austax: Implement creating multiple CGT adjustments

src/main.ts

@@ -46,8 +46,9 @@ async function initApp() {
 		{ path: '/trial-balance', name: 'trial-balance', component: () => import('./reports/TrialBalanceReport.vue') },
 		// TODO: Generate this list dynamically
 		{ path: '/austax/cgt-adjustments', name: 'cgt-adjustments', component: () => import('./plugins/austax/CGTAdjustmentsView.vue') },
-		{ path: '/austax/cgt-adjustments/new', name: 'cgt-adjustments-new', component: () => import('./plugins/austax/NewCGTAdjustmentView.vue') },
 		{ path: '/austax/cgt-adjustments/edit/:id', name: 'cgt-adjustments-edit', component: () => import('./plugins/austax/EditCGTAdjustmentView.vue') },
+		{ path: '/austax/cgt-adjustments/new', name: 'cgt-adjustments-new', component: () => import('./plugins/austax/NewCGTAdjustmentView.vue') },
+		{ path: '/austax/cgt-adjustments/multinew', name: 'cgt-adjustments-multinew', component: () => import('./plugins/austax/MultiNewCGTAdjustmentView.vue') },
 		{ path: '/austax/cgt-assets', name: 'cgt-assets', component: () => import('./plugins/austax/CGTAssetsView.vue') },
 		{ path: '/austax/tax-summary', name: 'tax-summary', component: () => import('./plugins/austax/TaxSummaryReport.vue') },
 	];

src/plugins/austax/CGTAdjustmentsView.vue

@@ -26,6 +26,10 @@
 			<PlusIcon class="w-4 h-4" />
 			New CGT adjustment
 		</a>
+		<a :href="$router.resolve({name: 'cgt-adjustments-multinew'}).fullPath" class="btn-secondary pl-2 text-emerald-700 ring-emerald-600" onclick="return openLinkInNewWindow(this);">
+			<PlusIcon class="w-4 h-4" />
+			Multiple CGT adjustments
+		</a>
 	</div>
 	
 	<table class="min-w-full">

src/plugins/austax/MultiNewCGTAdjustmentView.vue

@@ -0,0 +1,214 @@
+<!--
+	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/>.
+-->
+
+<template>
+	<h1 class="page-heading mb-4">
+		Multiple CGT adjustments
+	</h1>
+	
+	<div class="grid grid-cols-[max-content_1fr] space-y-2 mb-4 items-baseline">
+		<h2 class="col-span-2 text-xl text-gray-900 font-semibold">CGT assets</h2>
+		
+		<label for="account" class="block text-gray-900 pr-4">Account</label>
+		<ComboBoxAccounts v-model="account" />
+		<label for="commodity" class="block text-gray-900 pr-4">Commodity</label>
+		<div>
+			<input type="text" class="bordered-field" name="commodity" id="commodity" placeholder=" " v-model="commodity">
+		</div>
+		
+		<div class="rounded-md bg-blue-50 p-4 col-span-2">
+			<div class="flex">
+				<div class="flex-shrink-0">
+					<InformationCircleIcon class="w-5 h-5 text-blue-400" />
+				</div>
+				<div class="ml-3 flex-1">
+					<p class="text-sm text-blue-700">The total cost adjustment will be distributed proportionally across all matching CGT assets.</p>
+				</div>
+			</div>
+		</div>
+		
+		<h2 class="col-span-2 text-xl text-gray-900 font-semibold pt-4">CGT adjustment</h2>
+		
+		<label for="dt" class="block text-gray-900 pr-4">Adjustment date</label>
+		<div>
+			<input type="date" class="bordered-field" name="dt" id="dt" v-model="dt">
+		</div>
+		<label for="description" class="block text-gray-900 pr-4">Description</label>
+		<div>
+			<input type="text" class="bordered-field" name="description" id="description" placeholder=" " v-model="description">
+		</div>
+		<label for="cost_adjustment" class="block text-gray-900 pr-4">Total cost adjustment</label>
+		<div class="relative shadow-sm">
+			<div class="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3">
+				<span class="text-gray-500">{{ db.metadata.reporting_commodity }}</span>
+			</div>
+			<input type="number" class="bordered-field pl-7 pr-16" step="0.01" v-model="cost_adjustment_abs" placeholder="0.00">
+			<div class="absolute inset-y-0 right-0 flex items-center">
+				<select class="h-full border-0 bg-transparent py-0 pl-2 pr-8 text-gray-900 focus:ring-2 focus:ring-inset focus:ring-indigo-600" v-model="sign">
+					<option value="dr">Dr</option>
+					<option value="cr">Cr</option>
+				</select>
+			</div>
+		</div>
+	</div>
+	
+	<div class="flex justify-end mt-4 space-x-2">
+		<button class="btn-primary" @click="saveAdjustment">Save</button>
+	</div>
+</template>
+
+<script setup lang="ts">
+	import dayjs from 'dayjs';
+	import { InformationCircleIcon } from '@heroicons/vue/20/solid';
+	import { getCurrentWindow } from '@tauri-apps/api/window';
+	import { ref } from 'vue';
+	
+	import { CGTAsset } from './cgt.ts';
+	import ComboBoxAccounts from '../../components/ComboBoxAccounts.vue';
+	import { DT_FORMAT, JoinedTransactionPosting, db, deserialiseAmount } from '../../db.ts';
+	import { ppWithCommodity } from '../../display.ts';
+	
+	const account = ref('');
+	const commodity = ref('');
+	const dt = ref(dayjs().format('YYYY-MM-DD'));
+	const description = ref('');
+	const cost_adjustment_abs = ref(null! as number);
+	const sign = ref('dr');
+	
+	async function saveAdjustment() {
+		// TODO: Preview mode?
+		
+		const totalAdjustmentAbs = deserialiseAmount('' + cost_adjustment_abs.value);
+		const totalAdjustment = sign.value === 'dr' ? totalAdjustmentAbs.quantity : -totalAdjustmentAbs.quantity;
+		
+		// Get all postings to the CGT asset account
+		const session = await db.load();
+		const cgtPostings = await session.select(
+			`SELECT *
+			FROM joined_transactions
+			WHERE account = $1`,
+			[account.value]
+		) as JoinedTransactionPosting[];
+		
+		// Process postings to determine final balances
+		// Based on cgt.ts getCGTAssets
+		const assets: CGTAsset[] = [];
+		
+		for (const posting of cgtPostings) {
+			// Check for matching asset
+			if (posting.commodity.indexOf(' {') < 0) {
+				if (posting.commodity !== commodity.value) {
+					continue;
+				}
+			} else {
+				const postingCommodityName = posting.commodity.substring(0, posting.commodity.indexOf(' {'));
+				if (postingCommodityName !== commodity.value) {
+					continue;
+				}
+			}
+			
+			// This is a matching CGT asset
+			
+			if (posting.quantity >= 0) {
+				// Debit CGT asset - create new CGTAsset
+				assets.push(new CGTAsset(posting.quantity, posting.commodity, posting.account, posting.dt))
+			} else {
+				// Credit CGT asset
+				// Currently only a full disposal of a CGT asset is implemented
+				
+				// Find matching CGT asset
+				const asset = assets.find((a) => a.commodity === posting.commodity && a.account === posting.account);
+				
+				if (!asset) {
+					throw new Error('Attempted credit of ' + ppWithCommodity(posting.quantity, posting.commodity) + ' without preceding debit balance');
+				}
+				if (asset.quantity + posting.quantity < 0) {
+					throw new Error('Attempted credit of ' + ppWithCommodity(posting.quantity, posting.commodity) + ' which exceeds debit balance of ' + ppWithCommodity(asset.quantity, asset.commodity));
+				}
+				if (asset.quantity + posting.quantity != 0) {
+					throw new Error('Partial disposal of CGT asset not implemented');
+				}
+				
+				assets.splice(assets.indexOf(asset), 1);
+			}
+		}
+		
+		if (assets.length === 0) {
+			throw new Error('No matching CGT assets');
+		}
+		
+		// Distribute total adjustment across matching assets
+		const totalQuantity = assets.reduce((acc, asset) => acc + asset.quantity, 0)
+		const cgtAdjustments = [];
+		
+		for (let i = 0; i < assets.length; i++) {
+			// This might be fractional at this stage
+			cgtAdjustments[i] = totalAdjustment * assets[i].quantity / totalQuantity;
+		}
+		
+		// Compute the difference due to rounding
+		const roundingShortfall = cgtAdjustments.reduce((acc, adj) => acc - Math.floor(Math.abs(adj)), Math.abs(totalAdjustment));
+		
+		// Sort by largest remainder
+		const largestRemainders = cgtAdjustments.map((adj, i) => [Math.abs(adj) - Math.floor(Math.abs(adj)), i]);
+		largestRemainders.sort((a, b) => b[0] - a[0]);
+		
+		// Round up as many as required to equal the total adjustment
+		let i = 0;
+		for (; i < roundingShortfall; i++) {
+			const assetIndex = largestRemainders[i][1];
+			const cgtAdjustment: number = cgtAdjustments[assetIndex];
+			
+			// Round away from zero
+			const cgtAdjustmentAbs = Math.floor(Math.abs(cgtAdjustment)) + 1;
+			cgtAdjustments[assetIndex] = cgtAdjustmentAbs * Math.sign(cgtAdjustment);
+		}
+		
+		// Round others down
+		for (; i < largestRemainders.length; i++) {
+			const assetIndex = largestRemainders[i][1];
+			const cgtAdjustment: number = cgtAdjustments[assetIndex];
+			
+			// Round towards zero
+			const cgtAdjustmentAbs = Math.floor(Math.abs(cgtAdjustment));
+			cgtAdjustments[assetIndex] = cgtAdjustmentAbs * Math.sign(cgtAdjustment);
+		}
+		
+		// Sanity check
+		const totalRoundedAdjustment = cgtAdjustments.reduce((acc, adj) => acc + adj, 0);
+		if (totalRoundedAdjustment !== totalAdjustment) {
+			throw new Error('Rounding unexpectedly changed total CGT adjustment amount');
+		}
+		
+		// Add adjustments to database atomically
+		const dbTransaction = await session.begin();
+		for (let i = 0; i < assets.length; i++) {
+			const asset = assets[i];
+			const cgtAdjustment = cgtAdjustments[i];
+			
+			await dbTransaction.execute(
+				`INSERT INTO austax_cgt_cost_adjustments (quantity, commodity, account, acquisition_dt, dt, description, cost_adjustment)
+				VALUES ($1, $2, $3, $4, $5, $6, $7)`,
+				[asset.quantity, asset.commodity, asset.account, asset.acquisition_dt, dayjs(dt.value).format(DT_FORMAT), description.value, cgtAdjustment]
+			);
+		}
+		await dbTransaction.commit();
+		
+		await getCurrentWindow().close();
+	}
+</script>