task-085: displays running balances

2 files changed, 41 insertions, 14 deletions

diff --git a/schist_desktop_gui/src/gui/components/transactions_view.rs b/schist_desktop_gui/src/gui/components/transactions_view.rs
index 11249a1..27e18cd 100644
--- a/schist_desktop_gui/src/gui/components/transactions_view.rs
+++ b/schist_desktop_gui/src/gui/components/transactions_view.rs
@@ -1,6 +1,6 @@
 mod view_transactions_view;
 
-use std::collections::HashMap;
+use std::{collections::HashMap, mem::transmute};
 
 use itertools::Itertools;
 use schist_models::{Account, Bucket, Transaction};
@@ -12,6 +12,7 @@ use crate::{
 
 #[derive(Clone, Debug)]
 pub struct TransactionsView {
+    account_balances_by_transaction_id: HashMap<i32, i32>,
     buckets: Vec<Bucket>,
     navigation: Navigation<AccountNavigationEntry>,
     transactions_by_account_id: HashMap<i32, Vec<Transaction>>,
@@ -42,13 +43,30 @@ impl TransactionsView {
             account_navigation_entries.first().cloned(),
             account_navigation_entries,
         );
-        Self {
+        let mut transactions_view = Self {
+            account_balances_by_transaction_id: HashMap::with_capacity(transactions.len()),
             buckets: buckets.to_vec(),
             navigation: navigation,
-            transactions_by_account_id: transactions
-                .into_iter()
-                .cloned()
-                .into_group_map_by(|t| t.account_id),
+            transactions_by_account_id: HashMap::with_capacity(accounts.len()),
+        };
+        transactions_view.set_transactions(transactions);
+        transactions_view
+    }
+
+    fn set_transactions(&mut self, transactions: &[Transaction]) {
+        self.transactions_by_account_id = transactions
+            .into_iter()
+            .cloned()
+            .into_group_map_by(|t| t.account_id);
+        self.account_balances_by_transaction_id = HashMap::new();
+        for entry in self.transactions_by_account_id.iter_mut() {
+            entry.1.sort_by(|t1, t2| t2.date.cmp(&t1.date));
+            let mut running_balance = 0;
+            for transaction in entry.1.iter().rev() {
+                running_balance += transaction.amount;
+                self.account_balances_by_transaction_id
+                    .insert(transaction.id, running_balance);
+            }
         }
     }
 }
@@ -72,8 +90,7 @@ impl<'a> Component<'a, Message, Action> for TransactionsView {
             }
 
             Message::SetTransactions(transactions) => {
-                self.transactions_by_account_id =
-                    transactions.into_iter().into_group_map_by(|t| t.account_id);
+                self.set_transactions(&transactions);
                 Action::None
             }
 
diff --git a/schist_desktop_gui/src/gui/components/transactions_view/view_transactions_view.rs b/schist_desktop_gui/src/gui/components/transactions_view/view_transactions_view.rs
index f43ee48..4f61493 100644
--- a/schist_desktop_gui/src/gui/components/transactions_view/view_transactions_view.rs
+++ b/schist_desktop_gui/src/gui/components/transactions_view/view_transactions_view.rs
@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use iced::{
     alignment,
     widget::{
@@ -38,7 +40,7 @@ impl<'a> Viewable<'a, Message> for TransactionsView {
             ),
             column(
                 Text::default("Balance").width(iced::Length::Fixed(96.0)),
-                |_t: Transaction| view_balance_cell(),
+                |t: Transaction| view_balance_cell(t, &self.account_balances_by_transaction_id),
             ),
         ];
 
@@ -106,9 +108,17 @@ fn view_quantity_cell(t: Transaction) -> Text {
         .align_right()
 }
 
-fn view_balance_cell() -> Text {
-    Text::default("TODO")
-        .width(iced::Length::Fixed(96.0))
-        .small()
-        .clip()
+fn view_balance_cell(
+    transaction: Transaction,
+    account_balances_by_transaction_id: &HashMap<i32, i32>,
+) -> Text {
+    (account_balances_by_transaction_id
+        .get(&transaction.id)
+        .map_or_else(
+            || Text::default("Error").danger(),
+            |&balance| Text::currency(balance),
+        ))
+    .width(iced::Length::Fixed(96.0))
+    .small()
+    .clip()
 }