Show unclassified statement lines in reports

src/components/TransactionEditor.vue

@@ -111,7 +111,7 @@
 	
 	import { ref } from 'vue';
 	
-	import { Transaction, db, deserialiseAmount } from '../db.ts';
+	import { DT_FORMAT, Transaction, db, deserialiseAmount } from '../db.ts';
 	
 	interface EditingPosting {
 		id: number | null,
@@ -148,7 +148,7 @@
 		// Prepare transaction for save
 		const newTransaction = new Transaction(
 			transaction.id,
-			dayjs(transaction.dt).format('YYYY-MM-DD HH:mm:ss.SSS000'),
+			dayjs(transaction.dt).format(DT_FORMAT),
 			transaction.description,
 			[]
 		);

src/db.ts

@@ -25,6 +25,8 @@ import { reactive } from 'vue';
 import { asCost, Balance } from './amounts.ts';
 import { ExtendedDatabase } from './dbutil.ts';
 
+export const DT_FORMAT = 'YYYY-MM-DD HH:mm:ss.SSS000';
+
 export const db = reactive({
 	filename: null as (string | null),
 	
@@ -58,10 +60,10 @@ export const db = reactive({
 	},
 });
 
-export async function totalBalances(session: ExtendedDatabase): Promise<{account: string, quantity: number}[]> {
+export async function totalBalances(session: ExtendedDatabase): Promise<Map<string, number>> {
 	await updateRunningBalances(session);
 	
-	return await session.select(`
+	const resultsRaw: {account: string, quantity: number}[] = await session.select(`
 		SELECT p3.account AS account, running_balance AS quantity FROM
 		(
 			SELECT p1.account, max(p2.transaction_id) AS max_tid FROM
@@ -72,6 +74,8 @@ export async function totalBalances(session: ExtendedDatabase): Promise<{account
 		) p3
 		JOIN postings p4 ON p3.account = p4.account AND p3.max_tid = p4.transaction_id ORDER BY account
 	`);
+	
+	return new Map(resultsRaw.map((x) => [x.account, x.quantity]));
 }
 
 export async function updateRunningBalances(session: ExtendedDatabase) {
@@ -243,3 +247,13 @@ export interface JoinedTransactionPosting {
 	commodity: string,
 	running_balance?: number
 }
+
+export interface StatementLine {
+	id: number | null,
+	source_account: string,
+	dt: string,
+	description: string,
+	quantity: number,
+	balance: number | null,
+	commodity: string
+}

src/importers/ofx2.ts

@@ -0,0 +1,60 @@
+/*
+	DrCr: Web-based double-entry bookkeeping framework
+	Copyright (C) 2022–2024  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/>.
+*/
+
+import dayjs from 'dayjs';
+
+import { DT_FORMAT, StatementLine, db } from '../db.ts';
+
+export default function import_ofx2(sourceAccount: string, content: string): StatementLine[] {
+	// Import an OFX2 XML file
+	
+	// Convert OFX header to XML and parse
+	const xml_header = '<?xml version="1.0" encoding="UTF-8" standalone="no"?>';
+	const raw_payload = content.substring(content.indexOf('?>') + 2).replaceAll('&', '&amp;');
+	const tree = new DOMParser().parseFromString(xml_header + raw_payload, 'application/xml');
+	
+	// Read transactions
+	const statementLines: StatementLine[] = [];
+	
+	for (const transaction of tree.querySelectorAll('BANKMSGSRSV1 STMTTRNRS STMTRS BANKTRANLIST STMTTRN')) {
+		const dateRaw = transaction.querySelector('DTPOSTED')!.textContent;
+		const date = dayjs(dateRaw, 'YYYYMMDDHHmmss').hour(0).minute(0).second(0).millisecond(0).format(DT_FORMAT);
+		const description = transaction.querySelector('NAME')!.textContent;
+		const amount = transaction.querySelector('TRNAMT')!.textContent;
+		
+		if (amount === '0') {
+			// Continuation line
+			statementLines.at(-1)!.description += '\n' + description;
+		} else {
+			const quantity = Math.round(parseFloat(amount!) * Math.pow(10, db.metadata.dps));
+			if (!Number.isSafeInteger(quantity)) { throw new Error('Quantity not representable by safe integer'); }
+			
+			statementLines.push({
+				id: null,
+				source_account: sourceAccount,
+				dt: date,
+				description: description ?? '',
+				quantity: quantity,
+				balance: null,
+				commodity: db.metadata.reporting_commodity
+			});
+		}
+	}
+	
+	return statementLines;
+}

src/main.ts

@@ -35,6 +35,7 @@ async function initApp() {
 		{ path: '/journal/edit-transaction/:id', name: 'journal-edit-transaction', component: () => import('./pages/EditTransactionView.vue') },
 		{ path: '/journal/new-transaction', name: 'journal-new-transaction', component: () => import('./pages/NewTransactionView.vue') },
 		{ path: '/statement-lines', name: 'statement-lines', component: () => import('./pages/StatementLinesView.vue') },
+		{ path: '/statement-lines/import', name: 'import-statement', component: () => import('./pages/ImportStatementView.vue') },
 		{ path: '/transactions/:account', name: 'transactions', component: () => import('./pages/TransactionsView.vue') },
 		{ path: '/trial-balance', name: 'trial-balance', component: () => import('./pages/TrialBalanceView.vue') },
 	];

src/pages/GeneralLedgerView.vue

@@ -66,8 +66,9 @@
 	import { onUnmounted, ref, watch } from 'vue';
 	
 	import { asCost } from '../amounts.ts';
-	import { JoinedTransactionPosting, Transaction, db, joinedToTransactions } from '../db.ts';
+	import { Transaction, db } from '../db.ts';
 	import { pp, ppWithCommodity } from '../display.ts';
+	import { ReportingStage, ReportingWorkflow } from '../reporting.ts';
 	import { renderComponent } from '../webutil.ts';
 	
 	const commodityDetail = ref(false);
@@ -77,15 +78,14 @@
 	
 	async function load() {
 		const session = await db.load();
+		const reportingWorkflow = new ReportingWorkflow();
+		await reportingWorkflow.generate(session);
 		
-		const joinedTransactionPostings: JoinedTransactionPosting[] = await session.select(
-			`SELECT transaction_id, dt, transactions.description AS transaction_description, postings.id, postings.description, account, quantity, commodity
-			FROM transactions
-			JOIN postings ON transactions.id = postings.transaction_id
-			ORDER BY dt DESC, transaction_id DESC, postings.id`
-		);
+		transactions.value = reportingWorkflow.getTransactionsAtStage(ReportingStage.OrdinaryAPITransactions);
 		
-		transactions.value = joinedToTransactions(joinedTransactionPostings);
+		// Display transactions in reverse chronological order
+		// We must sort here because they are returned by reportingWorkflow in order of ReportingStage
+		transactions.value.sort((a, b) => (b.dt.localeCompare(a.dt)) || ((b.id ?? 0) - (a.id ?? 0)));
 	}
 	
 	function renderTable() {

src/pages/ImportStatementView.vue

@@ -0,0 +1,138 @@
+<!--
+	DrCr: Web-based double-entry bookkeeping framework
+	Copyright (C) 2022–2024  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/>.
+-->
+
+<template>
+	<h1 class="page-heading mb-4">
+		Import statement
+	</h1>
+	
+	<div class="grid grid-cols-[max-content_1fr] space-y-2 mb-4 items-baseline">
+		<label for="format" class="block text-gray-900 pr-4">File type</label>
+		<div>
+			<select class="bordered-field" id="format">
+				<!--<option value="ofx1">OFX 1.x</option>-->
+				<option value="ofx2">OFX 2.x</option>
+			</select>
+		</div>
+		<label for="account" class="block text-gray-900 pr-4">Source account</label>
+		<div class="relative combobox">
+			<!-- WebKit bug: Does not align baseline correctly unless some text or placeholder is present -->
+			<input type="text" class="bordered-field peer" id="account" placeholder=" " autocomplete="off" v-model="sourceAccount">
+			<!--{% include 'components/accounts_combobox_inner.html' %}-->
+		</div>
+		<label for="file" class="block text-gray-900 pr-4">File</label>
+		<div class="flex grow">
+			<!-- WebKit: file:hidden hides the filename as well so we have a dummy text input -->
+			<input type="text" class="bordered-field" :value="selectedFilename" @click="openFileDialog" placeholder=" " readonly>
+			<input type="file" class="hidden" id="file" accept=".ofx" ref="file" @change="fileInputChanged">
+			<label for="file" class="btn-primary bg-gray-600 hover:bg-gray-700">Browse</label>
+		</div>
+	</div>
+	
+	<div class="flex justify-end mt-4 space-x-2">
+		<button class="btn-secondary" @click="previewImport">Preview</button>
+	</div>
+	
+	<div v-if="statementLines.length > 0">
+		<h2 class="page-heading my-4">
+			Import statement preview
+		</h2>
+		
+		<table class="min-w-full">
+			<thead>
+				<tr class="border-b border-gray-300">
+					<th class="py-0.5 pr-1 text-gray-900 font-semibold text-start">Date</th>
+					<th class="py-0.5 px-1 text-gray-900 font-semibold text-start">Description</th>
+					<th class="py-0.5 px-1 text-gray-900 font-semibold text-end">Dr</th>
+					<th class="py-0.5 px-1 text-gray-900 font-semibold text-end">Cr</th>
+					<th class="py-0.5 pl-1 text-gray-900 font-semibold text-end">Balance</th>
+				</tr>
+			</thead>
+			<tbody>
+				<tr v-for="line in statementLines">
+					<td class="py-0.5 pr-1 text-gray-900">{{ dayjs(line.dt).format('YYYY-MM-DD') }}</td>
+					<td class="py-0.5 px-1 text-gray-900">{{ line.description }}</td>
+					<td class="py-0.5 px-1 text-gray-900 text-end">{{ line.quantity >= 0 ? ppWithCommodity(line.quantity, line.commodity) : '' }}</td>
+					<td class="py-0.5 px-1 text-gray-900 text-end">{{ line.quantity < 0 ? ppWithCommodity(-line.quantity, line.commodity) : '' }}</td>
+					<td class="py-0.5 pl-1 text-gray-900 text-end">{{ line.balance ?? '' }}</td>
+				</tr>
+			</tbody>
+		</table>
+		
+		<div class="flex justify-end mt-4 space-x-2">
+			<button class="btn-primary" @click="doImport">Import</button>
+		</div>
+	</div>
+</template>
+
+<script setup lang="ts">
+	import dayjs from 'dayjs';
+	
+	import { defineModel, ref, useTemplateRef } from 'vue';
+	import { useRouter } from 'vue-router';
+	
+	import { StatementLine, db } from '../db.ts';
+	import { ppWithCommodity } from '../display.ts';
+	import import_ofx2 from '../importers/ofx2.ts';
+	
+	const fileInput = useTemplateRef('file');
+	
+	const selectedFilename = defineModel('selectedFilename', { default: '' });
+	const sourceAccount = defineModel('sourceAccount', { default: '' });
+	
+	const router = useRouter();
+	
+	const statementLines = ref([] as StatementLine[]);
+	
+	function openFileDialog() {
+		fileInput.value?.click();
+	}
+	
+	function fileInputChanged() {
+		selectedFilename.value = fileInput.value!.files?.item(0)?.name ?? '';
+	}
+	
+	async function previewImport() {
+		const file = fileInput.value!.files?.item(0);
+		if (!file) {
+			return;
+		}
+		
+		const content = await file.text();
+		
+		statementLines.value = import_ofx2(sourceAccount.value, content);
+	}
+	
+	async function doImport() {
+		// Import statement lines to database atomically
+		const session = await db.load();
+		const dbTransaction = await session.begin();
+		
+		for (const line of statementLines.value) {
+			await dbTransaction.execute(
+				`INSERT INTO statement_lines (source_account, dt, description, quantity, balance, commodity)
+				VALUES (?, ?, ?, ?, ?, ?)`,
+				[line.source_account, line.dt, line.description, line.quantity, line.balance, line.commodity]
+			);
+		}
+		
+		dbTransaction.commit();
+		
+		router.push({ name: 'statement-lines' });
+	}
+</script>

src/pages/StatementLinesView.vue

@@ -25,11 +25,11 @@
 		<div class="grow flex gap-x-2 items-baseline">
 			<!--<button class="btn-secondary text-emerald-700 ring-emerald-600">
 				Reconcile selected as transfer
-			</button>
-			<a href="#" class="btn-secondary">
+			</button>-->
+			<RouterLink :to="{ name: 'import-statement' }" class="btn-secondary">
 				Import statement
-			</a>
-			<a href="{{ url_for('statement_lines', **dict(request.args, unclassified=1)) }}" class="btn-secondary">
+			</RouterLink>
+			<!--<a href="{{ url_for('statement_lines', **dict(request.args, unclassified=1)) }}" class="btn-secondary">
 				Show only unclassified lines
 			</a>-->
 		</div>
@@ -91,7 +91,7 @@ import { ppWithCommodity } from '../display.ts';
 		const session = await db.load();
 		
 		const joinedStatementLines: any[] = await session.select(
-			`SELECT statement_lines.id, source_account, statement_lines.dt, statement_lines.description, statement_lines.quantity, statement_lines.balance, statement_lines.commodity, p2.transaction_id, p2.account AS posting_account
+			`SELECT statement_lines.*, p2.transaction_id, p2.account AS posting_account
 			FROM statement_lines
 			LEFT JOIN statement_line_reconciliations ON statement_lines.id = statement_line_reconciliations.statement_line_id
 			LEFT JOIN postings ON statement_line_reconciliations.posting_id = postings.id

src/pages/TransactionsView.vue

@@ -41,7 +41,8 @@
 	import { ref } from 'vue';
 	import { useRoute } from 'vue-router';
 	
-	import { JoinedTransactionPosting, Transaction, db, joinedToTransactions, updateRunningBalances } from '../db.ts';
+	import { Transaction, db } from '../db.ts';
+	import { ReportingStage, ReportingWorkflow } from '../reporting.ts';
 	import TransactionsWithCommodityView from './TransactionsWithCommodityView.vue';
 	import TransactionsWithoutCommodityView from './TransactionsWithoutCommodityView.vue';
 	
@@ -52,20 +53,17 @@
 	
 	async function load() {
 		const session = await db.load();
+		const reportingWorkflow = new ReportingWorkflow();
+		await reportingWorkflow.generate(session);  // This also ensures running balances are up to date
 		
-		// Ensure running balances are up to date because we use these
-		await updateRunningBalances(session);
+		const transactionsRaw = reportingWorkflow.getTransactionsAtStage(ReportingStage.OrdinaryAPITransactions);
 		
-		const joinedTransactionPostings: JoinedTransactionPosting[] = await session.select(
-			`SELECT transaction_id, dt, transactions.description AS transaction_description, postings.id, postings.description, account, quantity, commodity, running_balance
-			FROM transactions
-			JOIN postings ON transactions.id = postings.transaction_id
-			WHERE transactions.id IN (SELECT transaction_id FROM postings WHERE postings.account = $1)
-			ORDER by dt DESC, transaction_id DESC, postings.id`,
-			[route.params.account]
-		);
+		// Filter only transactions affecting this account
+		transactions.value = transactionsRaw.filter((t) => t.postings.some((p) => p.account === route.params.account));
 		
-		transactions.value = joinedToTransactions(joinedTransactionPostings);
+		// Display transactions in reverse chronological order
+		// We must sort here because they are returned by reportingWorkflow in order of ReportingStage
+		transactions.value.sort((a, b) => (b.dt.localeCompare(a.dt)) || ((b.id ?? 0) - (a.id ?? 0)));
 	}
 	load();
 </script>

src/pages/TransactionsWithoutCommodityView.vue

@@ -60,6 +60,19 @@
 	let clusterize: Clusterize | null = null;
 	
 	function renderTable() {
+		// Recompute running balances
+		// This is necessary because running_balance is cached only considering database transactions
+		let balance = 0;
+		for (let i = transactions.length - 1; i >= 0; i--) {
+			const transaction = transactions[i];
+			for (const posting of transaction.postings) {
+				if (posting.account === route.params.account) {
+					balance += asCost(posting.quantity, posting.commodity);
+					posting.running_balance = balance;  // We should absolutely not commit this to the database!
+				}
+			}
+		}
+		
 		// Render table
 		const PencilIconHTML = renderComponent(PencilIcon, { 'class': 'w-4 h-4 inline align-middle -mt-0.5' });  // Pre-render the pencil icon
 		const rows = [];

src/pages/TrialBalanceView.vue

@@ -21,7 +21,7 @@
 		Trial balance
 	</h1>
 	
-	<table class="min-w-full">
+	<table class="min-w-full" v-if="report">
 		<thead>
 			<tr class="border-b border-gray-300">
 				<th class="py-0.5 pr-1 text-gray-900 font-semibold text-start">Account</th>
@@ -30,19 +30,19 @@
 			</tr>
 		</thead>
 		<tbody>
-			<tr v-for="account in accounts">
-				<td class="py-0.5 pr-1 text-gray-900"><RouterLink :to="{ name: 'transactions', params: { 'account': account.account } }" class="hover:text-blue-700 hover:underline">{{ account.account }}</RouterLink></td>
+			<tr v-for="[account, quantity] in report.balances.entries()">
+				<td class="py-0.5 pr-1 text-gray-900"><RouterLink :to="{ name: 'transactions', params: { account: account } }" class="hover:text-blue-700 hover:underline">{{ account }}</RouterLink></td>
 				<td class="py-0.5 px-1 text-gray-900 text-end">
-					<template v-if="account.quantity >= 0">{{ pp(account.quantity) }}</template>
+					<template v-if="quantity >= 0">{{ pp(quantity) }}</template>
 				</td>
 				<td class="py-0.5 pl-1 text-gray-900 text-end">
-					<template v-if="account.quantity < 0">{{ pp(-account.quantity) }}</template>
+					<template v-if="quantity < 0">{{ pp(-quantity) }}</template>
 				</td>
 			</tr>
 			<tr>
 				<th class="py-0.5 pr-1 text-gray-900 font-semibold text-start">Total</th>
-				<th class="py-0.5 px-1 text-gray-900 text-end">{{ pp(total_dr) }}</th>
-				<th class="py-0.5 pl-1 text-gray-900 text-end">{{ pp(-total_cr) }}</th>
+				<th class="py-0.5 px-1 text-gray-900 text-end">{{ pp(total_dr!) }}</th>
+				<th class="py-0.5 pl-1 text-gray-900 text-end">{{ pp(-total_cr!) }}</th>
 			</tr>
 		</tbody>
 	</table>
@@ -51,17 +51,28 @@
 <script setup lang="ts">
 	import { computed, ref } from 'vue';
 	
-	import { db, totalBalances } from '../db.ts';
+	import { db } from '../db.ts';
 	import { pp } from '../display.ts';
+	import { ReportingStage, ReportingWorkflow, TrialBalanceReport } from '../reporting.ts';
 	
-	const accounts = ref([] as {account: string, quantity: number}[]);
+	const report = ref(null as TrialBalanceReport | null);
 	
-	const total_dr = computed(() => accounts.value.reduce((acc, x) => x.quantity > 0 ? acc + x.quantity : acc, 0));
-	const total_cr = computed(() => accounts.value.reduce((acc, x) => x.quantity < 0 ? acc + x.quantity : acc, 0));
+	// WebKit: Iterator.reduce not supported - https://bugs.webkit.org/show_bug.cgi?id=248650
+	const total_dr = computed(() => report.value ?
+		[...report.value.balances.values()].reduce((acc, x) => x > 0 ? acc + x : acc, 0)
+		: 0
+	);
+	const total_cr = computed(() => report.value ?
+		[...report.value.balances.values()].reduce((acc, x) => x < 0 ? acc + x : acc, 0)
+		: 0
+	);
 	
 	async function load() {
 		const session = await db.load();
-		accounts.value = await totalBalances(session);
+		const reportingWorkflow = new ReportingWorkflow();
+		await reportingWorkflow.generate(session);
+		
+		report.value = reportingWorkflow.getReportAtStage(ReportingStage.OrdinaryAPITransactions, TrialBalanceReport) as TrialBalanceReport;
 	}
 	load();
 </script>

src/reporting.ts

@@ -0,0 +1,154 @@
+/*
+	DrCr: Web-based double-entry bookkeeping framework
+	Copyright (C) 2022–2024  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/>.
+*/
+
+import { asCost } from './amounts.ts';
+import { JoinedTransactionPosting, StatementLine, Transaction, joinedToTransactions, totalBalances } from './db.ts';
+import { ExtendedDatabase } from './dbutil.ts';
+
+export enum ReportingStage {
+	// Load transactions from database
+	TransactionsFromDatabase = 100,
+	
+	// Load unreconciled statement lines and other ordinary API transactions
+	OrdinaryAPITransactions = 200,
+}
+
+export class ReportingWorkflow {
+	transactionsForStage: Map<ReportingStage, Transaction[]> = new Map();
+	reportsForStage: Map<ReportingStage, Report[]> = new Map();
+	
+	async generate(session: ExtendedDatabase) {
+		// ------------------------
+		// TransactionsFromDatabase
+		
+		let balances: Map<string, number>;
+		
+		{
+			// Load balances from database
+			balances = await totalBalances(session);
+			this.reportsForStage.set(ReportingStage.TransactionsFromDatabase, [new TrialBalanceReport(balances)]);
+			
+			// Load transactions from database
+			const joinedTransactionPostings: JoinedTransactionPosting[] = await session.select(
+				`SELECT transaction_id, dt, transactions.description AS transaction_description, postings.id, postings.description, account, quantity, commodity, running_balance
+				FROM transactions
+				JOIN postings ON transactions.id = postings.transaction_id
+				ORDER BY dt, transaction_id, postings.id`
+			);
+			const transactions = joinedToTransactions(joinedTransactionPostings);
+			this.transactionsForStage.set(ReportingStage.TransactionsFromDatabase, transactions);
+		}
+		
+		// -----------------------
+		// OrdinaryAPITransactions
+		
+		{
+			// Get unreconciled statement lines
+			const unreconciledStatementLines: StatementLine[] = await session.select(
+				// On testing, JOIN is much faster than WHERE NOT EXISTS
+				`SELECT statement_lines.* FROM statement_lines
+				LEFT JOIN statement_line_reconciliations ON statement_lines.id = statement_line_reconciliations.statement_line_id
+				WHERE statement_line_reconciliations.id IS NULL`
+			);
+			
+			const transactions = [];
+			for (const line of unreconciledStatementLines) {
+				const unclassifiedAccount = line.quantity >= 0 ? 'Unclassified Statement Line Debits' : 'Unclassified Statement Line Credits';
+				transactions.push(new Transaction(
+					null,
+					line.dt,
+					line.description,
+					[
+						{
+							id: null,
+							description: null,
+							account: line.source_account,
+							quantity: line.quantity,
+							commodity: line.commodity
+						},
+						{
+							id: null,
+							description: null,
+							account: unclassifiedAccount,
+							quantity: -line.quantity,
+							commodity: line.commodity
+						}
+					]
+				));
+			}
+			this.transactionsForStage.set(ReportingStage.OrdinaryAPITransactions, transactions);
+			
+			// Recompute balances
+			balances = applyTransactionsToBalances(balances, transactions);
+			this.reportsForStage.set(ReportingStage.OrdinaryAPITransactions, [new TrialBalanceReport(balances)]);
+		}
+	}
+	
+	getReportAtStage(stage: ReportingStage, reportType: any): Report {
+		// TODO: This function needs generics
+		const reportsForTheStage = this.reportsForStage.get(stage);
+		if (!reportsForTheStage) {
+			throw new Error('Attempt to get report for unavailable stage');
+		}
+		
+		const report = reportsForTheStage.find((r) => r instanceof reportType);
+		if (!report) {
+			throw new Error('Report does not exist');
+		}
+		
+		return report;
+	}
+	
+	getTransactionsAtStage(stage: ReportingStage): Transaction[] {
+		const transactions: Transaction[] = [];
+		for (const [curStage, curTransactions] of this.transactionsForStage.entries()) {
+			if (curStage <= stage) {
+				transactions.push(...curTransactions);
+			}
+		}
+		return transactions;
+	}
+}
+
+interface Report {
+}
+
+export class TrialBalanceReport implements Report {
+	constructor(
+		public balances: Map<string, number>
+	) {}
+}
+
+function applyTransactionsToBalances(balances: Map<string, number>, transactions: Transaction[]): Map<string, number> {
+	// Initialise new balances
+	const newBalances: Map<string, number> = new Map([...balances.entries()]);
+	
+	// Apply transactions
+	for (const transaction of transactions) {
+		for (const posting of transaction.postings) {
+			const openingBalance = newBalances.get(posting.account) ?? 0;
+			const quantityCost = asCost(posting.quantity, posting.commodity);
+			const runningBalance = openingBalance + quantityCost;
+			
+			newBalances.set(posting.account, runningBalance);
+		}
+	}
+	
+	// Sort accounts
+	return new Map([...newBalances.entries()].sort((a, b) => a[0].localeCompare(b[0])));
+}