from django.contrib import messages
from django.contrib.auth import update_session_auth_hash
from django.db import IntegrityError, transaction
from django.shortcuts import redirect, render as django_render
from django.utils.translation import ugettext as _
from django.views.decorators.debug import sensitive_post_parameters

from misago.conf import settings
from misago.core.mail import mail_user

from misago.users.decorators import deny_guests
from misago.users.forms.usercp import (ChangeForumOptionsForm,
                                       ChangeUsernameForm,
                                       ChangeEmailPasswordForm)
from misago.users.sites import usercp
from misago.users.changedcredentials import (cache_new_credentials,
                                             get_new_credentials)
from misago.users.namechanges import UsernameChanges


def render(request, template, context=None):
    context = context or {}
    context['pages'] = usercp.get_pages(request)

    for page in context['pages']:
        if page['is_active']:
            context['active_page'] = page
            break

    return django_render(request, template, context)


@deny_guests
def change_forum_options(request):
    form = ChangeForumOptionsForm(instance=request.user)
    if request.method == 'POST':
        form = ChangeForumOptionsForm(request.POST, instance=request.user)
        if form.is_valid():
            form.save()

            message = _("Your forum options have been changed.")
            messages.success(request, message)

            return redirect('misago:usercp_change_forum_options')

    return render(request, 'misago/usercp/change_forum_options.html',
                  {'form': form})


@deny_guests
@transaction.atomic()
def change_username(request):
    namechanges = UsernameChanges(request.user)

    form = ChangeUsernameForm()
    if request.method == 'POST' and namechanges.left:
        form = ChangeUsernameForm(request.POST, user=request.user)
        if form.is_valid():
            request.user.set_username(form.cleaned_data['new_username'])
            request.user.save(update_fields=['username', 'username_slug'])

            message = _("Your username has been changed.")
            messages.success(request, message)

            return redirect('misago:usercp_change_username')

    return render(request, 'misago/usercp/change_username.html', {
            'form': form,
            'changes_left': namechanges.left,
            'next_change_on': namechanges.next_on
        })


@sensitive_post_parameters()
@deny_guests
def change_email_password(request):
    form = ChangeEmailPasswordForm()
    if request.method == 'POST':
        form = ChangeEmailPasswordForm(request.POST, user=request.user)
        if form.is_valid():
            new_email = ''
            new_password = ''

            # Store original data
            old_email = request.user.email
            old_password = request.user.password

            # Assign new creds to user temporarily
            if form.cleaned_data['new_email']:
                request.user.set_email(form.cleaned_data['new_email'])
                new_email = request.user.email
            if form.cleaned_data['new_password']:
                request.user.set_password(form.cleaned_data['new_password'])
                new_password = request.user.password

            request.user.email = old_email
            request.user.password = old_password

            credentials_token = cache_new_credentials(
                request.user, new_email, new_password)

            mail_subject = _("Confirm changes to %(username)s account "
                             "on %(forum_title)s forums")
            subject_formats = {'username': request.user.username,
                               'forum_title': settings.forum_name}
            mail_subject = mail_subject % subject_formats

            if new_email:
                # finally override email before sending message
                request.user.email = new_email

            mail_user(request, request.user, mail_subject,
                      'misago/emails/change_email_password',
                      {'credentials_token': credentials_token})

            message = _("E-mail was sent to %(email)s with a link that "
                        "you have to click to confirm changes.")
            messages.info(request, message % {'email': request.user.email})
            return redirect('misago:usercp_change_email_password')

    return render(request, 'misago/usercp/change_email_password.html',
                  {'form': form})


@deny_guests
def confirm_email_password_change(request, token):
    new_credentials = get_new_credentials(request.user, token)
    if not new_credentials:
        messages.error(request, _("Confirmation link is invalid."))
    else:
        changes_made = []
        if new_credentials['email']:
            request.user.set_email(new_credentials['email'])
            changes_made.extend(['email', 'email_hash'])
        if new_credentials['password']:
            request.user.password = new_credentials['password']
            update_session_auth_hash(request, request.user)
            changes_made.append('password')

        try:
            request.user.save(update_fields=changes_made)
            message = _("Changes in e-mail and password have been saved.")
            messages.success(request, message)
        except IntegrityError:
            messages.error(request, _("Confirmation link is invalid."))
    return redirect('misago:usercp_change_email_password')