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Improve ledger.py
[misc] / ledger.py
index c3f0ab9c22d028d92b1c2741e7c411a4d9efa499..ee6ed807ef72b4a9601acf32d25fad6ec1e0757a 100755 (executable)
--- a/ledger.py
+++ b/ledger.py
@@ -1,6 +1,10 @@
 from http.server import BaseHTTPRequestHandler, HTTPServer
 import sys
 import os
+import html
+import jinja2 
+import decimal
+from urllib.parse import parse_qs, urlparse
 hostName = "localhost"
 serverPort = 8082
 
@@ -23,15 +27,114 @@ def apply_booking_to_account_balances(account_sums, account, currency, amount):
         account_sums[account][currency] += amount
 
 
+def add_taxes(lines):
+    bookings, _ = parse_lines(lines)
+    _, account_sums = bookings_to_account_tree(bookings)
+    expenses_so_far = -1 * account_sums['Assets']['€']
+    needed_income_before_krankenkasse = expenses_so_far
+    ESt_this_month = 0
+    left_over = needed_income_before_krankenkasse - ESt_this_month
+    too_low = 0
+    too_high = 2 * needed_income_before_krankenkasse 
+    E0 = decimal.Decimal(10908)
+    E1 = decimal.Decimal(15999)
+    E2 = decimal.Decimal(62809) 
+    E3 = decimal.Decimal(277825) 
+    while True:
+        zvE = 12 * needed_income_before_krankenkasse
+        if zvE < E0:
+            ESt = decimal.Decimal(0)
+        elif zvE < E1:
+            y = (zvE - E0)/10000
+            ESt = (decimal.Decimal(979.18) * y + 1400) * y
+        elif zvE < E2:
+            y = (zvE - E1)/10000
+            ESt = (decimal.Decimal(192.59) * y + 2397) * y + decimal.Decimal(966.53)
+        elif zvE < E3:
+            ESt = decimal.Decimal(0.42) * (zvE - decimal.Decimal(62809))  + decimal.Decimal(16405.54)
+        else: 
+            ESt = decimal.Decimal(0.45) * (zvE - decimal.Decimal(277825)) + decimal.Decimal(106713.52) 
+        ESt_this_month = ESt / 12
+        left_over = needed_income_before_krankenkasse - ESt_this_month
+        if abs(left_over - expenses_so_far) < 0.001:
+            break
+        elif left_over < expenses_so_far:
+            too_low = needed_income_before_krankenkasse
+        elif left_over > expenses_so_far:
+            too_high = needed_income_before_krankenkasse
+        needed_income_before_krankenkasse = too_low + (too_high - too_low)/2
+    ESt_this_month = ESt_this_month.quantize(decimal.Decimal('0.00'))
+    line_income_tax = f'  Reserves:Einkommenssteuer  {ESt_this_month}€ ; expenses so far: {expenses_so_far:.2f}€; zvE: {zvE:.2f}€; ESt total: {ESt:.2f}€; needed before Krankenkasse: {needed_income_before_krankenkasse:.2f}€'
+    kk_minimum_income = decimal.Decimal(1096.67) 
+    kk_factor = decimal.Decimal(0.189) 
+    kk_minimum_tax = decimal.Decimal(207.27).quantize(decimal.Decimal('0.00'))
+    # kk_minimum_income = 1131.67 
+    # kk_factor = decimal.Decimal(0.191) 
+    # kk_minimum_tax = decimal.Decimal(216.15)
+    # kk_factor = decimal.Decimal(0.197) 
+    # kk_minimum_tax = decimal.Decimal(222.94)
+    kk_add = max(0, kk_factor * needed_income_before_krankenkasse - kk_minimum_tax)
+    kk_add = decimal.Decimal(kk_add).quantize(decimal.Decimal('0.00'))
+    line_kk_minimum = f'  Reserves:Month:Krankenkassendefaultbeitrag  {kk_minimum_tax}€  ; assumed minimum income {kk_minimum_income:.2f}€ * {kk_factor:.3f}'
+    line_kk_add = f'  Reserves:Month:Krankenkassenbeitragswachstum {kk_add}€  ; max(0, {kk_factor:.3f} * {needed_income_before_krankenkasse:.2f}€ - {kk_minimum_tax}€)'
+    final_minus = expenses_so_far + ESt_this_month + kk_minimum_tax + kk_add 
+    line_finish = f'  Assets  -{ESt_this_month + kk_minimum_tax + kk_add} € ; -{final_minus}€'
+    return [line_income_tax, line_kk_minimum, line_kk_add, line_finish]
+
+
+def bookings_to_account_tree(bookings):
+    account_sums = {}
+    for booking in bookings:
+        for account, changes in booking.account_changes.items():
+            for currency, amount in changes.items():
+                apply_booking_to_account_balances(account_sums, account, currency, amount)
+    account_tree = {}
+    def collect_branches(account_name, path):
+        node = account_tree
+        path_copy = path[:]
+        while len(path_copy) > 0:
+            step = path_copy.pop(0)
+            node = node[step]
+        toks = account_name.split(":", maxsplit=1)
+        parent = toks[0]
+        if parent in node.keys():
+            child = node[parent]
+        else:
+            child = {}
+            node[parent] = child
+        if len(toks) == 2:
+            k, v = collect_branches(toks[1], path + [parent])
+            if k not in child.keys():
+                child[k] = v
+            else:
+                child[k].update(v)
+        return parent, child
+    for account_name in sorted(account_sums.keys()):
+        k, v = collect_branches(account_name, [])
+        if k not in account_tree.keys():
+            account_tree[k] = v
+        else:
+            account_tree[k].update(v)
+    def collect_totals(parent_path, tree_node):
+        for k, v in tree_node.items():
+            child_path = parent_path + ":" + k
+            for currency, amount in collect_totals(child_path, v).items():
+                apply_booking_to_account_balances(account_sums, parent_path, currency, amount)
+        return account_sums[parent_path]
+    for account_name in account_tree.keys():
+        account_sums[account_name] = collect_totals(account_name, account_tree[account_name])
+    return account_tree, account_sums
+
+
 def parse_lines(lines):
     import datetime
-    import decimal
     inside_booking = False
     date_string, description = None, None
     booking_lines = []
     start_line = 0
     bookings = []
     comments = []
+    lines = lines.copy() + [''] # to ensure a booking-ending last line
     for i, line in enumerate(lines):
         prefix = f"line {i}"
         # we start with the case of an utterly empty line
@@ -52,7 +155,7 @@ def parse_lines(lines):
         # if non-empty line, first get comment if any, and commit to DB
         split_by_comment = stripped_line.split(sep=";", maxsplit=1)
         if len(split_by_comment) == 2:
-            comments[i] = split_by_comment[1]
+            comments[i] = split_by_comment[1].lstrip()
         # 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
         non_comment = split_by_comment[0].rstrip()
         if non_comment.rstrip() == '':
@@ -73,6 +176,7 @@ def parse_lines(lines):
             except IndexError:
                 raise HandledException(f"{prefix} bad description: {description}")
             inside_booking = True
+            booking_lines += [non_comment]
             continue
         # otherwise, read as transfer data
         toks = non_comment.split()  # ignore specification's allowance of single spaces in names
@@ -142,6 +246,7 @@ def parse_lines(lines):
         raise HandledException(f"{prefix} last booking unfinished")
     return bookings, comments
 
+
 class Booking:
 
     def __init__(self, date_string, description, booking_lines, start_line):
@@ -150,13 +255,14 @@ class Booking:
         self.lines = booking_lines
         self.start_line = start_line
         self.validate_booking_lines()
+        self.sink = {}
         self.account_changes = self.parse_booking_lines_to_account_changes()
 
     def validate_booking_lines(self):
         prefix = f"booking at line {self.start_line}"
         sums = {}
         empty_values = 0
-        for line in self.lines:
+        for line in self.lines[1:]:
             if line == '':
                 continue
             _, amount, currency = line
@@ -171,7 +277,7 @@ class Booking:
         if empty_values == 0:
             for k, v in sums.items():
                 if v != 0:
-                    raise HandledException(f"{prefix} does not sum up to zero")
+                    raise HandledException(f"{prefix} does not add up to zero")
         else:
             sinkable = False
             for k, v in sums.items():
@@ -184,7 +290,7 @@ class Booking:
         account_changes = {}
         debt = {}
         sink_account = None
-        for line in self.lines:
+        for line in self.lines[1:]:
             if line == '':
                 continue
             account, amount, currency = line
@@ -199,23 +305,43 @@ class Booking:
         if sink_account:
             for currency, amount in debt.items():
                 apply_booking_to_account_balances(account_changes, sink_account, currency, -amount)
+                self.sink[currency] = -amount
         return account_changes
 
 
 
 class Database:
 
-    def __init__(self, load_from_file=True):
+    def __init__(self):
         db_name = "_ledger"
         self.db_file = db_name + ".json"
         self.lock_file = db_name+ ".lock"
         self.bookings = []
         self.comments = []
-        if load_from_file and os.path.exists(self.db_file):
+        self.real_lines = []
+        if os.path.exists(self.db_file):
             with open(self.db_file, "r") as f:
-                ret = parse_lines(f.readlines())
-                self.bookings += ret[0]
-                self.comments += ret[1]
+                self.real_lines += [l.rstrip() for l in f.readlines()]
+        ret = parse_lines(self.real_lines)
+        self.bookings += ret[0]
+        self.comments += ret[1]
+
+    def get_lines(self, start, end):
+        return self.real_lines[start:end]
+
+    def replace(self, start, end, lines):
+        import shutil
+        if os.path.exists(self.lock_file):
+            raise HandledException('Sorry, lock file!')
+        if os.path.exists(self.db_file):
+            shutil.copy(self.db_file, self.db_file + ".bak")
+        f = open(self.lock_file, 'w+')
+        f.close()
+        total_lines = self.real_lines[:start] + lines + self.real_lines[end:]
+        text = '\n'.join(total_lines)
+        with open(self.db_file, 'w') as f:
+            f.write(text);
+        os.remove(self.lock_file)
 
     def append(self, lines):
         import shutil
@@ -226,30 +352,94 @@ class Database:
         f = open(self.lock_file, 'w+')
         f.close()
         with open(self.db_file, 'a') as f:
-            f.write('\n' + '\n'.join(lines) + '\n');
+            f.write('\n\n' + '\n'.join(lines) + '\n\n');
         os.remove(self.lock_file)
 
 
 class MyServer(BaseHTTPRequestHandler):
-    header = '<html><meta charset="UTF-8"><body><a href="/ledger">ledger</a> <a href="/balance">balance</a> <a href="/add">add</a><hr />'
-    footer = '</body><html>'
+    header = """<html>
+<meta charset="UTF-8">
+<style>
+body { color: #000000; }
+table { margin-bottom: 2em; }
+th, td { text-align: left }
+input[type=number] { text-align: right; font-family: monospace; }
+.money { font-family: monospace; text-align: right; }
+.comment { font-style: italic; color: #777777; }
+.full_line_comment { display: block; white-space: nowrap; width: 0; }
+</style>
+<body>
+<a href="/ledger">ledger</a>
+<a href="/balance">balance</a>
+<a href="/add_free">add free</a>
+<a href="/add_structured">add structured</a>
+<hr />
+"""
+    footer = "</body>\n<html>"
 
     def do_POST(self):
-        from urllib.parse import parse_qs
+        db = Database()
         length = int(self.headers['content-length'])
         postvars = parse_qs(self.rfile.read(length).decode(), keep_blank_values=1)
-        lines = postvars['booking'][0].splitlines()
+        parsed_url = urlparse(self.path)
+        lines = []
+        add_empty_line = None 
+        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
+                if 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} {currency}'
+                if '' == new_main.rstrip() == comment.rstrip():  # don't write empty lines
+                    continue
+                j += 1
+                new_line = new_main
+                if comment.rstrip() != '':
+                    new_line += f' ; {comment}'
+                lines += [new_line]
+            if 'add_taxes' in postvars.keys():
+                lines += add_taxes(lines)
+        elif '/add_free' == parsed_url.path:
+            lines = postvars['booking'][0].splitlines()
+        start = int(postvars['start'][0])
+        end = int(postvars['end'][0])
         try:
-            bookings, comments = parse_lines(lines)
-            db.append(lines)
-            self.send_response(200)
-            self.end_headers()
-            page = f"{self.header}Success!{self.footer}"
-            self.wfile.write(bytes(page, "utf-8"))
+            _, _ = parse_lines(lines)
+            if 'save' in postvars.keys():
+                if start == end == 0:
+                    db.append(lines)
+                    redir_url = f'/#last'
+                else:
+                    db.replace(start, end, lines)
+                    redir_url = f'/#{start}'
+                self.send_response(301)
+                self.send_header('Location', redir_url)
+                self.end_headers()
+            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"))
         except HandledException as e:
             self.send_response(400)
+            self.send_header("Content-type", "text/html")
             self.end_headers()
-            page = f"{self.header}{e}{self.footer}"
+            page = f'{self.header}ERROR: {e}{self.footer}'
             self.wfile.write(bytes(page, "utf-8"))
 
     def do_GET(self):
@@ -257,58 +447,31 @@ class MyServer(BaseHTTPRequestHandler):
         self.send_header("Content-type", "text/html")
         self.end_headers()
         db = Database()
+        parsed_url = urlparse(self.path)
         page = self.header + ''
-        if self.path == '/balance':
+        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':
             page += self.balance_as_html(db)
-        elif self.path == '/add':
-            page += self.add()
+        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):
-        account_sums = {}
-        for booking in db.bookings:
-            for account, changes in booking.account_changes.items():
-                for currency, amount in changes.items():
-                    apply_booking_to_account_balances(account_sums, account, currency, amount)
-        account_tree = {}
-        def collect_branches(account_name, path):
-            node = account_tree
-            path_copy = path[:]
-            while len(path_copy) > 0:
-                step = path_copy.pop(0)
-                node = node[step]
-            toks = account_name.split(":", maxsplit=1)
-            parent = toks[0]
-            if parent in node.keys():
-                child = node[parent]
-            else:
-                child = {}
-                node[parent] = child
-            if len(toks) == 2:
-                k, v = collect_branches(toks[1], path + [parent])
-                if k not in child.keys():
-                    child[k] = v
-                else:
-                    child[k].update(v)
-            return parent, child
-        for account_name in sorted(account_sums.keys()):
-            k, v = collect_branches(account_name, [])
-            if k not in account_tree.keys():
-                account_tree[k] = v
-            else:
-                account_tree[k].update(v)
-        def collect_totals(parent_path, tree_node):
-            for k, v in tree_node.items():
-                child_path = parent_path + ":" + k
-                for currency, amount in collect_totals(child_path, v).items():
-                    apply_booking_to_account_balances(account_sums, parent_path, currency, amount)
-            return account_sums[parent_path]
-        for account_name in account_tree.keys():
-            account_sums[account_name] = collect_totals(account_name, account_tree[account_name])
         lines = []
+        account_tree, account_sums = bookings_to_account_tree(db.bookings)
         def print_subtree(lines, indent, node, subtree, path):
             line = f"{indent}{node}"
             n_tabs = 5 - (len(line) // 8)
@@ -330,30 +493,226 @@ class MyServer(BaseHTTPRequestHandler):
         content = "\n".join(lines)
         return f"<pre>{content}</pre>"
 
+    def ledger2_as_html(self, db):
+        single_c_tmpl = jinja2.Template('<span class="comment">{{c|e}}</span><br />')
+        booking_tmpl = jinja2.Template("""
+<p id="{{start}}"><a href="#{{start}}">{{date}}</a> {{desc}} <span class="comment">{{head_comment|e}}</span>
+[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>]
+<table>
+{% for l in booking_lines %}
+<tr><td>{{l.acc|e}}</td><td class="money">{{l.money|e}}</td><td class="money">{{l.balance|e}}</td></tr>
+{% endfor %}
+</table></p>
+""")
+        elements_to_write = []
+        account_sums = {}
+        for booking in db.bookings:
+            i = booking.start_line
+            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, 'balance':balance}] 
+            elements_to_write += [booking_tmpl.render(
+                start=booking.start_line,
+                end=booking_end,
+                date=booking.date_string,
+                desc=booking.description,
+                head_comment=db.comments[booking.start_line],
+                booking_lines = booking_lines)]
+        return '\n'.join(elements_to_write) 
+
     def ledger_as_html(self, db):
-        lines = []
-        for comment in db.comments:
-            lines += [f"; {comment}" if comment != '' else '']
+        single_c_tmpl = jinja2.Template('<span class="comment">{{c|e}}</span><br />')
+        booking_tmpl = jinja2.Template("""
+<p id="{{start}}"><a {% if last %}id="last"{% endif %} href="#{{start}}">{{date}}</a> {{desc}} <span class="comment">{{head_comment|e}}</span>
+[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>]
+<table>
+{% for l in booking_lines %}
+{% if l.acc %}
+<tr><td>{{l.acc|e}}</td><td class="money">{{l.money|e}}</td><td class="comment">{{l.comment|e}}</td></tr>
+{% else %}
+<tr><td><div class="comment full_line_comment">{{l.comment|e}}</div></td></tr>
+{% endif %}
+{% endfor %}
+</table></p>
+""")
+        elements_to_write = []
+        last_i = i = 0
+        last_start = db.bookings[-1].start_line
         for booking in db.bookings:
             i = booking.start_line
-            suffix = f" {lines[i]}" if len(lines[i]) > 0 else ""
-            lines[i] = f"{booking.date_string} {booking.description}{suffix}"
-            for booking_line in booking.lines:
+            elements_to_write += [single_c_tmpl.render(c=c) for c in db.comments[last_i:i] if c != '']
+            booking_end = last_i = booking.start_line + len(booking.lines)
+            booking_lines = []
+            for booking_line in booking.lines[1:]:
                 i += 1
+                comment = db.comments[i] 
                 if booking_line == '':
+                    booking_lines += [{'acc': None, 'money': None, 'comment': comment}]
                     continue
-                suffix = f" {lines[i]}" if len(lines[i]) > 0 else ""
-                value = f" {booking_line[1]} {booking_line[2]}" if booking_line[1] else ""
-                lines[i] = f"{booking_line[0]}{value}{suffix}"
-        content = "\n".join(lines)
-        return f"<pre>{content}</pre>"
+                account = booking_line[0] 
+                money = ''
+                if booking_line[1] is not None:
+                    money = f'{booking_line[1]} {booking_line[2]}'
+                booking_lines += [{'acc': booking_line[0], 'money':money, 'comment':comment}] 
+            elements_to_write += [booking_tmpl.render(
+                last=booking.start_line == last_start,
+                start=booking.start_line,
+                end=booking_end,
+                date=booking.date_string,
+                desc=booking.description,
+                head_comment=db.comments[booking.start_line],
+                booking_lines = booking_lines)]
+        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(self):
-        return '<form method="POST" action="/"><textarea name="booking" rows="8" cols="80"></textarea><input type="submit"></form>'
+    def add_free(self, db, start=0, end=0, copy=False):
+        tmpl = jinja2.Template("""
+<form method="POST" action="{{action|e}}">
+<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>
+""")
+        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" />
+<input type="submit" name="add_taxes" value="add taxes" />
+<br />
+<input name="date" value="{{date|e}}" size=9 />
+<input name="description" value="{{desc|e}}" list="descriptions" />
+<textarea name="line_0_comment" rows=1 cols=20>{{head_comment|e}}</textarea>
+<input type="submit" name="line_0_add" value="[+]" />
+<br />
+{% for line in booking_lines %}
+<input name="line_{{line.i}}_account" value="{{line.acc|e}}" size=40 list="accounts" />
+<input type="number" name="line_{{line.i}}_amount" step=0.01 value="{{line.amt}}" size=10 />
+<input name="line_{{line.i}}_currency" value="{{line.curr|e}}" size=3 list="currencies" />
+<textarea name="line_{{line.i}}_comment" rows=1 cols={% if line.comm_cols %}{{line.comm_cols}}{% else %}20{% endif %}>{{line.comment|e}}</textarea>
+<input type="submit" name="line_{{line.i}}_delete" value="[x]" />
+<input type="submit" name="line_{{line.i}}_add" value="[+]" />
+<br />
+{% endfor %}
+{% for name, items in datalist_sets.items() %}
+<datalist id="{{name}}">
+{% for item in items %}
+  <option value="{{item|e}}">{{item|e}}</option>
+{% 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>
+""")
+        import datetime
+        lines = temp_lines if len(''.join(temp_lines)) > 0 else db.get_lines(start, end)
+        bookings, comments = parse_lines(lines)
+        if len(bookings) > 1:
+            raise HandledException('can only edit single Booking')
+        if add_empty_line is not None:
+            comments = comments[:add_empty_line+1] + [''] + comments[add_empty_line+1:]
+            booking = bookings[0]
+            booking.lines = booking.lines[:add_empty_line+1] + [''] + booking.lines[add_empty_line+1:] 
+        action = 'add_structured'
+        datalist_sets = {'descriptions': set(), 'accounts': set(), 'currencies': set()}
+        for b in db.bookings:
+            datalist_sets['descriptions'].add(b.description)
+            for account, moneys in b.account_changes.items():
+                datalist_sets['accounts'].add(account)
+                for currency in moneys.keys():
+                    datalist_sets['currencies'].add(currency)
+        content = ''
+        today = str(datetime.datetime.now())[:10]
+        booking_lines = []
+        if copy:
+            start = end = 0
+        desc = head_comment = ''
+        if len(bookings) == 0:
+            for i in range(1, 3):
+                booking_lines += [{'i': i, 'acc': '', 'amt': '', 'curr': '', 'comment': ''}]
+            date=today 
+        else:
+            booking = bookings[0]
+            desc = booking.description
+            date = today if copy else booking.date_string
+            head_comment=comments[0]
+            last_line = len(comments)
+            for i in range(1, len(comments)):
+                account = amount = currency = ''
+                if i < len(booking.lines) and booking.lines[i] != '':
+                    account = booking.lines[i][0]
+                    amount = booking.lines[i][1]
+                    currency = booking.lines[i][2]
+                booking_lines += [{
+                        'i': i, 
+                        'acc': account,
+                        'amt': amount, 
+                        'curr': currency if currency else '',
+                        'comment': comments[i],
+                        'comm_cols': len(comments[i])}]
+        content += tmpl.render(
+                action=action, 
+                date=date,
+                desc=desc,
+                head_comment=head_comment, 
+                booking_lines=booking_lines,
+                datalist_sets=datalist_sets,
+                start=start,
+                end=end) 
+        return content 
 
 
-db = Database()
-if __name__ == "__main__":      
+if __name__ == "__main__":    
     webServer = HTTPServer((hostName, serverPort), MyServer)
     print(f"Server started http://{hostName}:{serverPort}")
     try: