add new api: nearest

.sqlx/query-f9d7de7f6e5e6297a3e80a4748d730def5c5236bdcc704b89abc0a1dca24f13e.json

@@ -0,0 +1,29 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n        SELECT \n            id,\n            data_time\n        FROM data_ingestion\n        WHERE source = $1\n        ORDER BY ABS(EXTRACT(EPOCH FROM (data_time - $2)))\n        LIMIT 1\n        ",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "data_time",
+        "type_info": "Timestamp"
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Text",
+        "Timestamp"
+      ]
+    },
+    "nullable": [
+      false,
+      false
+    ]
+  },
+  "hash": "f9d7de7f6e5e6297a3e80a4748d730def5c5236bdcc704b89abc0a1dca24f13e"
+}

src/app.rs

@@ -1,4 +1,4 @@
-use axum::{Error, response::Response};
+use axum::{Error, Json, response::Response};
 use std::num::NonZero;
 
 use crate::{
@@ -48,6 +48,7 @@ pub async fn create_router(config: &Config) -> Router {
     Router::new()
         .route("/api/v1/health", get(health_handler))
         .route("/api/v1/data", get(data_handler))
+        .route("/api/v1/data/nearest", get(data_nearest_handler))
         .layer(CorsLayer::permissive())
         .with_state(app_state)
 }
@@ -173,6 +174,35 @@ async fn data_handler(
     }
 }
 
+async fn data_nearest_handler(
+    Query(params): Query<TileInfo>,
+    State(mut state): State<AppState>,
+) -> impl IntoResponse {
+    match chrono::NaiveDateTime::parse_from_str(&params.datetime, "%Y%m%d%H%M%S") {
+        Ok(naive_datetime) => {
+            let datetime = naive_datetime.and_utc();
+            let area = params.area.unwrap_or_default();
+
+            match state.service.get_nearest_tile_data(datetime, &area).await {
+                Ok(tile_response) => (StatusCode::OK, Json(tile_response)).into_response(),
+                Err(e) => (
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    format!("数据库错误: {:?}", e),
+                )
+                    .into_response(),
+            }
+        }
+        Err(e) => {
+            // 返回400错误状态码
+            (
+                StatusCode::BAD_REQUEST,
+                format!("日期格式错误: {}. 期望格式: YYYYMMDDHHMMSS", e),
+            )
+                .into_response()
+        }
+    }
+}
+
 async fn download_image(url: &str) -> Result<(Vec<u8>, String), Box<dyn std::error::Error>> {
     let client = reqwest::Client::new();
     let response = client.get(url).send().await?;

src/model/responses.rs

@@ -11,6 +11,12 @@ pub struct TileResponse {
     pub storage_url: String,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct NearestTileResponse {
+    pub id: Uuid,
+    pub nearest_data_time: DateTime<Utc>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ImageInfo {
     pub url: String,

src/service/mod.rs

@@ -1,4 +1,4 @@
-use crate::model::responses::TileResponse;
+use crate::model::responses::{NearestTileResponse, TileResponse};
 use axum::Error;
 use chrono::{DateTime, Utc};
 use sqlx::PgPool;
@@ -52,4 +52,38 @@ impl Service {
             ))),
         }
     }
+
+    pub async fn get_nearest_tile_data(
+        &self,
+        datetime: DateTime<Utc>,
+        area: &str,
+    ) -> Result<NearestTileResponse, Error> {
+        let primitive_datetime = datetime.format("%Y%m%d%H%M%S").to_string();
+
+        // 查找距离指定 datetime 最近的数据
+        let record = sqlx::query!(
+            r#"
+        SELECT 
+            id,
+            data_time
+        FROM data_ingestion
+        WHERE source = $1
+        ORDER BY ABS(EXTRACT(EPOCH FROM (data_time - $2)))
+        LIMIT 1
+        "#,
+            area,
+            datetime.naive_utc()
+        )
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(|e| Error::new(format!("Database error: {}", e)))?;
+
+        match record {
+            Some(row) => Ok(NearestTileResponse {
+                id: row.id,
+                nearest_data_time: row.data_time.and_utc(),
+            }),
+            None => Err(Error::new(format!("No tile data found for area: {}", area))),
+        }
+    }
 }