package com.lincfusion.udyamlinc.features;

import jakarta.persistence.*;
import lombok.*;

import java.time.LocalDateTime;

/**
 * The feature catalogue. A row here is the contract for one engineered
 * indicator: what it means, what unit it carries, and how old it is allowed to
 * be before anything downstream may act on it.
 *
 * <p>{@code stalenessToleranceDays} is the column trip-wires read. A rule firing
 * on a three-week-old price is worse than no rule, and the tolerance is per
 * feature because a mandi price goes stale in days while a CBS extract is
 * monthly by design.
 */
@Entity
@Table(name = "feature_definition", indexes = @Index(name = "ix_feature_def_code", columnList = "code", unique = true))
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class FeatureDefinition {

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

    /** snake_case, matching the name a trip-wire expression uses. */
    @Column(nullable = false, unique = true, length = 48)
    private String code;

    @Column(nullable = false, length = 96)
    private String label;

    /** LIQUIDITY | BEHAVIOURAL | TREND_VOLATILITY | OBLIGATION_LOAD | EXTERNAL_SHOCK | QUALITY */
    @Column(nullable = false, length = 32)
    private String family;

    /** RATIO | PCT | DAYS | INDEX */
    @Column(length = 16)
    private String unit;

    /** Which upstream table it derives from — AGMARKNET, CLIMATE, LEDGER, CBS, UPI. */
    @Column(length = 32)
    private String sourceKind;

    /** Beyond this age the value must not be acted on. Null means it never goes stale. */
    private Integer stalenessToleranceDays;

    /** HIGHER_IS_WORSE | LOWER_IS_WORSE */
    @Column(length = 24)
    private String direction;

    @Column(length = 512)
    private String derivation;

    private Boolean active;

    private LocalDateTime updatedAt;

    @PrePersist
    @PreUpdate
    void stamp() {
        if (active == null) active = Boolean.TRUE;
        updatedAt = LocalDateTime.now();
    }
}