Add balancing capabilities

If payment are too unbalanced, it’s easier to make a transfer.

1 files changed, 19 insertions, 1 deletions

diff --git a/src/controller/balance.rs b/src/controller/balance.rs
index 309f15c..6cb937b 100644
--- a/src/controller/balance.rs
+++ b/src/controller/balance.rs
@@ -7,6 +7,7 @@ use crate::controller::utils;
 use crate::controller::wallet::Wallet;
 use crate::db;
 use crate::model::user::User;
+use crate::model::balancing::Balancing;
 use crate::payer;
 use crate::templates;
 
@@ -22,7 +23,10 @@ pub async fn get(wallet: &Wallet) -> Response<Full<Bytes>> {
         get_template_user_incomes(&users, &user_incomes);
     let total_income: i64 = user_incomes.values().sum();
 
-    let user_payments = db::payments::repartition(&wallet.db_conn).await;
+    let user_payments = with_balancing(
+        db::payments::repartition(&wallet.db_conn).await,
+        db::balancing::list(&wallet.db_conn).await
+    );
     let template_user_payments =
         get_template_user_payments(&users, &user_payments);
     let total_payments: i64 = user_payments.iter().map(|p| p.1).sum();
@@ -67,3 +71,17 @@ fn get_template_user_incomes(
     user_incomes.sort_by_key(|i| i.1);
     user_incomes
 }
+
+fn with_balancing(
+    user_payments: HashMap<i64, i64>,
+    balancings: Vec<Balancing>
+) -> HashMap<i64, i64> {
+    let mut user_payments = user_payments;
+    for balancing in balancings {
+        let src = user_payments.entry(balancing.source).or_insert(0);
+        *src += balancing.amount;
+        let dest = user_payments.entry(balancing.destination).or_insert(0);
+        *dest -= balancing.amount;
+    }
+    user_payments
+}