import elixir
from elixir import has_field, belongs_to, has_many, using_options, using_options_defaults
from sqlalchemy import types as T

from functools import partial

elixir.metadata.bind = "sqlite:///test.sqlite"
elixir.metadata.bind.echo = True

has_req_field = partial(has_field, required = True)

class Entity (elixir.Entity):
    using_options(abstract = True)

    using_options_defaults(shortnames = True)

class Category (Entity):
    
    has_field('name', T.String(50), unique = True)

    def __repr__ (self):
        return '<Category "%s">' % self.name

class Expense (Entity):
    using_options(inheritance='multi')

    has_field('description', T.String(50))
    has_req_field('expense', T.Numeric(scale = 2))

    belongs_to('category', of_kind = 'Category', required = True)

class SingleExpense (Expense):
    using_options(inheritance='multi')

    has_req_field('date', T.Date)

class ConstExpense (Expense):
    using_options(inheritance='multi')

    has_req_field('months', T.Integer)
    has_req_field('start', T.Date)
    has_req_field('end', T.Date)

elixir.setup_all()

session = elixir.session

if __name__ == "__main__":
    elixir.create_all()