def add_user(request, project):
    obj = get_project(request, project)

    form = AddUserForm(request.POST)

    if not obj.enable_acl:
        messages.error(request, _('ACL not enabled for this project!'))
    elif form.is_valid():
        try:
            user = User.objects.get(
                Q(username=form.cleaned_data['name']) |
                Q(email=form.cleaned_data['name'])
            )
            obj.add_user(user)
            messages.success(
                request, _('User has been added to this project.')
            )
        except User.DoesNotExist:
            messages.error(request, _('No matching user found!'))
        except User.MultipleObjectsReturned:
            messages.error(request, _('More users matched!'))
    else:
        messages.error(request, _('Invalid user specified!'))

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def show_check(request, name):
    """
    Details about failing check.
    """
    try:
        check = CHECKS[name]
    except KeyError:
        raise Http404("No check matches the given query.")

    ignore = "ignored" in request.GET

    url_params = {}

    if ignore:
        url_params["ignored"] = "true"

    checks = acl_checks(request.user).filter(check=name, ignore=ignore)

    if "language" in request.GET:
        checks = checks.filter(language__code=request.GET["language"])
        url_params["language"] = request.GET["language"]

    if "project" in request.GET:
        return redirect_param(
            "show_check_project", encode_optional(url_params), project=request.GET["project"], name=name
        )

    checks = checks.values("project__slug").annotate(count=Count("id"))

    return render(
        request,
        "check.html",
        {"checks": checks, "title": check.name, "check": check, "url_params": encode_optional(url_params)},
    )

def delete_user(request, project):
    obj = get_project(request, project)

    form = AddUserForm(request.POST)

    if form.is_valid():
        try:
            user = User.objects.get(
                username=form.cleaned_data['name']
            )
            obj.remove_user(user)
            messages.success(
                request, _('User has been removed from this project.')
            )
        except User.DoesNotExist:
            messages.error(request, _('No matching user found!'))
        except User.MultipleObjectsReturned:
            messages.error(request, _('More users matched!'))
    else:
        messages.error(request, _('Invalid user specified!'))

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def delete_dictionary(request, project, lang, pk):
    prj = get_project(request, project)
    if not request.user.has_perm('glossary.delete', prj):
        raise PermissionDenied()

    lang = get_object_or_404(Language, code=lang)
    word = get_object_or_404(
        Dictionary,
        project=prj,
        language=lang,
        id=pk
    )

    word.delete()

    params = {}
    for param in ('letter', 'limit', 'page'):
        if param in request.POST:
            params[param] = request.POST[param]

    if params:
        param = '?' + urlencode(params)
    else:
        param = ''

    return redirect_param(
        'show_dictionary',
        param,
        project=prj.slug,
        lang=lang.code
    )

def make_owner(request, project):
    obj, form = check_user_form(request, project)

    if form is not None:
        obj.owners.add(form.cleaned_data['user'])

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def execute_locked(request, obj, message, call, *args, **kwargs):
    """
    Helper function to catch possible lock exception.
    """
    try:
        result = call(request, *args, **kwargs)
        # With False the call is supposed to show errors on its own
        if result is None or result:
            messages.success(request, message)
    except FileLockException:
        messages.error(request, _("Failed to lock the repository, another operation in progress."))

    return redirect_param(obj, "#repository")

def add_user(request, project):
    obj, form = check_user_form(request, project)

    if form is not None and obj.enable_acl:
        obj.add_user(form.cleaned_data['user'])
        messages.success(
            request, _('User has been added to this project.')
        )

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def unlock_component(request, project, component):
    obj = get_component(request, project, component)

    if not request.user.has_perm('component.lock', obj):
        raise PermissionDenied()

    obj.do_lock(request.user, False)

    messages.success(
        request,
        _('Component is now open for translation updates.')
    )

    return redirect_param(obj, '#repository')

def lock_project(request, project):
    obj = get_project(request, project)

    if not request.user.has_perm('component.lock', obj):
        raise PermissionDenied()

    for component in obj.component_set.all():
        component.do_lock(request.user)

    messages.success(
        request,
        _('All components are now locked for translation updates!')
    )

    return redirect_param(obj, '#repository')

def execute_locked(request, obj, message, call, *args, **kwargs):
    """Helper function to catch possible lock exception."""
    try:
        result = call(*args, **kwargs)
        # With False the call is supposed to show errors on its own
        if result is None or result:
            messages.success(request, message)
    except Timeout as error:
        messages.error(
            request,
            _('Failed to lock the repository, another operation is in progress.')
        )
        report_error(error, request)

    return redirect_param(obj, '#repository')

def remove_translation(request, project, component, lang):
    obj = get_translation(request, project, component, lang)

    if not request.user.has_perm('translation.delete', obj):
        raise PermissionDenied()

    form = DeleteForm(obj, request.POST)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#delete')

    obj.remove(request.user)
    messages.success(request, _('Translation has been removed.'))

    return redirect(obj.component)

def revoke_owner(request, project):
    obj, form = check_user_form(request, project)

    if form is not None:
        if obj.owners.count() <= 1:
            messages.error(request, _('You can not remove last owner!'))
        else:
            # Ensure owner stays within project
            obj.add_user(form.cleaned_data['user'])

            obj.owners.remove(form.cleaned_data['user'])

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def whiteboard_project(request, project):
    obj = get_project(request, project)

    if not request.user.has_perm('project.edit', obj):
        raise PermissionDenied()

    form = WhiteboardForm(request.POST)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#whiteboard')

    WhiteboardMessage.objects.create(
        project=obj,
        **form.cleaned_data
    )

    return redirect(obj)

def perform_rename(form_cls, request, obj, perm, **kwargs):
    if not request.user.has_perm(perm, obj):
        raise PermissionDenied()

    form = form_cls(request, request.POST, instance=obj)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#delete')

    form.save()
    Change.objects.create(
        user=request.user,
        author=request.user,
        **kwargs
    )

    return redirect(obj)

def show_check(request, name):
    '''
    Details about failing check.
    '''
    try:
        check = CHECKS[name]
    except KeyError:
        raise Http404('No check matches the given query.')

    ignore = ('ignored' in request.GET)

    url_params = {}

    if ignore:
        url_params['ignored'] = 'true'

    checks = acl_checks(request.user).filter(
        check=name,
        ignore=ignore,
    )

    if 'language' in request.GET:
        checks = checks.filter(language__code=request.GET['language'])
        url_params['language'] = request.GET['language']

    if 'project' in request.GET:
        return redirect_param(
            'show_check_project',
            encode_optional(url_params),
            project=request.GET['project'],
            name=name,
        )

    checks = checks.values('project__slug').annotate(count=Count('id'))

    return render(
        request,
        'check.html',
        {
            'checks': checks,
            'title': check.name,
            'check': check,
            'url_params': encode_optional(url_params),
        }
    )

def whiteboard_translation(request, project, component, lang):
    obj = get_translation(request, project, component, lang)

    if not request.user.has_perm('component.edit', obj):
        raise PermissionDenied()

    form = WhiteboardForm(request.POST)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#whiteboard')

    WhiteboardMessage.objects.create(
        project=obj.component.project,
        component=obj.component,
        language=obj.language,
        **form.cleaned_data
    )

    return redirect(obj)

def remove_project(request, project):
    obj = get_project(request, project)

    if not request.user.has_perm('project.edit', obj):
        raise PermissionDenied()

    form = DeleteForm(obj, request.POST)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#delete')

    project_removal.delay(obj.pk)
    messages.success(request, _('Project was scheduled for removal.'))
    Change.objects.create(
        action=Change.ACTION_REMOVE_PROJECT,
        target=obj.slug,
        user=request.user,
        author=request.user
    )

    return redirect('home')

def remove_component(request, project, component):
    obj = get_component(request, project, component)

    if not request.user.has_perm('component.edit', obj):
        raise PermissionDenied()

    form = DeleteForm(obj, request.POST)
    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#delete')

    obj.delete()
    messages.success(request, _('Translation component has been removed.'))
    Change.objects.create(
        project=obj.project,
        action=Change.ACTION_REMOVE_COMPONENT,
        target=obj.slug,
        user=request.user,
        author=request.user
    )

    return redirect(obj.project)

def delete_user(request, project):
    obj, form = check_user_form(request, project)

    if form is not None and obj.enable_acl:
        is_owner = obj.owners.filter(
            id=form.cleaned_data['user'].id
        ).exists()
        if is_owner and obj.owners.count() <= 1:
            messages.error(request, _('You can not remove last owner!'))
        else:
            if is_owner:
                obj.owners.remove(form.cleaned_data['user'])
            obj.remove_user(form.cleaned_data['user'])
            messages.success(
                request, _('User has been removed from this project.')
            )

    return redirect_param(
        'project',
        '#acl',
        project=obj.slug,
    )

def get_credits(request, project, component):
    """View for credits"""
    obj = get_component(request, project, component)

    if not request.user.has_perm('reports.view', obj):
        raise PermissionDenied()

    form = ReportsForm(request.POST)

    if not form.is_valid():
        show_form_errors(request, form)
        return redirect_param(obj, '#reports')

    data = generate_credits(
        obj,
        form.cleaned_data['start_date'],
        form.cleaned_data['end_date'],
    )

    if form.cleaned_data['style'] == 'json':
        return JsonResponse(data=data, safe=False)

    if form.cleaned_data['style'] == 'html':
        start = '<table>'
        row_start = '<tr>'
        language_format = '<th>{0}</th>'
        translator_start = '<td><ul>'
        translator_format = '<li><a href="mailto:{0}">{1}</a></li>'
        translator_end = '</ul></td>'
        row_end = '</tr>'
        mime = 'text/html'
        end = '</table>'
    else:
        start = ''
        row_start = ''
        language_format = '* {0}\n'
        translator_start = ''
        translator_format = '    * {1} <{0}>'
        translator_end = ''
        row_end = ''
        mime = 'text/plain'
        end = ''

    result = []

    result.append(start)

    for language in data:
        name, translators = language.popitem()
        result.append(row_start)
        result.append(language_format.format(name))
        result.append(
            ''.join((
                translator_start,
                '\n'.join(
                    [translator_format.format(*t) for t in translators]
                ),
                translator_end,
            ))
        )
        result.append(row_end)

    result.append(end)

    return HttpResponse(
        '\n'.join(result),
        content_type='{0}; charset=utf-8'.format(mime),
    )