# -*- coding: UTF-8 -*-
# Copyright 2016-2019 Rumma & Ko Ltd
# License: BSD, see LICENSE for more details.
"""Defines the :class:`DashboardItem` class.

"""
from __future__ import unicode_literals
from builtins import str

from lino.api import _
from lino.core.permissions import Permittable
from etgen.html import E, tostring

class DashboardItem(Permittable):
    """Base class for all dashboard items.

    .. attribute:: name

        The name used to reference this item in
        :attr:`Widget.item_name`.

    .. attribute:: width

        The width in percent of total available width.

    .. attribute:: min_count

        Hide this item if there are less than min_count rows.

    """

    width = None
    header_level = None
    min_count = None

    def __init__(self, name, header_level=2, min_count=1):
        self.name = name
        self.header_level = header_level
        self.min_count = min_count


    def render(self, ar):
        """Yield a list of etree html elements"""

    def render_request(self, ar, sar):
        """
        Render the given table action
        request. `ar` is the incoming request (the one which displays
        the dashboard), `sar` is the table we want to show (a child of
        `ar`).

        This is a helper function for shared use by :class:`ActorItem`
        and :class:`RequestItem`.
        """
        T = sar.actor
        if self.min_count is not None:
            if sar.get_total_count() < self.min_count:
                # print("20180212 render no rows in ", sar)
                return
        if self.header_level is not None:
            buttons = sar.plain_toolbar_buttons()
            buttons.append(sar.open_in_own_window_button())
            elems = []
            for b in buttons:
                elems.append(b)
                elems.append(' ')

            yield E.h2(str(
                sar.actor.get_title_base(sar)), ' ', *elems)

        yield sar

class ActorItem(DashboardItem):
    """A dashboard item which simply renders a given actor.
    The actor should be a table, other usage is untested.

    Usage examples:
    - :mod:`lino_xl.lib.blogs`
    - :mod:`lino_book.projects.events`

    .. attribute:: header_level

        The header level.

    """
    def __init__(self, actor, **kwargs):
        self.actor = actor
        super(ActorItem, self).__init__(str(actor), **kwargs)

    def get_view_permission(self, user_type):
        return self.actor.default_action.get_view_permission(user_type)

    def render(self, ar):
        """Render this table to the dashboard.

        - Do nothing if there is no data.

        - If :attr:`header_level` is not None, add a header

        - Render the table itself by calling
          :meth:`lino.core.requests.BaseRequest.show`

        """
        T = self.actor
        sar = ar.spawn(T, limit=T.preview_limit)
        for i in self.render_request(ar, sar):
            yield i

class RequestItem(DashboardItem):
    """
    Experimentally used in `lino_book.projects.events`.
    """
    def __init__(self, sar, **kwargs):
        self.sar = sar
        super(RequestItem, self).__init__(None, **kwargs)

    def get_view_permission(self, user_type):
        return self.sar.get_permission()

    def render(self, ar):
        for i in self.render_request(ar, self.sar):
            yield i


# class CustomItem(DashboardItem):
#     """Won't work. Not used and not tested."""
#     def __init__(self, name, func, *args, **kwargs):
#         self.func = func
#         self.args = args
#         self.kwargs = kwargs
#         super(CustomItem, self).__init__(name)

#     def render(self, ar):
#         return self.func(ar, *self.args, **self.kwargs)
