diff --git a/config.example.yml b/config.example.yml
index 360dda7..574f4bc 100644
--- a/config.example.yml
+++ b/config.example.yml
@@ -1,7 +1,7 @@
 # Set up how we will call Ledger
 ledger_file: /path/to/ledger.journal
 ledger_args: ['--pedantic', '--recursive-aliases']
-report_currency: $
+report_currency: ['$', True] # True if prefix, False if suffix
 
 # Tell ledger-pyreport about the top-level account categories
 assets_account: Assets
diff --git a/ledger_pyreport/__init__.py b/ledger_pyreport/__init__.py
index 692eb4b..97f7ee4 100644
--- a/ledger_pyreport/__init__.py
+++ b/ledger_pyreport/__init__.py
@@ -16,6 +16,8 @@
 
 from . import accounting
 from . import ledger
+from .config import config
+from .model import *
 
 from datetime import datetime, timedelta
 from decimal import Decimal
@@ -39,36 +41,45 @@ def trial():
 	
 	if compare == 0:
 		# Get trial balance
-		trial_balance = ledger.trial_balance(date, pstart)
+		l = ledger.raw_transactions_at_date(date)
+		trial_balance = accounting.trial_balance(l, date, pstart)
 		
-		total_dr = Decimal(0)
-		total_cr = Decimal(0)
+		report_currency = Currency(*config['report_currency'])
+		trial_balance = accounting.add_unrealized_gains(trial_balance, report_currency)
 		
-		for account in trial_balance.accounts.values():
-			balance = trial_balance.get_balance(account.name)
+		total_dr = Amount(0, report_currency)
+		total_cr = Amount(0, report_currency)
+		
+		for account in l.accounts.values():
+			# Display in "cost basis" as we have already accounted for unrealised gains
+			balance = trial_balance.get_balance(account).exchange(report_currency, True)
 			if balance > 0:
 				total_dr += balance
 			else:
 				total_cr -= balance
 		
-		return flask.render_template('trial.html', trial_balance=trial_balance, total_dr=total_dr, total_cr=total_cr)
+		return flask.render_template('trial.html', date=date, pstart=pstart, trial_balance=trial_balance, accounts=sorted(l.accounts.values(), key=lambda a: a.name), total_dr=total_dr, total_cr=total_cr, report_currency=report_currency)
 	else:
 		# Get multiple trial balances for comparison
 		dates = [date.replace(year=date.year - i) for i in range(0, compare + 1)]
 		pstarts = [pstart.replace(year=pstart.year - i) for i in range(0, compare + 1)]
 		
-		trial_balances = [ledger.trial_balance(d, p) for d, p in zip(dates, pstarts)]
+		report_currency = Currency(*config['report_currency'])
+		l = ledger.raw_transactions_at_date(date)
+		trial_balances = [accounting.add_unrealized_gains(accounting.trial_balance(l, d, p), report_currency) for d, p in zip(dates, pstarts)]
 		
 		# Delete accounts with always zero balances
-		accounts = list(trial_balances[0].accounts.values())
+		accounts = list(trial_balances[0].ledger.accounts.values())
 		for account in accounts[:]:
-			if all(t.get_balance(account.name) == 0 for t in trial_balances):
+			if all(t.get_balance(account) == 0 for t in trial_balances):
 				accounts.remove(account)
 		
-		return flask.render_template('trial_multiple.html', trial_balances=trial_balances, accounts=accounts)
+		return flask.render_template('trial_multiple.html', trial_balances=trial_balances, accounts=sorted(accounts, key=lambda a: a.name), report_currency=report_currency)
 
 @app.route('/balance')
 def balance():
+	raise Exception('NYI')
+	
 	date = datetime.strptime(flask.request.args['date'], '%Y-%m-%d')
 	pstart = datetime.strptime(flask.request.args['pstart'], '%Y-%m-%d')
 	compare = int(flask.request.args['compare'])
@@ -89,6 +100,8 @@ def balance():
 
 @app.route('/pandl')
 def pandl():
+	raise Exception('NYI')
+	
 	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'])
@@ -118,36 +131,45 @@ def pandl():
 def transactions():
 	date = datetime.strptime(flask.request.args['date'], '%Y-%m-%d')
 	pstart = datetime.strptime(flask.request.args['pstart'], '%Y-%m-%d')
+	account = flask.request.args.get('account', None)
 	
-	trial_balance_pstart = ledger.trial_balance(pstart, pstart)
-	account = trial_balance_pstart.get_account(flask.request.args['account'])
-	opening_balance = trial_balance_pstart.get_balance(account.name)
+	# General ledger
+	l = ledger.raw_transactions_at_date(date)
 	
-	balance = opening_balance
-	transactions = account.get_transactions(date, pstart)
-	for transaction in transactions:
-		for posting in transaction.postings[:]:
-			if posting.account == account.name:
-				transaction.postings.remove(posting)
-			else:
-				posting.amount = -posting.amount # In terms of effect on this account
-				balance += posting.amount
-				posting.balance = balance
+	# Unrealized gains
+	report_currency = Currency(*config['report_currency'])
+	l = accounting.add_unrealized_gains(accounting.trial_balance(l, date, pstart), report_currency).ledger
 	
-	trial_balance = ledger.trial_balance(date, pstart)
-	closing_balance = trial_balance.get_balance(account.name)
-	
-	return flask.render_template('transactions.html', date=date, pstart=pstart, account=account, transactions=transactions, opening_balance=opening_balance, closing_balance=closing_balance)
+	if not account:
+		transactions = [t for t in l.transactions if t.date <= date and t.date >= pstart]
+		
+		total_dr = sum((p.amount for t in transactions for p in t.postings if p.amount > 0), Balance()).exchange(report_currency, True)
+		total_cr = sum((p.amount for t in transactions for p in t.postings if p.amount < 0), Balance()).exchange(report_currency, True)
+		
+		return flask.render_template('transactions.html', date=date, pstart=pstart, account=None, ledger=l, transactions=transactions, total_dr=total_dr, total_cr=total_cr, report_currency=report_currency)
+	else:
+		account = l.get_account(account)
+		transactions = [t for t in l.transactions if t.date <= date and t.date >= pstart and any(p.account == account for p in t.postings)]
+		
+		opening_balance = accounting.trial_balance(l, pstart, pstart).get_balance(account).exchange(report_currency, True)
+		closing_balance = accounting.trial_balance(l, date, pstart).get_balance(account).exchange(report_currency, True)
+		
+		return flask.render_template('transactions.html', date=date, pstart=pstart, account=account, ledger=l, transactions=transactions, opening_balance=opening_balance, closing_balance=closing_balance, report_currency=report_currency)
 
 @app.template_filter('a')
 def filter_amount(amt):
-	if amt < 0.005 and amt >= -0.005:
+	if amt.amount < 0.005 and amt.amount >= -0.005:
 		return flask.Markup('0.00&nbsp;')
 	elif amt > 0:
-		return flask.Markup('{:,.2f}&nbsp;'.format(amt).replace(',', '&#8239;')) # Narrow no-break space
+		return flask.Markup('{:,.2f}&nbsp;'.format(amt.amount).replace(',', '&#8239;')) # Narrow no-break space
 	else:
-		return flask.Markup('({:,.2f})'.format(-amt).replace(',', '&#8239;'))
+		return flask.Markup('({:,.2f})'.format(-amt.amount).replace(',', '&#8239;'))
 
 @app.template_filter('b')
 def filter_amount_positive(amt):
-	return flask.Markup('{:,.2f}'.format(amt).replace(',', '&#8239;'))
+	return flask.Markup('{:,.2f}'.format(amt.amount).replace(',', '&#8239;'))
+	#return flask.Markup('{:,.2f} {}'.format(amt.amount, amt.currency.name).replace(',', '&#8239;'))
+
+@app.template_filter('bb')
+def filter_balance_positive(balance):
+	return flask.Markup('<br>'.join(filter_amount_positive(a) for a in balance.amounts))
diff --git a/ledger_pyreport/accounting.py b/ledger_pyreport/accounting.py
index 3eac578..468f124 100644
--- a/ledger_pyreport/accounting.py
+++ b/ledger_pyreport/accounting.py
@@ -17,18 +17,36 @@
 import csv
 from decimal import Decimal
 
-from . import ledger
+from .model import *
 
-# Generate balance sheet
+def add_unrealized_gains(tb, currency):
+	for account in list(tb.ledger.accounts.values()):
+		if not account.is_market:
+			continue
+		
+		total_cost = tb.get_balance(account).exchange(currency, True)
+		total_market = tb.get_balance(account).exchange(currency, False, tb.date, tb.ledger)
+		unrealized_gain = total_market - total_cost
+		
+		if unrealized_gain != 0:
+			transaction = Transaction(tb.ledger, None, tb.date, '<Unrealized Gains>')
+			transaction.postings.append(Posting(transaction, account, unrealized_gain))
+			transaction.postings.append(Posting(transaction, tb.ledger.get_account(config['unrealized_gains']), -unrealized_gain))
+			tb.ledger.transactions.append(transaction)
+	
+	return trial_balance(tb.ledger, tb.date, tb.pstart)
 
-def balance_sheet(date, pstart):
-	# Get trial balance
-	trial_balance = ledger.trial_balance(date, pstart)
+def trial_balance(ledger, date, pstart):
+	tb = TrialBalance(ledger, date, pstart)
 	
-	# Calculate Profit/Loss
-	total_pandl = trial_balance.get_total(ledger.config['income_account']) + trial_balance.get_total(ledger.config['expenses_account'])
+	for transaction in ledger.transactions:
+		if transaction.date > date:
+			continue
+		
+		for posting in transaction.postings:
+			if (posting.account.is_income or posting.account.is_expense) and transaction.date < pstart:
+				tb.balances[config['retained_earnings']] = tb.get_balance(ledger.get_account(config['retained_earnings'])) + posting.amount
+			else:
+				tb.balances[posting.account.name] = tb.get_balance(posting.account) + posting.amount
 	
-	# Add Current Year Earnings account
-	trial_balance.set_balance(ledger.config['current_year_earnings'], trial_balance.get_balance(ledger.config['current_year_earnings']) + total_pandl)
-	
-	return trial_balance
+	return tb
diff --git a/ledger_pyreport/config.py b/ledger_pyreport/config.py
new file mode 100644
index 0000000..0e6cb8c
--- /dev/null
+++ b/ledger_pyreport/config.py
@@ -0,0 +1,20 @@
+#   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/>.
+
+import yaml
+
+with open('config.yml', 'r') as f:
+	config = yaml.safe_load(f)
diff --git a/ledger_pyreport/jinja2/index.html b/ledger_pyreport/jinja2/index.html
index 8f5d6ae..54768c4 100644
--- a/ledger_pyreport/jinja2/index.html
+++ b/ledger_pyreport/jinja2/index.html
@@ -47,6 +47,13 @@
 				<label>Compare <input name="compare" value="0" style="width: 2em;" oninput="txtc(this)"> periods</label>
 				{#<label><input name="cash" type="checkbox" oninput="chbc(this)"> Cash basis</label>#}
 			</form></li>
+			
+			<li><form action="{{ url_for('transactions') }}">
+				<button type="submit">General ledger</button>
+				<label>Date: <input name="date" value="{{ date.strftime('%Y-%m-%d') }}" style="width: 6em;" oninput="txtc(this)"></label>
+				<label>Period start: <input name="pstart" value="{{ pstart.strftime('%Y-%m-%d') }}" style="width: 6em;" oninput="txtc(this)"></label>
+				{#<label><input name="cash" type="checkbox" oninput="chbc(this)"> Cash basis</label>#}
+			</form></li>
 		</ul>
 		
 		<script>
diff --git a/ledger_pyreport/jinja2/transactions.html b/ledger_pyreport/jinja2/transactions.html
index aba5c84..907570b 100644
--- a/ledger_pyreport/jinja2/transactions.html
+++ b/ledger_pyreport/jinja2/transactions.html
@@ -20,13 +20,17 @@
 <html>
 	<head>
 		<meta charset="utf-8">
-		<title>Account Transactions for {{ account.name }} as at {{ date.strftime('%d %B %Y') }}</title>
+		<title>{% if account %}Account Transactions{% else %}General Ledger{% endif %} as at {{ date.strftime('%d %B %Y') }}</title>
 		<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/8.0.1/normalize.min.css" integrity="sha256-l85OmPOjvil/SOvVt3HnSSjzF1TUMyT9eV0c2BzEGzU=" crossorigin="anonymous">
 		<link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='main.css') }}">
 	</head>
 	<body>
-		<h1>Account Transactions</h1>
-		<h2 style="margin-bottom: 0;">For {{ account.name }}</h2>
+		{% if account %}
+			<h1>Account Transactions</h1>
+			<h2 style="margin-bottom: 0;">For {{ account.name }}</h2>
+		{% else %}
+			<h1>General Ledger</h1>
+		{% endif %}
 		<h2>As at {{ date.strftime('%d %B %Y') }}</h2>
 		
 		<table class="ledger">
@@ -36,56 +40,81 @@
 				<th style="max-width: 8em;">Account</th>
 				<th class="h1" style="text-align: right; width: 5em;">Dr</th>
 				<th class="h1" style="text-align: right; width: 5em;">Cr</th>
-				<th class="h1" style="text-align: right; width: 6em;">Balance</th>
-			</tr>
-			<tr class="total">
-				<td>{{ pstart.strftime('%Y-%m-%d') }}</td>
-				<td>Opening Balance</td>
-				<td></td>
-				<td style="text-align: right;"></td>
-				<td style="text-align: right;"></td>
-				<td style="text-align: right;">
-					{% if opening_balance >= 0 %}
-						{{ opening_balance|b }} Dr
-					{% else %}
-						{{ -opening_balance|b }} Cr
-					{% endif %}
-				</td>
+				{% if account %}<th class="h1" style="text-align: right; width: 6em;">Balance</th>{% endif %}
 			</tr>
+			
+			{% set ns = namespace(balance=None) %}
+			{% if account %}
+				<tr class="total">
+					<td>{{ pstart.strftime('%Y-%m-%d') }}</td>
+					<td>Opening Balance</td>
+					<td></td>
+					<td style="text-align: right;"></td>
+					<td style="text-align: right;"></td>
+					<td style="text-align: right;">
+						{% if opening_balance >= 0 %}
+							{{ opening_balance|b }} Dr
+						{% else %}
+							{{ -opening_balance|b }} Cr
+						{% endif %}
+					</td>
+				</tr>
+				{% set ns.balance = opening_balance %}
+			{% endif %}
+			
 			{% for transaction in transactions %}
-				{% for posting in transaction.postings if posting.amount >= 0.05 or posting.amount < -0.05 %}
+				{% for posting in transaction.postings if (posting.amount.amount >= 0.05 or posting.amount.amount < -0.05) and posting.account != account %}
+					{% set amount = posting.exchange(report_currency, transaction.date) %}
+					{% set ns.balance = ns.balance - amount %}
 					<tr>
 						<td>{% if loop.first %}{{ transaction.date.strftime('%Y-%m-%d') }}{% endif %}</td>
-						<td>{% if loop.first %}{{ transaction.payee }}{% endif %}</td>
-						<td><a href="/transactions?{{ {'date': date.strftime('%Y-%m-%d'), 'pstart': pstart.strftime('%Y-%m-%d'), 'account': posting.account}|urlencode }}">{{ (posting.account|e).__str__().replace(':', ':<wbr>')|safe }}</a></td>
-						<td style="text-align: right;">{% if posting.amount > 0 %}{{ posting.amount|b }}{% endif %}</td>
-						<td style="text-align: right;">{% if posting.amount < 0 %}{{ -posting.amount|b }}{% endif %}</td>
-						<td style="text-align: right;">
-							{% if loop.last %}
-								{% if posting.balance >= 0 %}
-									{{ posting.balance|b }} Dr
-								{% else %}
-									{{ -posting.balance|b }} Cr
+						<td>{% if loop.first %}{{ transaction.description }}{% endif %}</td>
+						<td><a href="/transactions?{{ {'date': date.strftime('%Y-%m-%d'), 'pstart': pstart.strftime('%Y-%m-%d'), 'account': posting.account.name}|urlencode }}">{{ (posting.account.name|e).__str__().replace(':', ':<wbr>')|safe }}</a></td>
+						{% if account %}
+							{# Reverse Dr/Cr so it's from the "perspective" of this account #}
+							<td style="text-align: right;">{% if amount < 0 %}<span title="{{ (-posting.amount).tostr(False) }}">{{ -amount|b }}</span>{% endif %}</td>
+							<td style="text-align: right;">{% if amount > 0 %}<span title="{{ posting.amount.tostr(False) }}">{{ amount|b }}</span>{% endif %}</td>
+							<td style="text-align: right;">
+								{% if loop.last %}
+									{% if ns.balance >= 0 %}
+										{{ ns.balance|b }} Dr
+									{% else %}
+										{{ -ns.balance|b }} Cr
+									{% endif %}
 								{% endif %}
-							{% endif %}
-						</td>
+							</td>
+						{% else %}
+							<td style="text-align: right;">{% if amount > 0 %}<span title="{{ posting.amount.tostr(False) }}">{{ amount|b }}</span>{% endif %}</td>
+							<td style="text-align: right;">{% if amount < 0 %}<span title="{{ (-posting.amount).tostr(False) }}">{{ -amount|b }}</span>{% endif %}</td>
+						{% endif %}
 					</tr>
 				{% endfor %}
 			{% endfor %}
-			<tr class="total">
-				<td>{{ date.strftime('%Y-%m-%d') }}</td>
-				<td>Closing Balance</td>
-				<td></td>
-				<td style="text-align: right;"></td>
-				<td style="text-align: right;"></td>
-				<td style="text-align: right;">
-					{% if closing_balance >= 0 %}
-						{{ closing_balance|b }} Dr
-					{% else %}
-						{{ -closing_balance|b }} Cr
-					{% endif %}
-				</td>
-			</tr>
+			
+			{% if account %}
+				<tr class="total">
+					<td>{{ date.strftime('%Y-%m-%d') }}</td>
+					<td>Closing Balance</td>
+					<td></td>
+					<td style="text-align: right;"></td>
+					<td style="text-align: right;"></td>
+					<td style="text-align: right;">
+						{% if closing_balance >= 0 %}
+							{{ closing_balance|b }} Dr
+						{% else %}
+							{{ -closing_balance|b }} Cr
+						{% endif %}
+					</td>
+				</tr>
+			{% else %}
+				<tr class="total">
+					<td>{{ date.strftime('%Y-%m-%d') }}</td>
+					<td>Total</td>
+					<td></td>
+					<td style="text-align: right;">{{ total_dr|b }}</td>
+					<td style="text-align: right;">{{ -total_cr|b }}</td>
+				</tr>
+			{% endif %}
 		</table>
 	</body>
 </html>
diff --git a/ledger_pyreport/jinja2/trial.html b/ledger_pyreport/jinja2/trial.html
index 709d610..5b73652 100644
--- a/ledger_pyreport/jinja2/trial.html
+++ b/ledger_pyreport/jinja2/trial.html
@@ -34,8 +34,9 @@
 				<th class="h1">Dr</th>
 				<th class="h1">Cr</th>
 			</tr>
-			{% for account in trial_balance.accounts.values() %}
-				{% set balance = trial_balance.get_balance(account.name) %}
+			{% for account in accounts %}
+				{# Display in "cost basis" as we have already accounted for unrealised gains #}
+				{% set balance = trial_balance.get_balance(account).exchange(report_currency, True) %}
 				{% set trn_url = "/transactions?" + {'date': trial_balance.date.strftime('%Y-%m-%d'), 'pstart': trial_balance.pstart.strftime('%Y-%m-%d'), 'account': account.name}|urlencode %}
 				{% if balance != 0 %}
 					<tr>
diff --git a/ledger_pyreport/jinja2/trial_multiple.html b/ledger_pyreport/jinja2/trial_multiple.html
index 775b6a2..c290067 100644
--- a/ledger_pyreport/jinja2/trial_multiple.html
+++ b/ledger_pyreport/jinja2/trial_multiple.html
@@ -37,7 +37,7 @@
 				<tr>
 					<td>{{ account.name }}</td>
 					{% for trial_balance in trial_balances %}
-						{% set balance = trial_balance.get_balance(account.name) %}
+						{% set balance = trial_balance.get_balance(account).exchange(report_currency, True) %}
 						<td>{% if balance != 0 %}{{ balance|a }}{% endif %}</td>
 					{% endfor %}
 				</tr>
diff --git a/ledger_pyreport/ledger.py b/ledger_pyreport/ledger.py
index de89ddf..bbc9801 100644
--- a/ledger_pyreport/ledger.py
+++ b/ledger_pyreport/ledger.py
@@ -14,22 +14,19 @@
 #   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/>.
 
+from .config import config
+from .model import *
+
 import csv
 from datetime import datetime, timedelta
 from decimal import Decimal
 import re
 import subprocess
-import yaml
-
-# Load config
-with open('config.yml', 'r') as f:
-	config = yaml.safe_load(f)
 
 # Helper commands to run Ledger
 
 def run_ledger(*args):
-	ledger_args = ['ledger', '--args-only', '--file', config['ledger_file'], '-X', config['report_currency'], '--date-format', '%Y-%m-%d', '--unround'] + config['ledger_args'] + list(args)
-	#print(' '.join(ledger_args))
+	ledger_args = ['ledger', '--args-only', '--file', config['ledger_file'], '--date-format', '%Y-%m-%d', '--unround'] + config['ledger_args'] + list(args)
 	proc = subprocess.Popen(ledger_args, encoding='utf-8', stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 	stdout, stderr = proc.communicate()
 	
@@ -51,221 +48,56 @@ def financial_year(date):
 
 # Ledger logic
 
-class Account:
-	def __init__(self, name):
-		if not isinstance(name, str):
-			raise Exception('Account name must be a string')
-		
-		self.name = name
-		
-		self.parent = None
-		self.children = []
-	
-	def __repr__(self):
-		return '<Account "{}">'.format(self.name)
-	
-	@property
-	def bits(self):
-		return self.name.split(':')
-	
-	def matches(self, needle):
-		if self.name == needle or self.name.startswith(needle + ':'):
-			return True
-		return False
-	
-	def insert_into_tree(self, accounts):
-		if ':' in self.name:
-			parent_name = self.name[:self.name.rindex(':')]
-			if parent_name not in accounts:
-				parent = Account(parent_name)
-				accounts[parent_name] = parent
-				parent.insert_into_tree(accounts)
-			
-			self.parent = accounts[parent_name]
-			if self not in self.parent.children:
-				self.parent.children.append(self)
-	
-	@property
-	def is_asset(self):
-		return self.matches(config['assets_account'])
-	@property
-	def is_liability(self):
-		return self.matches(config['liabilities_account'])
-	@property
-	def is_equity(self):
-		return self.matches(config['equity_account'])
-	@property
-	def is_income(self):
-		return self.matches(config['income_account'])
-	@property
-	def is_expense(self):
-		return self.matches(config['expenses_account'])
-	@property
-	def is_cash(self):
-		return any(self.matches(a) for a in config['cash_asset_accounts'])
-	
-	def get_transactions(self, date, pstart):
-		transactions = []
-		
-		output = run_ledger_date(date, 'register', '--no-rounding', '--register-format', '%(quoted(format_date(date))),%(quoted(payee)),%(quoted(account)),%(quoted(display_amount))\n', '--limit', 'account=~/^{}$/'.format(re.escape(self.name).replace('/', '\\/')), '--cost' if self.is_income or self.is_expense else '--market', '--related-all', '--no-revalued')
-		
-		output += run_ledger_date(date, 'register', '--no-rounding', '--register-format', '%(quoted(format_date(date))),%(quoted(payee)),%(quoted(account)),%(quoted(display_amount))\n', '--limit', 'account=~/^{}$/'.format(re.escape(self.name).replace('/', '\\/')), '--cost' if self.is_income or self.is_expense else '--market', '--revalued-only')
-		
-		reader = csv.reader(output.splitlines())
-		for row in reader:
-			t_date = datetime.strptime(row[0], '%Y-%m-%d')
-			if t_date < pstart:
-				continue
-			
-			posting = Posting(row[2], parse_amount(row[3]))
-			
-			if posting.account == '<Revalued>':
-				posting.account = self.name
-			
-			if transactions and t_date == transactions[-1].date and row[1] == transactions[-1].payee:
-				# Posting for previous transaction
-				transactions[-1].postings.append(posting)
-			else:
-				# New transaction
-				transactions.append(Transaction(t_date, row[1], [posting]))
-		
-		transactions.sort(key=lambda t: t.date)
-		
-		# Balance transactions
-		for transaction in transactions:
-			t_total = sum(p.amount for p in transaction.postings)
-			if t_total != 0:
-				# Transaction requires balancing, probably due to unrealised gain/revaluation?
-				transaction.postings.append(Posting(config['unrealized_gains'], -t_total))
-		
-		return transactions
-
-class Transaction:
-	def __init__(self, date, payee, postings):
-		self.date = date
-		self.payee = payee
-		self.postings = postings
-
-class Posting:
-	def __init__(self, account, amount):
-		self.account = account
-		self.amount = amount
-		
-		self.balance = None
-
-class Snapshot:
-	def __init__(self, date):
-		self.date = date
-		self.pstart = None
-		
-		self.accounts = {}
-		self.balances = {}
-	
-	def get_account(self, account_name):
-		if account_name not in self.accounts:
-			account = Account(account_name)
-			self.accounts[account_name] = account
-			account.insert_into_tree(self.accounts)
-		
-		return self.accounts[account_name]
-	
-	def set_balance(self, account_name, balance):
-		if account_name not in self.accounts:
-			account = Account(account_name)
-			self.accounts[account_name] = account
-			account.insert_into_tree(self.accounts)
-		
-		if account_name not in self.balances:
-			self.balances[account_name] = Decimal(0)
-		
-		self.balances[account_name] = balance
-	
-	def get_balance(self, account_name):
-		if account_name not in self.accounts:
-			self.set_balance(account_name, Decimal(0))
-		
-		if account_name not in self.balances:
-			self.balances[account_name] = Decimal(0)
-		
-		return self.balances[account_name]
-	
-	def get_total(self, account_name):
-		return self.get_balance(account_name) + sum(self.get_total(c.name) for c in self.accounts[account_name].children)
-
 def parse_amount(amount):
-	if amount == '' or amount == '0':
-		return Decimal(0)
-	if not amount.startswith(config['report_currency']):
-		raise Exception('Unexpected currency returned by ledger: {}'.format(amount))
-	return Decimal(amount[len(config['report_currency']):])
+	if '{' in amount:
+		amount_str = amount[:amount.index('{')].strip()
+		price_str = amount[amount.index('{')+1:amount.index('}')].strip()
+	else:
+		amount_str = amount
+		price_str = None
+	
+	if amount_str[0] in list('0123456789-'):
+		# Currency follows number
+		bits = amount_str.split()
+		amount_num = Decimal(bits[0])
+		currency = Currency(bits[1], False)
+	else:
+		# Currency precedes number
+		currency = Currency(amount_str[0], True)
+		amount_num = Decimal(amount_str[1:])
+	
+	if price_str:
+		currency.price = parse_amount(price_str)
+	
+	return Amount(amount_num, currency)
 
-def get_accounts():
-	output = run_ledger('balance', '--balance-format', '%(account)\n', '--no-total', '--flat', '--empty')
-	account_names = output.rstrip('\n').split('\n')
+def get_pricedb():
+	output = run_ledger('prices', '--prices-format', '%(quoted(format_date(date))),%(quoted(display_account)),%(quoted(display_amount))\n')
 	
-	accounts = {n: Account(n) for n in account_names}
+	prices = []
 	
-	for account in list(accounts.values()):
-		account.insert_into_tree(accounts)
-	
-	return accounts
-
-# Raw Ledger output, unlikely to balance
-def get_raw_snapshot(date, basis=None):
-	snapshot = Snapshot(date)
-	
-	# Get balances from Ledger
-	output = (
-		run_ledger_date(date, 'balance', '--balance-format', '%(quoted(account)),%(quoted(display_total))\n', '--no-total', '--flat', '--empty', basis if basis is not None else '--market', config['assets_account'], config['liabilities_account'], config['equity_account']) +
-		run_ledger_date(date, 'balance', '--balance-format', '%(quoted(account)),%(quoted(display_total))\n', '--no-total', '--flat', '--empty', basis if basis is not None else '--cost', config['income_account'], config['expenses_account'])
-	)
 	reader = csv.reader(output.splitlines())
-	for row in reader:
-		snapshot.set_balance(row[0], parse_amount(row[1]))
+	for date_str, currency, price_str in reader:
+		prices.append((datetime.strptime(date_str, '%Y-%m-%d'), currency, parse_amount(price_str)))
 	
-	return snapshot
+	return prices
 
-# Ledger output, adjusted for Unrealized Gains
-def get_snapshot(date):
-	snapshot_cost = get_raw_snapshot(date, '--cost')
-	snapshot = get_raw_snapshot(date)
+def raw_transactions_at_date(date):
+	ledger = Ledger(date)
+	ledger.prices = get_pricedb()
 	
-	market_total = Decimal(0)
-	cost_total = Decimal(0)
+	output = run_ledger_date(date, 'csv', '--csv-format', '%(quoted(parent.id)),%(quoted(format_date(date))),%(quoted(payee)),%(quoted(account)),%(quoted(display_amount))\n')
 	
-	# Calculate unrealized gains
-	for account in snapshot.accounts.values():
-		if account.is_asset or account.is_liability:
-			market_total += snapshot.get_balance(account.name)
-			cost_total += snapshot_cost.get_balance(account.name)
+	reader = csv.reader(output.splitlines())
+	for trn_id, date_str, payee, account_str, amount_str in reader:
+		if not ledger.transactions or trn_id != ledger.transactions[-1].id:
+			transaction = Transaction(ledger, trn_id, datetime.strptime(date_str, '%Y-%m-%d'), payee)
+			ledger.transactions.append(transaction)
+		else:
+			# Transaction ID matches: continuation of previous transaction
+			transaction = ledger.transactions[-1]
+		
+		posting = Posting(transaction, ledger.get_account(account_str), parse_amount(amount_str))
+		transaction.postings.append(posting)
 	
-	# Add Unrealized Gains account
-	unrealized_gains_amt = market_total - cost_total
-	snapshot.set_balance(config['unrealized_gains'], snapshot.get_balance(config['unrealized_gains']) - unrealized_gains_amt)
-	
-	return snapshot
-
-# Ledger output, simulating closing of books
-def trial_balance(date, pstart):
-	# Get balances at period start
-	snapshot_pstart = get_snapshot(pstart - timedelta(days=1))
-	
-	# Get balances at date
-	snapshot = get_snapshot(date)
-	snapshot.pstart = pstart
-	
-	# Calculate Retained Earnings, and adjust income/expense accounts
-	total_pandl = Decimal(0)
-	for account in snapshot_pstart.accounts.values():
-		if account.is_income or account.is_expense:
-			total_pandl += snapshot_pstart.get_balance(account.name)
-	
-	# Add Retained Earnings account
-	snapshot.set_balance(config['retained_earnings'], snapshot.get_balance(config['retained_earnings']) + total_pandl)
-	
-	# Adjust income/expense accounts
-	for account in snapshot.accounts.values():
-		if account.is_income or account.is_expense:
-			snapshot.set_balance(account.name, snapshot.get_balance(account.name) - snapshot_pstart.get_balance(account.name))
-	
-	return snapshot
+	return ledger
diff --git a/ledger_pyreport/model.py b/ledger_pyreport/model.py
new file mode 100644
index 0000000..0a6d0fc
--- /dev/null
+++ b/ledger_pyreport/model.py
@@ -0,0 +1,299 @@
+#   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/>.
+
+from .config import config
+
+from decimal import Decimal
+import functools
+
+class Ledger:
+	def __init__(self, date):
+		self.date = date
+		
+		self.root_account = Account(self, '')
+		self.accounts = {}
+		self.transactions = []
+		
+		self.prices = []
+	
+	def get_account(self, name):
+		if name == '':
+			return self.root_account
+		
+		if name in self.accounts:
+			return self.accounts[name]
+		
+		account = Account(self, name)
+		if account.parent:
+			account.parent.children.append(account)
+		self.accounts[name] = account
+		
+		return account
+	
+	def get_price(self, currency_from, currency_to, date):
+		prices = [p for p in self.prices if p[1] == currency_from.name and p[2].currency == currency_to and p[0].date() <= date.date()]
+		
+		if not prices:
+			raise Exception('No price information for {} to {} at {:%Y-%m-%d}'.format(currency_from, currency_to, date))
+		
+		return max(prices, key=lambda p: p[0])[2]
+
+class Transaction:
+	def __init__(self, ledger, id, date, description):
+		self.ledger = ledger
+		self.id = id
+		self.date = date
+		self.description = description
+		self.postings = []
+	
+	def __repr__(self):
+		return '<Transaction {} "{}">'.format(self.id, self.description)
+	
+	def describe(self):
+		result = ['{:%Y-%m-%d} {}'.format(self.date, self.description)]
+		for posting in self.postings:
+			result.append('    {}  {}'.format(posting.account.name, posting.amount.tostr(False)))
+		return '\n'.join(result)
+
+class Posting:
+	def __init__(self, transaction, account, amount):
+		self.transaction = transaction
+		self.account = account
+		self.amount = Amount(amount)
+	
+	def __repr__(self):
+		return '<Posting "{}" {}>'.format(self.account.name, self.amount.tostr(False))
+	
+	def exchange(self, currency, date):
+		if self.amount.currency.name == currency.name and self.amount.currency.is_prefix == currency.is_prefix:
+			return Amount(self.amount)
+		
+		return self.amount.exchange(currency, True) # Cost basis
+
+class Account:
+	def __init__(self, ledger, name):
+		self.ledger = ledger
+		self.name = name
+		
+		self.children = []
+	
+	def __repr__(self):
+		return '<Account {}>'.format(self.name)
+	
+	@property
+	def bits(self):
+		return self.name.split(':')
+	
+	@property
+	def parent(self):
+		if self.name == '':
+			return None
+		return self.ledger.get_account(':'.join(self.bits[:-1]))
+	
+	def matches(self, part):
+		if self.name == part or self.name.startswith(part + ':'):
+			return True
+		return False
+	
+	@property
+	def is_income(self):
+		return self.matches(config['income_account'])
+	@property
+	def is_expense(self):
+		return self.matches(config['expenses_account'])
+	@property
+	def is_equity(self):
+		return self.matches(config['equity_account'])
+	@property
+	def is_asset(self):
+		return self.matches(config['assets_account'])
+	@property
+	def is_liability(self):
+		return self.matches(config['liabilities_account'])
+	
+	@property
+	def is_cost(self):
+		return self.is_income or self.is_expense or self.is_equity
+	@property
+	def is_market(self):
+		return self.is_asset or self.is_liability
+
+class Amount:
+	def __init__(self, amount, currency=None):
+		if isinstance(amount, Amount):
+			self.amount = amount.amount
+			self.currency = amount.currency
+		elif currency is None:
+			raise TypeError('currency is required')
+		else:
+			self.amount = Decimal(amount)
+			self.currency = currency
+	
+	def tostr(self, round=True):
+		if self.currency.is_prefix:
+			amount_str = ('{}{:.2f}' if round else '{}{}').format(self.currency.name, self.amount)
+		else:
+			amount_str = ('{:.2f} {}' if round else '{:.2f} {}').format(self.amount, self.currency.name)
+		
+		if self.currency.price:
+			return '{} {{{}}}'.format(amount_str, self.currency.price)
+		return amount_str
+	
+	def __repr__(self):
+		return '<Amount {}>'.format(self.tostr(False))
+	
+	def __str__(self):
+		return self.tostr()
+	
+	def compatible_currency(func):
+		@functools.wraps(func)
+		def wrapped(self, other):
+			if isinstance(other, Amount):
+				if other.currency != self.currency:
+					raise TypeError('Cannot combine Amounts of currency {} and {}'.format(self.currency.name, other.currency.name))
+				other = other.amount
+			elif other != 0:
+				raise TypeError('Cannot combine Amount with non-zero number')
+			return func(self, other)
+		return wrapped
+	
+	def __neg__(self):
+		return Amount(-self.amount, self.currency)
+	
+	@compatible_currency
+	def __eq__(self, other):
+		return self.amount == other
+	@compatible_currency
+	def __ne__(self, other):
+		return self.amount != other
+	@compatible_currency
+	def __gt__(self, other):
+		return self.amount > other
+	@compatible_currency
+	def __ge__(self, other):
+		return self.amount >= other
+	@compatible_currency
+	def __lt__(self, other):
+		return self.amount < other
+	@compatible_currency
+	def __le__(self, other):
+		return self.amount <= other
+	
+	@compatible_currency
+	def __add__(self, other):
+		return Amount(self.amount + other, self.currency)
+	@compatible_currency
+	def __radd__(self, other):
+		return Amount(other + self.amount, self.currency)
+	@compatible_currency
+	def __sub__(self, other):
+		return Amount(self.amount - other, self.currency)
+	@compatible_currency
+	def __rsub__(self, other):
+		return Amount(other - self.amount, self.currency)
+	
+	def exchange(self, currency, is_cost, price=None):
+		if self.currency.name == currency.name and self.currency.is_prefix == currency.is_prefix:
+			return Amount(self)
+		
+		if is_cost and self.currency.price and self.currency.price.currency.name == currency.name and self.currency.price.currency.is_prefix == currency.is_prefix:
+			return Amount(self.amount * self.currency.price.amount, currency)
+		
+		if price:
+			return Amount(self.amount * price.amount, currency)
+		
+		raise TypeError('Cannot exchange {} to {}'.format(self.currency, currency))
+
+class Balance:
+	def __init__(self, amounts=None):
+		self.amounts = amounts or []
+	
+	def tidy(self):
+		new_amounts = []
+		for amount in self.amounts:
+			new_amount = next((a for a in new_amounts if a.currency == amount.currency), None)
+		return Balance(new_amounts)
+	
+	def exchange(self, currency, is_cost, date=None, ledger=None):
+		result = Amount(0, currency)
+		for amount in self.amounts:
+			if is_cost or amount.currency.name == currency.name and amount.currency.is_prefix == amount.currency.is_prefix:
+				result += amount.exchange(currency, is_cost)
+			else:
+				result += amount.exchange(currency, is_cost, ledger.get_price(amount.currency, currency, date))
+		return result
+	
+	def __neg__(self):
+		return Balance([-a for a in self.amounts])
+	
+	def __eq__(self, other):
+		if isinstance(other, Balance):
+			raise Exception('NYI')
+		elif isinstance(other, Amount):
+			raise Exception('NYI')
+		elif other == 0:
+			return len(self.amounts) == 0
+		else:
+			raise TypeError('Cannot compare Balance with non-zero number')
+	
+	def __add__(self, other):
+		new_amounts = [Amount(a) for a in self.amounts]
+		
+		if isinstance(other, Balance):
+			for amount in other.amounts:
+				new_amount = next((a for a in new_amounts if a.currency == amount.currency), None)
+				if new_amount is None:
+					new_amount = Amount(0, amount.currency)
+					new_amounts.append(new_amount)
+				new_amount.amount += amount.amount
+		elif isinstance(other, Amount):
+			new_amount = next((a for a in new_amounts if a.currency == other.currency), None)
+			if new_amount is None:
+				new_amount = Amount(0, other.currency)
+				new_amounts.append(new_amount)
+			new_amount.amount += other.amount
+		else:
+			raise Exception('NYI')
+		
+		return Balance(new_amounts)
+
+class Currency:
+	def __init__(self, name, is_prefix, price=None):
+		self.name = name
+		self.is_prefix = is_prefix
+		self.price = price
+	
+	def __repr__(self):
+		return '<Currency {} ({})>'.format(self.name, 'prefix' if self.is_prefix else 'suffix')
+	
+	def __eq__(self, other):
+		if not isinstance(other, Currency):
+			return False
+		return self.name == other.name and self.is_prefix == other.is_prefix and self.price == other.price
+
+class TrialBalance:
+	def __init__(self, ledger, date, pstart):
+		self.ledger = ledger
+		self.date = date
+		self.pstart = pstart
+		
+		self.balances = {}
+	
+	def get_balance(self, account):
+		return self.balances.get(account.name, Balance())
+	
+	def get_total(self, account):
+		return self.get_balance(account) + sum(self.get_total(a) for a in account.children)