[enh] #807 add Percent of Average referential

src/sakia/money/__init__.py

@@ -2,5 +2,12 @@ from .quantitative import Quantitative
 from .relative import Relative
 from .quant_zerosum import QuantitativeZSum
 from .relative_zerosum import RelativeZSum
+from .percent_of_average import PercentOfAverage
 
-Referentials = (Quantitative, Relative, QuantitativeZSum, RelativeZSum)
+Referentials = (
+    Quantitative,
+    Relative,
+    PercentOfAverage,
+    QuantitativeZSum,
+    RelativeZSum,
+)

src/sakia/money/base_referential.py

+from typing import Optional
+
+
 class BaseReferential:
     """
     Interface to all referentials
     """
 
-    def __init__(self, amount, currency, app, block_number=None):
+    def __init__(
+        self, amount: float, currency: str, app, block_number: Optional[int] = None
+    ):
         """
+        Init base referential instance
 
-        :param int amount:
-        :param str currency:
-        :param sakia.app.Application app:
-        :param int block_number:
+        :param amount: Amount to transform
+        :param currency: Name of currency
+        :param app: Application instance
+        :param block_number: Block number
         """
         self.amount = amount
         self.app = app

src/sakia/money/percent_of_average.py

+from typing import Optional
+
+from .base_referential import BaseReferential
+from ..data.processors import BlockchainProcessor
+
+from PyQt5.QtCore import QCoreApplication, QT_TRANSLATE_NOOP, QLocale
+
+
+class PercentOfAverage(BaseReferential):
+    _NAME_STR_ = QT_TRANSLATE_NOOP("PercentOfAverage", "PoA")
+    _REF_STR_ = QT_TRANSLATE_NOOP("PercentOfAverage", "{0} {1}{2}")
+    _UNITS_STR_ = QT_TRANSLATE_NOOP("PercentOfAverage", "PoA")
+    _FORMULA_STR_ = QT_TRANSLATE_NOOP(
+        "PercentOfAverage",
+        """PoA = (Q / ( M(t-1) / N)) / 100
+                                        <br >
+                                        <table>
+                                        <tr><td>PoA</td><td>Percent of Average value</td></tr>
+                                        <tr><td>Q</td><td>Quantitative value</td></tr>
+                                        <tr><td>M</td><td>Monetary mass</td></tr>
+                                        <tr><td>N</td><td>Members count</td></tr>
+                                        </table>""",
+    )
+    _DESCRIPTION_STR_ = QT_TRANSLATE_NOOP(
+        "PercentOfAverage",
+        """Percent of Average referential of the money.<br />
+                                          Percent of Average value PoA is calculated by dividing the quantitative value Q by the average<br />
+                                           then multiply by one hundred.<br />
+                                          This referential is relative and more reliable to display prices and accounts, when UD is two low.<br />
+                                          No money creation or destruction is apparent here and every account tend to<br />
+                                           the average.
+                                          """,
+    )
+
+    def __init__(self, amount, currency, app, block_number=None):
+        super().__init__(amount, currency, app, block_number)
+        self._blockchain_processor = BlockchainProcessor.instanciate(self.app)
+
+    @classmethod
+    def instance(
+        cls, amount: float, currency: str, app, block_number: Optional[int] = None
+    ):
+        """
+        Init PercentOfAverage referential instance
+
+        :param amount: Amount to transform
+        :param currency: Name of currency
+        :param app: Application instance
+        :param block_number: Block number
+        :return:
+        """
+        return cls(amount, currency, app, block_number)
+
+    @classmethod
+    def translated_name(cls):
+        return QCoreApplication.translate(
+            "PercentOfAverage", PercentOfAverage._NAME_STR_
+        )
+
+    @property
+    def units(self):
+        return QCoreApplication.translate(
+            "PercentOfAverage", PercentOfAverage._UNITS_STR_
+        )
+
+    @property
+    def formula(self):
+        return QCoreApplication.translate(
+            "PercentOfAverage", PercentOfAverage._FORMULA_STR_
+        )
+
+    @property
+    def description(self):
+        return QCoreApplication.translate(
+            "PercentOfAverage", PercentOfAverage._DESCRIPTION_STR_
+        )
+
+    @property
+    def diff_units(self):
+        return self.units
+
+    @staticmethod
+    def base_str(base):
+        return ""
+
+    def value(self):
+        """
+        Return relative value of amount
+
+        value = amount / UD(t)
+
+        :param int amount:   Value
+        :param sakia.core.community.Community community: Community instance
+        :return: float
+        """
+        mass = self._blockchain_processor.last_mass(self.currency)
+        members = self._blockchain_processor.last_members_count(self.currency)
+        average = mass / members
+        if average > 0:
+            return self.amount / average * 100
+        else:
+            return self.amount
+
+    def differential(self):
+        return self.value()
+
+    def localized(self, units=False, show_base=False):
+        value = self.value()
+        localized_value = QLocale().toString(
+            float(value), "f", self.app.parameters.digits_after_comma
+        )
+
+        if units:
+            return QCoreApplication.translate(
+                "PercentOfAverage", PercentOfAverage._REF_STR_
+            ).format(localized_value, "", (self.units if units else ""))
+        else:
+            return localized_value
+
+    def diff_localized(self, units=False, show_base=False):
+        value = self.differential()
+        localized_value = QLocale().toString(
+            float(value), "f", self.app.parameters.digits_after_comma
+        )
+
+        if units:
+            return QCoreApplication.translate(
+                "PercentOfAverage", PercentOfAverage._REF_STR_
+            ).format(localized_value, "", (self.diff_units if units else ""))
+        else:
+            return localized_value