nj/crates/erp-diary/src/service/notification_service.rs

// 通知服务 — 将日记事件转化为 SSE 推送通知
//
// 此服务监听日记模块的领域事件，通过 EventBus 发布通知事件，
// SSE handler (erp-message) 负责将通知推送给在线用户。

use sea_orm::DatabaseConnection;
use uuid::Uuid;

use erp_core::events::{DomainEvent, EventBus};

use crate::dto::{NotificationPayload, NotificationType};

/// 通知服务 — 将日记领域事件转化为 SSE 推送
pub struct NotificationService;

impl NotificationService {
    /// 评语创建通知
    ///
    /// 当老师点评日记后，通知学生收到新评语。
    pub async fn notify_comment_created(
        tenant_id: Uuid,
        student_id: Uuid,
        teacher_id: Uuid,
        comment_id: Uuid,
        journal_id: Uuid,
        content_preview: String,
        db: &DatabaseConnection,
        event_bus: &EventBus,
    ) {
        let payload = NotificationPayload {
            notification_type: NotificationType::CommentReceived,
            recipient_id: student_id,
            title: "收到新评语".to_string(),
            body: content_preview,
            business_id: Some(comment_id),
            extra: Some(serde_json::json!({
                "journal_id": journal_id,
                "teacher_id": teacher_id,
            })),
        };

        Self::publish_notification(tenant_id, payload, db, event_bus).await;
    }

    /// 主题布置通知
    ///
    /// 当老师布置新主题后，通知班级所有学生。
    pub async fn notify_topic_assigned(
        tenant_id: Uuid,
        class_id: Uuid,
        topic_id: Uuid,
        title: String,
        db: &DatabaseConnection,
        event_bus: &EventBus,
    ) {
        let payload = NotificationPayload {
            notification_type: NotificationType::TopicAssigned,
            recipient_id: Uuid::nil(), // 班级广播，SSE handler 按 class_id 过滤
            title: "新主题布置".to_string(),
            body: title,
            business_id: Some(topic_id),
            extra: Some(serde_json::json!({
                "class_id": class_id,
            })),
        };

        Self::publish_notification(tenant_id, payload, db, event_bus).await;
    }

    /// 成就解锁通知
    ///
    /// 当用户解锁成就后，通知该用户。
    pub async fn notify_achievement_unlocked(
        tenant_id: Uuid,
        user_id: Uuid,
        achievement_code: String,
        achievement_name: String,
        db: &DatabaseConnection,
        event_bus: &EventBus,
    ) {
        let payload = NotificationPayload {
            notification_type: NotificationType::AchievementUnlocked,
            recipient_id: user_id,
            title: "恭喜解锁新成就！".to_string(),
            body: format!("你解锁了「{}」成就", achievement_name),
            business_id: None,
            extra: Some(serde_json::json!({
                "achievement_code": achievement_code,
            })),
        };

        Self::publish_notification(tenant_id, payload, db, event_bus).await;
    }

    /// 发布通知事件到 EventBus
    ///
    /// 使用 `diary.notification` 作为事件类型前缀，
    /// SSE handler 可据此识别并推送给在线用户。
    async fn publish_notification(
        tenant_id: Uuid,
        payload: NotificationPayload,
        db: &DatabaseConnection,
        event_bus: &EventBus,
    ) {
        let event_type = match &payload.notification_type {
            NotificationType::CommentReceived => "diary.notification.comment",
            NotificationType::TopicAssigned => "diary.notification.topic",
            NotificationType::AchievementUnlocked => "diary.notification.achievement",
            NotificationType::ClassUpdate => "diary.notification.class_update",
        };

        event_bus
            .publish(
                DomainEvent::new(
                    event_type,
                    tenant_id,
                    serde_json::to_value(&payload).unwrap_or_default(),
                ),
                db,
            )
            .await;
    }
}