WIP

Author: theangryangel

wip.py

@@ -0,0 +1,256 @@
+from typing import Callable, List, Optional, Tuple, Union
+
+
+from pydifact.segmentcollection import Interchange
+from pydifact.segments import Segment, SegmentProvider
+
+
+
+interchange = Interchange.from_str("""UNA:+.?*'
+UNB+UNOA:4+5021376940009:14+1111111111111:14+200421:1000+0001+ORDERS'
+UNH+1+ORDERS:D:01B:UN:EAN010'
+BGM+220+123456+9'
+DTM+137:20150410:102'
+DTM+2:20150710:102'
+FTX+DIN+++DELIVERY INSTRUCTIONS DESCRIPTION'
+NAD+BY+5021376940009::9'
+NAD+SU+1111111111111::9'
+RFF+IA:123456'
+NAD+ST+++Mr John Smith+The Bungalow:Hastings Road+Preston+:::Lancashire+SW1A 1AA'
+CTA+LB+:Mr John Smith'
+COM+01772 999999:TE'
+COM+johnsmith@gmail.com:EM'
+CUX+2:GBP:9'
+TDT+20+++++SD'
+LIN+1++121354654:BP'
+IMD+F++:::TPRG item description'
+QTY+21:2'
+MOA+203:200.00'
+PRI+AAA:100.00'
+RFF+LI:1'
+LIN+1++121354654:BP'
+IMD+F++:::TPRG item description'
+QTY+21:2'
+MOA+203:200.00'
+PRI+AAA:100.00'
+RFF+LI:1'
+UNS+S'
+CNT+2:1'
+UNT+32+1'
+UNZ+1+0001'""")
+
+import itertools
+import collections
+
+
+class BiDirectionalIterator(object):
+    def __init__(self, collection):
+        self.collection = collection
+        self.index = 0
+
+    def next(self):
+        try:
+            result = self.collection[self.index]
+            self.index += 1
+        except IndexError:
+            raise StopIteration
+        return result
+
+    def prev(self):
+        self.index -= 1
+        if self.index < 0:
+            raise StopIteration
+        return self.collection[self.index]
+
+    def __iter__(self):
+        return self
+
+
+class AbstractComponent:
+    """Abstract EDIFact Component, used as a base for Components, SegmentGroup, SegmentLoop"""
+    def __init__(self, **kwargs):
+        self.mandatory = kwargs.get("mandatory", False)
+
+    def _from_segment_iter(self, messages):
+        raise NotImplementedError()
+
+
+class Component(AbstractComponent, Segment):
+    """
+    EDIFact Component.
+    A simple wrapper for Segment
+    """
+    def __init__(
+        self,
+        tag: str,
+        *elements,
+        **kwargs
+    ):
+        AbstractComponent.__init__(self, **kwargs)
+        Segment.__init__(self, tag, *elements)
+
+    def _from_segment_iter(self, iterator):
+        segment = iterator.next()
+
+        if self.tag == segment.tag:
+            self.elements = segment.elements
+            return
+
+        if self.mandatory:
+            raise Exception("Missing %s, found %s" % (self.tag, segment))
+
+        iterator.prev()
+
+
+class SegmentGroupMetaClass(type):
+    """
+    Metaclass to maintain an ordered list of components.
+    Required for compatibility with Python 3.5. In 3.6 the
+    properties of a class are strictly ordered.
+    """
+    @classmethod
+    def __prepare__(cls, name, bases):
+        return collections.OrderedDict()
+
+    def __new__(cls, name, bases, classdict):
+        result = type.__new__(cls, name, bases, dict(classdict))
+        exclude = set(dir(type))
+
+        result.__components__ = []
+
+        for k, v in classdict.items():
+            if k not in exclude and isinstance(v, AbstractComponent):
+                result.__components__.append(k)
+        return result
+
+
+class SegmentGroup(AbstractComponent, metaclass=SegmentGroupMetaClass):
+    """
+    Describes a static group of Components
+    """
+    def _from_segment_iter(self, isegment):
+        i = 0
+
+        icomponent = iter(self.__components__)
+
+        try:
+            while True:
+                component_name = next(icomponent)
+                component = getattr(self, component_name)
+                component._from_segment_iter(isegment)
+        except StopIteration:
+            pass
+
+    def from_message(self, message):
+        imessage = BiDirectionalIterator(message.segments)
+        self._from_segment_iter(imessage)
+
+    def to_message(self):
+        raise NotImplementedError()
+
+    def __str__(self):
+        res = []
+        for component_name in iter(self.__components__):
+            component = getattr(self, component_name)
+            res.append(str(component))
+        return "\n".join(res)
+
+
+class SegmentLoop(AbstractComponent):
+    """
+    Describes a repeating SegmentGroup
+    """
+    def __init__(self, component, **kwargs):
+        super(SegmentLoop, self).__init__(**kwargs)
+        self.min = kwargs.get("min", 0)
+        self.max = kwargs.get("max", 0)
+
+        if self.mandatory and self.min < 1:
+            self.min = 1
+
+        if self.max < self.min:
+            self.max = self.min
+
+        self.__component__ = component
+        self.value = []
+
+    def _from_segment_iter(self, isegment):
+        i = 0
+        while i < self.max:
+
+            try:
+                component = self.__component__()
+                component._from_segment_iter(isegment)
+                self.value.append(component)
+            except BaseException:
+                isegment.prev()
+                if self.mandatory and i < self.min:
+                    raise Exception("Missing %s" %
+                                    (self.__component__.__name__))
+                break
+
+            i += 1
+
+        if i < self.min:
+            raise Exception("minimum required not met")
+
+    def __str__(self):
+        res = []
+        for v in self.value:
+            res.append(str(v))
+        return "{} = {}".format(
+            self.__component__.__name__,
+            str(res)
+        )
+
+
+class OrderLine(SegmentGroup):
+    line_id = Component("LIN", mandatory=True)
+    description = Component("IMD", mandatory=True)
+    quantity = Component("QTY", mandatory=True)
+    moa = Component("MOA")
+    pri = Component("PRI")
+    rff = Component("RFF", mandatory=True)
+
+
+
+
+class Order(SegmentGroup):
+    purchase_order_id = Component("BGM", mandatory=True)
+    date = Component("DTM", mandatory=True)
+    delivery_date = Component("DTM", mandatory=True)
+    delivery_instructions = Component("FTX", mandatory=True)
+    supplier_id_gln = Component("NAD", mandatory=True)
+    supplier_id_tprg = Component("NAD", mandatory=True)
+    ref = Component("RFF", mandatory=True)
+    ship_to = Component("NAD", mandatory=True)
+
+    ship_to_contact = Component("CTA", mandatory=True)
+    ship_to_phone = Component("COM", mandatory=True)
+    ship_to_email = Component("COM", mandatory=True)
+    cux = Component("CUX", mandatory=True)
+    tdt = Component("TDT", mandatory=True)
+
+    lines = SegmentLoop(
+        OrderLine,
+        max=99,
+        mandatory=True
+    )
+
+    uns = Component("UNS", mandatory=True)
+    cnt = Component("CNT", mandatory=True)
+
+
+TYPE_TO_PARSER_DICT = {
+    "ORDERS": Order
+}
+
+
+for message in interchange.get_messages():
+    cls = TYPE_TO_PARSER_DICT.get(message.type)
+    if not cls:
+        raise NotImplementedError("Unsupported message type '{}'".format(message.type))
+
+    obj = cls()
+    obj.from_message(message)
+    print(str(obj))