From: Christian Heller <c.heller@plomlompom.de>
Date: Fri, 13 Oct 2023 02:05:33 +0000 (+0200)
Subject: Add ledger append to ledger.py
X-Git-Url: https://plomlompom.com/repos/%7B%7B%20web_path%20%7D%7D/cards/%7B%7B%20card_id%20%7D%7D/todo?a=commitdiff_plain;h=2deeead813fbdf0fec4f94d238a43fd93514f94f;p=misc

Add ledger append to ledger.py
---

diff --git a/ledger.py b/ledger.py
index 334318f..c3f0ab9 100755
--- a/ledger.py
+++ b/ledger.py
@@ -1,5 +1,6 @@
 from http.server import BaseHTTPRequestHandler, HTTPServer
 import sys
+import os
 hostName = "localhost"
 serverPort = 8082
 
@@ -15,19 +16,138 @@ def handled_error_exit(msg):
 
 def apply_booking_to_account_balances(account_sums, account, currency, amount):
     if not account in account_sums:
-        account_sums[account] = {currency: amount} 
+        account_sums[account] = {currency: amount}
     elif not currency in account_sums[account].keys():
         account_sums[account][currency] = amount
     else:
         account_sums[account][currency] += amount
 
 
+def parse_lines(lines):
+    import datetime
+    import decimal
+    inside_booking = False
+    date_string, description = None, None
+    booking_lines = []
+    start_line = 0
+    bookings = []
+    comments = []
+    for i, line in enumerate(lines):
+        prefix = f"line {i}"
+        # we start with the case of an utterly empty line
+        comments += [""]
+        stripped_line = line.rstrip()
+        if stripped_line == '':
+            if inside_booking:
+                # assume we finished a booking, finalize, and commit to DB
+                if len(booking_lines) < 2:
+                    raise HandledException(f"{prefix} booking ends to early")
+                booking = Booking(date_string, description, booking_lines, start_line)
+                bookings += [booking]
+            # expect new booking to follow so re-zeroall booking data
+            inside_booking = False
+            date_string, description = None, None
+            booking_lines = []
+            continue
+        # 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]
+        # 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() == '':
+             if inside_booking:
+                 booking_lines += ['']
+             continue
+        # if we're starting a booking, parse by first-line pattern
+        if not inside_booking:
+            start_line = i
+            toks = non_comment.split(maxsplit=1)
+            date_string = toks[0]
+            try:
+                datetime.datetime.strptime(date_string, '%Y-%m-%d')
+            except ValueError:
+                raise HandledException(f"{prefix} bad date string: {date_string}")
+            try:
+                description = toks[1]
+            except IndexError:
+                raise HandledException(f"{prefix} bad description: {description}")
+            inside_booking = True
+            continue
+        # otherwise, read as transfer data
+        toks = non_comment.split()  # ignore specification's allowance of single spaces in names
+        if len(toks) > 3:
+            raise HandledException(f"{prefix} too many booking line tokens: {toks}")
+        amount, currency = None, None
+        account_name = toks[0]
+        if account_name[0] == '[' and account_name[-1] == ']':
+            # ignore specification's differentiation of "virtual" accounts
+            account_name = account_name[1:-1]
+        decimal_chars = ".-0123456789"
+        if len(toks) == 3:
+            i_currency = 1
+            try:
+                amount = decimal.Decimal(toks[1])
+                i_currency = 2
+            except decimal.InvalidOperation:
+                try:
+                    amount = decimal.Decimal(toks[2])
+                except decimal.InvalidOperation:
+                    raise HandledException(f"{prefix} no decimal number in: {toks[1:]}")
+            currency = toks[i_currency]
+            if currency[0] in decimal_chars:
+                raise HandledException(f"{prefix} currency starts with int, dot, or minus: {currency}")
+        elif len(toks) == 2:
+            value = toks[1]
+            inside_amount = False
+            inside_currency = False
+            amount_string = ""
+            currency = ""
+            dots_counted = 0
+            for i, c in enumerate(value):
+                if i == 0:
+                    if c in decimal_chars:
+                        inside_amount = True
+                    else:
+                        inside_currency = True
+                if inside_currency:
+                    if c in decimal_chars and len(amount_string) == 0:
+                        inside_currency = False
+                        inside_amount = True
+                    else:
+                        currency += c
+                        continue
+                if inside_amount:
+                    if c not in decimal_chars:
+                        if len(currency) > 0:
+                            raise HandledException(f"{prefix} amount has non-decimal chars: {value}")
+                        inside_currency = True
+                        inside_amount = False
+                        currency += c
+                        continue
+                    if c == '-' and len(amount_string) > 1:
+                        raise HandledException(f"{prefix} amount has non-start '-': {value}")
+                    if c == '.':
+                        if dots_counted > 1:
+                            raise HandledException(f"{prefix} amount has multiple dots: {value}")
+                        dots_counted += 1
+                    amount_string += c
+            if len(amount_string) == 0:
+                raise HandledException(f"{prefix} amount missing: {value}")
+            if len(currency) == 0:
+                raise HandledException(f"{prefix} currency missing: {value}")
+            amount = decimal.Decimal(amount_string)
+        booking_lines += [(account_name, amount, currency)]
+    if inside_booking:
+        raise HandledException(f"{prefix} last booking unfinished")
+    return bookings, comments
+
 class Booking:
 
     def __init__(self, date_string, description, booking_lines, start_line):
         self.date_string = date_string
-        self.description = description 
-        self.lines = booking_lines 
+        self.description = description
+        self.lines = booking_lines
         self.start_line = start_line
         self.validate_booking_lines()
         self.account_changes = self.parse_booking_lines_to_account_changes()
@@ -37,7 +157,7 @@ class Booking:
         sums = {}
         empty_values = 0
         for line in self.lines:
-            if line == '': 
+            if line == '':
                 continue
             _, amount, currency = line
             if amount is None:
@@ -56,7 +176,7 @@ class Booking:
             sinkable = False
             for k, v in sums.items():
                 if v != 0:
-                    sinkable = True 
+                    sinkable = True
             if not sinkable:
                 raise HandledException(f"{prefix} has empty value that cannot be filled")
 
@@ -65,7 +185,7 @@ class Booking:
         debt = {}
         sink_account = None
         for line in self.lines:
-            if line == '': 
+            if line == '':
                 continue
             account, amount, currency = line
             if amount is None:
@@ -86,7 +206,6 @@ class Booking:
 class Database:
 
     def __init__(self, load_from_file=True):
-        import os
         db_name = "_ledger"
         self.db_file = db_name + ".json"
         self.lock_file = db_name+ ".lock"
@@ -94,167 +213,87 @@ class Database:
         self.comments = []
         if load_from_file and os.path.exists(self.db_file):
             with open(self.db_file, "r") as f:
-                self.parse_lines(f.readlines())
+                ret = parse_lines(f.readlines())
+                self.bookings += ret[0]
+                self.comments += ret[1]
 
-    def parse_lines(self, lines): 
-        import datetime
-        import decimal 
-        inside_booking = False
-        date_string, description = None, None
-        booking_lines = []
-        start_line = 0
-        for i, line in enumerate(lines):
-            prefix = f"line {i}"
-            # we start with the case of an utterly empty line
-            self.comments += [""] 
-            stripped_line = line.rstrip()
-            if stripped_line == '':
-                if inside_booking:
-                    # assume we finished a booking, finalize, and commit to DB 
-                    if len(booking_lines) < 2:
-                        raise HandledException(f"{prefix} booking ends to early")
-                    booking = Booking(date_string, description, booking_lines, start_line)
-                    self.bookings += [booking]
-                # expect new booking to follow so re-zeroall booking data 
-                inside_booking = False
-                date_string, description = None, None
-                booking_lines = []
-                continue
-            # 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:
-                self.comments[i] = split_by_comment[1] 
-            # 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() == '': 
-                 if inside_booking: 
-                     booking_lines += ['']
-                 continue
-            # if we're starting a booking, parse by first-line pattern 
-            if not inside_booking:
-                start_line = i
-                toks = non_comment.split(maxsplit=1)
-                date_string = toks[0]
-                try:
-                    datetime.datetime.strptime(date_string, '%Y-%m-%d')
-                except ValueError:
-                    raise HandledException(f"{prefix} bad date string: {date_string}")
-                try:
-                    description = toks[1]
-                except IndexError:
-                    raise HandledException(f"{prefix} bad description: {description}")
-                inside_booking = True
-                continue
-            # otherwise, read as transfer data
-            toks = non_comment.split()  # ignore specification's allowance of single spaces in names
-            if len(toks) > 3:
-                raise HandledException(f"{prefix} too many booking line tokens: {toks}")
-            amount, currency = None, None
-            account_name = toks[0]
-            if account_name[0] == '[' and account_name[-1] == ']':
-                # ignore specification's differentiation of "virtual" accounts
-                account_name = account_name[1:-1]
-            decimal_chars = ".-0123456789"
-            if len(toks) == 3:
-                i_currency = 1 
-                try:
-                    amount = decimal.Decimal(toks[1])
-                    i_currency = 2
-                except decimal.InvalidOperation:
-                    try:
-                        amount = decimal.Decimal(toks[2])
-                    except decimal.InvalidOperation:
-                        raise HandledException(f"{prefix} no decimal number in: {toks[1:]}")
-                currency = toks[i_currency] 
-                if currency[0] in decimal_chars:
-                    raise HandledException(f"{prefix} currency starts with int, dot, or minus: {currency}")
-            elif len(toks) == 2:
-                value = toks[1]
-                inside_amount = False
-                inside_currency = False
-                amount_string = ""
-                currency = ""
-                dots_counted = 0
-                for i, c in enumerate(value):
-                    if i == 0:
-                        if c in decimal_chars: 
-                            inside_amount = True 
-                        else:
-                            inside_currency = True 
-                    if inside_currency:
-                        if c in decimal_chars and len(amount_string) == 0:
-                            inside_currency = False
-                            inside_amount = True 
-                        else:
-                            currency += c
-                            continue
-                    if inside_amount:
-                        if c not in decimal_chars:
-                            if len(currency) > 0:
-                                raise HandledException(f"{prefix} amount has non-decimal chars: {value}")
-                            inside_currency = True
-                            inside_amount = False 
-                            currency += c
-                            continue
-                        if c == '-' and len(amount_string) > 1:
-                            raise HandledException(f"{prefix} amount has non-start '-': {value}")
-                        if c == '.':
-                            if dots_counted > 1:
-                                raise HandledException(f"{prefix} amount has multiple dots: {value}")
-                            dots_counted += 1
-                        amount_string += c
-                if len(amount_string) == 0:
-                    raise HandledException(f"{prefix} amount missing: {value}")
-                if len(currency) == 0:
-                    raise HandledException(f"{prefix} currency missing: {value}")
-                amount = decimal.Decimal(amount_string)
-            booking_lines += [(account_name, amount, currency)]
+    def append(self, 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()
+        with open(self.db_file, 'a') as f:
+            f.write('\n' + '\n'.join(lines) + '\n');
+        os.remove(self.lock_file)
 
-    def ledger_as_html(self):
-        lines = []
-        for comment in self.comments:
-            lines += [f"; {comment}" if comment != '' else '']
-        for booking in self.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:
-                i += 1
-                if booking_line == '':
-                    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"<html><meta charset=\"UTF-8\"><pre>{content}</pre></html>"
 
-    def balance_as_html(self):
+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>'
+
+    def do_POST(self):
+        from urllib.parse import parse_qs
+        length = int(self.headers['content-length'])
+        postvars = parse_qs(self.rfile.read(length).decode(), keep_blank_values=1)
+        lines = postvars['booking'][0].splitlines()
+        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"))
+        except HandledException as e:
+            self.send_response(400)
+            self.end_headers()
+            page = f"{self.header}{e}{self.footer}"
+            self.wfile.write(bytes(page, "utf-8"))
+
+    def do_GET(self):
+        self.send_response(200)
+        self.send_header("Content-type", "text/html")
+        self.end_headers()
+        db = Database()
+        page = self.header + ''
+        if self.path == '/balance':
+            page += self.balance_as_html(db)
+        elif self.path == '/add':
+            page += self.add()
+        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 self.bookings:
+        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 
+            node = account_tree
             path_copy = path[:]
             while len(path_copy) > 0:
                 step = path_copy.pop(0)
-                node = node[step] 
+                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 
+                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 
+            return parent, child
         for account_name in sorted(account_sums.keys()):
             k, v = collect_branches(account_name, [])
             if k not in account_tree.keys():
@@ -265,21 +304,21 @@ class Database:
             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) 
+                    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 = []
         def print_subtree(lines, indent, node, subtree, path):
-            line = f"{indent}{node}" 
+            line = f"{indent}{node}"
             n_tabs = 5 - (len(line) // 8)
-            line += n_tabs * "\t" 
+            line += n_tabs * "\t"
             if "€" in account_sums[path + node].keys():
                 amount = account_sums[path + node]["€"]
                 line += f"{amount:9.2f} €\t"
             else:
                 line += f"\t\t"
-            for currency, amount in account_sums[path + node].items(): 
+            for currency, amount in account_sums[path + node].items():
                 if currency != '€' and amount > 0:
                     line += f"{amount:5.2f} {currency}\t"
             lines += [line]
@@ -289,23 +328,32 @@ class Database:
         for k, v in sorted(account_tree.items()):
             print_subtree(lines, "", k, v, "")
         content = "\n".join(lines)
-        return f"<html><meta charset=\"UTF-8\"><pre>{content}</pre></html>"
-
+        return f"<pre>{content}</pre>"
 
-class MyServer(BaseHTTPRequestHandler):
+    def ledger_as_html(self, db):
+        lines = []
+        for comment in db.comments:
+            lines += [f"; {comment}" if comment != '' else '']
+        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:
+                i += 1
+                if booking_line == '':
+                    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>"
 
-    def do_GET(self):
-        self.send_response(200)
-        self.send_header("Content-type", "text/html")
-        self.end_headers()
-        db = Database()
-        # page = db.ledger_as_html()
-        page = db.balance_as_html()
-        self.wfile.write(bytes(page, "utf-8"))
+    def add(self):
+        return '<form method="POST" action="/"><textarea name="booking" rows="8" cols="80"></textarea><input type="submit"></form>'
 
 
 db = Database()
-if __name__ == "__main__":        
+if __name__ == "__main__":      
     webServer = HTTPServer((hostName, serverPort), MyServer)
     print(f"Server started http://{hostName}:{serverPort}")
     try: