# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""

Custom paging classes

"""

import math

import re

from kallithea.config.routing import url

from webhelpers.html import literal, HTML

from webhelpers.paginate import Page as _Page

class Page(_Page):

    """

    Custom pager to match rendering style with YUI paginator emitting Bootstrap paginators

    """

    def __init__(self, *args, **kwargs):

        kwargs.setdefault('url', url.current)

        _Page.__init__(self, *args, **kwargs)

    def _get_pos(self, cur_page, max_page, items):

        edge = (items / 2) + 1

        if (cur_page <= edge):

            radius = max(items / 2, items - cur_page)

        elif (max_page - cur_page) < edge:

            radius = (items - 1) - (max_page - cur_page)

        else:

            radius = items / 2

        left = max(1, (cur_page - (radius)))

        right = min(max_page, cur_page + (radius))

        return left, cur_page, right

    def _range(self, regexp_match):

        """

        Return range of linked pages (e.g. '1 2 [3] 4 5 6 7 8').

        Arguments:

        regexp_match

            A "re" (regular expressions) match object containing the

            radius of linked pages around the current page in

            regexp_match.group(1) as a string

        This function is supposed to be called as a callable in

        re.sub.

        """

        radius = int(regexp_match.group(1))

        # Compute the first and last page number within the radius

        # e.g. '1 .. 5 6 [7] 8 9 .. 12'

        # -> leftmost_page  = 5

        # -> rightmost_page = 9

        leftmost_page, _cur, rightmost_page = self._get_pos(self.page,

                                                            self.last_page,

                                                            (radius * 2) + 1)

        nav_items = []

        result = Template(result).safe_substitute({

            'first_page': self.first_page,

            'last_page': self.last_page,

            'page': self.page,

            'page_count': self.page_count,

            'items_per_page': self.items_per_page,

            'first_item': self.first_item,

            'last_item': self.last_item,

            'item_count': self.item_count,

            'link_first': self.page > self.first_page and \

                    self._pagerlink(self.first_page, symbol_first) or '',

            'link_last': self.page < self.last_page and \

                    self._pagerlink(self.last_page, symbol_last) or '',

            'link_previous': HTML.li(self.previous_page and \

                    self._pagerlink(self.previous_page, symbol_previous) \

                    or HTML.a(symbol_previous)),

            'link_next': HTML.li(self.next_page and \

                    self._pagerlink(self.next_page, symbol_next) \

                    or HTML.a(symbol_next))

        })

        return literal(result)

class RepoPage(Page):

    def __init__(self, collection, page=1, items_per_page=20,

                 item_count=None, **kwargs):

        """Create a "RepoPage" instance. special pager for paging

        repository

        """

        # TODO: call baseclass __init__

        self._url_generator = kwargs.pop('url', url.current)

        # Safe the kwargs class-wide so they can be used in the pager() method

        self.kwargs = kwargs

        # Save a reference to the collection

        self.original_collection = collection

        self.collection = collection

        # The self.page is the number of the current page.

        # The first page has the number 1!

        try:

            self.page = int(page)  # make it int() if we get it as a string

        except (ValueError, TypeError):

            self.page = 1

        self.items_per_page = items_per_page

        # Unless the user tells us how many items the collections has

        # we calculate that ourselves.

        if item_count is not None:

            self.item_count = item_count

        else:

            self.item_count = len(self.collection)

        # Compute the number of the first and last available page

        if self.item_count > 0:

            self.first_page = 1

            self.page_count = int(math.ceil(float(self.item_count) /

                                            self.items_per_page))

            self.last_page = self.first_page + self.page_count - 1

            # Make sure that the requested page number is the range of

            # valid pages

            if self.page > self.last_page:

                self.page = self.last_page

            elif self.page < self.first_page:

                self.page = self.first_page

            # Note: the number of items on this page can be less than

            #       items_per_page if the last page is not full

            self.first_item = max(0, (self.item_count) - (self.page *

                                                          items_per_page))

            self.last_item = ((self.item_count - 1) - items_per_page *

                              (self.page - 1))

            self.items = list(self.collection[self.first_item:self.last_item + 1])

            # Links to previous and next page

            if self.page > self.first_page:

                self.previous_page = self.page - 1

            else:

                self.previous_page = None

            if self.page < self.last_page:

                self.next_page = self.page + 1

            else:

                self.next_page = None

        # No items available

        else:

            self.first_page = None