use proper hydro license; add fluctuation

src/model/waterlevel.rs

@@ -17,6 +17,13 @@ pub struct Waterlevel {
     pub tumittel: i64,
 }
 
+#[derive(Debug, Serialize)]
+pub struct WaterlevelDay {
+    pub day: NaiveDate,
+    pub avg: i64,
+    pub fluctuation: i64,
+}
+
 pub struct Create {
     pub day: NaiveDate,
     pub time: String,
@@ -53,15 +60,28 @@ impl Waterlevel {
         Ok(())
     }
 
-    pub async fn max_waterlevel_for_day(db: &SqlitePool, day: NaiveDate) -> Option<i64> {
-        sqlx::query!(
-            "SELECT MAX(mittel) as max FROM waterlevel WHERE day = ?",
+    pub async fn max_waterlevel_for_day(db: &SqlitePool, day: NaiveDate) -> Option<WaterlevelDay> {
+        let waterlevel = sqlx::query_as!(
+            Waterlevel,
+            "SELECT id, day, time, max, min, mittel, tumax, tumin, tumittel FROM waterlevel WHERE day = ? ORDER BY mittel DESC LIMIT 1",
             day
         )
-        .fetch_one(db)
-        .await
-        .unwrap()
-        .max
+        .fetch_optional(db)
+        .await.unwrap();
+
+        if let Some(waterlevel) = waterlevel {
+            let max_diff = (waterlevel.mittel - waterlevel.max).abs();
+            let min_diff = (waterlevel.mittel - waterlevel.min).abs();
+            let fluctuation = max_diff.max(min_diff);
+
+            return Some(WaterlevelDay {
+                day: waterlevel.day,
+                avg: waterlevel.mittel,
+                fluctuation,
+            });
+        }
+
+        None
     }
 
     pub async fn delete_all(db: &mut Transaction<'_, Sqlite>) {