Refactors importer to use core stuff

29 files changed, 22 insertions, 635 deletions

diff --git a/backend/app/src/queries/accounts/get_all.rs b/backend/app/src/queries/accounts/get_all.rs
deleted file mode 100644
index bc67f77..0000000
--- a/backend/app/src/queries/accounts/get_all.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-use budgeting_app_core::{models::account::Account, schema::accounts::dsl::accounts};
-use diesel::{result::Error, QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
-
-pub fn get_all_accounts(connection: &mut SqliteConnection) -> Result<Vec<Account>, Error> {
-    accounts.select(Account::as_select()).load(connection)
-}
diff --git a/backend/app/src/queries/accounts/insert.rs b/backend/app/src/queries/accounts/insert.rs
deleted file mode 100644
index 1d1a323..0000000
--- a/backend/app/src/queries/accounts/insert.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-use budgeting_app_core::{
-    models::account::Account,
-    schema::accounts::dsl::accounts as accounts_table,
-};
-use diesel::prelude::*;
-use diesel::result::Error;
-
-pub fn insert_account(
-    accounts: &[Account],
-    connection: &mut SqliteConnection,
-) -> Result<usize, Error> {
-    diesel::insert_into(accounts_table)
-        .values(accounts)
-        .execute(connection)
-}
diff --git a/backend/app/src/queries/accounts/mod.rs b/backend/app/src/queries/accounts/mod.rs
deleted file mode 100644
index 94fa360..0000000
--- a/backend/app/src/queries/accounts/mod.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-mod get_all;
-mod insert;
-
-pub use get_all::get_all_accounts;
-pub use insert::insert_account;
diff --git a/backend/app/src/queries/budget_updates/get_all.rs b/backend/app/src/queries/budget_updates/get_all.rs
deleted file mode 100644
index e6e4b59..0000000
--- a/backend/app/src/queries/budget_updates/get_all.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-use budgeting_app_core::{
-    models::budget_update::BudgetUpdate,
-    schema::budget_updates::dsl::budget_updates as budget_updates_table,
-};
-use diesel::{result::Error, QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
-
-pub fn get_all_budget_updates(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<BudgetUpdate>, Error> {
-    budget_updates_table
-        .select(BudgetUpdate::as_select())
-        .load::<BudgetUpdate>(connection)
-}
diff --git a/backend/app/src/queries/budget_updates/get_first_with_date.rs b/backend/app/src/queries/budget_updates/get_first_with_date.rs
deleted file mode 100644
index 3856557..0000000
--- a/backend/app/src/queries/budget_updates/get_first_with_date.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-use budgeting_app_core::{
-    models::budget_update::BudgetUpdate,
-    schema::budget_updates::{
-        self as budget_updates_schema, dsl::budget_updates as budget_updates_table,
-    },
-};
-use diesel::{
-    result::Error, ExpressionMethods, QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection,
-};
-
-pub fn get_first_budget_update_with_date(
-    date: &str,
-    connection: &mut SqliteConnection,
-) -> Result<BudgetUpdate, Error> {
-    budget_updates_table
-        .select(BudgetUpdate::as_select())
-        .filter(budget_updates_schema::date.eq(date))
-        .first(connection)
-}
diff --git a/backend/app/src/queries/budget_updates/get_most_recent_with_category_id.rs b/backend/app/src/queries/budget_updates/get_most_recent_with_category_id.rs
deleted file mode 100644
index 55012f5..0000000
--- a/backend/app/src/queries/budget_updates/get_most_recent_with_category_id.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-use budgeting_app_core::{
-    models::date_time_utc::DateTimeUtc,
-    schema::budget_updates::{
-        self as budget_updates_schema, dsl::budget_updates as budget_updates_table,
-    },
-};
-use diesel::{dsl::max, result::Error, ExpressionMethods, QueryDsl, RunQueryDsl, SqliteConnection};
-
-pub fn get_most_recent_budget_update_date_with_category_id(
-    category_id: i32,
-    connection: &mut SqliteConnection,
-) -> Result<Option<String>, Error> {
-    budget_updates_table
-        .select(max(budget_updates_schema::date))
-        .filter(budget_updates_schema::category_id.eq(category_id))
-        .filter(budget_updates_schema::date.le(DateTimeUtc::now().to_day_str()))
-        .first(connection)
-}
diff --git a/backend/app/src/queries/budget_updates/mod.rs b/backend/app/src/queries/budget_updates/mod.rs
deleted file mode 100644
index 3b514dd..0000000
--- a/backend/app/src/queries/budget_updates/mod.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-mod get_all;
-mod get_first_with_date;
-mod get_most_recent_with_category_id;
-
-pub use get_all::get_all_budget_updates;
-pub use get_first_with_date::get_first_budget_update_with_date;
-pub use get_most_recent_with_category_id::get_most_recent_budget_update_date_with_category_id;
diff --git a/backend/app/src/queries/categories/get_all.rs b/backend/app/src/queries/categories/get_all.rs
deleted file mode 100644
index b6ec756..0000000
--- a/backend/app/src/queries/categories/get_all.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-use budgeting_app_core::{models::category::Category, schema::categories::dsl::categories as categories_table};
-use diesel::{result::Error, QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
-
-pub fn get_all_categories(connection: &mut SqliteConnection) -> Result<Vec<Category>, Error> {
-    categories_table
-        .select(Category::as_select())
-        .load(connection)
-}
diff --git a/backend/app/src/queries/categories/get_all_ids.rs b/backend/app/src/queries/categories/get_all_ids.rs
deleted file mode 100644
index 48d5e57..0000000
--- a/backend/app/src/queries/categories/get_all_ids.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-use budgeting_app_core::schema::categories::{self as categories_schema, dsl::categories as categories_table};
-use diesel::{result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
-
-pub fn get_all_category_ids(connection: &mut SqliteConnection) -> Result<Vec<i32>, Error> {
-    categories_table
-        .select(categories_schema::id)
-        .load(connection)
-}
diff --git a/backend/app/src/queries/categories/mod.rs b/backend/app/src/queries/categories/mod.rs
deleted file mode 100644
index 80356b3..0000000
--- a/backend/app/src/queries/categories/mod.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-mod get_all;
-mod get_all_ids;
-
-pub use self::get_all::get_all_categories;
-pub use self::get_all_ids::get_all_category_ids;
diff --git a/backend/app/src/queries/category_balances/get_all.rs b/backend/app/src/queries/category_balances/get_all.rs
deleted file mode 100644
index 7ee474a..0000000
--- a/backend/app/src/queries/category_balances/get_all.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-use budgeting_app_core::models::category_balance::CategoryBalance;
-use crate::{
-    queries::{
-        budget_updates::get_all_budget_updates,
-        categories::get_all_categories,
-        category_transfers::{
-            sum_category_transfer_quantity_per_from_category_id,
-            sum_category_transfer_quantity_per_to_category_id,
-        },
-        transaction_categorisations::sum_transaction_categorisation_quantity_per_category_id,
-    },
-    utils::calculate_category_balance,
-};
-use diesel::{result::Error, SqliteConnection};
-
-pub fn get_all_category_balances(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<CategoryBalance>, Error> {
-    let categories = get_all_categories(connection)?;
-    let transaction_sums = sum_transaction_categorisation_quantity_per_category_id(connection)?;
-    let category_transfer_from_sums =
-        sum_category_transfer_quantity_per_from_category_id(connection)?;
-    let category_transfer_to_sums = sum_category_transfer_quantity_per_to_category_id(connection)?;
-    let budget_updates = get_all_budget_updates(connection)?;
-
-    let mut balances = Vec::<CategoryBalance>::new();
-    for category in categories {
-        let balance = calculate_category_balance(
-            &category,
-            &transaction_sums,
-            &category_transfer_from_sums,
-            &category_transfer_to_sums,
-            &budget_updates,
-        );
-
-        balances.push(CategoryBalance {
-            category_id: category.id,
-            balance: balance.try_into().unwrap(),
-        })
-    }
-
-    Ok(balances)
-}
diff --git a/backend/app/src/queries/category_balances/mod.rs b/backend/app/src/queries/category_balances/mod.rs
deleted file mode 100644
index 3fc1be2..0000000
--- a/backend/app/src/queries/category_balances/mod.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-mod get_all;
-
-pub use get_all::get_all_category_balances;
diff --git a/backend/app/src/queries/category_budgets/get_most_recent_per_category_id.rs b/backend/app/src/queries/category_budgets/get_most_recent_per_category_id.rs
deleted file mode 100644
index b71a5fb..0000000
--- a/backend/app/src/queries/category_budgets/get_most_recent_per_category_id.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-use budgeting_app_core::models::{budget::Budget, category_budget::CategoryBudget};
-use crate::queries::{
-    budget_updates::{
-        get_first_budget_update_with_date, get_most_recent_budget_update_date_with_category_id,
-    },
-    categories::get_all_category_ids,
-};
-use diesel::{result::Error, SqliteConnection};
-
-pub fn get_most_recent_category_budget_per_category_id(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<CategoryBudget>, Error> {
-    let category_ids: Vec<i32> = get_all_category_ids(connection)?;
-
-    let mut budgets = Vec::<CategoryBudget>::new();
-    for category_id in category_ids {
-        let most_recent_budget_update_date =
-            get_most_recent_budget_update_date_with_category_id(category_id, connection)?;
-
-        if most_recent_budget_update_date.is_none() {
-            budgets.push(CategoryBudget {
-                category_id,
-                budget: Option::None,
-            });
-            continue;
-        }
-
-        let most_recent_budget_update = get_first_budget_update_with_date(
-            most_recent_budget_update_date.unwrap().as_str(),
-            connection,
-        )?;
-
-        budgets.push(CategoryBudget {
-            category_id,
-            budget: Some(Budget::from(&most_recent_budget_update)),
-        });
-    }
-
-    Ok(budgets)
-}
diff --git a/backend/app/src/queries/category_budgets/mod.rs b/backend/app/src/queries/category_budgets/mod.rs
deleted file mode 100644
index 29fc246..0000000
--- a/backend/app/src/queries/category_budgets/mod.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-mod get_most_recent_per_category_id;
-
-pub use self::get_most_recent_per_category_id::get_most_recent_category_budget_per_category_id;
diff --git a/backend/app/src/queries/category_transfers/mod.rs b/backend/app/src/queries/category_transfers/mod.rs
deleted file mode 100644
index 85eb1c8..0000000
--- a/backend/app/src/queries/category_transfers/mod.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-mod sum_quantity_per_from_category_id;
-mod sum_quantity_per_to_category_id;
-
-pub use sum_quantity_per_from_category_id::sum_category_transfer_quantity_per_from_category_id;
-pub use sum_quantity_per_to_category_id::sum_category_transfer_quantity_per_to_category_id;
diff --git a/backend/app/src/queries/category_transfers/sum_quantity_per_from_category_id.rs b/backend/app/src/queries/category_transfers/sum_quantity_per_from_category_id.rs
deleted file mode 100644
index 3c077aa..0000000
--- a/backend/app/src/queries/category_transfers/sum_quantity_per_from_category_id.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-use budgeting_app_core::schema::category_transfers::{
-    self as category_transfers_schema,
-    dsl::category_transfers as category_transfers_table,
-};
-use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
-
-pub fn sum_category_transfer_quantity_per_from_category_id(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<(i32, Option<i64>)>, Error> {
-    category_transfers_table
-        .group_by(category_transfers_schema::from_category_id)
-        .select((
-            category_transfers_schema::from_category_id,
-            sum(category_transfers_schema::quantity),
-        ))
-        .load::<(i32, Option<i64>)>(connection)
-}
diff --git a/backend/app/src/queries/category_transfers/sum_quantity_per_to_category_id.rs b/backend/app/src/queries/category_transfers/sum_quantity_per_to_category_id.rs
deleted file mode 100644
index 6e81d7d..0000000
--- a/backend/app/src/queries/category_transfers/sum_quantity_per_to_category_id.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-use budgeting_app_core::schema::category_transfers::{
-    self as category_transfers_schema,
-    dsl::category_transfers as category_transfers_table,
-};
-use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
-
-pub fn sum_category_transfer_quantity_per_to_category_id(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<(i32, Option<i64>)>, Error> {
-    category_transfers_table
-        .group_by(category_transfers_schema::to_category_id)
-        .select((
-            category_transfers_schema::to_category_id,
-            sum(category_transfers_schema::quantity),
-        ))
-        .load::<(i32, Option<i64>)>(connection)
-}
diff --git a/backend/app/src/queries/mod.rs b/backend/app/src/queries/mod.rs
deleted file mode 100644
index 43328e2..0000000
--- a/backend/app/src/queries/mod.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-pub mod accounts;
-pub mod budget_updates;
-pub mod categories;
-pub mod category_balances;
-pub mod category_budgets;
-pub mod category_transfers;
-pub mod transaction_categorisations;
diff --git a/backend/app/src/queries/transaction_categorisations/mod.rs b/backend/app/src/queries/transaction_categorisations/mod.rs
deleted file mode 100644
index d4217cc..0000000
--- a/backend/app/src/queries/transaction_categorisations/mod.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-mod sum_quantity_per_category_id;
-
-pub use sum_quantity_per_category_id::sum_transaction_categorisation_quantity_per_category_id;
diff --git a/backend/app/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs b/backend/app/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs
deleted file mode 100644
index 90dc990..0000000
--- a/backend/app/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-use budgeting_app_core::schema::transaction_categorisations::{
-    self as transaction_categorisations_schema,
-    dsl::transaction_categorisations as transaction_categorisations_table,
-};
-use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
-
-pub fn sum_transaction_categorisation_quantity_per_category_id(
-    connection: &mut SqliteConnection,
-) -> Result<Vec<(i32, Option<i64>)>, Error> {
-    transaction_categorisations_table
-        .group_by(transaction_categorisations_schema::category_id)
-        .select((
-            transaction_categorisations_schema::category_id,
-            sum(transaction_categorisations_schema::quantity),
-        ))
-        .load::<(i32, Option<i64>)>(connection)
-}
diff --git a/backend/app/src/routes/account.rs b/backend/app/src/routes/account.rs
index 7c29233..e4eb153 100644
--- a/backend/app/src/routes/account.rs
+++ b/backend/app/src/routes/account.rs
@@ -1,11 +1,13 @@
-use budgeting_app_core::models::account::Account;
+use budgeting_app_core::{
+    models::account::Account,
+    queries::accounts::{get_all_accounts as get_all_accounts_query, insert_account},
+};
 use diesel::result::DatabaseErrorKind;
 use rocket::http::Status;
 use rocket::serde::json::Json;
 use rocket::{get, post, Responder};
 
 use crate::databases::UserDataDb;
-use crate::queries::accounts::{get_all_accounts as get_all_accounts_query, insert_account};
 
 #[get("/account")]
 pub async fn get_all_accounts(user_data_db: UserDataDb) -> Result<Json<Vec<Account>>, (Status, String)> {
diff --git a/backend/app/src/routes/balance.rs b/backend/app/src/routes/balance.rs
index 642aff1..2dcae7b 100644
--- a/backend/app/src/routes/balance.rs
+++ b/backend/app/src/routes/balance.rs
@@ -1,9 +1,11 @@
-use budgeting_app_core::models::category_balance::CategoryBalance;
+use budgeting_app_core::{
+    models::category_balance::CategoryBalance,
+    queries::category_balances::get_all_category_balances as get_all_category_balances_query,
+};
 use rocket::{get, http::Status, serde::json::Json};
 
 use crate::{
     databases::UserDataDb,
-    queries::category_balances::get_all_category_balances as get_all_category_balances_query,
 };
 
 #[get("/balance/category")]
diff --git a/backend/app/src/routes/budget.rs b/backend/app/src/routes/budget.rs
index 64b9e06..746635b 100644
--- a/backend/app/src/routes/budget.rs
+++ b/backend/app/src/routes/budget.rs
@@ -1,17 +1,19 @@
-use budgeting_app_core::models::category_budget::CategoryBudget;
+use budgeting_app_core::{
+    models::category_budget::CategoryBudget,
+    queries::category_budgets::get_most_recent_category_budget_per_category_id as get_most_recent_category_budget_per_category_id_query,
+};
 use rocket::get;
 use rocket::http::Status;
 use rocket::serde::json::Json;
 
 use crate::databases::UserDataDb;
-use crate::queries;
 
 #[get("/budget/category?current")]
 pub async fn get_current_category_budget_per_category(
     user_data_db: UserDataDb,
 ) -> Result<Json<Vec<CategoryBudget>>, Status> {
     user_data_db
-        .run(queries::category_budgets::get_most_recent_category_budget_per_category_id)
+        .run(get_most_recent_category_budget_per_category_id_query)
         .await
         .map(Json)
         .map_err(|_| Status { code: 500 })
diff --git a/backend/app/src/routes/budget_update.rs b/backend/app/src/routes/budget_update.rs
index 6def31a..86dda9f 100644
--- a/backend/app/src/routes/budget_update.rs
+++ b/backend/app/src/routes/budget_update.rs
@@ -1,17 +1,19 @@
-use budgeting_app_core::models::budget_update::BudgetUpdate;
+use budgeting_app_core::{
+    models::budget_update::BudgetUpdate,
+    queries::budget_updates::get_all_budget_updates as get_all_budget_updates_query,
+};
 use rocket::get;
 use rocket::http::Status;
 use rocket::serde::json::Json;
 
 use crate::databases::UserDataDb;
-use crate::queries;
 
 #[get("/budget-update")]
 pub async fn get_all_budget_updates(
     user_data_db: UserDataDb,
 ) -> Result<Json<Vec<BudgetUpdate>>, Status> {
     user_data_db
-        .run(queries::budget_updates::get_all_budget_updates)
+        .run(get_all_budget_updates_query)
         .await
         .map(Json)
         .map_err(|_| Status { code: 500 })
diff --git a/backend/app/src/routes/category.rs b/backend/app/src/routes/category.rs
index 43810e9..ca021fc 100644
--- a/backend/app/src/routes/category.rs
+++ b/backend/app/src/routes/category.rs
@@ -1,10 +1,12 @@
-use budgeting_app_core::models::category::Category;
+use budgeting_app_core::{
+    models::category::Category,
+    queries::categories::get_all_categories as get_all_categories_query,
+};
 use rocket::get;
 use rocket::http::Status;
 use rocket::serde::json::Json;
 
 use crate::databases::UserDataDb;
-use crate::queries::categories::get_all_categories as get_all_categories_query;
 
 #[get("/category")]
 pub async fn get_all_categories(user_data_db: UserDataDb) -> Result<Json<Vec<Category>>, Status> {
diff --git a/backend/app/src/utils/calculate_budgets_accrual.rs b/backend/app/src/utils/calculate_budgets_accrual.rs
deleted file mode 100644
index c0d3d3a..0000000
--- a/backend/app/src/utils/calculate_budgets_accrual.rs
+++ /dev/null
@@ -1,162 +0,0 @@
-use budgeting_app_core::models::{
-    budget_update::BudgetUpdate,
-    category::Category,
-    date_time_utc::DateTimeUtc
-};
-
-pub fn calculate_budgets_accrual(category: &Category, budget_updates: &[BudgetUpdate]) -> i64 {
-    let mut budget_updates = budget_updates
-        .iter()
-        .filter(|bu| bu.category_id == category.id)
-        .collect::<Vec<&BudgetUpdate>>();
-    budget_updates.sort_by_key(|bu| bu.date);
-    budget_updates.reverse();
-
-    let mut budgets_accrual = 0.0_f64;
-    let mut calculated_back_to_date = DateTimeUtc::now();
-
-    for budget_update in budget_updates {
-        let days_on_this_budget = calculated_back_to_date.day_diff(&budget_update.date);
-        if days_on_this_budget == 0_u32 {
-            continue;
-        }
-        let budget_per_day = budget_update.new_budget as f64 / budget_update.new_period as f64;
-        budgets_accrual += days_on_this_budget as f64 * budget_per_day;
-        calculated_back_to_date = budget_update.date;
-    }
-
-    budgets_accrual.floor() as i64
-}
-
-#[cfg(test)]
-mod test {
-    use budgeting_app_core::models::{
-        budget_update::BudgetUpdate, category::Category, date_time_utc::DateTimeUtc,
-    };
-    use chrono::{Days, Timelike, Utc};
-
-    use super::calculate_budgets_accrual;
-
-    #[test]
-    fn when_no_budget_updates_then_return_zero() {
-        let category = Category {
-            id: 0,
-            name: String::from("Groceries"),
-        };
-        let budget_updates = [];
-
-        let result = calculate_budgets_accrual(&category, &budget_updates);
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_one_budget_update_for_another_category_then_return_zero() {
-        let category = Category {
-            id: 0,
-            name: String::from("Groceries"),
-        };
-        let budget_updates = [BudgetUpdate {
-            id: 0,
-            category_id: 1,
-            date: DateTimeUtc::now(),
-            new_budget: 100,
-            new_period: 1,
-        }];
-
-        let result = calculate_budgets_accrual(&category, &budget_updates);
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_one_budget_update_then_return_quantity_times_days_in_past() {
-        let category = Category {
-            id: 0,
-            name: String::from("Groceries"),
-        };
-        let budget_updates = [BudgetUpdate {
-            id: 0,
-            category_id: 0,
-            date: DateTimeUtc::new(Utc::now().checked_sub_days(Days::new(120)).unwrap()),
-            new_budget: 100,
-            new_period: 1,
-        }];
-
-        let result = calculate_budgets_accrual(&category, &budget_updates);
-
-        assert_eq!(result, 12_000);
-    }
-
-    #[test]
-    fn when_two_budget_updates_then_calculates_as_expected() {
-        let category = Category {
-            id: 0,
-            name: String::from("Groceries"),
-        };
-        let budget_updates = [
-            BudgetUpdate {
-                id: 0,
-                category_id: 0,
-                date: DateTimeUtc::new(Utc::now().checked_sub_days(Days::new(60)).unwrap()),
-                new_budget: 200,
-                new_period: 1,
-            },
-            BudgetUpdate {
-                id: 0,
-                category_id: 0,
-                date: DateTimeUtc::new(Utc::now().checked_sub_days(Days::new(120)).unwrap()),
-                new_budget: 100,
-                new_period: 1,
-            },
-        ];
-
-        let result = calculate_budgets_accrual(&category, &budget_updates);
-
-        assert_eq!(result, 18_000);
-    }
-
-    #[test]
-    fn when_two_budget_updates_on_same_day_then_uses_latest_only() {
-        let category = Category {
-            id: 0,
-            name: String::from("Groceries"),
-        };
-        let budget_updates = [
-            BudgetUpdate {
-                id: 0,
-                category_id: 0,
-                date: DateTimeUtc::new(
-                    Utc::now()
-                        .checked_sub_days(Days::new(120))
-                        .unwrap()
-                        .with_hour(13)
-                        .unwrap(),
-                ),
-                new_budget: 200,
-                new_period: 1,
-            },
-            BudgetUpdate {
-                id: 0,
-                category_id: 0,
-                date: DateTimeUtc::new(
-                    Utc::now()
-                        .checked_sub_days(Days::new(120))
-                        .unwrap()
-                        .with_hour(12)
-                        .unwrap(),
-                ),
-                new_budget: 100,
-                new_period: 1,
-            },
-        ];
-        let mut budget_updates_reversed = budget_updates.clone();
-        budget_updates_reversed.reverse();
-
-        let result_leftways = calculate_budgets_accrual(&category, &budget_updates);
-        let result_rightways = calculate_budgets_accrual(&category, &budget_updates_reversed);
-
-        assert_eq!(result_leftways, 24_000);
-        assert_eq!(result_rightways, 24_000);
-    }
-}
diff --git a/backend/app/src/utils/calculate_category_balance.rs b/backend/app/src/utils/calculate_category_balance.rs
deleted file mode 100644
index e1de57e..0000000
--- a/backend/app/src/utils/calculate_category_balance.rs
+++ /dev/null
@@ -1,142 +0,0 @@
-use budgeting_app_core::models::{
-    budget_update::BudgetUpdate,
-    category::Category
-};
-
-use super::{calculate_budgets_accrual, find_by_id_or};
-
-pub fn calculate_category_balance(
-    category: &Category,
-    transaction_sums: &[(i32, Option<i64>)],
-    category_transfer_from_sums: &[(i32, Option<i64>)],
-    category_transfer_to_sums: &[(i32, Option<i64>)],
-    budget_updates: &[BudgetUpdate],
-) -> i64 {
-    let transaction_sum = find_by_id_or(transaction_sums, category.id, 0);
-    let category_transfer_from_sum = find_by_id_or(category_transfer_from_sums, category.id, 0);
-    let category_transfer_to_sum = find_by_id_or(category_transfer_to_sums, category.id, 0);
-    let budget_accruals_sum = calculate_budgets_accrual(category, budget_updates);
-
-    transaction_sum + budget_accruals_sum + category_transfer_to_sum - category_transfer_from_sum
-}
-
-#[cfg(test)]
-mod test {
-    use budgeting_app_core::models::{budget_update::BudgetUpdate, category::Category, date_time_utc::DateTimeUtc};
-    use chrono::{Days, Utc};
-
-    use crate::utils::calculate_category_balance;
-
-    #[test]
-    fn when_no_data_then_returns_zero() {
-        let category = Category {
-            id: 0,
-            name: String::new(),
-        };
-
-        let result = calculate_category_balance(&category, &[], &[], &[], &[]);
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_data_only_for_another_category_then_returns_zero() {
-        let category = Category {
-            id: 0,
-            name: String::new(),
-        };
-        let transaction_sums = [(1, Some(100))];
-        let category_transfer_from_sums = [(1, Some(91))];
-        let category_transfer_to_sums = [(2, Some(79))];
-        let budget_updates = [BudgetUpdate {
-            id: 0,
-            category_id: 1,
-            date: DateTimeUtc::new(Utc::now().checked_sub_days(Days::new(120)).unwrap()),
-            new_budget: 77,
-            new_period: 1,
-        }];
-
-        let result = calculate_category_balance(
-            &category,
-            &transaction_sums,
-            &category_transfer_from_sums,
-            &category_transfer_to_sums,
-            &budget_updates,
-        );
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_transaction_sum_is_none_then_returns_zero() {
-        let category = Category {
-            id: 0,
-            name: String::new(),
-        };
-        let transaction_sums = [(0, None)];
-        let category_transfer_from_sums = [];
-        let category_transfer_to_sums = [];
-        let budget_updates = [];
-
-        let result = calculate_category_balance(
-            &category,
-            &transaction_sums,
-            &category_transfer_from_sums,
-            &category_transfer_to_sums,
-            &budget_updates,
-        );
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_category_transfers_are_none_then_returns_zero() {
-        let category = Category {
-            id: 0,
-            name: String::new(),
-        };
-        let transaction_sums = [];
-        let category_transfer_from_sums = [(0, None)];
-        let category_transfer_to_sums = [(0, None)];
-        let budget_updates = [];
-
-        let result = calculate_category_balance(
-            &category,
-            &transaction_sums,
-            &category_transfer_from_sums,
-            &category_transfer_to_sums,
-            &budget_updates,
-        );
-
-        assert_eq!(result, 0_i64);
-    }
-
-    #[test]
-    fn when_some_data_then_calculates_as_expected() {
-        let category = Category {
-            id: 0,
-            name: String::new(),
-        };
-        let transaction_sums = [(0, Some(100))];
-        let category_transfer_from_sums = [(0, Some(91))];
-        let category_transfer_to_sums = [(0, Some(79))];
-        let budget_updates = [BudgetUpdate {
-            id: 0,
-            category_id: 0,
-            date: DateTimeUtc::new(Utc::now().checked_sub_days(Days::new(120)).unwrap()),
-            new_budget: 77,
-            new_period: 1,
-        }];
-
-        let result = calculate_category_balance(
-            &category,
-            &transaction_sums,
-            &category_transfer_from_sums,
-            &category_transfer_to_sums,
-            &budget_updates,
-        );
-
-        let expected_result = 100 + (-91) + 79 + 77 * 120;
-        assert_eq!(result, expected_result);
-    }
-}
diff --git a/backend/app/src/utils/find_by_id_or.rs b/backend/app/src/utils/find_by_id_or.rs
deleted file mode 100644
index f5add30..0000000
--- a/backend/app/src/utils/find_by_id_or.rs
+++ /dev/null
@@ -1,53 +0,0 @@
-pub fn find_by_id_or<Id: PartialEq, Val: Copy>(
-    arr: &[(Id, Option<Val>)],
-    id: Id,
-    default: Val,
-) -> Val {
-    arr.iter()
-        .find(|(elem_id, _)| *elem_id == id)
-        .map_or(default, |row| match row {
-            (_, Some(quantity)) => *quantity,
-            (_, _) => default,
-        })
-}
-
-#[cfg(test)]
-mod test {
-    use super::find_by_id_or;
-
-    #[test]
-    fn when_no_elements_then_return_default() {
-        let arr = [];
-
-        let result = find_by_id_or(&arr, 1, 42);
-
-        assert_eq!(result, 42);
-    }
-
-    #[test]
-    fn when_id_not_in_elements_then_return_default() {
-        let arr = [(0, Some(100)), (2, Some(200))];
-
-        let result = find_by_id_or(&arr, 1, 42);
-
-        assert_eq!(result, 42);
-    }
-
-    #[test]
-    fn when_value_is_none_then_return_default() {
-        let arr = [(1, None)];
-
-        let result = find_by_id_or(&arr, 1, 42);
-
-        assert_eq!(result, 42);
-    }
-
-    #[test]
-    fn when_value_is_some_then_return_value() {
-        let arr = [(1, Some(67))];
-
-        let result = find_by_id_or(&arr, 1, 42);
-
-        assert_eq!(result, 67);
-    }
-}
diff --git a/backend/app/src/utils/mod.rs b/backend/app/src/utils/mod.rs
deleted file mode 100644
index 84a27af..0000000
--- a/backend/app/src/utils/mod.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-mod calculate_budgets_accrual;
-mod calculate_category_balance;
-mod find_by_id_or;
-
-pub use calculate_budgets_accrual::calculate_budgets_accrual;
-pub use calculate_category_balance::calculate_category_balance;
-pub use find_by_id_or::find_by_id_or;