From a474fc89d7d1183cc66eb24048246f011e2d9654 Mon Sep 17 00:00:00 2001
From: RunasSudo <runassudo@yingtongli.me>
Date: Sat, 24 Dec 2022 20:13:11 +1100
Subject: [PATCH] Allow entry of general journal transaction with multiple
 postings

---
 drcr/models.py                                | 19 +++++--
 .../general_journal/general_journal_edit.html | 53 +++++++++++++++----
 2 files changed, 58 insertions(+), 14 deletions(-)

diff --git a/drcr/models.py b/drcr/models.py
index 0afcda8..57ccf2e 100644
--- a/drcr/models.py
+++ b/drcr/models.py
@@ -23,13 +23,20 @@ class Transaction:
 		self.postings = postings or []
 	
 	def assert_valid(self):
-		"""Assert that debits equal credits, and commodities are compatible"""
+		"""Assert that debits equal credits"""
 		
-		if any(p.commodity != self.postings[0].commodity for p in self.postings[1:]):
-			raise AssertionError('Transaction contains multiple commodities')
+		total_dr = 0
+		total_cr = 0
 		
-		if sum(p.quantity for p in self.postings) != 0:
-			raise AssertionError('Transaction debits and credits do not balance')
+		for posting in self.postings:
+			amount_cost = posting.amount().as_cost().quantity
+			if amount_cost > 0:
+				total_dr += amount_cost
+			elif amount_cost < 0:
+				total_cr -= amount_cost
+		
+		if total_dr != total_cr:
+			raise AssertionError('Transaction debits ({}) and credits ({}) do not balance'.format(total_dr, total_cr))
 
 class Posting:
 	def __init__(self, description=None, account=None, quantity=None, commodity=None):
@@ -86,6 +93,8 @@ class Amount:
 		
 		if '{{' in self.commodity:
 			cost = float(self.commodity[self.commodity.index('{{')+2:self.commodity.index('}}')])
+			if self.quantity < 0:
+				cost = -cost
 			return Amount(round(cost * (10**AMOUNT_DPS)), '$')
 		elif '{' in self.commodity:
 			cost = float(self.commodity[self.commodity.index('{')+1:self.commodity.index('}')])
diff --git a/drcr/templates/general_journal/general_journal_edit.html b/drcr/templates/general_journal/general_journal_edit.html
index 8724316..e0ea354 100644
--- a/drcr/templates/general_journal/general_journal_edit.html
+++ b/drcr/templates/general_journal/general_journal_edit.html
@@ -43,35 +43,36 @@
 					<td></td>
 					<td>
 						<div class="input-group">
-							<select class="form-select" name="sign" style="flex-grow:0;min-width:5em">
+							<select class="form-select" name="sign" style="flex-grow:0;min-width:5em" onchange="changeDrCr(this)">
 								<option value="dr" selected>Dr</option>
-								{#<option value="cr">Cr</option>#}
-								{# FIXME: Multiple postings, etc. #}
+								<option value="cr">Cr</option>
 							</select>
 							<input type="text" name="account" class="form-control">
+							<a class="btn btn-outline-primary" href="#" onclick="addPosting(this);return false;"><i class="bi bi-plus-circle-fill"></i></a>
 						</div>
 					</td>
-					<td>
+					<td class="amount-dr has-amount">
 						<div class="input-group">
 							<div class="input-group-text">$</div>
 							<input type="text" name="amount" value="" class="form-control">
 						</div>
-					<td></td>
+					<td class="amount-cr"></td>
 				</tr>
 				<tr>
 					<td></td>
 					<td></td>
 					<td>
 						<div class="input-group">
-							<select class="form-select" name="sign" style="flex-grow:0;min-width:5em">
-								{#<option value="dr">Dr</option>#}
+							<select class="form-select" name="sign" style="flex-grow:0;min-width:5em" onchange="changeDrCr(this)">
+								<option value="dr">Dr</option>
 								<option value="cr" selected>Cr</option>
 							</select>
 							<input type="text" name="account" class="form-control">
+							<a class="btn btn-outline-primary" href="#" onclick="addPosting(this);return false;"><i class="bi bi-plus-circle-fill"></i></a>
 						</div>
 					</td>
-					<td></td>
-					<td>
+					<td class="amount-dr"></td>
+					<td class="amount-cr has-amount">
 						<div class="input-group">
 							<div class="input-group-text">$</div>
 							<input type="text" name="amount" value="" class="form-control">
@@ -86,3 +87,37 @@
 		</div>
 	</form>
 {% endblock %}
+
+{% block scripts %}
+	<script>
+		function changeDrCr(el) {
+			let trPosting = el.parentNode.parentNode.parentNode;
+			let amountContent = trPosting.querySelector('.has-amount').innerHTML;
+			let amountValue = trPosting.querySelector('.has-amount input').value;
+			
+			// Remove input boxes
+			for (let td of trPosting.querySelectorAll('.amount-dr, .amount-cr')) {
+				td.innerHTML = '';
+				td.classList.remove('has-amount');
+			}
+			
+			// Add correct input box
+			let td = trPosting.querySelector(el.value === 'dr' ? '.amount-dr' : '.amount-cr');
+			td.innerHTML = amountContent;
+			td.classList.add('has-amount');
+			td.querySelector('input').value = amountValue;
+		}
+		
+		function addPosting(el) {
+			let trPosting = el.parentNode.parentNode.parentNode;
+			let sign = trPosting.querySelector('select').value; // Use same sign as row clicked
+			
+			let inputAmount = '<div class="input-group"><div class="input-group-text">$</div><input type="text" name="amount" class="form-control"></div>';
+			
+			// Add new posting row
+			let trNew = document.createElement('tr');
+			trNew.innerHTML = '<tr><td></td><td></td><td><div class="input-group"><select class="form-select" name="sign" style="flex-grow:0;min-width:5em" onchange="changeDrCr(this)"><option value="dr"' + (sign === 'dr' ? ' selected' : '') + '>Dr</option><option value="cr"' + (sign === 'cr' ? ' selected' : '') + '>Cr</option></select><input type="text" name="account" class="form-control"><a class="btn btn-outline-primary" href="#" onclick="addPosting(this);return false;"><i class="bi bi-plus-circle-fill"></i></a></div></td>' + (sign === 'dr' ? ('<td class="amount-dr has-amount">' + inputAmount + '</td>') : '<td class="amount-dr"></td>') + (sign === 'cr' ? ('<td class="amount-cr has-amount">' + inputAmount + '</td>') : '<td class="amount-cr"></td>') + '</tr>';
+			trPosting.after(trNew);
+		}
+	</script>
+{% endblock %}