lab_resource_manager/application/usecases/
notify_resource_usage_changes.rs

1use crate::application::ApplicationError;
2use crate::domain::aggregates::resource_usage::entity::ResourceUsage;
3use crate::domain::ports::repositories::ResourceUsageRepository;
4use crate::domain::ports::{NotificationEvent, Notifier};
5use std::collections::HashMap;
6
7/// 未来および進行中のリソース使用状況の変更を監視し、通知するユースケース
8///
9/// このユースケースは以下の変更を検知して通知します:
10/// - 新規作成: 新しいリソース使用予約が追加された
11/// - 更新: 既存の予約内容が変更された
12/// - 削除: **未来の予約**がキャンセル/削除された
13///
14/// # スコープ
15/// このユースケースは「未来および進行中」のリソース使用のみを監視対象とします。
16/// 予約期間が終了したリソースは自然に監視対象外となり、削除通知は送信されません。
17pub struct NotifyFutureResourceUsageChangesUseCase<R, N>
18where
19    R: ResourceUsageRepository,
20    N: Notifier,
21{
22    repository: R,
23    notifier: N,
24    previous_state: tokio::sync::Mutex<HashMap<String, ResourceUsage>>,
25}
26
27impl<R, N> NotifyFutureResourceUsageChangesUseCase<R, N>
28where
29    R: ResourceUsageRepository,
30    N: Notifier,
31{
32    pub async fn new(repository: R, notifier: N) -> Result<Self, ApplicationError> {
33        let instance = Self {
34            repository,
35            notifier,
36            previous_state: tokio::sync::Mutex::new(HashMap::new()),
37        };
38
39        let current_usages = instance.fetch_current_usages().await?;
40        *instance.previous_state.lock().await = current_usages;
41
42        Ok(instance)
43    }
44
45    pub async fn poll_once(&self) -> Result<(), ApplicationError> {
46        let current_usages = self.fetch_current_usages().await?;
47        let mut previous_usages = self.previous_state.lock().await;
48
49        self.detect_and_notify_created_usages(&previous_usages, &current_usages)
50            .await?;
51        self.detect_and_notify_updated_usages(&previous_usages, &current_usages)
52            .await?;
53        self.detect_and_notify_deleted_usages(&previous_usages, &current_usages)
54            .await?;
55
56        *previous_usages = current_usages;
57
58        Ok(())
59    }
60
61    async fn fetch_current_usages(
62        &self,
63    ) -> Result<HashMap<String, ResourceUsage>, ApplicationError> {
64        let usages = self.repository.find_future().await?;
65        Ok(usages
66            .into_iter()
67            .map(|usage| (usage.id().as_str().to_string(), usage))
68            .collect())
69    }
70
71    async fn detect_and_notify_created_usages(
72        &self,
73        previous: &HashMap<String, ResourceUsage>,
74        current: &HashMap<String, ResourceUsage>,
75    ) -> Result<(), ApplicationError> {
76        for (id, usage) in current {
77            if !previous.contains_key(id) {
78                self.notify_created(usage.clone()).await?;
79            }
80        }
81        Ok(())
82    }
83
84    async fn detect_and_notify_updated_usages(
85        &self,
86        previous: &HashMap<String, ResourceUsage>,
87        current: &HashMap<String, ResourceUsage>,
88    ) -> Result<(), ApplicationError> {
89        for (id, current_usage) in current {
90            if let Some(previous_usage) = previous.get(id)
91                && previous_usage != current_usage
92            {
93                self.notify_updated(current_usage.clone()).await?;
94            }
95        }
96        Ok(())
97    }
98
99    async fn detect_and_notify_deleted_usages(
100        &self,
101        previous: &HashMap<String, ResourceUsage>,
102        current: &HashMap<String, ResourceUsage>,
103    ) -> Result<(), ApplicationError> {
104        let now = chrono::Utc::now();
105
106        // previousを現在時刻基準で「まだ未来」のものだけに絞る
107        // (currentと同じ時間軸に合わせることで、自然な期限切れを削除と誤検知しない)
108        let previous_still_future: HashMap<_, _> = previous
109            .iter()
110            .filter(|(_, usage)| usage.time_period().end() > now)
111            .collect();
112
113        // フィルタリング後のpreviousとcurrentを比較
114        for (id, usage) in previous_still_future {
115            if !current.contains_key(id) {
116                self.notify_deleted(usage.clone()).await?;
117            }
118        }
119        Ok(())
120    }
121
122    async fn notify_created(&self, usage: ResourceUsage) -> Result<(), ApplicationError> {
123        let event = NotificationEvent::ResourceUsageCreated(usage);
124        self.notifier.notify(event).await?;
125        Ok(())
126    }
127
128    async fn notify_updated(&self, usage: ResourceUsage) -> Result<(), ApplicationError> {
129        let event = NotificationEvent::ResourceUsageUpdated(usage);
130        self.notifier.notify(event).await?;
131        Ok(())
132    }
133
134    async fn notify_deleted(&self, usage: ResourceUsage) -> Result<(), ApplicationError> {
135        let event = NotificationEvent::ResourceUsageDeleted(usage);
136        self.notifier.notify(event).await?;
137        Ok(())
138    }
139}
lab_resource_manager/application/usecases/notify_resource_usage_changes.rs

lab_resource_manager/application/usecases/
notify_resource_usage_changes.rs
