#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
    openslides.application.models
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Models for the application app.

    :copyright: 2011, 2012 by OpenSlides team, see AUTHORS.
    :license: GNU GPL, see LICENSE for more details.
"""

from datetime import datetime

from django.contrib.auth.models import User
from django.core.urlresolvers import reverse
from django.db import models
from django.db.models import Max
from django.dispatch import receiver
from django.utils.translation import pgettext
from django.utils.translation import ugettext_lazy as _, ugettext_noop

from openslides.utils.utils import _propper_unicode

from openslides.config.models import config
from openslides.config.signals import default_config_value

from openslides.participant.models import Profile

from openslides.poll.models import (BaseOption, BasePoll, CountVotesCast,
    CountInvalid, BaseVote)

from openslides.projector.api import register_slidemodel
from openslides.projector.models import SlideMixin

from openslides.agenda.models import Item


class Application(models.Model, SlideMixin):
    prefix = "application"
    STATUS = (
        ('pub', _('Published')),
        ('per', _('Permitted')),
        ('acc', _('Accepted')),
        ('rej', _('Rejected')),
        ('wit', _('Withdrawed')),
        ('adj', _('Adjourned')),
        ('noc', _('Not Concerned')),
        ('com', _('Commited a bill')),
        ('nop', _('Rejected (not permitted)')),
        ('rev', _('Needs Review')), # Where is this status used?
        #additional actions:
        # edit
        # delete
        # setnumber
        # support
        # unsupport
        # createitem
        # activateitem
        # genpoll
    )

    submitter = models.ForeignKey(User, verbose_name=_("Submitter"))
    supporter = models.ManyToManyField(User, related_name='supporter', \
                                       null=True, blank=True, verbose_name=_("Supporters"))
    number = models.PositiveSmallIntegerField(blank=True, null=True,
                                        unique=True)
    status = models.CharField(max_length=3, choices=STATUS, default='pub')
    permitted = models.ForeignKey('AVersion', related_name='permitted', \
                                  null=True, blank=True)
    log = models.TextField(blank=True, null=True)

    @property
    def last_version(self):
        """
        Return last version of the application.
        """
        try:
            return AVersion.objects.filter(application=self).order_by('id') \
                                   .reverse()[0]
        except IndexError:
            return None

    @property
    def public_version(self):
        """
        Return permitted, if the application was permitted, else last_version
        """
        if self.permitted is not None:
            return self.permitted
        else:
            return self.last_version

    def accept_version(self, version, user = None):
        """
        accept a Version
        """
        self.permitted = version
        self.save(nonewversion=True)
        version.rejected = False
        version.save()
        self.writelog(_("Version %d permitted") % (version.aid, ),
            user)

    def reject_version(self, version, user = None):
        if version.id > self.permitted.id:
            version.rejected = True
            version.save()
            self.writelog(pgettext("Rejected meens not permittd", "Version %d rejected")
                % (version.aid, ), user)
            return True
        return False

    @property
    def versions(self):
        """
        Return a list of all versions of the application.
        """
        return AVersion.objects.filter(application=self)

    @property
    def creation_time(self):
        """
        Return the time of the creation of the application.
        """
        try:
            return self.versions[0].time
        except IndexError:
            return None

    @property
    def notes(self):
        """
        Return some information of the application.
        """
        note = []
        if self.status == "pub" and not self.enough_supporters:
            note.append(_("Searching for supporters."))
        if self.status == "pub" and self.permitted is None:
            note.append(_("Not yet permitted."))
        elif self.unpermitted_changes and self.permitted:
            note.append(_("Not yet permitted changes."))
        return note

    @property
    def unpermitted_changes(self):
        """
        Return True if the application has unpermitted changes.

        The application has unpermitted changes, if the permitted-version
        is not the lastone and the lastone is not rejected.
        TODO: rename the property in unchecked__changes
        """
        if (self.last_version != self.permitted
        and not self.last_version.rejected):
            return True
        else:
            return False

    @property
    def enough_supporters(self):
        """
        Return True, if the application has enough supporters
        """
        min_supporters = int(config['application_min_supporters'])
        if self.status == "pub":
            return self.supporter.count() >= min_supporters
        else:
            return True

    @property
    def missing_supporters(self):
        """
        Return number of missing supporters
        """
        min_supporters = int(config['application_min_supporters'])
        delta = min_supporters - self.supporter.count()
        if delta > 0:
            return delta
        else:
            return 0

    def save(self, user=None, nonewversion=False, trivial_change=False):
        """
        Save the Application, and create a new AVersion if necessary
        """
        super(Application, self).save()
        if nonewversion:
            return
        last_version = self.last_version
        fields = ["text", "title", "reason"]
        if last_version is not None:
            changed_fields = [f for f in fields
                if getattr(last_version, f) != getattr(self, f)]
            if not changed_fields:
                return  # No changes
        try:
            if trivial_change and last_version is not None:
                last_version.text = self.text
                last_version.title = self.title
                last_version.reason = self.reason
                last_version.save()

                meta = AVersion._meta
                field_names = [unicode(meta.get_field(f).verbose_name)
                    for f in changed_fields]

                self.writelog(_("Trivial changes to version %(version)d; "
                    "changed fields: %(changed_fields)s")
                    % dict(version = last_version.aid,
                        changed_fields = ", ".join(field_names)))
                return # Done

            version = AVersion(title=getattr(self, 'title', ''),
                       text=getattr(self, 'text', ''),
                       reason=getattr(self, 'reason', ''),
                       application=self)
            version.save()
            self.writelog(_("Version %s created") % version.aid, user)
            is_manager = user.has_perm('application.can_manage_application')
        except AttributeError:
            is_manager = False

        if (self.status == "pub"
        and self.supporter.exists()
        and not is_manager):
            self.supporter.clear()
            self.writelog(_("Supporters removed"), user)

    def reset(self, user):
        """
        Reset the application.
        """
        self.status = "pub"
        self.permitted = None
        self.save()
        self.writelog(_("Status reseted to: %s") % (self.get_status_display()), user)

    def support(self, user):
        """
        Add a Supporter to the list of supporters of the application.
        """
        if user == self.submitter:
            raise NameError('Supporter can not be the submitter of a ' \
                            'application.')
        if self.permitted is not None:
            raise NameError('This application is already permitted.')
        if user not in self.supporter.all():
            self.supporter.add(user)
        self.writelog(_("Supporter: +%s") % (user))

    def unsupport(self, user):
        """
        remove a supporter from the list of supporters of the application
        """
        if self.permitted is not None:
            raise NameError('This application is already permitted.')
        if user in self.supporter.all():
            self.supporter.remove(user)
        self.writelog(_("Supporter: -%s") % (user))

    def set_number(self, number=None, user=None):
        """
        Set a number for ths application.
        """
        if self.number is not None:
            raise NameError('This application has already a number.')
        if number is None:
            try:
                number = Application.objects.aggregate(Max('number')) \
                            ['number__max'] + 1
            except TypeError:
                number = 1
        self.number = number
        self.save()
        self.writelog(_("Number set: %s") % (self.number), user)
        return self.number

    def permit(self, user=None):
        """
        Change the status of this application to permit.
        """
        self.set_status(user, "per")
        aversion = self.last_version
        if self.number is None:
            self.set_number()
        self.permitted = aversion
        self.save()
        self.writelog(_("Version %s permitted") % (aversion.aid), user)
        return self.permitted

    def notpermit(self, user=None):
        """
        Change the status of this application to 'not permitted (rejected)'.
        """
        self.set_status(user, "nop")
        #TODO: reject last version
        aversion = self.last_version
        #self.permitted = aversion
        if self.number is None:
            self.set_number()
        self.save()
        self.writelog(_("Version %s not permitted") % (self.last_version.aid), user)

    def set_status(self, user, status, force=False):
        """
        Set the status of the application.
        """
        error = True
        for a, b in Application.STATUS:
            if status == a:
                error = False
                break
        if error:
            raise NameError('%s is not a valid status.' % status)
        if self.status == status:
            raise NameError('The application status is already %s.' \
                            % self.status)

        actions = []
        actions = self.get_allowed_actions(user)
        if status not in actions and not force:
            raise NameError('The application status is: %s. You can not set' \
                            ' the status to %s.' % (self.status, status))

        oldstatus = self.get_status_display()
        self.status = status
        self.save()
        self.writelog(_("Status modified")+": %s -> %s" \
                      % (oldstatus, self.get_status_display()), user)

    def get_allowed_actions(self, user=None):
        """
        Return a list of all the allowed status.
        """
        actions = []
        is_admin = False
        if user:
            try:
                user.profile
            except Profile.DoesNotExist:
                is_admin = True

        # check if user allowed to withdraw an application
        if  ((self.status == "pub"
          and self.number
          and user == self.submitter)
        or   (self.status == "pub"
          and self.number
          and user.has_perm("application.can_manage_application"))
        or   (self.status == "per"
          and user == self.submitter)
        or (self.status == "per"
          and user.has_perm("application.can_manage_application"))):
            actions.append("wit")
        #Check if the user can review the application
        if  (self.status == "rev"
        and (self.submitter == user
          or user.has_perm("application.can_manage_application"))):
            actions.append("pub")

        # Check if the user can support and unspoort the application
        try:
            if  (self.status == "pub"
              and user != self.submitter
              and user not in self.supporter.all()
              and getattr(user, 'profile', None)):
                actions.append("support")
        except Profile.DoesNotExist:
            pass

        if self.status == "pub" and user in self.supporter.all():
            actions.append("unsupport")

        #Check if the user can edit the application
        if (user == self.submitter \
          and (self.status in ('pub', 'per'))) \
        or user.has_perm("application.can_manage_application"):
            actions.append("edit")

        # Check if the user can delete the application (admin, manager, owner)
        # reworked as requiered in #100
        if is_admin \
        or (user.has_perm("application.can_manage_application") \
            and (self.status == "pub" or self.number is None))  \
        or (self.submitter == user \
            and (self.status == "pub" or self.number is None)):
            actions.append("delete")

        #For the rest, all actions need the manage permission
        if not user.has_perm("application.can_manage_application"):
            return actions

        if self.status == "pub":
            actions.append("nop")
            actions.append("per")
            if self.number == None:
                actions.append("setnumber")

        if self.status == "per":
            actions.append("acc")
            actions.append("rej")
            actions.append("adj")
            actions.append("noc")
            actions.append("com")
            actions.append("genpoll")
            if self.unpermitted_changes:
                actions.append("permitversion")
                actions.append("rejectversion")

        return actions

    def delete(self, force=False):
        """
        Delete the application. It is not possible, if the application has
        allready a number
        """
        if self.number and not force:
            raise NameError('The application has already a number. ' \
                            'You can not delete it.')


        for item in Item.objects.filter(related_sid=self.sid):
            item.delete()
        super(Application, self).delete()

    def writelog(self, text, user=None):
        if not self.log:
            self.log = ""
        self.log += u"%s | %s" % (datetime.now().strftime("%d.%m.%Y %H:%M:%S"), _propper_unicode(text))
        if user is not None:
            self.log += u" (%s %s)" % (_("by"), _propper_unicode(user.username))
        self.log += "\n"
        self.save()

    def get_agenda_title(self):
        return self.public_version.title

    def __getattr__(self, name):
        """
        if name is title, text, reason or time,
            Return this attribute from the newest version of the application
        """
        if name in ('title', 'text', 'reason', 'time', 'aid'):
            try:
                if name == 'aid':
                    return self.last_version.aid
                return self.last_version.__dict__[name]
            except TypeError:
                raise AttributeError(name)
            except AttributeError:
                raise AttributeError(name)
        raise AttributeError(name)

    def gen_poll(self, user=None):
        """
        Generates a poll object for the application
        """
        poll = ApplicationPoll(application=self)
        poll.save()
        poll.set_options()
        self.writelog(_("Poll created"), user)
        return poll

    @property
    def polls(self):
        return self.applicationpoll_set.all()

    @property
    def results(self):
        return self.get_poll_results()

    def get_poll_results(self):
        """
        Return a list of voting results
        """
        results = []
        for poll in self.polls:
            for option in poll.get_options():
                if option.get_votes().exists():
                    results.append((option['Yes'], option['No'],
                        option['Abstain'], poll.print_votesinvalid(),
                        poll.print_votescast()))
        return results


    def slide(self):
        """
        return the slide dict
        """
        data = super(Application, self).slide()
        data['application'] = self
        data['title'] = self.title
        data['template'] = 'projector/Application.html'
        return data

    def get_absolute_url(self, link='view'):
        if link == 'view':
            return reverse('application_view', args=[str(self.id)])
        if link == 'edit':
            return reverse('application_edit', args=[str(self.id)])
        if link == 'delete':
            return reverse('application_delete', args=[str(self.id)])

    def __unicode__(self):
        try:
            return self.last_version.title
        except AttributeError:
            return "no title jet"

    class Meta:
        permissions = (
            ('can_see_application', ugettext_noop("Can see application")),
            ('can_create_application', ugettext_noop("Can create application")),
            ('can_support_application', ugettext_noop("Can support application")),
            ('can_manage_application', ugettext_noop("Can manage application")),
        )


class AVersion(models.Model):
    title = models.CharField(max_length=100, verbose_name = _("Title"))
    text = models.TextField(verbose_name = _("Text"))
    reason = models.TextField(null=True, blank=True, verbose_name = _("Reason"))
    rejected = models.BooleanField() # = Not Permitted
    time = models.DateTimeField(auto_now=True)
    application = models.ForeignKey(Application)

    def __unicode__(self):
        return "%s %s" % (self.id, self.title)

    @property
    def aid(self):
        try:
            return self._aid
        except AttributeError:
            self._aid = AVersion.objects \
                .filter(application=self.application) \
                .filter(id__lte=self.id).count()
            return self._aid

register_slidemodel(Application)


class ApplicationVote(BaseVote):
    option = models.ForeignKey('ApplicationOption')


class ApplicationOption(BaseOption):
    poll = models.ForeignKey('ApplicationPoll')
    vote_class = ApplicationVote


class ApplicationPoll(BasePoll, CountInvalid, CountVotesCast):
    option_class = ApplicationOption
    vote_values = [ugettext_noop('Yes'), ugettext_noop('No'),
        ugettext_noop('Abstain')]

    application = models.ForeignKey(Application)

    def get_application(self):
        return self.application

    def set_options(self):
        #TODO: maybe it is possible with .create() to call this without poll=self
        self.get_option_class()(poll=self).save()

    def append_pollform_fields(self, fields):
        CountInvalid.append_pollform_fields(self, fields)
        CountVotesCast.append_pollform_fields(self, fields)

    def get_absolute_url(self):
        return reverse('application_poll_view', args=[self.id])

    def get_ballot(self):
        return self.application.applicationpoll_set.filter(id__lte=self.id).count()


@receiver(default_config_value, dispatch_uid="application_default_config")
def default_config(sender, key, **kwargs):
    return {
        'application_min_supporters': 0,
        'application_preamble': _('The Assembly may decide,'),
        'application_pdf_ballot_papers_selection': 'CUSTOM_NUMBER',
        'application_pdf_ballot_papers_number': '8',
        'application_pdf_title': _('Applications'),
        'application_pdf_preamble': '',
        'application_allow_trivial_change': False,
    }.get(key)