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)
        csum = sql.functions.sum(ConstExpense.monthly)

        query = SingleExpense.of_month(month, year).\
                group_by(SingleExpense.category_id).\
                values(SingleExpense.category_id, ssum)

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

        consts = ConstExpense.of_month(month, year).value(csum)
        if consts is None: consts = 0

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

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

class Add:

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

    form = form.Form(
            form.Textbox(
                "date",
                form.notnull,
                value = datetime.date.today().strftime(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, Add.dformat)),
                ("Not a valid decimal", lambda f: decimal.Decimal(f.expense)),
                ))
            )

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

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))