# 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())