    'Reference No.': 'REF-3',
+    'Payment Account': 'Petty Cash',
+    Statement: 'Quam cupiditate at nihil dicta dignissimos non fugit illo.',
+    'Bill No': 'B-122',
+    'Payment Amount': 100,
+  },
+];

packages/server/src/modules/BillPayments/dtos/BillPayment.dto.ts

@@ -0,0 +1,120 @@
+import { Type } from 'class-transformer';
+import {
+  IsArray,
+  IsDate,
+  IsNotEmpty,
+  IsNumber,
+  IsOptional,
+  IsString,
+  ValidateNested,
+} from 'class-validator';
+import { AttachmentLinkDto } from '@/modules/Attachments/dtos/Attachment.dto';
+import { ApiProperty } from '@nestjs/swagger';
+
+export class BillPaymentEntryDto {
+  @IsNumber()
+  billId: number;
+
+  @IsNumber()
+  paymentAmount: number;
+}
+
+export class CommandBillPaymentDTO {
+  @IsNumber()
+  @IsNotEmpty()
+  @ApiProperty({
+    description: 'The id of the vendor',
+    example: 1,
+  })
+  vendorId: number;
+
+  @IsNumber()
+  @IsOptional()
+  @ApiProperty({
+    description: 'The amount of the bill payment',
+    example: 100,
+  })
+  amount?: number;
+
+  @IsNumber()
+  @IsNotEmpty()
+  @ApiProperty({
+    description: 'The id of the payment account',
+    example: 1,
+  })
+  paymentAccountId: number;
+
+  @IsString()
+  @IsOptional()
+  @ApiProperty({
+    description: 'The payment number of the bill payment',
+    example: '123456',
+  })
+  paymentNumber?: string;
+
+  @IsDate()
+  @Type(() => Date)
+  @ApiProperty({
+    description: 'The payment date of the bill payment',
+    example: '2021-01-01',
+  })
+  paymentDate: Date | string;
+
+  @IsNumber()
+  @IsOptional()
+  @ApiProperty({
+    description: 'The exchange rate of the bill payment',
+    example: 1,
+  })
+  exchangeRate?: number;
+
+  @IsString()
+  @IsOptional()
+  @ApiProperty({
+    description: 'The statement of the bill payment',
+    example: '123456',
+  })
+  statement?: string;
+
+  @IsString()
+  @IsOptional()
+  @IsArray()
+  @ValidateNested({ each: true })
+  @Type(() => BillPaymentEntryDto)
+  @ApiProperty({
+    description: 'The entries of the bill payment',
+    example: [
+      {
+        billId: 1,
+        paymentAmount: 100,
+      },
+    ],
+  })
+  entries: BillPaymentEntryDto[];
+
+  @IsNumber()
+  @IsOptional()
+  @ApiProperty({
+    description: 'The id of the branch',
+    example: 1,
+  })
+  branchId?: number;
+
+  @IsArray()
+  @IsOptional()
+  @ValidateNested({ each: true })
+  @Type(() => AttachmentLinkDto)
+  @ApiProperty({
+    description: 'The attachments of the bill payment',
+    example: [
+      {
+        id: 1,
+        type: 'bill',
+      },
+    ],
+  })
+  attachments?: AttachmentLinkDto[];
+}
+
+export class CreateBillPaymentDto extends CommandBillPaymentDTO {}
+export class EditBillPaymentDto extends CommandBillPaymentDTO {}

packages/server/src/modules/BillPayments/models/BillPayment.ts

@@ -0,0 +1,185 @@
+import { Model, mixin } from 'objection';
+// import TenantModel from 'models/TenantModel';
+// import ModelSetting from './ModelSetting';
+// import BillPaymentSettings from './BillPayment.Settings';
+// import CustomViewBaseModel from './CustomViewBaseModel';
+// import { DEFAULT_VIEWS } from '@/services/Sales/PaymentReceived/constants';
+// import ModelSearchable from './ModelSearchable';
+import { BaseModel } from '@/models/Model';
+import { BillPaymentEntry } from './BillPaymentEntry';
+import { Vendor } from '@/modules/Vendors/models/Vendor';
+import { Document } from '@/modules/ChromiumlyTenancy/models/Document';
+
+export class BillPayment extends BaseModel{
+  vendorId: number;
+  amount: number;
+  currencyCode: string;
+  paymentAccountId: number;
+  paymentNumber: string;
+  paymentDate: string;
+  paymentMethod: string;
+  reference: string;
+  userId: number;
+  statement: string;
+  exchangeRate: number;
+
+  createdAt?: Date;
+  updatedAt?: Date;
+
+  branchId?: number;
+
+  entries?: BillPaymentEntry[];
+  vendor?: Vendor;
+  attachments?: Document[];
+
+  /**
+   * Table name
+   */
+  static get tableName() {
+    return 'bills_payments';
+  }
+
+  /**
+   * Timestamps columns.
+   */
+  get timestamps() {
+    return ['createdAt', 'updatedAt'];
+  }
+
+  /**
+   * Virtual attributes.
+   */
+  static get virtualAttributes() {
+    return ['localAmount'];
+  }
+
+  /**
+   * Payment amount in local currency.
+   * @returns {number}
+   */
+  get localAmount() {
+    return this.amount * this.exchangeRate;
+  }
+
+  /**
+   * Model settings.
+   */
+  // static get meta() {
+  //   return BillPaymentSettings;
+  // }
+
+  /**
+   * Relationship mapping.
+   */
+  // static get relationMappings() {
+  //   const BillPaymentEntry = require('models/BillPaymentEntry');
+  //   const AccountTransaction = require('models/AccountTransaction');
+  //   const Vendor = require('models/Vendor');
+  //   const Account = require('models/Account');
+  //   const Branch = require('models/Branch');
+  //   const Document = require('models/Document');
+
+  //   return {
+  //     entries: {
+  //       relation: Model.HasManyRelation,
+  //       modelClass: BillPaymentEntry.default,
+  //       join: {
+  //         from: 'bills_payments.id',
+  //         to: 'bills_payments_entries.billPaymentId',
+  //       },
+  //       filter: (query) => {
+  //         query.orderBy('index', 'ASC');
+  //       },
+  //     },
+
+  //     vendor: {
+  //       relation: Model.BelongsToOneRelation,
+  //       modelClass: Vendor.default,
+  //       join: {
+  //         from: 'bills_payments.vendorId',
+  //         to: 'contacts.id',
+  //       },
+  //       filter(query) {
+  //         query.where('contact_service', 'vendor');
+  //       },
+  //     },
+
+  //     paymentAccount: {
+  //       relation: Model.BelongsToOneRelation,
+  //       modelClass: Account.default,
+  //       join: {
+  //         from: 'bills_payments.paymentAccountId',
+  //         to: 'accounts.id',
+  //       },
+  //     },
+
+  //     transactions: {
+  //       relation: Model.HasManyRelation,
+  //       modelClass: AccountTransaction.default,
+  //       join: {
+  //         from: 'bills_payments.id',
+  //         to: 'accounts_transactions.referenceId',
+  //       },
+  //       filter(builder) {
+  //         builder.where('reference_type', 'BillPayment');
+  //       },
+  //     },
+
+  //     /**
+  //      * Bill payment may belongs to branch.
+  //      */
+  //     branch: {
+  //       relation: Model.BelongsToOneRelation,
+  //       modelClass: Branch.default,
+  //       join: {
+  //         from: 'bills_payments.branchId',
+  //         to: 'branches.id',
+  //       },
+  //     },
+
+  //     /**
+  //      * Bill payment may has many attached attachments.
+  //      */
+  //     attachments: {
+  //       relation: Model.ManyToManyRelation,
+  //       modelClass: Document.default,
+  //       join: {
+  //         from: 'bills_payments.id',
+  //         through: {
+  //           from: 'document_links.modelId',
+  //           to: 'document_links.documentId',
+  //         },
+  //         to: 'documents.id',
+  //       },
+  //       filter(query) {
+  //         query.where('model_ref', 'BillPayment');
+  //       },
+  //     },
+  //   };
+  // }
+
+  /**
+   * Retrieve the default custom views, roles and columns.
+   */
+  // static get defaultViews() {
+  //   return DEFAULT_VIEWS;
+  // }
+
+  /**
+   * Model search attributes.
+   */
+  static get searchRoles() {
+    return [
+      { fieldKey: 'payment_number', comparator: 'contains' },
+      { condition: 'or', fieldKey: 'reference_no', comparator: 'contains' },
+      { condition: 'or', fieldKey: 'amount', comparator: 'equals' },
+    ];
+  }
+
+  /**
+   * Prevents mutate base currency since the model is not empty.
+   */
+  static get preventMutateBaseCurrency() {
+    return true;
+  }
+}

packages/server/src/modules/BillPayments/models/BillPaymentEntry.ts

@@ -0,0 +1,56 @@
+import { Model } from 'objection';
+// import TenantModel from 'models/TenantModel';
+import { BaseModel } from '@/models/Model';
+import { Bill } from '@/modules/Bills/models/Bill';
+import { BillPayment } from './BillPayment';
+
+export class BillPaymentEntry extends BaseModel {
+  public billPaymentId: number;
+  public billId: number;
+  public paymentAmount: number;
+  public index: number;
+
+  bill?: Bill;
+  payment?: BillPayment;
+
+  /**
+   * Table name
+   */
+  static get tableName() {
+    return 'bills_payments_entries';
+  }
+
+  /**
+   * Timestamps columns.
+   */
+  get timestamps() {
+    return [];
+  }
+
+  /**
+   * Relationship mapping.
+   */
+  static get relationMappings() {
+    const { Bill } = require('../../Bills/models/Bill');
+    const { BillPayment } = require('../../BillPayments/models/BillPayment');
+
+    return {
+      payment: {
+        relation: Model.BelongsToOneRelation,
+        modelClass: BillPayment,
+        join: {
+          from: 'bills_payments_entries.billPaymentId',
+          to: 'bills_payments.id',
+        },
+      },
+      bill: {
+        relation: Model.BelongsToOneRelation,
+        modelClass: Bill,
+        join: {
+          from: 'bills_payments_entries.billId',
+          to: 'bills.id',
+        },
+      },
+    };
+  }
+}

packages/server/src/modules/BillPayments/queries/BillPaymentEntry.transformer.ts

@@ -0,0 +1,27 @@
+import { BillTransformer } from "../../Bills/queries/Bill.transformer";
+import { Transformer } from "../../Transformer/Transformer";
+
+export class BillPaymentEntryTransformer extends Transformer{
+  /**
+   * Include these attributes to bill payment object.
+   * @returns {Array}
+   */
+  public includeAttributes = (): string[] => {
+    return ['paymentAmountFormatted', 'bill'];
+  };
+
+  /**
+   * Retreives the bill.
+   */
+  protected bill = (entry) => {
+    return this.item(entry.bill, new BillTransformer());
+  };
+
+  /**
+   * Retreives the payment amount formatted.
+   * @returns {string}
+   */
+  protected paymentAmountFormatted(entry) {
+    return this.formatNumber(entry.paymentAmount, { money: false });
+  }
+}

packages/server/src/modules/BillPayments/queries/BillPaymentTransactionTransformer.ts

@@ -0,0 +1,60 @@
+import { Transformer } from '@/modules/Transformer/Transformer';
+
+export class BillPaymentTransactionTransformer extends Transformer {
+  /**
+   * Include these attributes to sale credit note object.
+   * @returns {Array}
+   */
+  public includeAttributes = (): string[] => {
+    return ['formattedPaymentAmount', 'formattedPaymentDate'];
+  };
+
+  /**
+   * Retrieve formatted bill payment amount.
+   * @param {ICreditNote} credit
+   * @returns {string}
+   */
+  protected formattedPaymentAmount = (entry): string => {
+    return this.formatNumber(entry.paymentAmount, {
+      currencyCode: entry.payment.currencyCode,
+    });
+  };
+
+  /**
+   * Retrieve formatted bill payment date.
+   * @param entry
+   * @returns {string}
+   */
+  protected formattedPaymentDate = (entry): string => {
+    return this.formatDate(entry.payment.paymentDate);
+  };
+
+  /**
+   *
+   * @param entry
+   * @returns
+   */
+  public transform = (entry) => {
+    return {
+      billId: entry.billId,
+      billPaymentId: entry.billPaymentId,
+
+      paymentDate: entry.payment.paymentDate,
+      formattedPaymentDate: entry.formattedPaymentDate,
+
+      paymentAmount: entry.paymentAmount,
+      formattedPaymentAmount: entry.formattedPaymentAmount,
+      currencyCode: entry.payment.currencyCode,
+
+      paymentNumber: entry.payment.paymentNumber,
+      paymentReferenceNo: entry.payment.reference,
+
+      billNumber: entry.bill.billNumber,
+      billReferenceNo: entry.bill.referenceNo,
+
+      paymentAccountId: entry.payment.paymentAccountId,
+      paymentAccountName: entry.payment.paymentAccount.name,
+      paymentAccountSlug: entry.payment.paymentAccount.slug,
+    };
+  };
+}

packages/server/src/modules/BillPayments/queries/BillPaymentTransformer.ts

@@ -0,0 +1,65 @@
+import { BillPaymentEntryTransformer } from './BillPaymentEntry.transformer';
+import { Transformer } from '@/modules/Transformer/Transformer';
+import { BillPayment } from '../models/BillPayment';
+import { AttachmentTransformer } from '@/modules/Attachments/Attachment.transformer';
+
+export class BillPaymentTransformer extends Transformer {
+  /**
+   * Include these attributes to sale invoice object.
+   * @returns {Array}
+   */
+  public includeAttributes = (): string[] => {
+    return [
+      'formattedPaymentDate',
+      'formattedCreatedAt',
+      'formattedAmount',
+      'entries',
+      'attachments',
+    ];
+  };
+
+  /**
+   * Retrieve formatted invoice date.
+   * @param {IBill} invoice
+   * @returns {String}
+   */
+  protected formattedPaymentDate = (billPayment: BillPayment): string => {
+    return this.formatDate(billPayment.paymentDate);
+  };
+
+  /**
+   * Retrieve formatted created at date.
+   * @param {IBillPayment} billPayment
+   * @returns {string}
+   */
+  protected formattedCreatedAt = (billPayment: BillPayment): string => {
+    return this.formatDate(billPayment.createdAt);
+  };
+
+  /**
+   * Retrieve formatted bill amount.
+   * @param {IBill} invoice
+   * @returns {string}
+   */
+  protected formattedAmount = (billPayment: BillPayment): string => {
+    return this.formatNumber(billPayment.amount, {
+      currencyCode: billPayment.currencyCode,
+    });
+  };
+
+  /**
+   * Retreives the bill payment entries.
+   */
+  protected entries = (billPayment: BillPayment) => {
+    return this.item(billPayment.entries, new BillPaymentEntryTransformer());
+  };
+
+  /**
+   * Retrieves the bill attachments.
+   * @param {ISaleInvoice} invoice
+   * @returns
+   */
+  protected attachments = (billPayment: BillPayment) => {
+    return this.item(billPayment.attachments, new AttachmentTransformer());
+  };
+}

packages/server/src/modules/BillPayments/queries/GetBillPayment.service.ts

@@ -0,0 +1,38 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { TransformerInjectable } from '../../Transformer/TransformerInjectable.service';
+import { BillPayment } from '../models/BillPayment';
+import { BillPaymentTransformer } from './BillPaymentTransformer';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class GetBillPayment {
+  constructor(
+    private readonly transformer: TransformerInjectable,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+  ) {}
+
+  /**
+   * Retrieves bill payment.
+   * @param {number} billPyamentId
+   * @return {Promise<BillPayment>}
+   */
+  public async getBillPayment(billPyamentId: number): Promise<BillPayment> {
+    const billPayment = await this.billPaymentModel()
+      .query()
+      .withGraphFetched('entries.bill')
+      .withGraphFetched('vendor')
+      .withGraphFetched('paymentAccount')
+      .withGraphFetched('transactions')
+      .withGraphFetched('branch')
+      .withGraphFetched('attachments')
+      .findById(billPyamentId)
+      .throwIfNotFound();
+
+    return this.transformer.transform(
+      billPayment,
+      new BillPaymentTransformer(),
+    );
+  }
+}

packages/server/src/modules/BillPayments/queries/GetPaymentBills.service.ts

@@ -0,0 +1,36 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Bill } from '@/modules/Bills/models/Bill';
+import { BillPayment } from '../models/BillPayment';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class GetPaymentBills {
+  /**
+   * @param {typeof Bill} billModel
+   * @param {typeof BillPayment} billPaymentModel
+   */
+  constructor(
+    @Inject(Bill.name)
+    private readonly billModel: TenantModelProxy<typeof Bill>,
+
+    @Inject(BillPayment.name)
+    private readonly billPaymentModel: TenantModelProxy<typeof BillPayment>,
+  ) {}
+
+  /**
+   * Retrieve payment made associated bills.
+   * @param {number} billPaymentId - Bill payment id.
+   */
+  public async getPaymentBills(billPaymentId: number) {
+    const billPayment = await this.billPaymentModel()
+      .query()
+      .findById(billPaymentId)
+      .throwIfNotFound();
+
+    const paymentBillsIds = billPayment.entries.map((entry) => entry.id);
+
+    const bills = await this.billModel().query().whereIn('id', paymentBillsIds);
+
+    return bills;
+  }
+}

packages/server/src/modules/BillPayments/subscribers/BillPaymentGLEntriesSubscriber.ts

@@ -0,0 +1,60 @@
+import {
+  IBillPaymentEventCreatedPayload,
+  IBillPaymentEventDeletedPayload,
+  IBillPaymentEventEditedPayload,
+} from '../types/BillPayments.types';
+import { BillPaymentGLEntries } from '../commands/BillPaymentGLEntries';
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { events } from '@/common/events/events';
+
+@Injectable()
+export class BillPaymentGLEntriesSubscriber {
+  constructor(
+    private readonly billPaymentGLEntries: BillPaymentGLEntries,
+  ) {}
+
+  /**
+   * Handle bill payment writing journal entries once created.
+   */
+  @OnEvent(events.billPayment.onCreated)
+  private async handleWriteJournalEntries({
+    billPayment,
+    trx,
+  }: IBillPaymentEventCreatedPayload) {
+    // Records the journal transactions after bills payment
+    // and change diff account balance.
+    await this.billPaymentGLEntries.writePaymentGLEntries(
+      billPayment.id,
+      trx
+    );
+  };
+
+  /**
+   * Handle bill payment re-writing journal entries once the payment transaction be edited.
+   */
+  @OnEvent(events.billPayment.onEdited)
+  private async handleRewriteJournalEntriesOncePaymentEdited({
+    billPayment,
+    trx,
+  }: IBillPaymentEventEditedPayload) {
+    await this.billPaymentGLEntries.rewritePaymentGLEntries(
+      billPayment.id,
+      trx
+    );
+  };
+
+  /**
+   * Reverts journal entries once bill payment deleted.
+   */
+  @OnEvent(events.billPayment.onDeleted)
+  private async handleRevertJournalEntries({
+    billPaymentId,
+    trx,
+  }: IBillPaymentEventDeletedPayload) {
+    await this.billPaymentGLEntries.revertPaymentGLEntries(
+      billPaymentId,
+      trx
+    );
+  };
+}

packages/server/src/modules/BillPayments/types/BillPayments.types.ts

@@ -0,0 +1,64 @@
+import { Knex } from 'knex';
+import { BillPayment } from '../models/BillPayment';
+import { AttachmentLinkDTO } from '@/modules/Attachments/Attachments.types';
+import { CreateBillPaymentDto, EditBillPaymentDto } from '../dtos/BillPayment.dto';
+
+export interface IBillReceivePageEntry {
+  billId: number;
+  entryType: string;
+  billNo: string;
+  dueAmount: number;
+  amount: number;
+  totalPaymentAmount: number;
+  paymentAmount: number;
+  currencyCode: string;
+  date: Date | string;
+}
+
+export interface IBillPaymentEventCreatedPayload {
+  billPayment: BillPayment;
+  billPaymentDTO: CreateBillPaymentDto;
+  billPaymentId: number;
+  trx: Knex.Transaction;
+}
+
+export interface IBillPaymentCreatingPayload {
+  billPaymentDTO: CreateBillPaymentDto;
+  trx: Knex.Transaction;
+}
+
+export interface IBillPaymentEditingPayload {
+  billPaymentDTO: EditBillPaymentDto;
+  oldBillPayment: BillPayment;
+  trx: Knex.Transaction;
+}
+export interface IBillPaymentEventEditedPayload {
+  billPaymentId: number;
+  billPayment: BillPayment;
+  oldBillPayment: BillPayment;
+  billPaymentDTO: EditBillPaymentDto;
+  trx: Knex.Transaction;
+}
+
+export interface IBillPaymentEventDeletedPayload {
+  billPaymentId: number;
+  oldBillPayment: BillPayment;
+  trx: Knex.Transaction;
+}
+
+export interface IBillPaymentDeletingPayload {
+  oldBillPayment: BillPayment;
+  trx: Knex.Transaction;
+}
+
+export interface IBillPaymentPublishingPayload {
+  oldBillPayment: BillPayment;
+  trx: Knex.Transaction;
+}
+
+export enum IPaymentMadeAction {
+  Create = 'Create',
+  Edit = 'Edit',
+  Delete = 'Delete',
+  View = 'View',
+}