Purchase Service

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Overview

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Core Entities

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Compra

• id (Long) - Primary key
• serie (String) - Unique purchase series (auto-generated)
• numero (String) - Unique purchase number (auto-generated)
• descripcion (String) - Purchase description
• proveedorId (Long) - Supplier ID reference
• proveedor (Proveedor) - Supplier data (transient, from Supplier service)
• detalle (List<CompraDetalle>) - Purchase line items
• fechaCompra (LocalDateTime) - Purchase timestamp
• baseImponible (Double) - Taxable base amount
• igv (Double) - Tax amount (IGV)
• total (Double) - Total amount
• formapagoId (Long) - Payment method ID reference
• formaPago (FormaPago) - Payment method data (transient)

• @PrePersist - Calculates totals and generates serie/numero
• @PreUpdate - Recalculates totals

• Serie: 3 random uppercase letters (e.g., “XYZ”)
• Numero: 6-digit random number (e.g., “001234”)

• One-to-many with CompraDetalle via compra_id
• References Proveedor (external service)
• References FormaPago (external service)

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CompraDetalle

• id (Long) - Primary key
• cantidad (Integer) - Quantity purchased
• precioUnitario (Double) - Unit cost
• baseImponible (Double) - Line taxable base (auto-calculated)
• igv (Double) - Line tax amount (auto-calculated, 18%)
• total (Double) - Line total (auto-calculated)
• productoId (Long) - Product ID reference
• producto (Producto) - Product data (transient)

• Many-to-one with Compra via compra_id
• References Producto (from Catalog service)

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Key Components

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Controllers

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CompraController

• POST /compra - Create new purchase
• GET /compra - List all purchases
• GET /compra/{id} - Get purchase by ID
• PUT /compra/{id} - Update purchase
• DELETE /compra/{id} - Delete purchase
• GET /compra/buscar-por-fechas - Search by date range
• GET /compra/buscar/serie - Search by serie
• GET /compra/buscar/numero - Search by number
• GET /compra/buscar/serie-numero - Find by serie and number

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Services

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CompraService

• createCompra() - Create purchase with inventory updates
• getAllCompra() - List all purchases with supplier/payment data
• getCompraById() - Get purchase with full details
• updateCompra() - Update purchase
• deleteCompra() - Delete purchase
• buscarPorRangoFechas() - Date range search
• buscarPorSerie() - Serie search
• buscarPorNumero() - Number search
• buscarPorSerieYNumero() - Exact match search

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Repositories

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CompraRepository

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Feign Clients

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ProductoFeign

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ProveedorFeign

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FormaPagoFeign

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CategoriaFeign

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DTOs

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Transient DTOs (from other services)

• Producto - Product data from Catalog service
• Proveedor - Supplier data from Supplier service
• FormaPago - Payment method from Payment service
• Categoria - Category data from Catalog service

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Dependencies

• spring-boot-starter-data-jpa - JPA/Hibernate
• spring-boot-starter-web - REST API
• spring-boot-starter-validation - Bean validation
• spring-cloud-starter-netflix-eureka-client:4.0.3 - Service discovery
• spring-cloud-starter-config:4.0.4 - Centralized configuration
• spring-cloud-starter-openfeign - Feign client for microservice communication
• spring-cloud-starter-circuitbreaker-resilience4j - Circuit breaker pattern
• springdoc-openapi-starter-webmvc-ui:2.0.2 - OpenAPI/Swagger UI
• mysql-connector-j - MySQL driver
• lombok - Code generation

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Configuration

server:
  port: ${PORT:${SERVER_PORT:0}}

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/compra-ms
    username: root
    password: ""
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8090/eureka

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Database Schema

• compra - Purchase transaction header
  • Primary key: id
  • Unique constraints: serie, numero
  • Foreign keys: proveedor_id, formapago_id (references external services)
• compra_detalle - Purchase line items
  • Primary key: id
  • Foreign keys: compra_id → compra.id, producto_id (external)

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Business Logic

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Tax Calculation

• Base Imponible: Sum of line item bases (quantity × unit cost)
• IGV (Tax): 18% of base imponible
• Total: Base imponible + IGV

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Purchase Number Generation

• Serie: 3 random uppercase letters
• Numero: 6-digit zero-padded number
• Both are unique and auto-generated on creation

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Inventory Integration

1. Validates product existence via Catalog service
2. Processes purchase transaction
3. Increases product quantities in Catalog service (inventory replenishment)

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Key Features

• Complete purchase transaction management
• Automatic purchase numbering (serie/numero)
• Tax calculation (IGV at 18%)
• Multi-line item support
• Integration with Supplier, Product, and Payment services
• Purchase search and filtering by date range
• Serie/number-based lookup
• Circuit breaker for fault tolerance
• Inventory replenishment automation
• OpenAPI/Swagger documentation
• Eureka service discovery integration

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Integration Points

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Consumes:

• Catalog Service (ProductoFeign, CategoriaFeign) - Product data and inventory updates
• Supplier Service (ProveedorFeign) - Supplier information
• Payment Service (FormaPagoFeign) - Payment method details

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APIs Exposed:

• Purchase CRUD operations
• Purchase search and filtering
• Date range queries
• Serie/number lookup

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Comparison with Sales Service

• Inbound transactions (purchases from suppliers) vs outbound (sales to customers)
• Inventory increases vs decreases
• Supplier management vs customer management
• Similar document numbering (serie/numero)
• Identical tax calculation logic (18% IGV)