plomlompom.com Git - misc/blob - ledger.py

   1 from http.server import BaseHTTPRequestHandler, HTTPServer
   2 import sys
   3 import os
   4 import html
   5 from urllib.parse import parse_qs, urlparse
   6 hostName = "localhost"
   7 serverPort = 8082
   8
   9
  10 class HandledException(Exception):
  11     pass
  12
  13
  14 def handled_error_exit(msg):
  15     print(f"ERROR: {msg}")
  16     sys.exit(1)
  17
  18
  19 def apply_booking_to_account_balances(account_sums, account, currency, amount):
  20     if not account in account_sums:
  21         account_sums[account] = {currency: amount}
  22     elif not currency in account_sums[account].keys():
  23         account_sums[account][currency] = amount
  24     else:
  25         account_sums[account][currency] += amount
  26
  27
  28 def parse_lines(lines):
  29     import datetime
  30     import decimal
  31     inside_booking = False
  32     date_string, description = None, None
  33     booking_lines = []
  34     start_line = 0
  35     bookings = []
  36     comments = []
  37     lines += [''] # to ensure a booking-ending last line
  38     for i, line in enumerate(lines):
  39         prefix = f"line {i}"
  40         # we start with the case of an utterly empty line
  41         comments += [""]
  42         stripped_line = line.rstrip()
  43         if stripped_line == '':
  44             if inside_booking:
  45                 # assume we finished a booking, finalize, and commit to DB
  46                 if len(booking_lines) < 2:
  47                     raise HandledException(f"{prefix} booking ends to early")
  48                 booking = Booking(date_string, description, booking_lines, start_line)
  49                 bookings += [booking]
  50             # expect new booking to follow so re-zeroall booking data
  51             inside_booking = False
  52             date_string, description = None, None
  53             booking_lines = []
  54             continue
  55         # if non-empty line, first get comment if any, and commit to DB
  56         split_by_comment = stripped_line.split(sep=";", maxsplit=1)
  57         if len(split_by_comment) == 2:
  58             comments[i] = split_by_comment[1]
  59         # if pre-comment empty: if inside_booking, this must be a comment-only line so we keep it for later ledger-output to capture those comments; otherwise, no more to process for this line
  60         non_comment = split_by_comment[0].rstrip()
  61         if non_comment.rstrip() == '':
  62              if inside_booking:
  63                  booking_lines += ['']
  64              continue
  65         # if we're starting a booking, parse by first-line pattern
  66         if not inside_booking:
  67             start_line = i
  68             toks = non_comment.split(maxsplit=1)
  69             date_string = toks[0]
  70             try:
  71                 datetime.datetime.strptime(date_string, '%Y-%m-%d')
  72             except ValueError:
  73                 raise HandledException(f"{prefix} bad date string: {date_string}")
  74             try:
  75                 description = toks[1]
  76             except IndexError:
  77                 raise HandledException(f"{prefix} bad description: {description}")
  78             inside_booking = True
  79             booking_lines += [non_comment]
  80             continue
  81         # otherwise, read as transfer data
  82         toks = non_comment.split()  # ignore specification's allowance of single spaces in names
  83         if len(toks) > 3:
  84             raise HandledException(f"{prefix} too many booking line tokens: {toks}")
  85         amount, currency = None, None
  86         account_name = toks[0]
  87         if account_name[0] == '[' and account_name[-1] == ']':
  88             # ignore specification's differentiation of "virtual" accounts
  89             account_name = account_name[1:-1]
  90         decimal_chars = ".-0123456789"
  91         if len(toks) == 3:
  92             i_currency = 1
  93             try:
  94                 amount = decimal.Decimal(toks[1])
  95                 i_currency = 2
  96             except decimal.InvalidOperation:
  97                 try:
  98                     amount = decimal.Decimal(toks[2])
  99                 except decimal.InvalidOperation:
 100                     raise HandledException(f"{prefix} no decimal number in: {toks[1:]}")
 101             currency = toks[i_currency]
 102             if currency[0] in decimal_chars:
 103                 raise HandledException(f"{prefix} currency starts with int, dot, or minus: {currency}")
 104         elif len(toks) == 2:
 105             value = toks[1]
 106             inside_amount = False
 107             inside_currency = False
 108             amount_string = ""
 109             currency = ""
 110             dots_counted = 0
 111             for i, c in enumerate(value):
 112                 if i == 0:
 113                     if c in decimal_chars:
 114                         inside_amount = True
 115                     else:
 116                         inside_currency = True
 117                 if inside_currency:
 118                     if c in decimal_chars and len(amount_string) == 0:
 119                         inside_currency = False
 120                         inside_amount = True
 121                     else:
 122                         currency += c
 123                         continue
 124                 if inside_amount:
 125                     if c not in decimal_chars:
 126                         if len(currency) > 0:
 127                             raise HandledException(f"{prefix} amount has non-decimal chars: {value}")
 128                         inside_currency = True
 129                         inside_amount = False
 130                         currency += c
 131                         continue
 132                     if c == '-' and len(amount_string) > 1:
 133                         raise HandledException(f"{prefix} amount has non-start '-': {value}")
 134                     if c == '.':
 135                         if dots_counted > 1:
 136                             raise HandledException(f"{prefix} amount has multiple dots: {value}")
 137                         dots_counted += 1
 138                     amount_string += c
 139             if len(amount_string) == 0:
 140                 raise HandledException(f"{prefix} amount missing: {value}")
 141             if len(currency) == 0:
 142                 raise HandledException(f"{prefix} currency missing: {value}")
 143             amount = decimal.Decimal(amount_string)
 144         booking_lines += [(account_name, amount, currency)]
 145     if inside_booking:
 146         raise HandledException(f"{prefix} last booking unfinished")
 147     return bookings, comments
 148
 149 class Booking:
 150
 151     def __init__(self, date_string, description, booking_lines, start_line):
 152         self.date_string = date_string
 153         self.description = description
 154         self.lines = booking_lines
 155         self.start_line = start_line
 156         self.validate_booking_lines()
 157         self.account_changes = self.parse_booking_lines_to_account_changes()
 158
 159     def validate_booking_lines(self):
 160         prefix = f"booking at line {self.start_line}"
 161         sums = {}
 162         empty_values = 0
 163         for line in self.lines[1:]:
 164             if line == '':
 165                 continue
 166             _, amount, currency = line
 167             if amount is None:
 168                 if empty_values > 0:
 169                     raise HandledException(f"{prefix} relates more than one empty value of same currency {currency}")
 170                 empty_values += 1
 171                 continue
 172             if currency not in sums:
 173                 sums[currency] = 0
 174             sums[currency] += amount
 175         if empty_values == 0:
 176             for k, v in sums.items():
 177                 if v != 0:
 178                     raise HandledException(f"{prefix} does not sum up to zero")
 179         else:
 180             sinkable = False
 181             for k, v in sums.items():
 182                 if v != 0:
 183                     sinkable = True
 184             if not sinkable:
 185                 raise HandledException(f"{prefix} has empty value that cannot be filled")
 186
 187     def parse_booking_lines_to_account_changes(self):
 188         account_changes = {}
 189         debt = {}
 190         sink_account = None
 191         for line in self.lines[1:]:
 192             if line == '':
 193                 continue
 194             account, amount, currency = line
 195             if amount is None:
 196                 sink_account = account
 197                 continue
 198             apply_booking_to_account_balances(account_changes, account, currency, amount)
 199             if currency not in debt:
 200                 debt[currency] = amount
 201             else:
 202                 debt[currency] += amount
 203         if sink_account:
 204             for currency, amount in debt.items():
 205                 apply_booking_to_account_balances(account_changes, sink_account, currency, -amount)
 206         return account_changes
 207
 208
 209
 210 class Database:
 211
 212     def __init__(self):
 213         db_name = "_ledger"
 214         self.db_file = db_name + ".json"
 215         self.lock_file = db_name+ ".lock"
 216         self.bookings = []
 217         self.comments = []
 218         self.real_lines = []
 219         if os.path.exists(self.db_file):
 220             with open(self.db_file, "r") as f:
 221                 self.real_lines += f.readlines()
 222         ret = parse_lines(self.real_lines)
 223         self.bookings += ret[0]
 224         self.comments += ret[1]
 225
 226     def get_lines(self, start, end):
 227         return db.real_lines[start:end]
 228
 229     def replace(self, start, end, lines):
 230         import shutil
 231         if os.path.exists(self.lock_file):
 232             raise HandledException('Sorry, lock file!')
 233         if os.path.exists(self.db_file):
 234             shutil.copy(self.db_file, self.db_file + ".bak")
 235         f = open(self.lock_file, 'w+')
 236         f.close()
 237         text = ''.join(self.real_lines[:start]) + '\n'.join(lines) + ''.join(self.real_lines[end:])
 238         with open(self.db_file, 'w') as f:
 239             f.write(text);
 240         os.remove(self.lock_file)
 241
 242     def append(self, lines):
 243         import shutil
 244         if os.path.exists(self.lock_file):
 245             raise HandledException('Sorry, lock file!')
 246         if os.path.exists(self.db_file):
 247             shutil.copy(self.db_file, self.db_file + ".bak")
 248         f = open(self.lock_file, 'w+')
 249         f.close()
 250         with open(self.db_file, 'a') as f:
 251             f.write('\n' + '\n'.join(lines) + '\n');
 252         os.remove(self.lock_file)
 253
 254
 255 class MyServer(BaseHTTPRequestHandler):
 256     header = """<html>
 257 <meta charset="UTF-8">
 258 <body>
 259 <a href="/ledger">ledger</a>
 260 <a href="/balance">balance</a>
 261 <a href="/add_free">add free</a>
 262 <a href="/add_structured">add structured</a>
 263 <hr />
 264 """
 265     footer = "</body>\n<html>"
 266
 267     def do_POST(self):
 268         length = int(self.headers['content-length'])
 269         postvars = parse_qs(self.rfile.read(length).decode(), keep_blank_values=1)
 270         parsed_url = urlparse(self.path)
 271         if '/add_structured' == parsed_url.path:
 272             n_lines = int(len(postvars) / 4)
 273             date = postvars['date'][0]
 274             description = postvars['description'][0]
 275             start_comment = postvars['line_0_comment'][0]
 276             lines = [f'{date} {description} ; {start_comment}']
 277             for i in range(1, n_lines):
 278                 account = postvars[f'line_{i}_account'][0]
 279                 amount = postvars[f'line_{i}_amount'][0]
 280                 currency = postvars[f'line_{i}_currency'][0]
 281                 comment = postvars[f'line_{i}_comment'][0]
 282                 new_main = f'{account} {amount} {currency}'
 283                 if '' == new_main.rstrip() == comment.rstrip():  # don't write empty lines
 284                     continue
 285                 lines += [f'{new_main} ; {comment}']
 286         elif '/add_free' == parsed_url.path:
 287             lines = postvars['booking'][0].splitlines()
 288         start = int(postvars['start'][0])
 289         end = int(postvars['end'][0])
 290         try:
 291             _, _ = parse_lines(lines)
 292             if start == end == 0:
 293                 db.append(lines)
 294             else:
 295                 db.replace(start, end, lines)
 296             self.send_response(301)
 297             self.send_header('Location', '/')
 298             self.end_headers()
 299         except HandledException as e:
 300             self.send_response(400)
 301             self.end_headers()
 302             page = f'{self.header}ERROR: {e}{self.footer}'
 303             self.wfile.write(bytes(page, "utf-8"))
 304
 305     def do_GET(self):
 306         self.send_response(200)
 307         self.send_header("Content-type", "text/html")
 308         self.end_headers()
 309         db = Database()
 310         parsed_url = urlparse(self.path)
 311         page = self.header + ''
 312         params = parse_qs(parsed_url.query)
 313         start = int(params.get('start', ['0'])[0])
 314         end = int(params.get('end', ['0'])[0])
 315         if parsed_url.path == '/balance':
 316             page += self.balance_as_html(db)
 317         elif parsed_url.path == '/add_free':
 318             page += self.add_free(db, start, end)
 319         elif parsed_url.path == '/add_structured':
 320             bonus_lines = int(params.get('bonus_lines', ['0'])[0])
 321             page += self.add_structured(db, start, end)
 322         else:
 323             page += self.ledger_as_html(db)
 324         page += self.footer
 325         self.wfile.write(bytes(page, "utf-8"))
 326
 327     def balance_as_html(self, db):
 328         account_sums = {}
 329         for booking in db.bookings:
 330             for account, changes in booking.account_changes.items():
 331                 for currency, amount in changes.items():
 332                     apply_booking_to_account_balances(account_sums, account, currency, amount)
 333         account_tree = {}
 334         def collect_branches(account_name, path):
 335             node = account_tree
 336             path_copy = path[:]
 337             while len(path_copy) > 0:
 338                 step = path_copy.pop(0)
 339                 node = node[step]
 340             toks = account_name.split(":", maxsplit=1)
 341             parent = toks[0]
 342             if parent in node.keys():
 343                 child = node[parent]
 344             else:
 345                 child = {}
 346                 node[parent] = child
 347             if len(toks) == 2:
 348                 k, v = collect_branches(toks[1], path + [parent])
 349                 if k not in child.keys():
 350                     child[k] = v
 351                 else:
 352                     child[k].update(v)
 353             return parent, child
 354         for account_name in sorted(account_sums.keys()):
 355             k, v = collect_branches(account_name, [])
 356             if k not in account_tree.keys():
 357                 account_tree[k] = v
 358             else:
 359                 account_tree[k].update(v)
 360         def collect_totals(parent_path, tree_node):
 361             for k, v in tree_node.items():
 362                 child_path = parent_path + ":" + k
 363                 for currency, amount in collect_totals(child_path, v).items():
 364                     apply_booking_to_account_balances(account_sums, parent_path, currency, amount)
 365             return account_sums[parent_path]
 366         for account_name in account_tree.keys():
 367             account_sums[account_name] = collect_totals(account_name, account_tree[account_name])
 368         lines = []
 369         def print_subtree(lines, indent, node, subtree, path):
 370             line = f"{indent}{node}"
 371             n_tabs = 5 - (len(line) // 8)
 372             line += n_tabs * "\t"
 373             if "€" in account_sums[path + node].keys():
 374                 amount = account_sums[path + node]["€"]
 375                 line += f"{amount:9.2f} €\t"
 376             else:
 377                 line += f"\t\t"
 378             for currency, amount in account_sums[path + node].items():
 379                 if currency != '€' and amount > 0:
 380                     line += f"{amount:5.2f} {currency}\t"
 381             lines += [line]
 382             indent += "  "
 383             for k, v in sorted(subtree.items()):
 384                 print_subtree(lines, indent, k, v, path + node + ":")
 385         for k, v in sorted(account_tree.items()):
 386             print_subtree(lines, "", k, v, "")
 387         content = "\n".join(lines)
 388         return f"<pre>{content}</pre>"
 389
 390     def ledger_as_html(self, db):
 391         lines = []
 392         line_sep = '<br />'
 393         for comment in db.comments:
 394             line = f'; {comment}' if comment != '' else ''
 395             lines += [line + line_sep]
 396         for booking in db.bookings:
 397             i = booking.start_line
 398             suffix = lines[i]
 399             lines[i] = f'<p>{booking.date_string} {booking.description}{suffix}'
 400             for booking_line in booking.lines[1:]:
 401                 i += 1
 402                 if booking_line == '':
 403                     continue
 404                 suffix = f' {lines[i]}' if len(lines[i]) > 0 else ''
 405                 value = f' {booking_line[1]} {booking_line[2]}' if booking_line[1] else ''
 406                 lines[i] = f'{booking_line[0]}{value}{suffix}'
 407             lines[i] = lines[i][:-len(line_sep)] + f"""</p>
 408 edit:
 409 <a href="/add_structured?start={booking.start_line}&end={i+1}">structured</a>
 410 / <a href="/add_free?start={booking.start_line}&end={i+1}">free</a>
 411 <br />"""
 412         return '\n'.join(lines)
 413
 414     def header_add_form(self, action):
 415         return f"<form method=\"POST\" action=\"/{action}\">\n"
 416
 417     def footer_add_form(self, start, end):
 418         return f"""
 419 <input type="hidden" name="start" value={start} />
 420 <input type="hidden" name="end" value={end} />
 421 <input type="submit">
 422 </form>"""
 423
 424     def add_free(self, db, start=0, end=0):
 425         content = html.escape(''.join(db.get_lines(start, end)))
 426         return f'{self.header_add_form("add_free")}<textarea name="booking" rows="8" cols="80">{content}</textarea>{self.footer_add_form(start, end)}'
 427
 428     def add_structured(self, db, start=0, end=0, bonus_lines=10):
 429         import datetime
 430         lines = db.get_lines(start, end)
 431         bookings, comments = parse_lines(lines)
 432         if len(bookings) > 1:
 433             raise HandledException('can only edit single Booking')
 434         input_lines = ''
 435         last_line = 0
 436         def inpu(name, val=""):
 437             safe_val = html.escape(str(val))
 438             return f'<input name="{name}" value="{safe_val}" />'
 439         if len(bookings) == 0:
 440             today = str(datetime.datetime.now())[:10]
 441             input_lines += f'{inpu("date", today)} {inpu("description")} ; {inpu("comment")}<br />'
 442             last_line = 1
 443         else:
 444             booking = bookings[0]
 445             last_line = len(comments)
 446             input_lines += f'{inpu("date", booking.date_string)} {inpu("description", booking.description)} ; {inpu("comment", comments[0])}<br />'
 447             for i in range(1, len(comments)):
 448                 account = amount = currency = ''
 449                 if i < len(booking.lines) and booking.lines[i] != '':
 450                     account = booking.lines[i][0]
 451                     amount = booking.lines[i][1]
 452                     currency = booking.lines[i][2]
 453                 input_lines += f'{inpu("line_{i}_account", account)} {inpu("line_{i}_amount", amount)} {inpu("line_{i}_currency", currency)} ; {inpu("line_{i}_comment", comments[i])}<br />'
 454         for j in range(bonus_lines):
 455             i = j + last_line
 456             input_lines += f'{inpu("line_{i}_account")} {inpu("line_{i}_amount")} {inpu("line_{i}_currency")} ; {inpu("line_{i}_comment")}<br />'
 457         return f'{self.header_add_form("add_structured")}{input_lines}{self.footer_add_form(start, end)}'
 458
 459
 460 db = Database()
 461 if __name__ == "__main__":
 462     webServer = HTTPServer((hostName, serverPort), MyServer)
 463     print(f"Server started http://{hostName}:{serverPort}")
 464     try:
 465         webServer.serve_forever()
 466     except KeyboardInterrupt:
 467         pass
 468     webServer.server_close()
 469     print("Server stopped.")