Basic implementation of DBBalances

Cargo.toml

@@ -9,4 +9,7 @@ downcast-rs = "2.0.1"
 dyn-clone = "1.0.19"
 dyn-eq = "0.1.3"
 dyn-hash = "0.2.2"
+futures = "0.3.31"
 indexmap = "2.9.0"
+sqlx = { version = "0.8", features = [ "runtime-tokio", "sqlite" ] }
+tokio = { version = "1.45.0", features = ["full"] }

src/db.rs

@@ -0,0 +1,85 @@
+/*
+	DrCr: Web-based double-entry bookkeeping framework
+	Copyright (C) 2022-2025  Lee Yingtong Li (RunasSudo)
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Affero General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Affero General Public License for more details.
+
+	You should have received a copy of the GNU Affero General Public License
+	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use std::collections::HashMap;
+use std::ops::DerefMut;
+use std::{cell::RefCell, future::Future};
+
+use chrono::NaiveDate;
+use sqlx::{Connection, Row, SqliteConnection};
+use tokio::runtime::Runtime;
+
+use crate::{util::format_date, QuantityInt};
+
+pub struct DbConnection {
+	sqlx_connection: RefCell<SqliteConnection>,
+}
+
+fn run_blocking<F: Future>(future: F) -> F::Output {
+	let rt = Runtime::new().unwrap();
+	rt.block_on(future)
+}
+
+impl DbConnection {
+	/// Connect to the given Sqlite database
+	pub fn connect(url: &str) -> Self {
+		Self {
+			sqlx_connection: RefCell::new(run_blocking(Self::connect_async(url))),
+		}
+	}
+
+	async fn connect_async(url: &str) -> SqliteConnection {
+		SqliteConnection::connect(url).await.expect("SQL error")
+	}
+
+	/// Get account balances from the database
+	pub fn get_balances(&self, date: NaiveDate) -> HashMap<String, QuantityInt> {
+		run_blocking(self.get_balances_async(date))
+	}
+
+	async fn get_balances_async(&self, date: NaiveDate) -> HashMap<String, QuantityInt> {
+		let mut connection = self.sqlx_connection.borrow_mut();
+
+		let rows = sqlx::query(
+		"-- Get last transaction for each account
+			WITH max_dt_by_account AS (
+				SELECT account, max(dt) AS max_dt
+				FROM joined_transactions
+				WHERE DATE(dt) <= DATE($1)
+				GROUP BY account
+			),
+			max_tid_by_account AS (
+				SELECT max_dt_by_account.account, max(transaction_id) AS max_tid
+				FROM max_dt_by_account
+				JOIN joined_transactions ON max_dt_by_account.account = joined_transactions.account AND max_dt_by_account.max_dt = joined_transactions.dt
+				GROUP BY max_dt_by_account.account
+			)
+			-- Get running balance at last transaction for each account
+			SELECT max_tid_by_account.account, running_balance AS quantity
+			FROM max_tid_by_account
+			JOIN transactions_with_running_balances ON max_tid = transactions_with_running_balances.transaction_id AND max_tid_by_account.account = transactions_with_running_balances.account"
+		).bind(format_date(date)).fetch_all(connection.deref_mut()).await.unwrap();
+
+		let mut balances = HashMap::new();
+		for row in rows {
+			balances.insert(row.get("account"), row.get("quantity"));
+		}
+
+		balances
+	}
+}

src/lib.rs

@@ -1,5 +1,6 @@
+pub mod db;
 pub mod reporting;
 pub mod transaction;
 pub mod util;
 
-pub type QuantityInt = u64;
+pub type QuantityInt = i64;

src/main.rs

@@ -17,6 +17,7 @@
 */
 
 use chrono::NaiveDate;
+use libdrcr::db::DbConnection;
 use libdrcr::reporting::builders::register_dynamic_builders;
 use libdrcr::reporting::generate_report;
 use libdrcr::reporting::steps::{
@@ -29,7 +30,13 @@ use libdrcr::reporting::types::{
 };
 
 fn main() {
-	let mut context = ReportingContext::new(NaiveDate::from_ymd_opt(2025, 6, 30).unwrap());
+	// Connect to database
+	let db_connection = DbConnection::connect("sqlite:drcr_testing.db");
+
+	// Initialise ReportingContext
+	let mut context =
+		ReportingContext::new(db_connection, NaiveDate::from_ymd_opt(2025, 6, 30).unwrap());
+
 	register_lookup_fns(&mut context);
 	register_dynamic_builders(&mut context);
 
@@ -82,5 +89,6 @@ fn main() {
 		})
 		.unwrap();
 
+	//println!("{}", products);
 	println!("{:?}", result);
 }

src/reporting/builders.rs

@@ -17,7 +17,7 @@
 */
 
 //! This module contains implementations of dynamic step builders
-//! 
+//!
 //! See [ReportingContext::register_dynamic_builder][super::types::ReportingContext::register_dynamic_builder].
 
 use std::collections::HashMap;
@@ -548,7 +548,7 @@ impl ReportingStep for UpdateBalancesAt {
 		products.insert(
 			ReportingProductId {
 				name: self.step_name,
-				kind: ReportingProductKind::BalancesBetween,
+				kind: ReportingProductKind::BalancesAt,
 				args: Box::new(self.args.clone()),
 			},
 			Box::new(balances),

src/reporting/steps.rs

@@ -46,9 +46,9 @@ pub fn register_lookup_fns(context: &mut ReportingContext) {
 }
 
 /// Target representing all transactions except charging retained earnings to equity
-/// 
+///
 /// By default, this is [CombineOrdinaryTransactions] and, if requested, [CalculateIncomeTax].
-/// 
+///
 /// Used as the basis for the income statement.
 #[derive(Debug)]
 pub struct AllTransactionsExceptRetainedEarnings {
@@ -160,9 +160,9 @@ impl ReportingStep for AllTransactionsExceptRetainedEarnings {
 }
 
 /// Target representing all transactions including charging retained earnings to equity
-/// 
+///
 /// In other words, this is [AllTransactionsExceptRetainedEarnings] and [RetainedEarningsToEquity].
-/// 
+///
 /// Used as the basis for the balance sheet.
 #[derive(Debug)]
 pub struct AllTransactionsIncludingRetainedEarnings {
@@ -367,7 +367,7 @@ impl ReportingStep for CalculateIncomeTax {
 }
 
 /// Combines all steps producing ordinary transactions
-/// 
+///
 /// By default, these are [DBBalances] and [PostUnreconciledStatementLines]
 #[derive(Debug)]
 pub struct CombineOrdinaryTransactions {
@@ -510,15 +510,14 @@ impl ReportingStep for DBBalances {
 
 	fn execute(
 		&self,
-		_context: &ReportingContext,
+		context: &ReportingContext,
 		_steps: &Vec<Box<dyn ReportingStep>>,
 		_dependencies: &ReportingGraphDependencies,
 		products: &mut ReportingProducts,
 	) -> Result<(), ReportingExecutionError> {
-		eprintln!("Stub: DBBalances.execute");
-
+		// Get balances from DB
 		let balances = BalancesAt {
-			balances: HashMap::new(),
+			balances: context.db_connection.get_balances(self.args.date),
 		};
 
 		products.insert(

src/reporting/types.rs

@@ -26,6 +26,7 @@ use dyn_eq::DynEq;
 use dyn_hash::DynHash;
 use indexmap::IndexMap;
 
+use crate::db::DbConnection;
 use crate::transaction::TransactionWithPostings;
 use crate::QuantityInt;
 
@@ -37,7 +38,11 @@ use super::executor::ReportingExecutionError;
 
 /// Records the context for a single reporting job
 pub struct ReportingContext {
+	// Configuration
+	pub db_connection: DbConnection,
 	pub eofy_date: NaiveDate,
+
+	// State
 	pub(crate) step_lookup_fn: HashMap<
 		(&'static str, &'static [ReportingProductKind]),
 		(ReportingStepTakesArgsFn, ReportingStepFromArgsFn),
@@ -47,8 +52,9 @@ pub struct ReportingContext {
 
 impl ReportingContext {
 	/// Initialise a new [ReportingContext]
-	pub fn new(eofy_date: NaiveDate) -> Self {
+	pub fn new(db_connection: DbConnection, eofy_date: NaiveDate) -> Self {
 		Self {
+			db_connection: db_connection,
 			eofy_date: eofy_date,
 			step_lookup_fn: HashMap::new(),
 			step_dynamic_builders: Vec::new(),

src/util.rs

@@ -20,5 +20,10 @@ use chrono::{Datelike, NaiveDate};
 
 /// Return the start date of the financial year, given the end date of the financial year
 pub fn sofy_from_eofy(date_eofy: NaiveDate) -> NaiveDate {
-	return date_eofy.with_year(date_eofy.year() - 1).unwrap().succ_opt().unwrap();
+	date_eofy.with_year(date_eofy.year() - 1).unwrap().succ_opt().unwrap()
+}
+
+/// Format the [NaiveDate] as a string
+pub fn format_date(date: NaiveDate) -> String {
+	date.format("%Y-%m-%d 00:00:00.000000").to_string()
 }