Add TransactionSpecification.from_text() constructor

netsgiro/records.py

@@ -1,6 +1,6 @@
 import datetime
 import re
-from typing import List, Optional, Sequence, Union
+from typing import Iterable, List, Optional, Sequence, Tuple, Union
 
 import attr
 from attr.validators import instance_of, optional
@@ -627,9 +627,47 @@ class TransactionSpecification(TransactionRecord):
     ]
 
     _MAX_LINES = 42
+    _MAX_LINE_LENGTH = 80
     _MAX_COLUMNS = 2
     _MAX_RECORDS = _MAX_LINES * _MAX_COLUMNS
 
+    @classmethod
+    def from_text(
+            cls, *,
+            service_code, transaction_type, transaction_number, text
+            ) -> Iterable['TransactionSpecification']:
+        for line, column, text in (
+                cls._split_text_to_lines_and_columns(text)):
+            yield cls(
+                service_code=service_code,
+                transaction_type=transaction_type,
+                transaction_number=transaction_number,
+
+                line_number=line,
+                column_number=column,
+                text=text,
+            )
+
+    @classmethod
+    def _split_text_to_lines_and_columns(
+            cls, text) -> Iterable[Tuple[int, int, str]]:
+        lines = text.splitlines()
+
+        if len(lines) > cls._MAX_LINES:
+            raise ValueError(
+                'Max {} specification lines allowed, got {}'
+                .format(cls._MAX_LINES, len(lines)))
+
+        for line_number, line_text in enumerate(lines, 1):
+            if len(line_text) > cls._MAX_LINE_LENGTH:
+                raise ValueError(
+                    'Specification lines must be max {} chars long, '
+                    'got {}: {!r}'
+                    .format(cls._MAX_LINE_LENGTH, len(line_text), line_text))
+
+            yield (line_number, 1, '{:40}'.format(line_text[0:40]))
+            yield (line_number, 2, '{:40}'.format(line_text[40:80]))
+
     @classmethod
     def to_text(cls, records: Sequence['TransactionSpecification']) -> str:
         if len(records) > cls._MAX_RECORDS:

tests/test_record_writing.py

@@ -262,6 +262,34 @@ def test_transaction_specification_for_avtalegiro_payment_request():
     )
 
 
+def test_transaction_specification_from_longer_text():
+    records = list(netsgiro.TransactionSpecification.from_text(
+        service_code=netsgiro.ServiceCode.AVTALEGIRO,
+        transaction_type=(
+            netsgiro.TransactionType.AVTALEGIRO_WITH_BANK_NOTIFICATION),
+        transaction_number=1,
+        text=' Gjelder Faktura: 168837  Dato: 19/03/04\nFoo bar baz quux',
+    ))
+
+    assert len(records) == 4
+    assert records[0].to_ocr() == (
+        'NY212149000000140011 Gjelder Faktura: 16'
+        '8837  Dato: 19/03/0400000000000000000000'
+    )
+    assert records[1].to_ocr() == (
+        'NY212149000000140012                    '
+        '                    00000000000000000000'
+    )
+    assert records[2].to_ocr() == (
+        'NY212149000000140021Foo bar baz quux    '
+        '                    00000000000000000000'
+    )
+    assert records[3].to_ocr() == (
+        'NY212149000000140022                    '
+        '                    00000000000000000000'
+    )
+
+
 def test_avtalegiro_agreements():
     record = netsgiro.AvtaleGiroAgreement(
         service_code=netsgiro.ServiceCode.AVTALEGIRO,