from __future__ import with_statement

import web
from web import form

from model import *
from helper import appdir
from renderer import render

import datetime, decimal
import operator as op
from sqlalchemy import sql

class Show:
    def GET(self, year = '', month = ''):
        if year:
            return self.render([self.calc(year, month)])
        else:
            d = datetime.date.today()
            
            first = self.calc(d.year, d.month)
            if d.month == 1:
                second = self.calc(d.year - 1, 12)
            else:
                second = self.calc(d.year, d.month - 1)

            return self.render([first, second])

    def calc(self, year, month):

        year = int(year)
        month = int(month)

        ssum = sql.functions.sum(SingleExpense.expense)
        query = SingleExpense.of_month(month, year)

        result = query.group_by(SingleExpense.category_id).\
                 values(SingleExpense.category_id, ssum)

        exps = [CatExpense(Category.query.get(c), s, query.filter(SingleExpense.category_id == c)) for c,s in result]

        return MonthExpense(datetime.date(int(year), int(month), 1), exps)

    def render(self, exps):
        return render("show", exps = exps)

class Add:

    dformat = "%d.%m.%Y"

    def GET(self):
        return render("add", form = self.form())

    def POST(self):
        f = self.form()
        if f.validates():
            e = SingleExpense(category = Category.get_by(name = f.category.value))

            e.date = datetime.datetime.strptime(f.date.value, self.dformat)
            e.expense = decimal.Decimal(f.expense.value)
            e.description = f.description.value

            raise web.seeother("/")
        else:
            return render("add", form = f)

    @property
    def form(self):
        return form.Form(
                form.Textbox(
                    "date",
                    form.notnull,
                    value = datetime.date.today().strftime(self.dformat)
                    ),
                form.Textbox(
                    "expense",
                    form.notnull,
                    ),
                form.Textbox(
                    "description",
                    form.notnull
                    ),
                form.Dropdown(
                    "category",
                    map(op.itemgetter(0), sorted(Category.query.values(Category.name)))
                    ),
                validators = map(lambda x: form.Validator(*x), (
                    ("Date Format does not match", lambda f: datetime.datetime.strptime(f.date, self.dformat)),
                    ("Not a valid decimal", lambda f: decimal.Decimal(f.expense)),
                    ))
                )

class Edit:
    def GET(self, id):
        return "Edit " + id

class Const:
    def GET(self):
        return "Const"

class ConstAdd:
    def GET(self):
        return "Add new const"

class ConstEdit:
    def GET(self, id):
        return "Const Edit " + id

class Cat:
    def GET(self, id = '/'):
        if id:
            id = id[1:]

        if not id: return "Add new cat"
        else: return "Edit cat " + id

class FourOhFour:
    """
    404 error page.
    """

    def GET (self, p):
        raise self.catch(p)

    @staticmethod
    def catch (page = "?"):
        return web.notfound(render("404", page = page))