package com.paymentlink.model.entity;

import jakarta.persistence.*;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.time.LocalDateTime;

@Entity
@Table(name = "exchange_rates",
       indexes = @Index(name = "idx_currency_pair", columnList = "fromCurrency,toCurrency"))
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class ExchangeRate {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, length = 3)
    private String fromCurrency; // "USD"

    @Column(nullable = false, length = 3)
    private String toCurrency; // "EUR", "GBP", etc.

    @Column(nullable = false)
    private Double rate; // Exchange rate (e.g., 0.92 for USD to EUR)

    @Column(nullable = false)
    private LocalDateTime fetchedAt;

    @Column(nullable = false)
    private LocalDateTime expiresAt; // Cache for 1 hour

    // For load balancing - prevents duplicate refresh jobs
    @Version
    private Long version;
}