from django.template.loader import render_to_string


class BaseItem:
    template = 'wagtailadmin/userbar/item_base.html'

    def render(self, request):
        return render_to_string(self.template, dict(self=self, request=request), request=request)


class AdminItem(BaseItem):
    template = 'wagtailadmin/userbar/item_admin.html'

    def render(self, request):

        # Don't render if user doesn't have permission to access the admin area
        if not request.user.has_perm('wagtailadmin.access_admin'):
            return ""

        return super().render(request)


class AddPageItem(BaseItem):
    template = 'wagtailadmin/userbar/item_page_add.html'

    def __init__(self, page):
        self.page = page
        self.parent_page = page.get_parent()

    def render(self, request):
        # Don't render if the page doesn't have an id
        if not self.page.id:
            return ""

        # Don't render if user doesn't have permission to access the admin area
        if not request.user.has_perm('wagtailadmin.access_admin'):
            return ""

        # Don't render if user doesn't have ability to add children here
        permission_checker = self.page.permissions_for_user(request.user)
        if not permission_checker.can_add_subpage():
            return ""

        return super().render(request)


class ExplorePageItem(BaseItem):
    template = 'wagtailadmin/userbar/item_page_explore.html'

    def __init__(self, page):
        self.page = page
        self.parent_page = page.get_parent()

    def render(self, request):
        # Don't render if the page doesn't have an id
        if not self.page.id:
            return ""

        # Don't render if user doesn't have permission to access the admin area
        if not request.user.has_perm('wagtailadmin.access_admin'):
            return ""

        # Don't render if user doesn't have ability to edit or publish sub-pages on the parent page
        permission_checker = self.parent_page.permissions_for_user(request.user)
        if not permission_checker.can_edit() and not permission_checker.can_publish_subpage():
            return ""

        return super().render(request)


class EditPageItem(BaseItem):
    template = 'wagtailadmin/userbar/item_page_edit.html'

    def __init__(self, page):
        self.page = page

    def render(self, request):
        # Don't render if the page doesn't have an id
        if not self.page.id:
            return ""

        # Don't render if user doesn't have permission to access the admin area
        if not request.user.has_perm('wagtailadmin.access_admin'):
            return ""

        # Don't render if the user doesn't have permission to edit this page
        permission_checker = self.page.permissions_for_user(request.user)
        if not permission_checker.can_edit():
            return ""

        return super().render(request)


class ModeratePageItem(BaseItem):
    def __init__(self, revision):
        self.revision = revision

    def render(self, request):
        if not self.revision.id:
            return ""

        if not self.revision.submitted_for_moderation:
            return ""

        if not request.user.has_perm('wagtailadmin.access_admin'):
            return ""

        if not self.revision.page.permissions_for_user(request.user).can_publish():
            return ""

        return super().render(request)


class ApproveModerationEditPageItem(ModeratePageItem):
    template = 'wagtailadmin/userbar/item_page_approve.html'


class RejectModerationEditPageItem(ModeratePageItem):
    template = 'wagtailadmin/userbar/item_page_reject.html'