feat(plugin): timeseries 聚合 API — date_trunc 时间序列

crates/erp-plugin/src/data_service.rs

@@ -581,6 +581,52 @@ impl PluginDataService {
         // TODO: 未来版本添加 Redis 缓存层
         Self::aggregate(plugin_id, entity_name, tenant_id, db, group_by_field, filter).await
     }
+
+    /// 时间序列聚合 — 按时间字段截断为 day/week/month 统计计数
+    pub async fn timeseries(
+        plugin_id: Uuid,
+        entity_name: &str,
+        tenant_id: Uuid,
+        db: &sea_orm::DatabaseConnection,
+        time_field: &str,
+        time_grain: &str,
+        start: Option<String>,
+        end: Option<String>,
+    ) -> AppResult<Vec<crate::data_dto::TimeseriesItem>> {
+        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;
+
+        let (sql, values) = DynamicTableManager::build_timeseries_sql(
+            &info.table_name,
+            tenant_id,
+            time_field,
+            time_grain,
+            start.as_deref(),
+            end.as_deref(),
+        )
+        .map_err(|e| AppError::Validation(e))?;
+
+        #[derive(FromQueryResult)]
+        struct TsRow {
+            period: Option<String>,
+            count: i64,
+        }
+
+        let rows = TsRow::find_by_statement(Statement::from_sql_and_values(
+            sea_orm::DatabaseBackend::Postgres,
+            sql,
+            values,
+        ))
+        .all(db)
+        .await?;
+
+        Ok(rows
+            .into_iter()
+            .map(|r| crate::data_dto::TimeseriesItem {
+                period: r.period.unwrap_or_default(),
+                count: r.count,
+            })
+            .collect())
+    }
 }
 
 /// 从 plugins 表解析 manifest metadata.id（如 "erp-crm"）