package com.mydreamjob.assessment;

import jakarta.persistence.*;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.data.annotation.CreatedDate;
import org.springframework.data.annotation.LastModifiedDate;
import org.springframework.data.jpa.domain.support.AuditingEntityListener;

import java.time.LocalDateTime;

/**
 * 答卷主记录（V34/V35）。
 *
 * <p>状态流转：DRAFT → IN_PROGRESS → COMPLETED。{@code samplingSeed} 用于抽题随机种子，
 * 持久化但不下发前端。{@code idempotencyKey} 与 {@code studentUserId} 联合唯一实现创建幂等。</p>
 */
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name = "assessment_attempts")
@EntityListeners(AuditingEntityListener.class)
public class AssessmentAttempt {

    public static final String STATUS_DRAFT = "DRAFT";
    public static final String STATUS_IN_PROGRESS = "IN_PROGRESS";
    public static final String STATUS_COMPLETED = "COMPLETED";
    public static final String STATUS_EXPIRED = "EXPIRED";

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

    @Column(name = "student_user_id", nullable = false)
    private Long studentUserId;

    @Column(name = "definition_id", nullable = false)
    private Long definitionId;

    @Column(nullable = false, length = 20)
    @Builder.Default
    private String status = STATUS_DRAFT;

    @Column(name = "sampling_seed")
    private Long samplingSeed;

    @Column(name = "question_set_version", nullable = false, length = 40)
    private String questionSetVersion;

    @Column(name = "selected_question_count", nullable = false)
    private Integer selectedQuestionCount;

    @Column(name = "answered_count", nullable = false)
    @Builder.Default
    private Integer answeredCount = 0;

    @Column(name = "idempotency_key", length = 64)
    private String idempotencyKey;

    /** 活跃答卷唯一键：DRAFT/IN_PROGRESS 非空，终态后置 NULL（数据库唯一约束保证同学生同类型仅一份活跃） */
    @Column(name = "active_key", length = 255)
    private String activeKey;

    @Version
    @Column(nullable = false)
    @Builder.Default
    private Long version = 0L;

    @Column(name = "started_at")
    private LocalDateTime startedAt;

    @Column(name = "submitted_at")
    private LocalDateTime submittedAt;

    @Column(name = "completed_at")
    private LocalDateTime completedAt;

    @CreatedDate
    @Column(name = "created_at", nullable = false, updatable = false)
    private LocalDateTime createdAt;

    @LastModifiedDate
    @Column(name = "updated_at", nullable = false)
    private LocalDateTime updatedAt;
}