o Adding PriceBreak. Parsing price breaks from DK.

o Adding Money type with parsing.

1 files changed, 297 insertions, 0 deletions

diff --git a/src/ee/money.py b/src/ee/money.py
new file mode 100644
index 0000000..139d0d7
--- /dev/null
+++ b/src/ee/money.py
@@ -0,0 +1,297 @@
+from decimal import Decimal
+from typing import Union, Optional, Mapping, Set
+
+from ee import EeException
+
+__all__ = [
+    "Money",
+    "MoneyContext",
+    "get_default_context",
+    "set_default_context",
+]
+
+
+def _parse(amount: str) -> (str, str):
+    def read_space():
+        nonlocal idx
+        while idx < end:
+            if amount[idx] != " ":
+                break
+
+            idx += 1
+
+    def read_num():
+        nonlocal idx
+        tmp = ""
+        while idx < end:
+            c_ = amount[idx]
+            if not c_.isnumeric():
+                break
+            tmp += c_
+            idx += 1
+
+        return tmp
+
+    def read_word():
+        nonlocal idx
+        tmp = ""
+        while idx < end:
+            c_ = amount[idx]
+
+            if c_.isnumeric() or c_ in (" ", ",", "."):
+                break
+
+            tmp += c_
+            idx += 1
+
+        return tmp
+
+    amount = amount.strip()
+
+    idx = 0
+    end = len(amount)
+
+    if end == 0:
+        return None, None
+
+    # extract leading currency
+    prefix = read_word()
+
+    read_space()
+
+    # If the number starts with '.' or ',' we assume it is a whole separator
+    # if idx < end:
+    #     c = amount[idx]
+    #     if c == "." or c == ",":
+    #         s1 = c
+    #         idx += 1
+
+    num = read_num()
+    # if len(num) > 3:
+    #     return None, None
+
+    # First and second separators
+    s1 = s2 = None
+    s0s = []  # stuff before first separator
+    s1s = []
+    s2s = []
+
+    if num:
+        s0s.append(num)
+
+    while idx < end:
+        c = amount[idx]
+
+        is_separator = c in (",", ".")
+
+        if not is_separator and c == " ":
+            next_c = amount[idx + 1] if idx + 1 < end else None
+
+            if next_c is None or not next_c.isnumeric():
+                idx += 1
+                break
+
+            is_separator = True
+
+        if not is_separator:
+            return None, None
+
+        if not s1:
+            s1 = c
+        elif s1 and c == s1:
+            pass
+        elif s1 and c != s1 and not s2:
+            s2 = c
+        else:
+            return None, None
+        idx += 1
+
+        num = read_num()
+        if not num:
+            if idx == end:
+                break
+            return None, None
+
+        if s2:
+            s2s.append(num)
+        else:
+            s1s.append(num)
+
+        del num
+
+    if s1 == ' ':
+        s1 = s2
+        s2 = None
+        s0s.extend(s1s)
+        s1s = s2s
+        s2s = []
+
+    if not s1 and not s2:
+        wholes = "".join(s0s)
+        parts = "0"
+    elif s1 and not s2:
+        wholes = "".join(s0s)
+        parts = "".join(s1s)
+    elif s1 and s2:
+        wholes = "".join(s0s) + "".join(s1s)
+        parts = "".join(s2s)
+    else:
+        return None, None
+
+    read_space()
+
+    postfix = read_word()
+
+    # Check that there is no junk left
+    if amount[idx:].strip():
+        return None, None
+
+    # wholes = wholes if wholes else "0"
+    # parts = parts if parts else "0"
+
+    currency = None
+    if len(prefix):
+        currency = prefix
+
+    if len(postfix):
+        if currency:
+            return None, None
+        currency = postfix
+
+    while parts.endswith("0"):
+        parts = parts[:-1]
+
+    return wholes + "." + parts, currency
+
+
+class Money(object):
+    def __init__(self, amount: Decimal, currency: Optional[str] = None):
+        self.amount: Decimal = amount
+        self.currency = currency
+
+    def assert_same_currency(self, other):
+        if isinstance(other, int):
+            return
+
+        if self.currency is None and other.currency is None:
+            return
+        if self.currency == other.currency:
+            return
+
+        raise EeException("Can't relate to instances of Money with different currencies.")
+
+    def __truediv__(self, other: Union["Money", int]):
+        self.assert_same_currency(other)
+
+        if isinstance(other, int):
+            return Money(amount=self.amount.__truediv__(other), currency=self.currency)
+
+        return Money(amount=self.amount.__truediv__(other), currency=self.currency)
+
+    def __mul__(self, other: Union["Money", int]):
+        self.assert_same_currency(other)
+
+        if isinstance(other, int):
+            return Money(amount=self.amount.__mul__(other), currency=self.currency)
+
+        return Money(amount=self.amount.__mul__(other), currency=self.currency)
+
+    def _amount_str(self):
+        amount = str(self.amount)
+
+        (sign, _int, _exp) = self.amount.as_tuple()
+        if _exp >= 0:
+            return amount
+
+        while amount.endswith("0"):
+            amount = amount[0:-1]
+
+        if amount.endswith("."):
+            amount = amount[0:-1]
+
+        return amount
+
+    def __repr__(self):
+        return self._amount_str() + ((" " + self.currency) if self.currency else "")
+
+    def __str__(self):
+        amount = self._amount_str()
+
+        if self.currency is None:
+            return amount
+
+        first, last = (self.currency, amount) if self.currency in _prefix_currencies else (amount, self.currency)
+
+        return first + " " + last
+
+    def __eq__(self, other: "Money"):
+        if not isinstance(other, Money):
+            return False
+
+        return self.amount == other.amount and self.currency == other.currency
+
+
+class MoneyContext(object):
+    def __init__(self, symbols_to_currency: Mapping[str, str], prefix_currencies: Set[str]):
+        self.symbols_to_currency = symbols_to_currency
+        self.prefix_currencies = prefix_currencies
+
+    @staticmethod
+    def parse(amount: Union[str, int, float, Decimal], currency: Optional[str] = None) -> Money:
+        m = MoneyContext.try_parse(amount, currency)
+
+        if m is None:
+            raise EeException("Could not parse money: '{}'".format(amount))
+
+        return m
+
+    @staticmethod
+    def try_parse(amount: Union[str, int, float, Decimal], currency: Optional[str] = None) -> Optional[Money]:
+        if isinstance(amount, str):
+            (a, c) = _parse(amount)
+
+            if a is None:
+                return None
+
+            amount = Decimal(a)
+
+            if c is not None:
+                if currency is not None and currency != c:
+                    return None
+
+                currency = c
+        elif isinstance(amount, int) or isinstance(amount, float):
+            amount = Decimal(amount)
+        elif isinstance(amount, Decimal):
+            pass
+        else:
+            raise EeException("Unsupported value type: {}".format(type(amount)))
+
+        if currency is not None:
+            currency = _symbols_to_currency.get(currency, currency)
+
+        return Money(amount, currency)
+
+
+_symbols_to_currency = {
+    "$": "USD"
+}
+
+_prefix_currencies = {
+    "USD",
+}
+
+_default_context = None
+
+
+def get_default_context():
+    global _default_context
+    if _default_context is None:
+        _default_context = MoneyContext(_symbols_to_currency, _prefix_currencies)
+
+    return _default_context
+
+
+def set_default_context(ctx: MoneyContext):
+    global _default_context
+    _default_context = ctx