#!/usr/bin/env python3

from math import ceil, floor
from paramecio2.libraries.urls import add_get_parameters
from paramecio2.libraries.i18n import I18n

class Pages: 
    """Simple class for create html pagination code"""
    
    css_class='link_pages'

    @staticmethod
    def show( begin_page, total_elements, num_elements, link ,initial_num_pages=20, variable='begin_page', label='', func_jscript=''):
        """Static method for create the html pagination
        
        With this method, you can create html pagination code with automated urls for load every page. You can use it also how base for ajax pagination
        
        Args:
            begin_page (int): The number where pagination begin
            total_elements (int): The total items in pages
            num_elements (int): The number of items for every page
            link (str): The url of every page
            initial_num_pages (int): Optional. Number of pages showed in pagination, if you have 50 pages, if this value is 20, an interval of 20 pages is showed, with first pages links, and after pages links for navigate between many pages.
            variable (str): Optional. The name of GET url variable used for send the first element in the query for get the page.
            label (str): Optional. In the future will be used for identify some html tags
            func_jscript (str): Javascript function to be executed when page url is clicked. 

        """
        
        pages='';

        if begin_page>total_elements:
            begin_page=0

        # Calculamos el total de todas las páginas

        total_page=ceil(total_elements/num_elements)
        
        # Calculamos en que página nos encontramos

        actual_page=ceil(begin_page/num_elements)

        # Calculamos el total de intervalos

        total_interval=ceil(total_page/initial_num_pages)

        # Calculamos el intervalo en el que estamos

        actual_interval=floor(actual_page/initial_num_pages)

        # Calculamos el elemento de inicio del intervalo

        initial_page=ceil(actual_interval*initial_num_pages*num_elements)

        last_page=ceil(actual_interval*initial_num_pages*num_elements)+ceil(initial_num_pages*num_elements)

        if last_page>total_elements:
            last_page=total_elements

        if initial_page>0:
            initial_link=add_get_parameters(link, **{variable: '0'});
            middle_link=add_get_parameters(link, **{variable: str((initial_page-num_elements)) } );
            pages += "<a class=\""+Pages.css_class+"\" href=\""+initial_link+"\" onclick=\"${func_jscript}\">1</a> <a class=\""+Pages.css_class+"\" href=\""+middle_link+"\">&lt;&lt;</a> "

        arr_pages={}

        #for(x=initial_page;x<last_page;x+=num_elements)
        for x in range(initial_page, last_page, num_elements):
            
            middle_link=add_get_parameters(link, **{variable: str(x)} )

            num_page=ceil(x/num_elements)+1;
            arr_pages[x]="<a class=\""+Pages.css_class+"\" href=\""+middle_link+"\">"+str(num_page)+"</a> "
            arr_pages[begin_page]='<span class="selected_page">'+str(num_page)+'</span> ';
            pages += arr_pages[x]

        
        if last_page<total_elements:

            middle_link=add_get_parameters(link, **{variable: str(x+num_elements)} );
            last_link=add_get_parameters(link, **{variable: str( ( ( total_page*num_elements ) - num_elements) ) } )

            pages += "<a class=\""+Pages.css_class+"\" href=\""+middle_link+"\" onclick=\"func_jscript\">&gt;&gt;</a> <a class=\"link_pages\" href=\""+last_link+"\" onclick=\"func_jscript\">"+I18n.lang('common', 'last', 'Last')+"</a>"

        
        return pages