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Improve ledger.py.
[misc] / ledger.py
index b93b202e462cb47566bbc1fcf2aee598eec72775..c004d22126846415a916e02a6bc4aad6052df9bf 100755 (executable)
--- a/ledger.py
+++ b/ledger.py
@@ -1,10 +1,9 @@
 from http.server import BaseHTTPRequestHandler, HTTPServer
-import sys
 import os
 import html
 import jinja2
 import decimal
-import datetime
+from datetime import datetime, timedelta
 from urllib.parse import parse_qs, urlparse
 hostName = "localhost"
 serverPort = 8082
@@ -14,11 +13,6 @@ class HandledException(Exception):
     pass
 
 
-def handled_error_exit(msg):
-    print(f"ERROR: {msg}")
-    sys.exit(1)
-
-
 def apply_booking_to_account_balances(account_sums, account, currency, amount):
     if not account in account_sums:
         account_sums[account] = {currency: amount}
@@ -73,7 +67,6 @@ def bookings_to_account_tree(bookings):
 
 
 def parse_lines(lines, validate_bookings=True):
-    import datetime
     inside_booking = False
     date_string, description = None, None
     booking_lines = []
@@ -115,7 +108,7 @@ def parse_lines(lines, validate_bookings=True):
             toks = non_comment.split(maxsplit=1)
             date_string = toks[0]
             try:
-                datetime.datetime.strptime(date_string, '%Y-%m-%d')
+                datetime.strptime(date_string, '%Y-%m-%d')
             except ValueError:
                 raise HandledException(f"{prefix} bad date string: {date_string}")
             if last_date > date_string:
@@ -286,65 +279,93 @@ class Database:
         f = open(self.lock_file, 'w+')
         f.close()
 
-        # always back up most recent to .bak
-        bakpath = f'{self.db_file}.bak'
-        shutil.copy(self.db_file, bakpath)
-
         # collect modification times of numbered .bak files
-        bak_prefix = f'{bakpath}.'
+        bak_prefix = f'{self.db_file}.bak.'
         backup_dates = []
         i = 0
         bak_as = f'{bak_prefix}{i}'
         while os.path.exists(bak_as):
             mod_time = os.path.getmtime(bak_as)
-            backup_dates += [str(datetime.datetime.fromtimestamp(mod_time))]
+            backup_dates += [str(datetime.fromtimestamp(mod_time))]
             i += 1
             bak_as = f'{bak_prefix}{i}'
 
-        # collect what numbered .bak files to save
+        # collect what numbered .bak files to save: the older, the fewer; for each
+        # timedelta, keep the newest file that's older
+        ages_to_keep = [timedelta(minutes=4**i) for i in range(0, 8)]
+        now = datetime.now() 
         to_save = []
-        datetime_len = 19
-        now = str(datetime.datetime.now())[:datetime_len]
-        while datetime_len > 2:
-            for i, date in reversed(list(enumerate(backup_dates))):
-                if date[:datetime_len] == now:
-                    if i not in to_save:
-                        to_save += [i] 
-                        break
-            datetime_len -= 1 
-            now = now[:datetime_len]
+        for age in ages_to_keep:
+            limit = now - age 
+            for i, date in enumerate(reversed(backup_dates)):
+                if datetime.strptime(date, '%Y-%m-%d %H:%M:%S.%f') < limit:
+                    unreversed_i = len(backup_dates) - i - 1
+                    if unreversed_i not in to_save:
+                        to_save += [unreversed_i]
+                    break
 
         # remove redundant backup files 
         j = 0
-        for i in reversed(to_save):
+        for i in to_save:
             if i != j:
                 source = f'{bak_prefix}{i}'
                 target = f'{bak_prefix}{j}'
                 shutil.move(source, target)
-            else:
-                print("keeping", i)
             j += 1
         for i in range(j, len(backup_dates)):
-            print("removing", i)
             try:
                 os.remove(f'{bak_prefix}{i}')
             except FileNotFoundError:
                 pass
 
-        # 
+        # put copy of current state at end of bak list 
         shutil.copy(self.db_file, f'{bak_prefix}{j}')
         with open(self.db_file, mode) as f:
             f.write(text);
         os.remove(self.lock_file)
 
-    def replace(self, start, end, lines):
-        total_lines = self.real_lines[:start] + lines + self.real_lines[end:]
+    def insert_at_date(self, lines, date):
+        start_at = len(self.real_lines)
+        for b in self.bookings:
+            if b.date_string == date:
+                start_at = b.start_line 
+                break
+            elif b.date_string > date:
+                break
+        if start_at == len(self.real_lines):
+            lines = [''] + lines
+        return self.write_lines_in_total_lines_at(self.real_lines, start_at, lines)
+
+    def update(self, start, end, lines, date):
+        total_lines = self.real_lines[:start] + self.real_lines[end:]
+        n_original_lines = end - start
+        start_at = len(total_lines)
+        for b in self.bookings:
+            if b.date_string == date:
+                if start_at == len(total_lines) or b.start_line == start:
+                    start_at = b.start_line 
+                    if b.start_line > start:
+                        start_at -= n_original_lines
+            elif b.date_string > date:
+                break
+        if start_at == len(total_lines):
+            lines = [''] + lines
+        return self.write_lines_in_total_lines_at(total_lines, start_at, lines)
+
+    def write_lines_in_total_lines_at(self, total_lines, start_at, lines):
+        total_lines = total_lines[:start_at] + lines + [''] + total_lines[start_at:]
+        _, _ = parse_lines(lines)
         text = '\n'.join(total_lines)
         self.write_db(text)
+        return start_at
 
-    def append(self, lines):
-        text = '\n\n' + '\n'.join(lines) + '\n\n'
-        self.write_db(text, 'a')
+    def get_nth_for_booking_of_start_line(self, start_line):
+        nth = 0
+        for b in self.bookings:
+            if b.start_line >= start_line:
+                break
+            nth += 1
+        return nth
 
     def add_taxes(self, lines, finish=False):
         ret = []
@@ -383,11 +404,11 @@ class Database:
                     last_monthbreak_est = b.account_changes[acc_est]['€']
                     last_monthbreak_kk_minimum = b.account_changes[acc_kk_minimum]['€']
                     last_monthbreak_assets = b.account_changes[acc_buffer]['€']
-        old_needed_income = last_monthbreak_assets + last_monthbreak_kk_add + last_monthbreak_kk_minimum + last_monthbreak_est
+        old_needed_income_before_anything = - last_monthbreak_assets - last_monthbreak_kk_add - last_monthbreak_kk_minimum - last_monthbreak_est
         if finish:
-            ret += [f'  {acc_est}  {-last_monthbreak_est}€ ; for old assumption of needed income: {old_needed_income}€']
+            ret += [f'  {acc_est}  {-last_monthbreak_est}€ ; for old assumption of needed income: {old_needed_income_before_anything}€']
         _, account_sums = bookings_to_account_tree(bookings)
-        expenses_so_far = -1 * account_sums[acc_assets]['€'] - old_needed_income
+        expenses_so_far = -1 * account_sums[acc_assets]['€'] + old_needed_income_before_anything
         needed_income_before_kk = expenses_so_far
         ESt_this_month = 0
         left_over = needed_income_before_kk - ESt_this_month
@@ -435,21 +456,33 @@ class Database:
         else:
             kk_factor = decimal.Decimal(0.197)
             kk_minimum_tax = decimal.Decimal(222.94).quantize(decimal.Decimal('0.00'))
-        kk_add = max(0, kk_factor * needed_income_before_kk - kk_minimum_tax)
+        kk_add_so_far = account_sums[acc_kk_add]['€'] if acc_kk_add in account_sums.keys() else 0
+        kk_add = needed_income_before_kk / (1 - kk_factor) - needed_income_before_kk - kk_minimum_tax
+        hit_kk_minimum_income_limit = False
+        if kk_add_so_far + kk_add < 0:
+            hit_kk_minimum_income_limit = True 
+            kk_add_uncorrect = kk_add
+            kk_add = -(kk_add + kk_add_so_far) 
         kk_add = decimal.Decimal(kk_add).quantize(decimal.Decimal('0.00'))
         if finish:
-            ret += [f'  {acc_kk_add}  {-last_monthbreak_kk_add}€  ; max(0, {kk_factor:.3f} * {-(old_needed_income - last_monthbreak_est):.2f}€ - {kk_minimum_tax}€)']
+            ret += [f'  {acc_kk_add}  {-last_monthbreak_kk_add}€  ; for old assumption of needed income']
         else:
             ret += [f'  {acc_kk_minimum}  {kk_minimum_tax}€  ; assumed minimum income {kk_minimum_income:.2f}€ * {kk_factor:.3f}']
-        ret += [f'  {acc_kk_add}  {kk_add}€  ; max(0, {kk_factor:.3f} * {needed_income_before_kk:.2f}€ - {kk_minimum_tax}€)']
+        if hit_kk_minimum_income_limit:
+            ret += [f'  {acc_kk_add}  {kk_add}€  ; {needed_income_before_kk:.2f}€ / (1 - {kk_factor:.3f}) - {needed_income_before_kk:.2f}€ - {kk_minimum_tax}€ = {kk_add_uncorrect:.2f}€ would reduce current {acc_kk_dd} ({kk_add_so_far:.2f}€) below 0']
+        else:
+            ret += [f'  {acc_kk_add}  {kk_add}€  ; {needed_income_before_kk:.2f}€ / (1 - {kk_factor:.3f}) - {needed_income_before_kk:.2f}€ - {kk_minimum_tax}€']
         diff = - last_monthbreak_est + ESt_this_month - last_monthbreak_kk_add + kk_add
         if not finish:
             diff += kk_minimum_tax
-        final_minus = expenses_so_far + old_needed_income + diff
+        final_minus = expenses_so_far - old_needed_income_before_anything + diff
         ret += [f'  {acc_assets}  {-diff} €']
         ret += [f'  {acc_assets}  {final_minus} €']
         year_needed = buffer_expenses + final_minus + (12 - months_passed - 1) * final_minus 
-        ret += [f'  {acc_buffer}  {-final_minus} € ; assume as to earn in year: {acc_buffer} + {12 - months_passed - 1} * this = {-year_needed}']
+        if finish:
+            ret += [f'  {acc_buffer}  {-final_minus} €']
+        else:
+            ret += [f'  {acc_buffer}  {-final_minus} € ; assume as to earn in year: {acc_buffer} + {12 - months_passed - 1} * this = {year_needed}']
         return ret
 
 
@@ -467,20 +500,20 @@ input[type=number] { text-align: right; font-family: monospace; }
 .full_line_comment { display: block; white-space: nowrap; width: 0; }
 </style>
 <body>
-<a href="/ledger1">ledger1</a>
-<a href="/ledger2">ledger2</a>
+<a href="/">ledger</a>
 <a href="/balance">balance</a>
 <a href="/add_free">add free</a>
 <a href="/add_structured">add structured</a>
 <hr />
 """
     booking_tmpl = jinja2.Template("""
-<p id="{{start}}"><a href="#{{start}}">{{date}}</a> {{desc}} <span class="comment">{{head_comment|e}}</span><br />
+<p id="{{nth}}"><a href="#{{nth}}">{{date}}</a> {{desc}} <span class="comment">{{head_comment|e}}</span><br />
 <span class="meta">[edit: <a href="/add_structured?start={{start}}&end={{end}}">structured</a>
 / <a href="/add_free?start={{start}}&end={{end}}">free</a>
 | copy:<a href="/copy_structured?start={{start}}&end={{end}}">structured</a>
 / <a href="/copy_free?start={{start}}&end={{end}}">free</a>
-| balance <a href="/balance?stop={{date}}&plus={{steps_after_date}}">before</a> or <a href="/balance?stop={{date}}&plus={{steps_after_date + 1}}">after</a>
+| move {% if move_up %}<a href="/move_up?start={{start}}&end={{end}}">up</a>{% else %}up{% endif %}/{% if move_down %}<a href="/move_down?start={{start}}&end={{end}}">down</a>{% else %}down{% endif %}
+| <a href="/balance?stop={{nth+1}}">balance after</a>
 ]</span>
 <table>
 {% for l in booking_lines %}
@@ -492,133 +525,170 @@ input[type=number] { text-align: right; font-family: monospace; }
 {% endfor %}
 </table></p>
 """)
+    add_form_header = """<form method="POST" action="{{action|e}}">
+<input type="submit" name="check" value="check" />
+<input type="submit" name="revert" value="revert" />
+"""
+    add_form_footer = """
+<input type="hidden" name="start" value={{start}} />
+<input type="hidden" name="end" value={{end}} />
+<input type="submit" name="save" value="save!">
+</form>
+"""
     footer = "</body>\n<html>"
 
     def do_POST(self):
         try:
-            db = Database()
+            parsed_url = urlparse(self.path)
             length = int(self.headers['content-length'])
             postvars = parse_qs(self.rfile.read(length).decode(), keep_blank_values=1)
-            parsed_url = urlparse(self.path)
-            lines = []
-            add_empty_line = None
             start = int(postvars['start'][0])
             end = int(postvars['end'][0])
+            db = Database()
+            add_empty_line = None
+            lines = []
+            # get inputs
             if '/add_structured' == parsed_url.path and not 'revert' in postvars.keys():
-                date = postvars['date'][0]
-                description = postvars['description'][0]
-                start_comment = postvars['line_0_comment'][0]
-                lines = [f'{date} {description} ; {start_comment}']
-                if 'line_0_add' in postvars.keys():
-                    add_empty_line = 0
-                i = j = 1
-                while f'line_{i}_comment' in postvars.keys():
-                    if f'line_{i}_delete' in postvars.keys():
-                        i += 1
-                        continue
-                    elif f'line_{i}_delete_after' in postvars.keys():
-                        break 
-                    elif f'line_{i}_add' in postvars.keys():
-                        add_empty_line = j
-                    account = postvars[f'line_{i}_account'][0]
-                    amount = postvars[f'line_{i}_amount'][0]
-                    currency = postvars[f'line_{i}_currency'][0]
-                    comment = postvars[f'line_{i}_comment'][0]
-                    i += 1
-                    new_main = f'  {account}  {amount}'
-                    if '' == new_main.rstrip() == comment.rstrip():  # don't write empty lines, ignore currency if nothing else set
-                        continue
-                    if len(amount.rstrip()) > 0:
-                        new_main += f' {currency}'
-                    j += 1
-                    new_line = new_main
-                    if comment.rstrip() != '':
-                        new_line += f'  ; {comment}'
-                    lines += [new_line]
-                if 'add_sink' in postvars.keys():
-                    temp_lines = lines.copy() + ['_']
-                    try:
-                        temp_bookings, _ = parse_lines(temp_lines)
-                        for currency in temp_bookings[0].sink:
-                            amount = temp_bookings[0].sink[currency]
-                            lines += [f'Assets  {amount:.2f} {currency}']
-                    except HandledException:
-                        pass
-                if 'add_taxes' in postvars.keys():
-                    lines += db.add_taxes(lines, finish=False)
-                elif 'add_taxes2' in postvars.keys():
-                    lines += db.add_taxes(lines, finish=True)
-            elif '/add_free' == parsed_url.path:
+                lines, add_empty_line = self.booking_lines_from_postvars(postvars, db) 
+            elif '/add_free' == parsed_url.path and not 'revert' in postvars.keys():
                 lines = postvars['booking'][0].splitlines()
+            # validate where appropriate
             if ('save' in postvars.keys()) or ('check' in postvars.keys()):
                 _, _ = parse_lines(lines)
+            # if saving, process where to and where to redirect after
             if 'save' in postvars.keys():
+                last_date = str(datetime.now())[:10]
+                if len(db.bookings) > 0:
+                    last_date = db.bookings[-1].date_string
+                target_date = last_date[:] 
+                first_line_tokens = lines[0].split() if len(lines) > 0 else ''
+                first_token = first_line_tokens[0] if len(first_line_tokens) > 0 else ''
+                try:
+                    datetime.strptime(first_token, '%Y-%m-%d')
+                    target_date = first_token
+                except ValueError:
+                     pass
                 if start == end == 0:
-                    db.append(lines)
-                    redir_url = f'/#last'
+                    start = db.insert_at_date(lines, target_date)
+                    nth = db.get_nth_for_booking_of_start_line(start) 
                 else:
-                    db.replace(start, end, lines)
-                    redir_url = f'/#{start}'
-                self.send_response(301)
-                self.send_header('Location', redir_url)
-                self.end_headers()
+                    new_start = db.update(start, end, lines, target_date)
+                    nth = db.get_nth_for_booking_of_start_line(new_start)
+                    if new_start > start: 
+                        nth -= 1 
+                redir_url = f'/#{nth}'
+                self.send_code_and_headers(302, [('Location', redir_url)])
+            # otherwise just re-build editing form
             else:
-                page = self.header + self.add_structured(db, start, end, temp_lines=lines, add_empty_line=add_empty_line) + self.footer
-                self.send_response(200)
-                self.send_header("Content-type", "text/html")
-                self.end_headers()
-                self.wfile.write(bytes(page, "utf-8"))
+                if '/add_structured' == parsed_url.path: 
+                    edit_content = self.add_structured(db, start, end, temp_lines=lines, add_empty_line=add_empty_line)
+                else:
+                    edit_content = self.add_free(db, start, end)
+                self.send_HTML(self.header + edit_content + self.footer)
         except HandledException as e:
-            self.send_response(400)
-            self.send_header("Content-type", "text/html")
-            self.end_headers()
-            page = f'{self.header}ERROR: {e}{self.footer}'
-            self.wfile.write(bytes(page, "utf-8"))
+            self.fail_400(e)
 
     def do_GET(self):
-        self.send_response(200)
-        self.send_header("Content-type", "text/html")
+        try:
+            parsed_url = urlparse(self.path)
+            params = parse_qs(parsed_url.query)
+            start = int(params.get('start', ['0'])[0])
+            end = int(params.get('end', ['0'])[0])
+            db = Database()
+            page = self.header
+            if parsed_url.path == '/balance':
+                stop = params.get('stop', [None])[0]
+                page += self.balance_as_html(db, stop)
+            elif parsed_url.path == '/add_free':
+                page += self.add_free(db, start, end)
+            elif parsed_url.path == '/add_structured':
+                page += self.add_structured(db, start, end)
+            elif parsed_url.path == '/copy_free':
+                page += self.add_free(db, start, end, copy=True)
+            elif parsed_url.path == '/copy_structured':
+                page += self.add_structured(db, start, end, copy=True)
+            elif parsed_url.path == '/move_up':
+                nth = self.move_up(db, start, end)
+                self.send_code_and_headers(302, [('Location', f'/#{nth}')])
+                return
+            elif parsed_url.path == '/move_down':
+                nth = self.move_down(db, start, end)
+                self.send_code_and_headers(302, [('Location', f'/#{nth}')])
+                return
+            else:
+                page += self.ledger_as_html(db)
+            page += self.footer
+            self.send_HTML(page)
+        except HandledException as e:
+            self.fail_400(e)
+
+    def fail_400(self, e):
+        page = f'{self.header}ERROR: {e}{self.footer}'
+        self.send_HTML(page, 400)
+
+    def send_HTML(self, html, code=200):
+        self.send_code_and_headers(code, [('Content-type', 'text/html')])
+        self.wfile.write(bytes(html, "utf-8"))
+
+    def send_code_and_headers(self, code, headers=[]):
+        self.send_response(code)
+        for fieldname, content in headers:
+            self.send_header(fieldname, content)
         self.end_headers()
-        db = Database()
-        parsed_url = urlparse(self.path)
-        page = self.header + ''
-        params = parse_qs(parsed_url.query)
-        start = int(params.get('start', ['0'])[0])
-        end = int(params.get('end', ['0'])[0])
-        if parsed_url.path == '/balance':
-            stop_date = params.get('stop', [None])[0]
-            plus = int(params.get('plus', [0])[0])
-            page += self.balance_as_html(db, stop_date, plus)
-        elif parsed_url.path == '/add_free':
-            page += self.add_free(db, start, end)
-        elif parsed_url.path == '/add_structured':
-            page += self.add_structured(db, start, end)
-        elif parsed_url.path == '/copy_free':
-            page += self.add_free(db, start, end, copy=True)
-        elif parsed_url.path == '/copy_structured':
-            page += self.add_structured(db, start, end, copy=True)
-        elif parsed_url.path == '/ledger2':
-            page += self.ledger2_as_html(db)
-        else:
-            page += self.ledger_as_html(db)
-        page += self.footer
-        self.wfile.write(bytes(page, "utf-8"))
 
-    def balance_as_html(self, db, stop_date=None, plus=0):
+    def booking_lines_from_postvars(self, postvars, db):
+        add_empty_line = None
+        date = postvars['date'][0]
+        description = postvars['description'][0]
+        start_comment = postvars['line_0_comment'][0]
+        start_line = f'{date} {description}'
+        if start_comment.rstrip() != '':
+            start_line += f' ; {start_comment}' 
+        lines = [start_line]
+        if 'line_0_add' in postvars.keys():
+            add_empty_line = 0
+        i = j = 1
+        while f'line_{i}_comment' in postvars.keys():
+            if f'line_{i}_delete' in postvars.keys():
+                i += 1
+                continue
+            elif f'line_{i}_delete_after' in postvars.keys():
+                break 
+            elif f'line_{i}_add' in postvars.keys():
+                add_empty_line = j
+            account = postvars[f'line_{i}_account'][0]
+            amount = postvars[f'line_{i}_amount'][0]
+            currency = postvars[f'line_{i}_currency'][0]
+            comment = postvars[f'line_{i}_comment'][0]
+            i += 1
+            new_main = f'  {account}  {amount}'
+            if '' == new_main.rstrip() == comment.rstrip():  # don't write empty lines, ignore currency if nothing else set
+                continue
+            if len(amount.rstrip()) > 0:
+                new_main += f' {currency}'
+            j += 1
+            new_line = new_main
+            if comment.rstrip() != '':
+                new_line += f'  ; {comment}'
+            lines += [new_line]
+        if 'add_sink' in postvars.keys():
+            temp_lines = lines.copy() + ['_']
+            try:
+                temp_bookings, _ = parse_lines(temp_lines)
+                for currency in temp_bookings[0].sink:
+                    amount = temp_bookings[0].sink[currency]
+                    lines += [f'Assets  {amount:.2f} {currency}']
+            except HandledException:
+                pass
+        if 'add_taxes' in postvars.keys():
+            lines += db.add_taxes(lines, finish=False)
+        elif 'add_taxes2' in postvars.keys():
+            lines += db.add_taxes(lines, finish=True)
+        return lines, add_empty_line
+
+    def balance_as_html(self, db, until=None):
+        bookings = db.bookings[:until if until is None else int(until)]
         lines = []
-        bookings = db.bookings
-        if stop_date:
-            bookings = []
-            i = -1
-            for b in db.bookings:
-                if b.date_string == stop_date:
-                    if -1 == i:
-                        i = 0
-                if i >= plus:
-                    break
-                if i > -1:
-                    i += 1
-                bookings += [b]
         account_tree, account_sums = bookings_to_account_tree(bookings)
         def print_subtree(lines, indent, node, subtree, path):
             line = f"{indent}{node}"
@@ -641,84 +711,22 @@ input[type=number] { text-align: right; font-family: monospace; }
         content = "\n".join(lines)
         return f"<pre>{content}</pre>"
 
-    def ledger2_as_html(self, db):
-        elements_to_write = []
-        account_sums = {}  ##
-        nth_of_same_date = 0
-        same_date = ''
-        for booking in db.bookings:
-            if booking.date_string == same_date:
-                nth_of_same_date += 1
-            else:
-                same_date = booking.date_string
-                nth_of_same_date = 0
-            booking_end = booking.start_line + len(booking.lines)
-            booking_lines = []
-            for booking_line in booking.lines[1:]:
-                if booking_line == '':
-                    continue
-                account = booking_line[0]  ##
-                account_toks = account.split(':')  ##
-                path = ''  ##
-                for tok in account_toks: ##
-                    path += tok  ##
-                    if not path in account_sums.keys():  ##
-                        account_sums[path] = {}  ##
-                    path += ':'  ##
-                moneys = []  ##
-                money = ''
-                if booking_line[1] is not None:
-                    moneys += [(booking_line[1], booking_line[2])]  ##
-                    money = f'{moneys[0][0]} {moneys[0][1]}'
-                else:  ##
-                    for currency, amount in booking.sink.items():  ##
-                        moneys += {(amount, currency)}  ##
-                    money = '['  ##
-                    for m in moneys:  ##
-                        money += f'{m[0]} {m[1]} ' ##
-                    money += ']'  ##
-                balance = ''  ##
-                for amount, currency in moneys:  ##
-                    path = ''  ##
-                    for tok in account_toks:  ##
-                        path += tok  ##
-                        if not currency in account_sums[path].keys():  ##
-                            account_sums[path][currency] = 0  ##
-                        account_sums[path][currency] += amount  ##
-                        path += ':'   ##
-                    balance += f'{account_sums[account][currency]} {currency}'  ##
-                booking_lines += [{'acc': booking_line[0], 'money':money, 'comment':balance}]  ##
-            elements_to_write += [self.booking_tmpl.render(
-                start=booking.start_line,
-                end=booking_end,
-                date=booking.date_string,
-                desc=booking.description,
-                head_comment=db.comments[booking.start_line],
-                steps_after_date=nth_of_same_date,
-                booking_lines = booking_lines)]
-        return '\n'.join(elements_to_write)
-
     def ledger_as_html(self, db):
-        single_c_tmpl = jinja2.Template('<span class="comment">{{c|e}}</span><br />')
+        single_c_tmpl = jinja2.Template('<span class="comment">{{c|e}}</span><br />')  ##
         elements_to_write = []
         last_i = i = 0  ##
-        nth_of_same_date = 0
-        same_date = ''
-        for booking in db.bookings:
-            if booking.date_string == same_date:
-                nth_of_same_date += 1
-            else:
-                same_date = booking.date_string
-                nth_of_same_date = 0
-            i = booking.start_line  ##
-            elements_to_write += [single_c_tmpl.render(c=c) for c in db.comments[last_i:i] if c != '']  ##
+        for nth, booking in enumerate(db.bookings):
+            move_up = nth > 0 and db.bookings[nth - 1].date_string == booking.date_string
+            move_down = nth < len(db.bookings) - 1 and db.bookings[nth + 1].date_string == booking.date_string
             booking_end = last_i = booking.start_line + len(booking.lines)
             booking_lines = []
+            i = booking.start_line  ##
+            elements_to_write += [single_c_tmpl.render(c=c) for c in db.comments[last_i:i] if c != '']  ##
             for booking_line in booking.lines[1:]:
-                 i += 1
-                 comment = db.comments[i]
+                 i += 1  ##
+                 comment = db.comments[i]  ##
                  if booking_line == '':
-                     booking_lines += [{'acc': None, 'money': None, 'comment': comment}]
+                     booking_lines += [{'acc': None, 'money': None, 'comment': comment}]  ##
                      continue
                  account = booking_line[0]
                  money = ''
@@ -726,38 +734,32 @@ input[type=number] { text-align: right; font-family: monospace; }
                      money = f'{booking_line[1]} {booking_line[2]}'
                  booking_lines += [{'acc': booking_line[0], 'money':money, 'comment':comment}]  ##
             elements_to_write += [self.booking_tmpl.render(
+                nth=nth,
                 start=booking.start_line,
                 end=booking_end,
                 date=booking.date_string,
                 desc=booking.description,
                 head_comment=db.comments[booking.start_line],
-                steps_after_date=nth_of_same_date,
+                move_up=move_up,
+                move_down=move_down,
                 booking_lines = booking_lines)]
-        elements_to_write += [single_c_tmpl.render(c=c) for c in db.comments[last_i:] if c != '']
+        elements_to_write += [single_c_tmpl.render(c=c) for c in db.comments[last_i:] if c != '']  #
         return '\n'.join(elements_to_write)
 
     def add_free(self, db, start=0, end=0, copy=False):
-        tmpl = jinja2.Template("""
-<form method="POST" action="{{action|e}}">
+        tmpl = jinja2.Template(self.add_form_header + """<br />
 <textarea name="booking" rows=10 cols=80>
 {% for line in lines %}{{ line }}
 {% endfor %}
 </textarea>
-<input type="hidden" name="start" value={{start}} />
-<input type="hidden" name="end" value={{end}} />
-<input type="submit" name="save" value="save!">
-</form>
-""")
+""" + self.add_form_footer)
         lines = db.get_lines(start, end)
         if copy:
             start = end = 0
         return tmpl.render(action='add_free', start=start, end=end, lines=lines)
 
     def add_structured(self, db, start=0, end=0, copy=False, temp_lines=[], add_empty_line=None):
-        tmpl = jinja2.Template("""
-<form method="POST" action="{{action|e}}">
-<input type="submit" name="check" value="check" />
-<input type="submit" name="revert" value="revert" />
+        tmpl = jinja2.Template(self.add_form_header + """
 <input type="submit" name="add_taxes" value="add taxes" />
 <input type="submit" name="add_taxes2" value="add taxes2" />
 <input type="submit" name="add_sink" value="add sink" />
@@ -784,15 +786,11 @@ input[type=number] { text-align: right; font-family: monospace; }
 {% endfor %}
 </datalist>
 {% endfor %}
-<input type="hidden" name="start" value={{start}} />
-<input type="hidden" name="end" value={{end}} />
-<input type="submit" name="save" value="save!">
-</form>
-""")
+""" + self.add_form_footer)
         lines = temp_lines if len(''.join(temp_lines)) > 0 else db.get_lines(start, end)
         bookings, comments = parse_lines(lines, validate_bookings=False)
         if len(bookings) > 1:
-            raise HandledException('can only edit single Booking')
+            raise HandledException('can only structurally edit single Booking')
         if add_empty_line is not None:
             comments = comments[:add_empty_line+1] + [''] + comments[add_empty_line+1:]
             booking = bookings[0]
@@ -806,7 +804,7 @@ input[type=number] { text-align: right; font-family: monospace; }
                 for currency in moneys.keys():
                     datalist_sets['currencies'].add(currency)
         content = ''
-        today = str(datetime.datetime.now())[:10]
+        today = str(datetime.now())[:10]
         booking_lines = []
         if copy:
             start = end = 0
@@ -845,6 +843,31 @@ input[type=number] { text-align: right; font-family: monospace; }
                 end=end)
         return content
 
+    def move_up(self, db, start, end):
+        prev_booking = None
+        for redir_nth, b in enumerate(db.bookings):
+            if b.start_line >= start:
+                break
+            prev_booking = b
+        start_at = prev_booking.start_line 
+        self.make_move(db, start, end, start_at)
+        return redir_nth - 1
+
+    def move_down(self, db, start, end):
+        next_booking = None
+        for redir_nth, b in enumerate(db.bookings):
+            if b.start_line > start:
+                next_booking = b
+                break
+        start_at = next_booking.start_line + len(next_booking.lines) - (end - start) + 1 
+        self.make_move(db, start, end, start_at)
+        return redir_nth
+
+    def make_move(self, db, start, end, start_at):
+        lines = db.get_lines(start, end)
+        total_lines = db.real_lines[:start] + db.real_lines[end:]
+        db.write_lines_in_total_lines_at(total_lines, start_at, lines)
+
 
 if __name__ == "__main__":  
     webServer = HTTPServer((hostName, serverPort), MyServer)