"""
Handle expenditures
"""

import logging

from decimal import Decimal, InvalidOperation

from bluechips.lib.base import *

from pylons import request, app_globals as g
from pylons.decorators.rest import dispatch_on
from pylons.decorators import validate
from pylons.controllers.util import abort

from formencode import validators, Schema
from formencode.foreach import ForEach
from formencode.variabledecode import NestedVariables
from formencode.schema import SimpleFormValidator

from mailer import Message

log = logging.getLogger(__name__)


class ShareSchema(Schema):
    "Validate individual user shares."
    allow_extra_fields = False
    user_id = validators.Int(not_empty=True)
    amount = validators.Number(not_empty=True)


def validate_state(value_dict, state, validator):
    if all(s['amount'] == 0 for s in value_dict['shares']):
        return {'shares-0.amount': 'Need at least one non-zero share'}
ValidateNotAllZero = SimpleFormValidator(validate_state)


class ExpenditureSchema(Schema):
    "Validate an expenditure."
    allow_extra_fields = False
    pre_validators = [NestedVariables()]
    spender_id = validators.Int(not_empty=True)
    amount = model.types.CurrencyValidator(not_empty=True)
    description = validators.UnicodeString()
    date = validators.DateConverter()
    shares = ForEach(ShareSchema)
    chained_validators = [ValidateNotAllZero]
    

class SpendController(BaseController):
    def index(self):
        return self.edit()
    
    def edit(self, id=None):
        c.users = meta.Session.query(model.User.id, model.User)
        if id is None:
            c.title = 'Add a New Expenditure'
            c.expenditure = model.Expenditure()
            c.expenditure.spender_id = request.environ['user'].id

            num_residents = meta.Session.query(model.User).\
                    filter_by(resident=True).count()
            # Pre-populate split percentages for an even split.
            c.values = {}
            for ii, user_row in enumerate(c.users):
                user_id, user = user_row
                if user.resident:
                    val = Decimal(100) / Decimal(num_residents)
                else:
                    val = 0
                c.values['shares-%d.amount' % ii] = val
        else:
            c.title = 'Edit an Expenditure'
            c.expenditure = meta.Session.query(model.Expenditure).get(id)
            if c.expenditure is None:
                abort(404)
            c.values = {}
            for ii, user_row in enumerate(c.users):
                user_id, user = user_row
                try:
                    share = [s.share for s in c.expenditure.splits
                             if s.user == user][0]
                    if c.expenditure.amount == 0:
                        percent = 0
                    else:
                        percent = (Decimal(100) * Decimal(int(share)) /
                                   Decimal(int(c.expenditure.amount))).\
                                quantize(Decimal("0.001"))
                except IndexError:
                    percent = 0
                c.values['shares-%d.amount' % ii] = percent

        return render('/spend/index.mako')

    @validate(schema=ExpenditureSchema(), form='edit', variable_decode=True)
    def update(self, id=None):
        # Either create a new object, or, if we're editing, get the
        # old one
        if id is None:
            e = model.Expenditure()
            meta.Session.add(e)
            op = 'created'
        else:
            e = meta.Session.query(model.Expenditure).get(id)
            if e is None:
                abort(404)
            op = 'updated'
        
        # Set the fields that were submitted
        shares = self.form_result.pop('shares')
        update_sar(e, self.form_result)

        users = dict(meta.Session.query(model.User.id, model.User).all())
        split_dict = {}
        for share_params in shares:
            user = users[share_params['user_id']]
            split_dict[user] = Decimal(str(share_params['amount']))
        e.split(split_dict)
        
        meta.Session.commit()
       
        show = ("Expenditure of %s paid for by %s %s." %
                (e.amount, e.spender, op))
        h.flash(show)

        # Send email notification to involved users if they have an email set.
        involved_users = set(sp.user for sp in e.splits if sp.share != 0)
        involved_users.add(e.spender)
        body = render('/emails/expenditure.txt',
                      extra_vars={'expenditure': e,
                                  'op': op})
        g.handle_notification(involved_users, show, body)

        return h.redirect_to('/')