Implement cash flow statement (direct)

ledger_pyreport/__init__.py

@@ -136,6 +136,43 @@ def pandl():
 	
 	return flask.render_template('pandl.html', period=describe_period(date_end, date_beg), ledger=l, pandls=pandls, accounts=accounts, config=config, report_currency=report_currency, cash=cash, scope=scope)
 
+@app.route('/cashflow')
+def cashflow():
+	date_beg = datetime.strptime(flask.request.args['date_beg'], '%Y-%m-%d')
+	date_end = datetime.strptime(flask.request.args['date_end'], '%Y-%m-%d')
+	compare = int(flask.request.args['compare'])
+	method = flask.request.args['method']
+	
+	dates_beg = [date_beg.replace(year=date_beg.year - i) for i in range(0, compare + 1)]
+	dates_end = [date_end.replace(year=date_end.year - i) for i in range(0, compare + 1)]
+	
+	report_currency = Currency(*config['report_currency'])
+	l = ledger.raw_transactions_at_date(date_end)
+	
+	cash_accounts = [a for a in l.accounts.values() if a.is_cash]
+	
+	# Calculate opening and closing cash
+	opening_balances = []
+	closing_balances = []
+	cashflows = []
+	for de, db in zip(dates_end, dates_beg):
+		tb = accounting.trial_balance(l.clone(), db - timedelta(days=1), db, report_currency)
+		opening_balances.append(sum((tb.get_balance(a) for a in cash_accounts), Balance()).exchange(report_currency, True))
+		
+		tb = accounting.trial_balance(l.clone(), de, db, report_currency)
+		closing_balances.append(sum((tb.get_balance(a) for a in cash_accounts), Balance()).exchange(report_currency, True))
+		
+		cashflows.append(accounting.account_flows(tb.ledger, de, db, cash_accounts))
+	
+	if method == 'direct':
+		# Delete accounts with always zero balances
+		accounts = list(l.accounts.values())
+		for account in accounts[:]:
+			if all(p.get_balance(account) == 0 and p.get_total(account) == 0 for p in cashflows):
+				accounts.remove(account)
+		
+		return flask.render_template('cashflow_direct.html', period=describe_period(date_end, date_beg), ledger=l, cashflows=cashflows, opening_balances=opening_balances, closing_balances=closing_balances, accounts=accounts, config=config, report_currency=report_currency)
+
 @app.route('/transactions')
 def transactions():
 	date_beg = datetime.strptime(flask.request.args['date_beg'], '%Y-%m-%d')

ledger_pyreport/accounting.py

@@ -166,3 +166,18 @@ def ledger_to_cash(ledger, currency):
 			account_to_cash(account, currency)
 	
 	return ledger
+
+# Summarise related transactions
+def account_flows(ledger, date, pstart, accounts):
+	transactions = [t for t in ledger.transactions if any(p.account in accounts for p in t.postings) and t.date <= date and t.date >= pstart]
+	
+	tb = TrialBalance(ledger, date, pstart)
+	
+	for transaction in transactions:
+		for posting in transaction.postings:
+			if posting.account in accounts:
+				continue
+			
+			tb.balances[posting.account.name] = tb.get_balance(posting.account) - posting.amount
+	
+	return tb

ledger_pyreport/jinja2/cashflow_direct.html

@@ -0,0 +1,76 @@
+{#
+    ledger-pyreport
+    Copyright © 2020  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/>.
+#}
+
+{% extends 'base_report.html' %}
+
+{% macro print_rows(account, invert=False, level=0) %}
+	<tr>
+		<td style="padding-left: calc(2px + {{ level }}em);">
+			{% if cashflows|length == 1 %}
+				<a href="/transactions?{{ {'date_end': cashflows[0].date.strftime('%Y-%m-%d'), 'date_beg': cashflows[0].pstart.strftime('%Y-%m-%d'), 'account': account.name, 'cash': 'on' if cash else ''}|urlencode }}">{{ account.bits[-1] }}</a>
+			{% else %}
+				{{ account.bits[-1] }}
+			{% endif %}
+		</td>
+		{% for cashflow in cashflows %}
+			{% set amount = (-cashflow.get_balance(account) if invert else cashflow.get_balance(account)).exchange(report_currency, True) %}
+			<td>{% if not amount.near_zero %}{{ amount|a('/transactions?' + {'date': cashflow.date.strftime('%Y-%m-%d'), 'pstart': cashflow.pstart.strftime('%Y-%m-%d'), 'account': account.name, 'cash': 'on' if cash else ''}|urlencode) }}{% endif %}</td>
+		{% endfor %}
+	</tr>
+	
+	{% for child in account.children|sort(attribute='name') if child in accounts %}
+		{{ print_rows(child, invert, level + 1) }}
+	{% endfor %}
+{% endmacro %}
+
+{% block title %}Cash Flow Statement for the {{ period }}{% endblock %}
+
+{% block report %}
+	<h1>Cash Flow Statement</h1>
+	<h2>For the {{ period }}</h2>
+	
+	<table class="ledger onedesc">
+		{# Cash flows #}
+		<tr>
+			<th class="h2">Cash Inflows (Outflows)</th>
+			{% for cashflow in cashflows %}<th class="h2">{{ cashflow.date.strftime('%Y') }}&nbsp;</th>{% endfor %}
+		</tr>
+		{% for account in ledger.root_account.children|sort(attribute='name') if account in accounts %}
+			{{ print_rows(account, invert=invert) }}
+		{% endfor %}
+		<tr class="total">
+			<td>Net Cash Inflow (Outflow)</td>
+			{% for cashflow in cashflows %}<td>{{ cashflow.get_total(ledger.root_account).exchange(report_currency, True)|a }}</td>{% endfor %}
+		</tr>
+		<tr><td colspan="{{ cashflows|length + 1 }}">&nbsp;</td></tr>
+		
+		{# Summary #}
+		<tr>
+			<td>Opening Cash</td>
+			{% for opening_balance in opening_balances %}<td>{{ opening_balance|a }}</td>{% endfor %}
+		</tr>
+		<tr>
+			<td>Net Cash Inflow (Outflow)</td>
+			{% for cashflow in cashflows %}<td>{{ cashflow.get_total(ledger.root_account).exchange(report_currency, True)|a }}</td>{% endfor %}
+		</tr>
+		<tr class="total">
+			<td>Closing Cash</td>
+			{% for closing_balance in closing_balances %}<td>{{ closing_balance|a }}</td>{% endfor %}
+		</tr>
+	</table>
+{% endblock %}

ledger_pyreport/jinja2/index.html

@@ -56,6 +56,19 @@
 		</form>
 	</div>
 	
+	<div style="margin-bottom: 1em;">
+		<form action="{{ url_for('cashflow') }}">
+			<button type="submit">Cash flows</button>
+			<label>Begin date: <input name="date_beg" data-inputgroup="pstart" value="{{ pstart.strftime('%Y-%m-%d') }}" style="width: 6em;" oninput="txtc(this)"></label>
+			<label>End date: <input name="date_end" data-inputgroup="date" value="{{ date.strftime('%Y-%m-%d') }}" style="width: 6em;" oninput="txtc(this)"></label>
+			<label>Compare <input name="compare" data-inputgroup="compare" value="0" style="width: 2em;" oninput="txtc(this)"> periods</label>
+			<label>Method: <select name="method">
+				<option value="indirect" selected>Indirect</option>
+				<option value="direct">Direct</option>
+			</select></label>
+		</form>
+	</div>
+	
 	<div style="margin-bottom: 1em;">
 		<form action="{{ url_for('transactions') }}">
 			<button type="submit">General ledger</button>