feat(nestjs): migrate to NestJS

packages/server/src/modules/Customers/CustomerGLEntries.ts

@@ -0,0 +1,117 @@
+// import { Service, Inject } from 'typedi';
+// import { AccountNormal, ICustomer, ILedgerEntry } from '@/interfaces';
+// import Ledger from '@/services/Accounting/Ledger';
+
+// @Service()
+// export class CustomerGLEntries {
+//   /**
+//    * Retrieves the customer opening balance common entry attributes.
+//    * @param {ICustomer} customer
+//    */
+//   private getCustomerOpeningGLCommonEntry = (customer: ICustomer) => {
+//     return {
+//       exchangeRate: customer.openingBalanceExchangeRate,
+//       currencyCode: customer.currencyCode,
+
+//       transactionType: 'CustomerOpeningBalance',
+//       transactionId: customer.id,
+
+//       date: customer.openingBalanceAt,
+//       userId: customer.userId,
+//       contactId: customer.id,
+
+//       credit: 0,
+//       debit: 0,
+
+//       branchId: customer.openingBalanceBranchId,
+//     };
+//   };
+
+//   /**
+//    * Retrieves the customer opening GL credit entry.
+//    * @param   {number} ARAccountId
+//    * @param   {ICustomer} customer
+//    * @returns {ILedgerEntry}
+//    */
+//   private getCustomerOpeningGLCreditEntry = (
+//     ARAccountId: number,
+//     customer: ICustomer
+//   ): ILedgerEntry => {
+//     const commonEntry = this.getCustomerOpeningGLCommonEntry(customer);
+
+//     return {
+//       ...commonEntry,
+//       credit: 0,
+//       debit: customer.localOpeningBalance,
+//       accountId: ARAccountId,
+//       accountNormal: AccountNormal.DEBIT,
+//       index: 1,
+//     };
+//   };
+
+//   /**
+//    * Retrieves the customer opening GL debit entry.
+//    * @param   {number} incomeAccountId
+//    * @param   {ICustomer} customer
+//    * @returns {ILedgerEntry}
+//    */
+//   private getCustomerOpeningGLDebitEntry = (
+//     incomeAccountId: number,
+//     customer: ICustomer
+//   ): ILedgerEntry => {
+//     const commonEntry = this.getCustomerOpeningGLCommonEntry(customer);
+
+//     return {
+//       ...commonEntry,
+//       credit: customer.localOpeningBalance,
+//       debit: 0,
+//       accountId: incomeAccountId,
+//       accountNormal: AccountNormal.CREDIT,
+
+//       index: 2,
+//     };
+//   };
+
+//   /**
+//    * Retrieves the customer opening GL entries.
+//    * @param   {number} ARAccountId
+//    * @param   {number} incomeAccountId
+//    * @param   {ICustomer} customer
+//    * @returns {ILedgerEntry[]}
+//    */
+//   public getCustomerOpeningGLEntries = (
+//     ARAccountId: number,
+//     incomeAccountId: number,
+//     customer: ICustomer
+//   ) => {
+//     const debitEntry = this.getCustomerOpeningGLDebitEntry(
+//       incomeAccountId,
+//       customer
+//     );
+//     const creditEntry = this.getCustomerOpeningGLCreditEntry(
+//       ARAccountId,
+//       customer
+//     );
+//     return [debitEntry, creditEntry];
+//   };
+
+//   /**
+//    * Retrieves the customer opening balance ledger.
+//    * @param   {number} ARAccountId
+//    * @param   {number} incomeAccountId
+//    * @param   {ICustomer} customer
+//    * @returns {ILedger}
+//    */
+//   public getCustomerOpeningLedger = (
+//     ARAccountId: number,
+//     incomeAccountId: number,
+//     customer: ICustomer
+//   ) => {
+//     const entries = this.getCustomerOpeningGLEntries(
+//       ARAccountId,
+//       incomeAccountId,
+//       customer
+//     );
+//     return new Ledger(entries);
+//   };
+// }

packages/server/src/modules/Customers/CustomerGLEntriesStorage.ts

@@ -0,0 +1,90 @@
+// import { Knex } from 'knex';
+// import LedgerStorageService from '@/services/Accounting/LedgerStorageService';
+// import HasTenancyService from '@/services/Tenancy/TenancyService';
+// import { Service, Inject } from 'typedi';
+// import { CustomerGLEntries } from './CustomerGLEntries';
+
+// @Service()
+// export class CustomerGLEntriesStorage {
+//   @Inject()
+//   private tenancy: HasTenancyService;
+
+//   @Inject()
+//   private ledegrRepository: LedgerStorageService;
+
+//   @Inject()
+//   private customerGLEntries: CustomerGLEntries;
+
+//   /**
+//    * Customer opening balance journals.
+//    * @param {number} tenantId
+//    * @param {number} customerId
+//    * @param {Knex.Transaction} trx
+//    */
+//   public writeCustomerOpeningBalance = async (
+//     tenantId: number,
+//     customerId: number,
+//     trx?: Knex.Transaction
+//   ) => {
+//     const { Customer } = this.tenancy.models(tenantId);
+//     const { accountRepository } = this.tenancy.repositories(tenantId);
+
+//     const customer = await Customer.query(trx).findById(customerId);
+
+//     // Finds the income account.
+//     const incomeAccount = await accountRepository.findOne({
+//       slug: 'other-income',
+//     });
+//     // Find or create the A/R account.
+//     const ARAccount = await accountRepository.findOrCreateAccountReceivable(
+//       customer.currencyCode,
+//       {},
+//       trx
+//     );
+//     // Retrieves the customer opening balance ledger.
+//     const ledger = this.customerGLEntries.getCustomerOpeningLedger(
+//       ARAccount.id,
+//       incomeAccount.id,
+//       customer
+//     );
+//     // Commits the ledger entries to the storage.
+//     await this.ledegrRepository.commit(tenantId, ledger, trx);
+//   };
+
+//   /**
+//    * Reverts the customer opening balance GL entries.
+//    * @param {number} tenantId
+//    * @param {number} customerId
+//    * @param {Knex.Transaction} trx
+//    */
+//   public revertCustomerOpeningBalance = async (
+//     tenantId: number,
+//     customerId: number,
+//     trx?: Knex.Transaction
+//   ) => {
+//     await this.ledegrRepository.deleteByReference(
+//       tenantId,
+//       customerId,
+//       'CustomerOpeningBalance',
+//       trx
+//     );
+//   };
+
+//   /**
+//    * Writes the customer opening balance GL entries.
+//    * @param {number} tenantId
+//    * @param {number} customerId
+//    * @param {Knex.Transaction} trx
+//    */
+//   public rewriteCustomerOpeningBalance = async (
+//     tenantId: number,
+//     customerId: number,
+//     trx?: Knex.Transaction
+//   ) => {
+//     // Reverts the customer opening balance entries.
+//     await this.revertCustomerOpeningBalance(tenantId, customerId, trx);
+
+//     // Write the customer opening balance entries.
+//     await this.writeCustomerOpeningBalance(tenantId, customerId, trx);    
+//   };
+// }

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

@@ -0,0 +1,59 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  Param,
+  Post,
+  Put,
+} from '@nestjs/common';
+import { CustomersApplication } from './CustomersApplication.service';
+import { ICustomerOpeningBalanceEditDTO } from './types/Customers.types';
+import { ApiOperation, ApiTags } from '@nestjs/swagger';
+import { CreateCustomerDto } from './dtos/CreateCustomer.dto';
+import { EditCustomerDto } from './dtos/EditCustomer.dto';
+
+@Controller('customers')
+@ApiTags('customers')
+export class CustomersController {
+  constructor(private customersApplication: CustomersApplication) {}
+
+  @Get(':id')
+  @ApiOperation({ summary: 'Retrieves the customer details.' })
+  getCustomer(@Param('id') customerId: number) {
+    return this.customersApplication.getCustomer(customerId);
+  }
+
+  @Post()
+  @ApiOperation({ summary: 'Create a new customer.' })
+  createCustomer(@Body() customerDTO: CreateCustomerDto) {
+    return this.customersApplication.createCustomer(customerDTO);
+  }
+
+  @Put(':id')
+  @ApiOperation({ summary: 'Edit the given customer.' })
+  editCustomer(
+    @Param('id') customerId: number,
+    @Body() customerDTO: EditCustomerDto,
+  ) {
+    return this.customersApplication.editCustomer(customerId, customerDTO);
+  }
+
+  @Delete(':id')
+  @ApiOperation({ summary: 'Delete the given customer.' })
+  deleteCustomer(@Param('id') customerId: number) {
+    return this.customersApplication.deleteCustomer(customerId);
+  }
+
+  @Put(':id/opening-balance')
+  @ApiOperation({ summary: 'Edit the opening balance of the given customer.' })
+  editOpeningBalance(
+    @Param('id') customerId: number,
+    @Body() openingBalanceDTO: ICustomerOpeningBalanceEditDTO,
+  ) {
+    return this.customersApplication.editOpeningBalance(
+      customerId,
+      openingBalanceDTO,
+    );
+  }
+}

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

@@ -0,0 +1,35 @@
+import { Module } from '@nestjs/common';
+import { TenancyContext } from '../Tenancy/TenancyContext.service';
+import { TenancyDatabaseModule } from '../Tenancy/TenancyDB/TenancyDB.module';
+import { TransformerInjectable } from '../Transformer/TransformerInjectable.service';
+import { ActivateCustomer } from './commands/ActivateCustomer.service';
+import { CreateCustomer } from './commands/CreateCustomer.service';
+import { CustomerValidators } from './commands/CustomerValidators.service';
+import { EditCustomer } from './commands/EditCustomer.service';
+import { EditOpeningBalanceCustomer } from './commands/EditOpeningBalanceCustomer.service';
+import { GetCustomerService } from './queries/GetCustomer.service';
+import { CreateEditCustomerDTO } from './commands/CreateEditCustomerDTO.service';
+import { CustomersController } from './Customers.controller';
+import { CustomersApplication } from './CustomersApplication.service';
+import { DeleteCustomer } from './commands/DeleteCustomer.service';
+
+@Module({
+  imports: [TenancyDatabaseModule],
+  controllers: [CustomersController],
+  providers: [
+    ActivateCustomer,
+    CreateCustomer,
+    CustomerValidators,
+    EditCustomer,
+    EditOpeningBalanceCustomer,
+    CustomerValidators,
+    CreateEditCustomerDTO,
+    GetCustomerService,
+    CustomersApplication,
+    DeleteCustomer,
+    TenancyContext,
+    TransformerInjectable,
+    GetCustomerService
+  ],
+})
+export class CustomersModule {}

packages/server/src/modules/Customers/CustomersApplication.service.ts

@@ -0,0 +1,86 @@
+import { Injectable } from '@nestjs/common';
+import { GetCustomerService } from './queries/GetCustomer.service';
+import { CreateCustomer } from './commands/CreateCustomer.service';
+import { EditCustomer } from './commands/EditCustomer.service';
+import { DeleteCustomer } from './commands/DeleteCustomer.service';
+import { EditOpeningBalanceCustomer } from './commands/EditOpeningBalanceCustomer.service';
+import { ICustomerOpeningBalanceEditDTO } from './types/Customers.types';
+import { CreateCustomerDto } from './dtos/CreateCustomer.dto';
+import { EditCustomerDto } from './dtos/EditCustomer.dto';
+
+@Injectable()
+export class CustomersApplication {
+  constructor(
+    private getCustomerService: GetCustomerService,
+    private createCustomerService: CreateCustomer,
+    private editCustomerService: EditCustomer,
+    private deleteCustomerService: DeleteCustomer,
+    private editOpeningBalanceService: EditOpeningBalanceCustomer,
+    // private getCustomersService: GetCustomers,
+  ) {}
+
+  /**
+   * Retrieves the given customer details.
+   * @param {number} tenantId
+   * @param {number} customerId
+   */
+  public getCustomer = (customerId: number) => {
+    return this.getCustomerService.getCustomer(customerId);
+  };
+
+  /**
+   * Creates a new customer.
+   * @param {ICustomerNewDTO} customerDTO
+   * @returns {Promise<ICustomer>}
+   */
+  public createCustomer = (customerDTO: CreateCustomerDto) => {
+    return this.createCustomerService.createCustomer(customerDTO);
+  };
+
+  /**
+   * Edits details of the given customer.
+   * @param {number} customerId - Customer id.
+   * @param {ICustomerEditDTO} customerDTO - Customer edit DTO.
+   * @return {Promise<ICustomer>}
+   */
+  public editCustomer = (customerId: number, customerDTO: EditCustomerDto) => {
+    return this.editCustomerService.editCustomer(customerId, customerDTO);
+  };
+
+  /**
+   * Deletes the given customer and associated transactions.
+   * @param {number} tenantId
+   * @param {number} customerId
+   * @param {ISystemUser} authorizedUser
+   * @returns {Promise<void>}
+   */
+  public deleteCustomer = (customerId: number) => {
+    return this.deleteCustomerService.deleteCustomer(customerId);
+  };
+
+  /**
+   * Changes the opening balance of the given customer.
+   * @param {number} tenantId
+   * @param {number} customerId
+   * @param {Date|string} openingBalanceEditDTO
+   * @returns {Promise<ICustomer>}
+   */
+  public editOpeningBalance = (
+    customerId: number,
+    openingBalanceEditDTO: ICustomerOpeningBalanceEditDTO,
+  ) => {
+    return this.editOpeningBalanceService.changeOpeningBalance(
+      customerId,
+      openingBalanceEditDTO,
+    );
+  };
+
+  /**
+   * Retrieve customers paginated list.
+   * @param {number} tenantId - Tenant id.
+   * @param {ICustomersFilter} filter - Cusotmers filter.
+   */
+  // public getCustomers = (filterDTO: ICustomersFilter) => {
+  // return this.getCustomersService.getCustomersList(filterDTO);
+  // };
+}

packages/server/src/modules/Customers/CustomersExportable.ts

@@ -0,0 +1,30 @@
+// import { Inject, Service } from 'typedi';
+// import { IItemsFilter } from '@/interfaces';
+// import { CustomersApplication } from './CustomersApplication';
+// import { Exportable } from '@/services/Export/Exportable';
+// import { EXPORT_SIZE_LIMIT } from '@/services/Export/constants';
+
+// @Service()
+// export class CustomersExportable extends Exportable {
+//   @Inject()
+//   private customersApplication: CustomersApplication;
+
+//   /**
+//    * Retrieves the accounts data to exportable sheet.
+//    * @param {number} tenantId
+//    * @returns
+//    */
+//   public exportable(tenantId: number, query: IItemsFilter) {
+//     const parsedQuery = {
+//       sortOrder: 'DESC',
+//       columnSortBy: 'created_at',
+//       ...query,
+//       page: 1,
+//       pageSize: EXPORT_SIZE_LIMIT,
+//     } as IItemsFilter;
+
+//     return this.customersApplication
+//       .getCustomers(tenantId, parsedQuery)
+//       .then((output) => output.customers);
+//   }
+// }

packages/server/src/modules/Customers/CustomersImportable.ts

@@ -0,0 +1,34 @@
+// import { Inject, Service } from 'typedi';
+// import { Importable } from '@/services/Import/Importable';
+// import { CreateCustomer } from './CRUD/CreateCustomer';
+// import { Knex } from 'knex';
+// import { ICustomer, ICustomerNewDTO } from '@/interfaces';
+// import { CustomersSampleData } from './_SampleData';
+
+// @Service()
+// export class CustomersImportable extends Importable {
+//   @Inject()
+//   private createCustomerService: CreateCustomer;
+
+//   /**
+//    * Mapps the imported data to create a new customer service.
+//    * @param {number} tenantId
+//    * @param {ICustomerNewDTO} createDTO
+//    * @param {Knex.Transaction} trx
+//    * @returns {Promise<void>}
+//    */
+//   public async importable(
+//     tenantId: number,
+//     createDTO: ICustomerNewDTO,
+//     trx?: Knex.Transaction<any, any[]>
+//   ): Promise<void> {
+//     await this.createCustomerService.createCustomer(tenantId, createDTO, trx);
+//   }
+
+//   /**
+//    * Retrieves the sample data of customers used to download sample sheet.
+//    */
+//   public sampleData(): any[] {
+//     return CustomersSampleData;
+//   }
+// }

packages/server/src/modules/Customers/_SampleData.ts

@@ -0,0 +1,158 @@
+
+export const CustomersSampleData = [
+  {
+    "Customer Type": "Business",
+    "First Name": "Nicolette",
+    "Last Name": "Schamberger",
+    "Company Name": "Homenick - Hane",
+    "Display Name": "Rowland Rowe",
+    "Email": "cicero86@yahoo.com",
+    "Personal Phone Number": "811-603-2235",
+    "Work Phone Number": "906-993-5190",
+    "Website": "http://google.com",
+    "Opening Balance": 54302.23,
+    "Opening Balance At": "2022-02-02",
+    "Opening Balance Ex. Rate": 2,
+    "Currency": "LYD",
+    "Active": "F",
+    "Note": "Doloribus autem optio temporibus dolores mollitia sit.",
+    "Billing Address 1": "862 Jessika Well",
+    "Billing Address 2": "1091 Dorthy Mount",
+    "Billing Address City": "Deckowfort",
+    "Billing Address Country": "Ghana",
+    "Billing Address Phone": "825-011-5207",
+    "Billing Address Postcode": "38228",
+    "Billing Address State": "Oregon",
+    "Shipping Address 1": "37626 Thiel Villages",
+    "Shipping Address 2": "132 Batz Avenue",
+    "Shipping Address City": "Pagacburgh",
+    "Shipping Address Country": "Albania",
+    "Shipping Address Phone": "171-546-3701",
+    "Shipping Address Postcode": "13709",
+    "Shipping Address State": "Georgia"
+  },
+  {
+    "Customer Type": "Business",
+    "First Name": "Hermann",
+    "Last Name": "Crooks",
+    "Company Name": "Veum - Schaefer",
+    "Display Name": "Harley Veum",
+    "Email": "immanuel56@hotmail.com",
+    "Personal Phone Number": "449-780-9999",
+    "Work Phone Number": "970-473-5785",
+    "Website": "http://google.com",
+    "Opening Balance": 54302.23,
+    "Opening Balance At": "2022-02-02",
+    "Opening Balance Ex. Rate": 2,
+    "Currency": "LYD",
+    "Active": "T",
+    "Note": "Doloribus dolore dolor dicta vitae in fugit nisi quibusdam.",
+    "Billing Address 1": "532 Simonis Spring",
+    "Billing Address 2": "3122 Nicolas Inlet",
+    "Billing Address City": "East Matteofort",
+    "Billing Address Country": "Holy See (Vatican City State)",
+    "Billing Address Phone": "366-084-8629",
+    "Billing Address Postcode": "41607",
+    "Billing Address State": "Montana",
+    "Shipping Address 1": "2889 Tremblay Plaza",
+    "Shipping Address 2": "71355 Kutch Isle",
+    "Shipping Address City": "D'Amorehaven",
+    "Shipping Address Country": "Monaco",
+    "Shipping Address Phone": "614-189-3328",
+    "Shipping Address Postcode": "09634-0435",
+    "Shipping Address State": "Nevada"
+  },
+  {
+    "Customer Type": "Business",
+    "First Name": "Nellie",
+    "Last Name": "Gulgowski",
+    "Company Name": "Boyle, Heller and Jones",
+    "Display Name": "Randall Kohler",
+    "Email": "anibal_frami@yahoo.com",
+    "Personal Phone Number": "498-578-0740",
+    "Work Phone Number": "394-550-6827",
+    "Website": "http://google.com",
+    "Opening Balance": 54302.23,
+    "Opening Balance At": "2022-02-02",
+    "Opening Balance Ex. Rate": 2,
+    "Currency": "LYD",
+    "Active": "T",
+    "Note": "Vero quibusdam rem fugit aperiam est modi.",
+    "Billing Address 1": "214 Sauer Villages",
+    "Billing Address 2": "30687 Kacey Square",
+    "Billing Address City": "Jayceborough",
+    "Billing Address Country": "Benin",
+    "Billing Address Phone": "332-820-1127",
+    "Billing Address Postcode": "16425-3887",
+    "Billing Address State": "Mississippi",
+    "Shipping Address 1": "562 Diamond Loaf",
+    "Shipping Address 2": "9595 Satterfield Trafficway",
+    "Shipping Address City": "Alexandrinefort",
+    "Shipping Address Country": "Puerto Rico",
+    "Shipping Address Phone": "776-500-8456",
+    "Shipping Address Postcode": "30258",
+    "Shipping Address State": "South Dakota"
+  },
+  {
+    "Customer Type": "Business",
+    "First Name": "Stone",
+    "Last Name": "Jerde",
+    "Company Name": "Cassin, Casper and Maggio",
+    "Display Name": "Clint McLaughlin",
+    "Email": "nathanael22@yahoo.com",
+    "Personal Phone Number": "562-790-6059",
+    "Work Phone Number": "686-838-0027",
+    "Website": "http://google.com",
+    "Opening Balance": 54302.23,
+    "Opening Balance At": "2022-02-02",
+    "Opening Balance Ex. Rate": 2,
+    "Currency": "LYD",
+    "Active": "F",
+    "Note": "Quis cumque molestias rerum.",
+    "Billing Address 1": "22590 Cathy Harbor",
+    "Billing Address 2": "24493 Brycen Brooks",
+    "Billing Address City": "Elnorashire",
+    "Billing Address Country": "Andorra",
+    "Billing Address Phone": "701-852-8005",
+    "Billing Address Postcode": "5680",
+    "Billing Address State": "Nevada",
+    "Shipping Address 1": "5355 Erdman Bridge",
+    "Shipping Address 2": "421 Jeanette Camp",
+    "Shipping Address City": "East Philip",
+    "Shipping Address Country": "Venezuela",
+    "Shipping Address Phone": "426-119-0858",
+    "Shipping Address Postcode": "34929-0501",
+    "Shipping Address State": "Tennessee"
+  },
+  {
+    "Customer Type": "Individual",
+    "First Name": "Lempi",
+    "Last Name": "Kling",
+    "Company Name": "Schamberger, O'Connell and Bechtelar",
+    "Display Name": "Alexie Barton",
+    "Email": "eulah.kreiger@hotmail.com",
+    "Personal Phone Number": "745-756-1063",
+    "Work Phone Number": "965-150-1945",
+    "Website": "http://google.com",
+    "Opening Balance": 54302.23,
+    "Opening Balance At": "2022-02-02",
+    "Opening Balance Ex. Rate": 2,
+    "Currency": "LYD",
+    "Active": "F",
+    "Note": "Maxime laboriosam hic voluptate maiores est officia.",
+    "Billing Address 1": "0851 Jones Flat",
+    "Billing Address 2": "845 Bailee Drives",
+    "Billing Address City": "Kamrenport",
+    "Billing Address Country": "Niger",
+    "Billing Address Phone": "220-125-0608",
+    "Billing Address Postcode": "30311",
+    "Billing Address State": "Delaware",
+    "Shipping Address 1": "929 Ferry Row",
+    "Shipping Address 2": "020 Adam Plaza",
+    "Shipping Address City": "West Carmellaside",
+    "Shipping Address Country": "Ghana",
+    "Shipping Address Phone": "053-333-6679",
+    "Shipping Address Postcode": "79221-4681",
+    "Shipping Address State": "Illinois"
+  }
+]

packages/server/src/modules/Customers/commands/ActivateCustomer.service.ts

@@ -0,0 +1,67 @@
+import { Knex } from 'knex';
+import { Inject, Injectable } from '@nestjs/common';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { CustomerValidators } from './CustomerValidators.service';
+import {
+  ICustomerActivatedPayload,
+  ICustomerActivatingPayload,
+} from '../types/Customers.types';
+import { Customer } from '@/modules/Customers/models/Customer';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { events } from '@/common/events/events';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class ActivateCustomer {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {CustomerValidators} validators - Customer validators service.
+   * @param {typeof Customer} customerModel - Customer model.
+   */
+  constructor(
+    private uow: UnitOfWork,
+    private eventPublisher: EventEmitter2,
+    private validators: CustomerValidators,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Inactive the given contact.
+   * @param {number} customerId - Customer id.
+   * @returns {Promise<void>}
+   */
+  public async activateCustomer(customerId: number): Promise<void> {
+    // Retrieves the customer or throw not found error.
+    const oldCustomer = await this.customerModel()
+      .query()
+      .findById(customerId)
+      .throwIfNotFound();
+
+    this.validators.validateNotAlreadyPublished(oldCustomer);
+
+    // Edits the given customer with associated transactions on unit-of-work environment.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onCustomerActivating` event.
+      await this.eventPublisher.emitAsync(events.customers.onActivating, {
+        trx,
+        oldCustomer,
+      } as ICustomerActivatingPayload);
+
+      // Update the given customer details.
+      const customer = await this.customerModel()
+        .query(trx)
+        .findById(customerId)
+        .updateAndFetchById(customerId, { active: true });
+
+      // Triggers `onCustomerActivated` event.
+      await this.eventPublisher.emitAsync(events.customers.onActivated, {
+        trx,
+        oldCustomer,
+        customer,
+      } as ICustomerActivatedPayload);
+    });
+  }
+}

packages/server/src/modules/Customers/commands/CreateCustomer.service.ts

@@ -0,0 +1,68 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import { CreateEditCustomerDTO } from './CreateEditCustomerDTO.service';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Customer } from '../models/Customer';
+import { events } from '@/common/events/events';
+import {
+  ICustomerEventCreatedPayload,
+  ICustomerEventCreatingPayload,
+} from '../types/Customers.types';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { CreateCustomerDto } from '../dtos/CreateCustomer.dto';
+
+@Injectable()
+export class CreateCustomer {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {CreateEditCustomerDTO} customerDTO - Customer DTO.
+   * @param {typeof Customer} customerModel - Customer model.
+   */
+  constructor(
+    private readonly uow: UnitOfWork,
+    private readonly eventPublisher: EventEmitter2,
+    private readonly customerDTO: CreateEditCustomerDTO,
+
+    @Inject(Customer.name)
+    private readonly customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Creates a new customer.
+   * @param  {ICustomerNewDTO} customerDTO
+   * @return {Promise<ICustomer>}
+   */
+  public async createCustomer(
+    customerDTO: CreateCustomerDto,
+    trx?: Knex.Transaction,
+  ): Promise<Customer> {
+    // Transformes the customer DTO to customer object.
+    const customerObj = await this.customerDTO.transformCreateDTO(customerDTO);
+
+    // Creates a new customer under unit-of-work envirement.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onCustomerCreating` event.
+      await this.eventPublisher.emitAsync(events.customers.onCreating, {
+        customerDTO,
+        trx,
+      } as ICustomerEventCreatingPayload);
+
+      // Creates a new contact as customer.
+      const customer = await this.customerModel()
+        .query(trx)
+        .insertAndFetch({
+          ...customerObj,
+        });
+      // Triggers `onCustomerCreated` event.
+      await this.eventPublisher.emitAsync(events.customers.onCreated, {
+        customer,
+        customerId: customer.id,
+        trx,
+      } as ICustomerEventCreatedPayload);
+
+      return customer;
+    }, trx);
+  }
+}

packages/server/src/modules/Customers/commands/CreateEditCustomerDTO.service.ts

@@ -0,0 +1,72 @@
+import * as moment from 'moment';
+import { defaultTo, omit, isEmpty } from 'lodash';
+import { Injectable } from '@nestjs/common';
+import { TenancyContext } from '@/modules/Tenancy/TenancyContext.service';
+import { ICustomerEditDTO, ICustomerNewDTO } from '../types/Customers.types';
+import { ContactService } from '@/modules/Contacts/types/Contacts.types';
+
+@Injectable()
+export class CreateEditCustomerDTO {
+  /**
+   * @param {TenancyContext} tenancyContext - Tenancy context service.
+   */
+  constructor(private readonly tenancyContext: TenancyContext) {}
+
+  /**
+   * Transformes the create/edit DTO.
+   * @param {ICustomerNewDTO | ICustomerEditDTO} customerDTO
+   * @returns
+   */
+  private transformCommonDTO = (
+    customerDTO: ICustomerNewDTO | ICustomerEditDTO,
+  ) => {
+    return {
+      ...omit(customerDTO, ['customerType']),
+      contactType: customerDTO.customerType,
+    };
+  };
+
+  /**
+   * Transformes the create DTO.
+   * @param {ICustomerNewDTO} customerDTO
+   * @returns {Promise<Partial<Customer>>}
+   */
+  public transformCreateDTO = async (customerDTO: ICustomerNewDTO) => {
+    const commonDTO = this.transformCommonDTO(customerDTO);
+
+    // Retrieves the tenant metadata.
+    const tenantMeta = await this.tenancyContext.getTenant(true);
+
+    return {
+      ...commonDTO,
+      currencyCode:
+        commonDTO.currencyCode || tenantMeta?.metadata?.baseCurrency,
+      active: defaultTo(customerDTO.active, true),
+      contactService: ContactService.Customer,
+      ...(!isEmpty(customerDTO.openingBalanceAt)
+        ? {
+            openingBalanceAt: moment(
+              customerDTO?.openingBalanceAt,
+            ).toMySqlDateTime(),
+          }
+        : {}),
+      openingBalanceExchangeRate: defaultTo(
+        customerDTO.openingBalanceExchangeRate,
+        1,
+      ),
+    };
+  };
+
+  /**
+   * Transformes the edit DTO.
+   * @param   {ICustomerEditDTO} customerDTO
+   * @returns
+   */
+  public transformEditDTO = (customerDTO: ICustomerEditDTO) => {
+    const commonDTO = this.transformCommonDTO(customerDTO);
+
+    return {
+      ...commonDTO,
+    };
+  };
+}

packages/server/src/modules/Customers/commands/CustomerValidators.service.ts

@@ -0,0 +1,17 @@
+import { ERRORS } from '../constants';
+import { Injectable } from '@nestjs/common';
+import { Customer } from '../models/Customer';
+import { ServiceError } from '@/modules/Items/ServiceError';
+
+@Injectable()
+export class CustomerValidators {
+  /**
+   * Validates the given customer is not already published.
+   * @param {ICustomer} customer
+   */
+  public validateNotAlreadyPublished = (customer: Customer) => {
+    if (customer.active) {
+      throw new ServiceError(ERRORS.CUSTOMER_ALREADY_ACTIVE);
+    }
+  };
+}

packages/server/src/modules/Customers/commands/DeleteCustomer.service.ts

@@ -0,0 +1,62 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import {
+  ICustomerDeletingPayload,
+  ICustomerEventDeletedPayload,
+} from '../types/Customers.types';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { Customer } from '../models/Customer';
+import { events } from '@/common/events/events';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class DeleteCustomer {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {typeof Customer} contactModel - Customer model.
+   */
+  constructor(
+    private uow: UnitOfWork,
+    private eventPublisher: EventEmitter2,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Deletes the given customer from the storage.
+   * @param {number} customerId - Customer ID.
+   * @return {Promise<void>}
+   */
+  public async deleteCustomer(customerId: number): Promise<void> {
+    // Retrieve the customer or throw not found service error.
+    const oldCustomer = await this.customerModel()
+      .query()
+      .findById(customerId)
+      .throwIfNotFound();
+    // .queryAndThrowIfHasRelations({
+    //   type: ERRORS.CUSTOMER_HAS_TRANSACTIONS,
+    // });
+
+    // Triggers `onCustomerDeleting` event.
+    await this.eventPublisher.emitAsync(events.customers.onDeleting, {
+      customerId,
+      oldCustomer,
+    } as ICustomerDeletingPayload);
+
+    // Deletes the customer and associated entities under UOW transaction.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Delete the customer from the storage.
+      await this.customerModel().query(trx).findById(customerId).delete();
+
+      // Throws `onCustomerDeleted` event.
+      await this.eventPublisher.emitAsync(events.customers.onDeleted, {
+        customerId,
+        oldCustomer,
+        trx,
+      } as ICustomerEventDeletedPayload);
+    });
+  }
+}

packages/server/src/modules/Customers/commands/EditCustomer.service.ts

@@ -0,0 +1,77 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import {
+  ICustomerEditDTO,
+  ICustomerEventEditedPayload,
+  ICustomerEventEditingPayload,
+} from '../types/Customers.types';
+import { CreateEditCustomerDTO } from './CreateEditCustomerDTO.service';
+import { Customer } from '../models/Customer';
+import { events } from '@/common/events/events';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+import { EditCustomerDto } from '../dtos/EditCustomer.dto';
+
+@Injectable()
+export class EditCustomer {
+  /**
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {CreateEditCustomerDTO} customerDTO - Customer DTO.
+   * @param {TenantModelProxy<typeof Customer>} contactModel - Customer model.
+   */
+  constructor(
+    private uow: UnitOfWork,
+    private eventPublisher: EventEmitter2,
+    private customerDTO: CreateEditCustomerDTO,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Edits details of the given customer.
+   * @param {number} customerId
+   * @param {ICustomerEditDTO} customerDTO
+   * @return {Promise<ICustomer>}
+   */
+  public async editCustomer(
+    customerId: number,
+    customerDTO: EditCustomerDto,
+  ): Promise<Customer> {
+    // Retrieve the customer or throw not found error.
+    const oldCustomer = await this.customerModel()
+      .query()
+      .findById(customerId)
+      .throwIfNotFound();
+
+    // Transforms the given customer DTO to object.
+    const customerObj = this.customerDTO.transformEditDTO(customerDTO);
+
+    // Edits the given customer under unit-of-work environment.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onCustomerEditing` event.
+      await this.eventPublisher.emitAsync(events.customers.onEditing, {
+        customerDTO,
+        customerId,
+        trx,
+      } as ICustomerEventEditingPayload);
+
+      // Edits the customer details on the storage.
+      const customer = await this.customerModel()
+        .query()
+        .updateAndFetchById(customerId, {
+          ...customerObj,
+        });
+      // Triggers `onCustomerEdited` event.
+      await this.eventPublisher.emitAsync(events.customers.onEdited, {
+        customerId,
+        customer,
+        trx,
+      } as ICustomerEventEditedPayload);
+
+      return customer;
+    });
+  }
+}

packages/server/src/modules/Customers/commands/EditOpeningBalanceCustomer.service.ts

@@ -0,0 +1,74 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Knex } from 'knex';
+import {
+  ICustomerOpeningBalanceEditDTO,
+  ICustomerOpeningBalanceEditedPayload,
+  ICustomerOpeningBalanceEditingPayload,
+} from '../types/Customers.types';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { UnitOfWork } from '@/modules/Tenancy/TenancyDB/UnitOfWork.service';
+import { Customer } from '../models/Customer';
+import { events } from '@/common/events/events';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class EditOpeningBalanceCustomer {
+  /**
+   * @param {EventEmitter2} eventPublisher - Event emitter service.
+   * @param {UnitOfWork} uow - Unit of work service.
+   * @param {typeof Customer} customerModel - Customer model.
+   */
+  constructor(
+    private eventPublisher: EventEmitter2,
+    private uow: UnitOfWork,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Changes the opening balance of the given customer.
+   * @param {number} customerId - Customer ID.
+   * @param {ICustomerOpeningBalanceEditDTO} openingBalanceEditDTO
+   */
+  public async changeOpeningBalance(
+    customerId: number,
+    openingBalanceEditDTO: ICustomerOpeningBalanceEditDTO,
+  ): Promise<Customer> {
+    // Retrieves the old customer or throw not found error.
+    const oldCustomer = await this.customerModel()
+      .query()
+      .findById(customerId)
+      .throwIfNotFound();
+
+    // Mutates the customer opening balance under unit-of-work.
+    return this.uow.withTransaction(async (trx: Knex.Transaction) => {
+      // Triggers `onCustomerOpeningBalanceChanging` event.
+      await this.eventPublisher.emitAsync(
+        events.customers.onOpeningBalanceChanging,
+        {
+          oldCustomer,
+          openingBalanceEditDTO,
+          trx,
+        } as ICustomerOpeningBalanceEditingPayload,
+      );
+      // Mutates the customer on the storage.
+      const customer = await this.customerModel()
+        .query()
+        .patchAndFetchById(customerId, {
+          ...openingBalanceEditDTO,
+        });
+      // Triggers `onCustomerOpeingBalanceChanged` event.
+      await this.eventPublisher.emitAsync(
+        events.customers.onOpeningBalanceChanged,
+        {
+          customer,
+          oldCustomer,
+          openingBalanceEditDTO,
+          trx,
+        } as ICustomerOpeningBalanceEditedPayload,
+      );
+      return customer;
+    });
+  }
+}

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

@@ -0,0 +1,27 @@
+export const DEFAULT_VIEW_COLUMNS = [];
+
+export const DEFAULT_VIEWS = [
+  {
+    name: 'Overdue',
+    slug: 'overdue',
+    rolesLogicExpression: '1',
+    roles: [
+      { index: 1, fieldKey: 'status', comparator: 'equals', value: 'overdue' },
+    ],
+    columns: DEFAULT_VIEW_COLUMNS,
+  },
+  {
+    name: 'Unpaid',
+    slug: 'unpaid',
+    rolesLogicExpression: '1',
+    roles: [
+      { index: 1, fieldKey: 'status', comparator: 'equals', value: 'unpaid' },
+    ],
+    columns: DEFAULT_VIEW_COLUMNS,
+  },
+];
+
+export const ERRORS = {
+  CUSTOMER_HAS_TRANSACTIONS: 'CUSTOMER_HAS_TRANSACTIONS',
+  CUSTOMER_ALREADY_ACTIVE: 'CUSTOMER_ALREADY_ACTIVE',
+};

packages/server/src/modules/Customers/dtos/ContactAddress.dto.ts

@@ -0,0 +1,84 @@
+import { IsEmail, IsOptional, IsString } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+
+export class ContactAddressDto {
+  @ApiProperty({ required: false, description: 'Billing address line 1' })
+  @IsOptional()
+  @IsString()
+  billingAddress1?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address line 2' })
+  @IsOptional()
+  @IsString()
+  billingAddress2?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address city' })
+  @IsOptional()
+  @IsString()
+  billingAddressCity?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address country' })
+  @IsOptional()
+  @IsString()
+  billingAddressCountry?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address email' })
+  @IsOptional()
+  @IsEmail()
+  billingAddressEmail?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address zipcode' })
+  @IsOptional()
+  @IsString()
+  billingAddressZipcode?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address phone' })
+  @IsOptional()
+  @IsString()
+  billingAddressPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Billing address state' })
+  @IsOptional()
+  @IsString()
+  billingAddressState?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address line 1' })
+  @IsOptional()
+  @IsString()
+  shippingAddress1?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address line 2' })
+  @IsOptional()
+  @IsString()
+  shippingAddress2?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address city' })
+  @IsOptional()
+  @IsString()
+  shippingAddressCity?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address country' })
+  @IsOptional()
+  @IsString()
+  shippingAddressCountry?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address email' })
+  @IsOptional()
+  @IsEmail()
+  shippingAddressEmail?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address zipcode' })
+  @IsOptional()
+  @IsString()
+  shippingAddressZipcode?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address phone' })
+  @IsOptional()
+  @IsString()
+  shippingAddressPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Shipping address state' })
+  @IsOptional()
+  @IsString()
+  shippingAddressState?: string;
+}

packages/server/src/modules/Customers/dtos/CreateCustomer.dto.ts

@@ -0,0 +1,100 @@
+import {
+  IsBoolean,
+  IsEmail,
+  IsNotEmpty,
+  IsNumber,
+  IsOptional,
+  IsString,
+} from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+import { ContactAddressDto } from './ContactAddress.dto';
+
+export class CreateCustomerDto extends ContactAddressDto {
+  @ApiProperty({ required: true, description: 'Customer type' })
+  @IsString()
+  @IsNotEmpty()
+  customerType: string;
+
+  @ApiProperty({ required: true, description: 'Currency code' })
+  @IsString()
+  @IsNotEmpty()
+  currencyCode: string;
+
+  @ApiProperty({ required: false, description: 'Opening balance' })
+  @IsOptional()
+  @IsNumber()
+  openingBalance?: number;
+
+  @ApiProperty({ required: false, description: 'Opening balance date' })
+  @IsOptional()
+  @IsString()
+  openingBalanceAt?: string;
+
+  @ApiProperty({
+    required: false,
+    description: 'Opening balance exchange rate',
+  })
+  @IsOptional()
+  @IsNumber()
+  openingBalanceExchangeRate?: number;
+
+  @ApiProperty({ required: false, description: 'Opening balance branch ID' })
+  @IsOptional()
+  @IsNumber()
+  openingBalanceBranchId?: number;
+
+  @ApiProperty({ required: false, description: 'Salutation' })
+  @IsOptional()
+  @IsString()
+  salutation?: string;
+
+  @ApiProperty({ required: false, description: 'First name' })
+  @IsOptional()
+  @IsString()
+  firstName?: string;
+
+  @ApiProperty({ required: false, description: 'Last name' })
+  @IsOptional()
+  @IsString()
+  lastName?: string;
+
+  @ApiProperty({ required: false, description: 'Company name' })
+  @IsOptional()
+  @IsString()
+  companyName?: string;
+
+  @ApiProperty({ required: true, description: 'Display name' })
+  @IsString()
+  @IsNotEmpty()
+  displayName: string;
+
+  @ApiProperty({ required: false, description: 'Website' })
+  @IsOptional()
+  @IsString()
+  website?: string;
+
+  @ApiProperty({ required: false, description: 'Email' })
+  @IsOptional()
+  @IsEmail()
+  email?: string;
+
+  @ApiProperty({ required: false, description: 'Work phone' })
+  @IsOptional()
+  @IsString()
+  workPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Personal phone' })
+  @IsOptional()
+  @IsString()
+  personalPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Note' })
+  @IsOptional()
+  @IsString()
+  note?: string;
+
+  @ApiProperty({ required: false, description: 'Active status', default: true })
+  @IsOptional()
+  @IsBoolean()
+  active?: boolean;
+}

packages/server/src/modules/Customers/dtos/EditCustomer.dto.ts

@@ -0,0 +1,65 @@
+import { IsBoolean, IsEmail, IsNotEmpty, IsOptional, IsString } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+import { ContactAddressDto } from './ContactAddress.dto';
+
+export class EditCustomerDto extends ContactAddressDto {
+  @ApiProperty({ required: true, description: 'Customer type' })
+  @IsString()
+  @IsNotEmpty()
+  customerType: string;
+
+  @ApiProperty({ required: false, description: 'Salutation' })
+  @IsOptional()
+  @IsString()
+  salutation?: string;
+
+  @ApiProperty({ required: false, description: 'First name' })
+  @IsOptional()
+  @IsString()
+  firstName?: string;
+
+  @ApiProperty({ required: false, description: 'Last name' })
+  @IsOptional()
+  @IsString()
+  lastName?: string;
+
+  @ApiProperty({ required: false, description: 'Company name' })
+  @IsOptional()
+  @IsString()
+  companyName?: string;
+
+  @ApiProperty({ required: true, description: 'Display name' })
+  @IsString()
+  @IsNotEmpty()
+  displayName: string;
+
+  @ApiProperty({ required: false, description: 'Website' })
+  @IsOptional()
+  @IsString()
+  website?: string;
+
+  @ApiProperty({ required: false, description: 'Email' })
+  @IsOptional()
+  @IsEmail()
+  email?: string;
+
+  @ApiProperty({ required: false, description: 'Work phone' })
+  @IsOptional()
+  @IsString()
+  workPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Personal phone' })
+  @IsOptional()
+  @IsString()
+  personalPhone?: string;
+
+  @ApiProperty({ required: false, description: 'Note' })
+  @IsOptional()
+  @IsString()
+  note?: string;
+
+  @ApiProperty({ required: false, description: 'Active status' })
+  @IsOptional()
+  @IsBoolean()
+  active?: boolean;
+}

packages/server/src/modules/Customers/models/Customer.ts

@@ -0,0 +1,216 @@
+import { TenantBaseModel } from '@/modules/System/models/TenantBaseModel';
+
+
+export class Customer extends TenantBaseModel{
+  contactService: string;
+  contactType: string;
+
+  balance: number;
+  currencyCode: string;
+
+  openingBalance: number;
+  openingBalanceAt: Date | string;
+  openingBalanceExchangeRate: number;
+  openingBalanceBranchId?: number;
+
+  salutation?: string;
+  firstName?: string;
+  lastName?: string;
+  companyName?: string;
+
+  displayName: string;
+
+  email?: string;
+  workPhone?: string;
+  personalPhone?: string;
+  website?: string;
+
+  billingAddress1?: string;
+  billingAddress2?: string;
+  billingAddressCity?: string;
+  billingAddressCountry?: string;
+  billingAddressEmail?: string;
+  billingAddressPostcode?: string;
+  billingAddressPhone?: string;
+  billingAddressState?: string;
+
+  shippingAddress1?: string;
+  shippingAddress2?: string;
+  shippingAddressCity?: string;
+  shippingAddressCountry?: string;
+  shippingAddressEmail?: string;
+  shippingAddressPostcode?: string;
+  shippingAddressPhone?: string;
+  shippingAddressState?: string;
+
+  note: string;
+  active: boolean;
+
+
+  /**
+   * Query builder.
+   */
+  // static get QueryBuilder() {
+  //   return CustomerQueryBuilder;
+  // }
+
+  /**
+   * Table name
+   */
+  static get tableName() {
+    return 'contacts';
+  }
+
+  /**
+   * Model timestamps.
+   */
+  get timestamps() {
+    return ['createdAt', 'updatedAt'];
+  }
+
+  /**
+   * Defined virtual attributes.
+   */
+  static get virtualAttributes() {
+    return ['localOpeningBalance', 'closingBalance', 'contactNormal'];
+  }
+
+  /**
+   * Closing balance attribute.
+   */
+  get closingBalance() {
+    return this.balance;
+  }
+
+  /**
+   * Retrieves the local opening balance.
+   * @returns {number}
+   */
+  get localOpeningBalance() {
+    return this.openingBalance
+      ? this.openingBalance * this.openingBalanceExchangeRate
+      : 0;
+  }
+
+  /**
+   * Retrieve the contact noraml;
+   */
+  get contactNormal() {
+    return 'debit';
+  }
+
+  /**
+   *
+   */
+  get contactAddresses() {
+    return [
+      {
+        mail: this.email,
+        label: this.displayName,
+        primary: true
+      },
+    ].filter((c) => c.mail);
+  }
+
+  /**
+   * Model modifiers.
+   */
+  static get modifiers() {
+    return {
+      /**
+       * Inactive/Active mode.
+       */
+      inactiveMode(query, active = false) {
+        query.where('active', !active);
+      },
+
+      /**
+       * Filters the active customers.
+       */
+      active(query) {
+        query.where('active', 1);
+      },
+      /**
+       * Filters the inactive customers.
+       */
+      inactive(query) {
+        query.where('active', 0);
+      },
+      /**
+       * Filters the customers that have overdue invoices.
+       */
+      overdue(query) {
+        query.select(
+          '*',
+          Customer.relatedQuery('overDueInvoices', query.knex())
+            .count()
+            .as('countOverdue')
+        );
+        query.having('countOverdue', '>', 0);
+      },
+      /**
+       * Filters the unpaid customers.
+       */
+      unpaid(query) {
+        query.whereRaw('`BALANCE` + `OPENING_BALANCE` <> 0');
+      },
+    };
+  }
+
+  /**
+   * Relationship mapping.
+   */
+  // static get relationMappings() {
+  //   const SaleInvoice = require('models/SaleInvoice');
+
+  //   return {
+  //     salesInvoices: {
+  //       relation: Model.HasManyRelation,
+  //       modelClass: SaleInvoice.default,
+  //       join: {
+  //         from: 'contacts.id',
+  //         to: 'sales_invoices.customerId',
+  //       },
+  //     },
+
+  //     overDueInvoices: {
+  //       relation: Model.HasManyRelation,
+  //       modelClass: SaleInvoice.default,
+  //       join: {
+  //         from: 'contacts.id',
+  //         to: 'sales_invoices.customerId',
+  //       },
+  //       filter: (query) => {
+  //         query.modify('overdue');
+  //       },
+  //     },
+  //   };
+  // }
+
+  // static get meta() {
+  //   return CustomerSettings;
+  // }
+
+  // /**
+  //  * Retrieve the default custom views, roles and columns.
+  //  */
+  // static get defaultViews() {
+  //   return DEFAULT_VIEWS;
+  // }
+
+  /**
+   * Model search attributes.
+   */
+  static get searchRoles() {
+    return [
+      { fieldKey: 'display_name', comparator: 'contains' },
+      { condition: 'or', fieldKey: 'first_name', comparator: 'contains' },
+      { condition: 'or', fieldKey: 'last_name', comparator: 'equals' },
+      { condition: 'or', fieldKey: 'company_name', comparator: 'equals' },
+      { condition: 'or', fieldKey: 'email', comparator: 'equals' },
+      { condition: 'or', fieldKey: 'work_phone', comparator: 'equals' },
+      { condition: 'or', fieldKey: 'personal_phone', comparator: 'equals' },
+      { condition: 'or', fieldKey: 'website', comparator: 'equals' },
+    ];
+  }
+}

packages/server/src/modules/Customers/queries/CustomerTransformer.ts

@@ -0,0 +1,38 @@
+import { ContactTransfromer } from "../../Contacts/Contact.transformer";
+
+export class CustomerTransfromer extends ContactTransfromer {
+  /**
+   * Include these attributes to expense object.
+   * @returns {Array}
+   */
+  public includeAttributes = (): string[] => {
+    return [
+      'formattedBalance',
+      'formattedOpeningBalance',
+      'formattedOpeningBalanceAt',
+      'customerType',
+      'formattedCustomerType',
+    ];
+  };
+
+  /**
+   * Retrieve customer type.
+   * @returns {string}
+   */
+  protected customerType = (customer): string => {
+    return customer.contactType;
+  };
+
+  /**
+   * Retrieve the formatted customer type.
+   * @param customer
+   * @returns {string}
+   */
+  protected formattedCustomerType = (customer): string => {
+    const keywords = {
+      individual: 'customer.type.individual',
+      business: 'customer.type.business',
+    };
+    return this.context.i18n.t(keywords[customer.contactType] || '');
+  };
+}

packages/server/src/modules/Customers/queries/GetCustomer.service.ts

@@ -0,0 +1,30 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { CustomerTransfromer } from './CustomerTransformer';
+import { TransformerInjectable } from '@/modules/Transformer/TransformerInjectable.service';
+import { Customer } from '../models/Customer';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class GetCustomerService {
+  constructor(
+    private transformer: TransformerInjectable,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Retrieve the given customer details.
+   * @param {number} customerId
+   */
+  public async getCustomer(customerId: number) {
+    // Retrieve the customer model or throw not found error.
+    const customer = await this.customerModel()
+      .query()
+      .findById(customerId)
+      .throwIfNotFound();
+
+    // Retrieves the transformered customers.
+    return this.transformer.transform(customer, new CustomerTransfromer());
+  }
+}

packages/server/src/modules/Customers/queries/GetCustomers.service.ts

@@ -0,0 +1,65 @@
+import { DynamicListService } from '@/modules/DynamicListing/DynamicList.service';
+import { TransformerInjectable } from '@/modules/Transformer/TransformerInjectable.service';
+import { Inject, Injectable } from '@nestjs/common';
+import * as R from 'ramda';
+import { Customer } from '../models/Customer';
+import { CustomerTransfromer } from './CustomerTransformer';
+import {
+  GetCustomersResponse,
+  ICustomersFilter,
+} from '../types/Customers.types';
+import { TenantModelProxy } from '@/modules/System/models/TenantBaseModel';
+
+@Injectable()
+export class GetCustomers {
+  constructor(
+    private dynamicListService: DynamicListService,
+    private transformer: TransformerInjectable,
+
+    @Inject(Customer.name)
+    private customerModel: TenantModelProxy<typeof Customer>,
+  ) {}
+
+  /**
+   * Parses customers list filter DTO.
+   * @param filterDTO -
+   */
+  private parseCustomersListFilterDTO(filterDTO) {
+    return R.compose(this.dynamicListService.parseStringifiedFilter)(filterDTO);
+  }
+
+  /**
+   * Retrieve customers paginated list.
+   * @param {ICustomersFilter} filter - Cusotmers filter.
+   * @returns {Promise<GetCustomersResponse>}
+   */
+  public async getCustomersList(
+    filterDTO: ICustomersFilter,
+  ): Promise<GetCustomersResponse> {
+    // Parses customers list filter DTO.
+    const filter = this.parseCustomersListFilterDTO(filterDTO);
+
+    const dynamicList = await this.dynamicListService.dynamicList(
+      this.customerModel(),
+      filter,
+    );
+    const { results, pagination } = await this.customerModel()
+      .query()
+      .onBuild((builder) => {
+        dynamicList.buildQuery()(builder);
+        builder.modify('inactiveMode', filter.inactiveMode);
+      })
+      .pagination(filter.page - 1, filter.pageSize);
+
+    // Retrieves the transformed customers.
+    const customers = await this.transformer.transform(
+      results,
+      new CustomerTransfromer(),
+    );
+    return {
+      customers,
+      pagination,
+      filterMeta: dynamicList.getResponseMeta(),
+    };
+  }
+}

packages/server/src/modules/Customers/subscribers/CustomerGLEntriesSubscriber.ts

@@ -0,0 +1,91 @@
+// import { Service, Inject } from 'typedi';
+// import {
+//   ICustomerEventCreatedPayload,
+//   ICustomerEventDeletedPayload,
+//   ICustomerOpeningBalanceEditedPayload,
+// } from '@/interfaces';
+// import events from '@/subscribers/events';
+// import { CustomerGLEntriesStorage } from '../CustomerGLEntriesStorage';
+
+// @Service()
+// export class CustomerWriteGLOpeningBalanceSubscriber {
+//   @Inject()
+//   private customerGLEntries: CustomerGLEntriesStorage;
+
+//   /**
+//    * Attaches events with handlers.
+//    */
+//   public attach(bus) {
+//     bus.subscribe(
+//       events.customers.onCreated,
+//       this.handleWriteOpenBalanceEntries
+//     );
+//     bus.subscribe(
+//       events.customers.onDeleted,
+//       this.handleRevertOpeningBalanceEntries
+//     );
+//     bus.subscribe(
+//       events.customers.onOpeningBalanceChanged,
+//       this.handleRewriteOpeningEntriesOnChanged
+//     );
+//   }
+
+//   /**
+//    * Handles the writing opening balance journal entries once the customer created.
+//    * @param {ICustomerEventCreatedPayload} payload -
+//    */
+//   private handleWriteOpenBalanceEntries = async ({
+//     tenantId,
+//     customer,
+//     trx,
+//   }: ICustomerEventCreatedPayload) => {
+//     // Writes the customer opening balance journal entries.
+//     if (customer.openingBalance) {
+//       await this.customerGLEntries.writeCustomerOpeningBalance(
+//         tenantId,
+//         customer.id,
+//         trx
+//       );
+//     }
+//   };
+
+//   /**
+//    * Handles the deleting opeing balance journal entrise once the customer deleted.
+//    * @param {ICustomerEventDeletedPayload} payload -
+//    */
+//   private handleRevertOpeningBalanceEntries = async ({
+//     tenantId,
+//     customerId,
+//     trx,
+//   }: ICustomerEventDeletedPayload) => {
+//     await this.customerGLEntries.revertCustomerOpeningBalance(
+//       tenantId,
+//       customerId,
+//       trx
+//     );
+//   };
+
+//   /**
+//    * Handles the rewrite opening balance entries once opening balnace changed.
+//    * @param {ICustomerOpeningBalanceEditedPayload} payload -
+//    */
+//   private handleRewriteOpeningEntriesOnChanged = async ({
+//     tenantId,
+//     customer,
+//     trx,
+//   }: ICustomerOpeningBalanceEditedPayload) => {
+//     if (customer.openingBalance) {
+//       await this.customerGLEntries.rewriteCustomerOpeningBalance(
+//         tenantId,
+//         customer.id,
+//         trx
+//       );
+//     } else {
+//       await this.customerGLEntries.revertCustomerOpeningBalance(
+//         tenantId,
+//         customer.id,
+//         trx
+//       );
+//     }
+//   };
+// }

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

@@ -0,0 +1,146 @@
+import { Knex } from 'knex';
+import { Customer } from '../models/Customer';
+import { IContactAddressDTO } from '@/modules/Contacts/types/Contacts.types';
+import { IDynamicListFilter } from '@/modules/DynamicListing/DynamicFilter/DynamicFilter.types';
+import { IFilterMeta, IPaginationMeta } from '@/interfaces/Model';
+import { CreateCustomerDto } from '../dtos/CreateCustomer.dto';
+import { EditCustomerDto } from '../dtos/EditCustomer.dto';
+
+// Customer Interfaces.
+// ----------------------------------
+export interface ICustomerNewDTO extends IContactAddressDTO {
+  customerType: string;
+
+  currencyCode: string;
+
+  openingBalance?: number;
+  openingBalanceAt?: string;
+  openingBalanceExchangeRate?: number;
+  openingBalanceBranchId?: number;
+
+  salutation?: string;
+  firstName?: string;
+  lastName?: string;
+  companyName?: string;
+  displayName: string;
+
+  website?: string;
+  email?: string;
+  workPhone?: string;
+  personalPhone?: string;
+
+  note?: string;
+  active?: boolean;
+}
+
+export interface ICustomerEditDTO extends IContactAddressDTO {
+  customerType: string;
+
+  salutation?: string;
+  firstName?: string;
+  lastName?: string;
+  companyName?: string;
+  displayName: string;
+
+  website?: string;
+  email?: string;
+  workPhone?: string;
+  personalPhone?: string;
+
+  note?: string;
+  active?: boolean;
+}
+
+export interface ICustomersFilter extends IDynamicListFilter {
+  stringifiedFilterRoles?: string;
+  page?: number;
+  pageSize?: number;
+}
+
+export interface GetCustomersResponse {
+  customers: Customer[];
+  pagination: IPaginationMeta;
+  filterMeta: IFilterMeta;
+}
+// Customer Events.
+// ----------------------------------
+export interface ICustomerEventCreatedPayload {
+  customerId: number;
+  customer: Customer;
+  trx: Knex.Transaction;
+}
+export interface ICustomerEventCreatingPayload {
+  customerDTO: CreateCustomerDto;
+  trx: Knex.Transaction;
+}
+export interface ICustomerEventEditedPayload {
+  customerId: number;
+  customer: Customer;
+  trx: Knex.Transaction;
+}
+
+export interface ICustomerEventEditingPayload {
+  customerDTO: EditCustomerDto;
+  customerId: number;
+  trx: Knex.Transaction;
+}
+
+export interface ICustomerDeletingPayload {
+  customerId: number;
+  oldCustomer: Customer;
+}
+
+export interface ICustomerEventDeletedPayload {
+  customerId: number;
+  oldCustomer: Customer;
+  trx: Knex.Transaction;
+}
+export interface ICustomerEventCreatingPayload {
+  customerDTO: CreateCustomerDto;
+  trx: Knex.Transaction;
+}
+export enum CustomerAction {
+  Create = 'Create',
+  Edit = 'Edit',
+  Delete = 'Delete',
+  View = 'View',
+}
+
+export enum VendorAction {
+  Create = 'Create',
+  Edit = 'Edit',
+  Delete = 'Delete',
+  View = 'View',
+}
+
+export interface ICustomerOpeningBalanceEditDTO {
+  openingBalance: number;
+  openingBalanceAt: Date | string;
+  openingBalanceExchangeRate: number;
+  openingBalanceBranchId?: number;
+}
+
+export interface ICustomerOpeningBalanceEditingPayload {
+  oldCustomer: Customer;
+  openingBalanceEditDTO: ICustomerOpeningBalanceEditDTO;
+  trx?: Knex.Transaction;
+}
+
+export interface ICustomerOpeningBalanceEditedPayload {
+  customer: Customer;
+  oldCustomer: Customer;
+  openingBalanceEditDTO: ICustomerOpeningBalanceEditDTO;
+  trx: Knex.Transaction;
+}
+
+
+export interface ICustomerActivatingPayload {
+  trx: Knex.Transaction,
+  oldCustomer: Customer;
+}
+
+export interface ICustomerActivatedPayload {
+  trx?: Knex.Transaction;
+  oldCustomer: Customer;
+  customer: Customer;
+}