1 files changed, 167 insertions, 0 deletions
diff --git a/app/model.py b/app/model.py
new file mode 100644
index 0000000..92b3710
--- /dev/null
+++ b/app/model.py
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+from flask.ext.sqlalchemy import SQLAlchemy
+from sqlalchemy import sql
+from sqlalchemy.ext.declarative import declared_attr
+
+import datetime
+import decimal
+from functools import partial
+from collections import namedtuple
+
+from . import app
+
+db = SQLAlchemy(app)
+
+__all__ = ["db", "Category", "SingleExpense", "ConstExpense", "CatExpense", "MonthExpense"]
+
+ReqColumn = partial(db.Column, nullable = False)
+ExpNum = db.Numeric(scale = 2, precision = 10)
+
+def to_exp(d):
+    """Converts decimal into expense"""
+    return d.quantize(decimal.Decimal('.01'), rounding = decimal.ROUND_UP)
+
+#
+# Database Entities
+class Model (db.Model):
+    __abstract__ = True
+
+    id = db.Column(db.Integer, primary_key=True)
+
+    @declared_attr
+    def __tablename__ (cls):
+        return cls.__name__.lower()
+
+    @classmethod
+    def get_by (cls, *args, **kwargs):
+        return cls.query.filter_by(*args, **kwargs).first()
+
+    @classmethod
+    def get_by_or_404 (cls, *args, **kwargs):
+        return cls.query.filter_by(*args, **kwargs).first_or_404()
+
+    @classmethod
+    def get (cls, *args, **kwargs):
+        return cls.query.get(*args, **kwargs)
+
+    @classmethod
+    def get_or_404 (cls, *args, **kwargs):
+        return cls.query.get_or_404(*args, **kwargs)
+
+class Category (Model):
+    name = ReqColumn(db.Unicode(50), unique = True)
+    parent_id = db.Column(db.Integer, db.ForeignKey('category.id'))
+
+    children = db.relationship('Category',
+                            backref=db.backref('parent', remote_side="Category.id"))
+
+    def __init__ (self, name, parent_id = None):
+        Model.__init__(self)
+        self.name = name
+        self.parent_id = parent_id
+
+    def __repr__ (self):
+        if self.parent:
+            return '<Category "%s" of "%s">' % (self.name, self.parent.name)
+        else:
+            return '<Category "%s">' % self.name
+
+class Expense (Model):
+    __abstract__ = True
+
+    description = db.Column(db.Unicode(50))
+    expense     = ReqColumn(ExpNum)
+
+    @declared_attr
+    def category_id(cls):
+        return ReqColumn(db.Integer, db.ForeignKey(Category.id))
+
+    @declared_attr
+    def category(cls):
+        return db.relationship(Category, innerjoin = True)
+
+class SingleExpense (Expense):
+    year = ReqColumn(db.Integer)
+    month = ReqColumn(db.SmallInteger)
+    day = ReqColumn(db.SmallInteger)
+
+    @classmethod
+    def of_month (cls, month, year):
+        comp = sql.and_(
+                cls.month == month,
+                cls.year == year)
+
+        return cls.query.filter(comp)
+
+    @property
+    def date (self):
+        return datetime.date(self.year, self.month, self.day)
+
+    @date.setter
+    def date (self, d):
+        self.year = d.year
+        self.month = d.month
+        self.day = d.day
+
+class ConstExpense (Expense):
+    months  = ReqColumn(db.SmallInteger)
+    start   = ReqColumn(db.Date, index = True)
+    end     = ReqColumn(db.Date, index = True)
+    prev_id = db.Column(db.Integer, db.ForeignKey('constexpense.id'))
+
+    prev = db.relationship('ConstExpense', remote_side = "ConstExpense.id", uselist = False,
+                         backref=db.backref('next', uselist = False))
+
+    @property
+    def monthly(self):
+        return to_exp(self.expense / self.months)
+    
+    @classmethod
+    def of_month (cls, month, year):
+        d = datetime.date(year, month, 1)
+        return cls.query.filter(sql.between(d, cls.start, cls.end))
+
+#
+# Work entities (not stored in DB)
+#
+class CatExpense (namedtuple('CatExpense', 'cat expense exps')):
+    __slots__ = ()
+
+    @property
+    def all (self):
+        return self.exps.order_by(SingleExpense.day).all()
+
+class MonthExpense (namedtuple('MonthExpense', 'date catexps')):
+    
+    def __init__ (self, *args, **kwargs):
+        self._consts = None
+        super(MonthExpense, self).__init__(*args, **kwargs)
+
+    @property
+    def consts (self):
+        if self._consts is None:
+            self._consts = ConstExpense.of_month(self.date.month, self.date.year).all()
+
+        return self._consts
+
+    @property
+    def constsum (self):
+        s = sum(c.monthly for c in self.consts)
+        return s or 0
+
+    @property
+    def sum (self):
+        return self.constsum + sum(x.expense for x in self.catexps)
+
+    @property
+    def all (self):
+        return SingleExpense.of_month(self.date.month, self.date.year).order_by(SingleExpense.day).all()
+
+    def __str__ (self):
+        return '<MonthExpense of "%s": %s>' % (self.date, self.sum)
+
+#
+# Extra indizes have to be here
+#
+
+db.Index('idx_single_date', SingleExpense.year, SingleExpense.month)
+db.Index('idx_start_end', ConstExpense.start, ConstExpense.end)