# Part of accounting-api project:
# https://gitorious.org/conservancy/accounting-api
# License: AGPLv3-or-later
import os
import sys
import subprocess
import logging
import re
from datetime import datetime
from xml.etree import ElementTree
from accounting.exceptions import AccountingException, TransactionNotFound, \
LedgerNotBalanced, TransactionIDCollision
from accounting.models import Account, Transaction, Posting, Amount
from accounting.storage import Storage
_log = logging.getLogger(__name__)
HAS_PYGIT = False
try:
import pygit2
HAS_PYGIT = True
except ImportError:
_log.warning('Failed to import pygit2')
class Ledger(Storage):
def __init__(self, app=None, ledger_file=None, ledger_bin=None):
if app:
ledger_file = app.config['LEDGER_FILE']
if ledger_file is None:
raise ValueError('ledger_file cannot be None')
self.ledger_bin = ledger_bin or 'ledger'
self.ledger_file = ledger_file
_log.info('ledger file: %s', ledger_file)
self.init_pygit()
def init_pygit(self):
if not HAS_PYGIT:
return False
try:
self.repository = pygit2.Repository(
os.path.join(os.path.dirname(self.ledger_file), '.git'))
except KeyError:
self.repository = None
_log.warning('ledger_file directory does not contain a .git'
' directory, will not track changes.')
# The signature used as author and committer in git commits
self.signature = pygit2.Signature(
name='accounting-api',
email='accounting-api@accounting.example')
def commit_changes(self, message):
'''
Commits any changes to :attr:`self.ledger_file` to the git repository
'''
if self.repository is None:
return
# Add the ledger file
self.repository.index.read()
self.repository.index.add(os.path.basename(self.ledger_file))
tree_id = self.repository.index.write_tree()
self.repository.index.write()
parents = []
try:
parents.append(self.repository.head.target)
except pygit2.GitError:
_log.info('Repository has no head, creating initial commit')
commit_id = self.repository.create_commit(
'HEAD',
self.signature,
self.signature,
message,
tree_id,
parents)
def assemble_arguments(self, command=None):
'''
Returns a list of arguments suitable for :class:`subprocess.Popen`
based on :attr:`self.ledger_bin` and :attr:`self.ledger_file`.
'''
args = [
self.ledger_bin,
'-f',
self.ledger_file,
]
if command is not None:
args.append(command)
return args
def run_command(self, command):
'''
Creates a new ledger process with the specified :data:`command` and
returns the output.
Raises an :class:`~accounting.exceptions.AccountingException`-based
Exception based on the ledger-cli stderr.
'''
_log.debug('Sending command: %r', command)
_log.debug('Starting ledger...')
p = subprocess.Popen(
self.assemble_arguments(command=command),
stdout=subprocess.PIPE,
stdin=subprocess.PIPE,
stderr=subprocess.PIPE)
output = p.stdout.read()
stderr = p.stderr.read().decode('utf8')
if stderr:
lines = stderr.split('\n')
if 'While balancing transaction from' in lines[1]:
raise LedgerNotBalanced('\n'.join(lines[2:]))
raise AccountingException(stderr)
p.send_signal(subprocess.signal.SIGTERM)
_log.debug('Waiting for ledger to shut down')
p.wait()
return output
def add_transaction(self, transaction):
'''
Writes a transaction to the ledger file by opening it in 'ab' mode and
writing a ledger transaction based on the
:class:`~accounting.models.Transaction` instance in
:data:`transaction`.
'''
if transaction.id is None:
_log.debug('No ID found. Generating an ID.')
transaction.generate_id()
exists = self.get_transaction(transaction.id)
if exists is not None:
raise TransactionIDCollision(
'A transaction with the id %s already exists: %s' %
(transaction.id, exists))
transaction.metadata.update({'Id': transaction.id})
transaction_template = ('\n{date} {t.payee}\n'
'{metadata}'
'{postings}')
metadata_template = ' ;{0}: {1}\n'
posting_template = (' {account} {p.amount.symbol}'
' {p.amount.amount}\n')
output = b''
out_postings = ''
for posting in transaction.postings:
out_postings += posting_template.format(
p=posting,
account=posting.account + ' ' * (
80 - (len(posting.account) + len(posting.amount.symbol) +
len(str(posting.amount.amount)) + 1 + 2))
)
if len(posting.metadata):
for k, v in posting.metadata.items():
out_postings += metadata_template.format(str(k), str(v))
# XXX: Even I hardly understands what this does, however I indent it it
# stays unreadable.
output += transaction_template.format(
date=transaction.date.strftime('%Y-%m-%d'),
t=transaction,
metadata=''.join([
metadata_template.format(str(k), str(v))
for k, v in transaction.metadata.items()]),
postings=out_postings
).encode('utf8')
with open(self.ledger_file, 'ab') as f:
f.write(output)
# Check to see that no errors were introduced
try:
self.get_transactions()
except AccountingException as exc:
# TODO: Do a hard reset on the repository using Repository.reset,
# this is on hold because of
# https://github.com/libgit2/pygit2/issues/271.
# This solution will work in the meantime
self.delete_transaction(transaction.id)
setattr(exc, 'transaction', transaction)
raise exc
self.commit_changes('Added transaction %s' % transaction.id)
_log.info('Added transaction %s', transaction.id)
_log.debug('written to file: %s', output)
return transaction.id
def bal(self):
output = self.run_command('xml')
if output is None:
raise RuntimeError('bal call returned no output')
accounts = []
xml = ElementTree.fromstring(output.decode('utf8'))
accounts = self._recurse_accounts(xml.find('./accounts'))
return accounts
def _recurse_accounts(self, root):
accounts = []
for account in root.findall('./account'):
name = account.find('./fullname').text
amounts = []
# Try to find an account total value, then try to find the account
# balance
account_amounts = account.findall(
'./account-total/balance/amount') or \
account.findall('./account-amount/amount') or \
account.findall('./account-total/amount')
if account_amounts:
for amount in account_amounts:
quantity = amount.find('./quantity').text
symbol = amount.find('./commodity/symbol').text
amounts.append(Amount(amount=quantity, symbol=symbol))
else:
_log.warning('Account %s does not have any amounts', name)
accounts.append(Account(name=name,
amounts=amounts,
accounts=self._recurse_accounts(account)))
return accounts
def get_transactions(self):
return self.reg()
def get_transaction(self, transaction_id):
transactions = self.get_transactions()
for transaction in transactions:
if transaction.id == transaction_id:
return transaction
def reg(self):
output = self.run_command('xml')
if output is None:
raise RuntimeError('reg call returned no output')
entries = []
reg_xml = ElementTree.fromstring(output.decode('utf8'))
for transaction in reg_xml.findall('./transactions/transaction'):
date = datetime.strptime(transaction.find('./date').text,
'%Y/%m/%d')
payee = transaction.find('./payee').text
postings = []
for posting in transaction.findall('./postings/posting'):
account = posting.find('./account/name').text
amount = posting.find('./post-amount/amount/quantity').text
symbol = posting.find(
'./post-amount/amount/commodity/symbol').text
# Get the posting metadata
metadata = {}
values = posting.findall('./metadata/value')
if values:
for value in values:
key = value.get('key')
value = value.find('./string').text
_log.debug('metadata: %s: %s', key, value)
metadata.update({key: value})
postings.append(
Posting(account=account,
metadata=metadata,
amount=Amount(amount=amount, symbol=symbol)))
# Get the transaction metadata
metadata = {}
values = transaction.findall('./metadata/value')
if values:
for value in values:
key = value.get('key')
value = value.find('./string').text
_log.debug('metadata: %s: %s', key, value)
metadata.update({key: value})
# Add a Transaction instance to the list
try:
id = metadata.pop('Id')
except KeyError:
_log.warning('Transaction on %s with payee %s does not have an'
' Id attribute. A temporary ID will be used.',
date, payee)
id = 'NO-ID'
entries.append(
Transaction(id=id, date=date, payee=payee, postings=postings,
metadata=metadata))
return entries
def delete_transaction(self, transaction_id):
'''
Delete a transaction from the ledger file.
This method opens the ledger file, loads all lines into memory and
looks for the transaction_id, then looks for the bounds of that
transaction in the ledger file, removes all lines within the bounds of
the transaction and removes them, then writes the lines back to the
ledger file.
Exceptions:
- RuntimeError: If all boundaries to the transaction are not found
- TransactionNotFound: If no such transaction_id can be found in
:data:`self.ledger_file`
'''
f = open(self.ledger_file, 'r')
lines = [i for i in f]
# A mapping of line meanings and their line numbers as found by the
# following logic
semantic_lines = dict(
id_location=None,
transaction_start=None,
next_transaction_or_eof=None
)
for i, line in enumerate(lines):
if transaction_id in line:
semantic_lines['id_location'] = i
break
if not semantic_lines['id_location']:
raise TransactionNotFound(
'No transaction with ID "{0}" found'.format(transaction_id))
transaction_start_pattern = re.compile(r'^\S')
cursor = semantic_lines['id_location'] - 1
# Find the first line of the transaction
while True:
if transaction_start_pattern.match(lines[cursor]):
semantic_lines['transaction_start'] = cursor
break
cursor -= 1
cursor = semantic_lines['id_location'] + 1
# Find the last line of the transaction
while True:
try:
if transaction_start_pattern.match(lines[cursor]):
semantic_lines['next_transaction_or_eof'] = cursor
break
except IndexError:
# Set next_line_without_starting_space_or_end_of_file to
# the cursor. The cursor will be an index not included in the
# list of lines
semantic_lines['next_transaction_or_eof'] = cursor
break
cursor += 1
if not all(map(lambda v: v is not None, semantic_lines.values())):
raise RuntimeError('Could not find all the values necessary for'
' safe deletion of a transaction.')
del_start = semantic_lines['transaction_start']
if len(lines) == semantic_lines['next_transaction_or_eof']:
_log.debug('There are no transactions below the transaction being'
' deleted. The line before the first line of the'
' transaction will be deleted.')
# Delete the preceding line to make the file
del_start -= 1
_log.info('Removing transaction with ID: %s (lines %d-%d)',
transaction_id,
del_start,
semantic_lines['next_transaction_or_eof'])
del lines[del_start:semantic_lines['next_transaction_or_eof']]
with open(self.ledger_file, 'w') as f:
for line in lines:
f.write(line)
self.commit_changes('Removed transaction %s' % transaction_id)
def update_transaction(self, transaction):
'''
Update a transaction in the ledger file.
Takes a :class:`~accounting.models.Transaction` object and removes
the old transaction using :data:`transaction.id` from the passed
:class:`~accounting.models.Transaction` instance and adds
:data:`transaction` to the database.
'''
if not transaction.id:
return AccountingException(('The transaction {0} has no'
' id attribute').format(transaction))
old_transaction = self.get_transaction(transaction.id)
self.delete_transaction(transaction.id)
try:
self.add_transaction(transaction)
except AccountingException as exc:
self.add_transaction(old_transaction)
raise exc
_log.info('Updated transaction %s', transaction.id)
_log.debug('Updated transaction from: %s to: %s', old_transaction,
transaction)
def main(argv=None):
import argparse
if argv is None:
argv = sys.argv
parser = argparse.ArgumentParser()
parser.add_argument('-v', '--verbosity',
default='INFO',
help=('Filter logging output. Possible values:' +
' CRITICAL, ERROR, WARNING, INFO, DEBUG'))
args = parser.parse_args(argv[1:])
logging.basicConfig(level=getattr(logging, args.verbosity, 'INFO'))
ledger = Ledger(ledger_file='non-profit-test-data.ledger')
print(ledger.bal())
print(ledger.reg())
if __name__ == '__main__':
sys.exit(main())