X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=type%2Fcentcount.py;fp=type%2Fcentcount.py;h=4181721bbc0d4ab7efe38608b821faa26ecf5bae;hb=4faa994d32223c8d560d9dad0ca90a3f7eb10d6a;hp=0000000000000000000000000000000000000000;hpb=c79ecbf708a63a54a9c3e8d189b65d4794930082;p=python_utils.git

diff --git a/type/centcount.py b/type/centcount.py
new file mode 100644
index 0000000..4181721
--- /dev/null
+++ b/type/centcount.py
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+#!/usr/bin/env python3
+
+import re
+from typing import Optional, TypeVar, Tuple
+
+import math_utils
+
+
+T = TypeVar('T', bound='CentCount')
+
+
+class CentCount(object):
+    """A class for representing monetary amounts potentially with
+    different currencies.
+    """
+
+    def __init__ (
+            self,
+            centcount,
+            currency: str = 'USD',
+            *,
+            strict_mode = False
+    ):
+        self.strict_mode = strict_mode
+        if isinstance(centcount, str):
+            ret = CentCount._parse(centcount)
+            if ret is None:
+                raise Exception(f'Unable to parse money string "{centcount}"')
+            centcount = ret[0]
+            currency = ret[1]
+        if isinstance(centcount, float):
+            centcount = int(centcount * 100.0)
+        if not isinstance(centcount, int):
+            centcount = int(centcount)
+        self.centcount = centcount
+        if not currency:
+            self.currency: Optional[str] = None
+        else:
+            self.currency: Optional[str] = currency
+
+    def __repr__(self):
+        a = float(self.centcount)
+        a /= 100
+        a = round(a, 2)
+        s = f'{a:,.2f}'
+        if self.currency is not None:
+            return '%s %s' % (s, self.currency)
+        else:
+            return '$%s' % s
+
+    def __pos__(self):
+        return CentCount(centcount=self.centcount, currency=self.currency)
+
+    def __neg__(self):
+        return CentCount(centcount=-self.centcount, currency=self.currency)
+
+    def __add__(self, other):
+        if isinstance(other, CentCount):
+            if self.currency == other.currency:
+                return CentCount(
+                    centcount = self.centcount + other.centcount,
+                    currency = self.currency
+                )
+            else:
+                raise TypeError('Incompatible currencies in add expression')
+        else:
+            if self.strict_mode:
+                raise TypeError('In strict_mode only two moneys can be added')
+            else:
+                return self.__add__(CentCount(other, self.currency))
+
+    def __sub__(self, other):
+        if isinstance(other, CentCount):
+            if self.currency == other.currency:
+                return CentCount(
+                    centcount = self.centcount - other.centcount,
+                    currency = self.currency
+                )
+            else:
+                raise TypeError('Incompatible currencies in add expression')
+        else:
+            if self.strict_mode:
+                raise TypeError('In strict_mode only two moneys can be added')
+            else:
+                return self.__sub__(CentCount(other, self.currency))
+
+    def __mul__(self, other):
+        if isinstance(other, CentCount):
+            raise TypeError('can not multiply monetary quantities')
+        else:
+            return CentCount(
+                centcount = int(self.centcount * float(other)),
+                currency = self.currency
+            )
+
+    def __truediv__(self, other):
+        if isinstance(other, CentCount):
+            raise TypeError('can not divide monetary quantities')
+        else:
+            return CentCount(
+                centcount = int(float(self.centcount) / float(other)),
+                currency = self.currency
+            )
+
+    def __int__(self):
+        return self.centcount.__int__()
+
+    def __float__(self):
+        return self.centcount.__float__() / 100.0
+
+    def truncate_fractional_cents(self):
+        x = int(self)
+        self.centcount = int(math_utils.truncate_float(x))
+        return self.centcount
+
+    def round_fractional_cents(self):
+        x = int(self)
+        self.centcount = int(round(x, 2))
+        return self.centcount
+
+    __radd__ = __add__
+
+    def __rsub__(self, other):
+        if isinstance(other, CentCount):
+            if self.currency == other.currency:
+                return CentCount(
+                    centcount = other.centcount - self.centcount,
+                    currency = self.currency
+                )
+            else:
+                raise TypeError('Incompatible currencies in sub expression')
+        else:
+            if self.strict_mode:
+                raise TypeError('In strict_mode only two moneys can be added')
+            else:
+                return CentCount(
+                    centcount = int(other) - self.centcount,
+                    currency = self.currency
+                )
+
+    __rmul__ = __mul__
+
+    #
+    # Override comparison operators to also compare currency.
+    #
+    def __eq__(self, other):
+        if other is None:
+            return False
+        if isinstance(other, CentCount):
+            return (
+                self.centcount == other.centcount and
+                self.currency == other.currency
+            )
+        if self.strict_mode:
+            raise TypeError("In strict mode only two CentCounts can be compared")
+        else:
+            return self.centcount == int(other)
+
+    def __ne__(self, other):
+        result = self.__eq__(other)
+        if result is NotImplemented:
+            return result
+        return not result
+
+    def __lt__(self, other):
+        if isinstance(other, CentCount):
+            if self.currency == other.currency:
+                return self.centcount < other.centcount
+            else:
+                raise TypeError('can not directly compare different currencies')
+        else:
+            if self.strict_mode:
+                raise TypeError('In strict mode, only two CentCounts can be compated')
+            else:
+                return self.centcount < int(other)
+
+    def __gt__(self, other):
+        if isinstance(other, CentCount):
+            if self.currency == other.currency:
+                return self.centcount > other.centcount
+            else:
+                raise TypeError('can not directly compare different currencies')
+        else:
+            if self.strict_mode:
+                raise TypeError('In strict mode, only two CentCounts can be compated')
+            else:
+                return self.centcount > int(other)
+
+    def __le__(self, other):
+        return self < other or self == other
+
+    def __ge__(self, other):
+        return self > other or self == other
+
+    def __hash__(self):
+        return self.__repr__
+
+    CENTCOUNT_RE = re.compile("^([+|-]?)(\d+)(\.\d+)$")
+    CURRENCY_RE = re.compile("^[A-Z][A-Z][A-Z]$")
+
+    @classmethod
+    def _parse(cls, s: str) -> Optional[Tuple[int, str]]:
+        centcount = None
+        currency = None
+        s = s.strip()
+        chunks = s.split(' ')
+        try:
+            for chunk in chunks:
+                if CentCount.CENTCOUNT_RE.match(chunk) is not None:
+                    centcount = int(float(chunk) * 100.0)
+                elif CentCount.CURRENCY_RE.match(chunk) is not None:
+                    currency = chunk
+        except:
+            pass
+        if centcount is not None and currency is not None:
+            return (centcount, currency)
+        elif centcount is not None:
+            return (centcount, 'USD')
+        return None
+
+    @classmethod
+    def parse(cls, s: str) -> T:
+        chunks = CentCount._parse(s)
+        if chunks is not None:
+            return CentCount(chunks[0], chunks[1])
+        raise Exception(f'Unable to parse money string "{s}"')