from ..engine import SearchEngine
from ..config import PROXY, TIMEOUT


class Bing(SearchEngine):
    '''Searches bing.com'''
    def __init__(self, proxy=PROXY, timeout=TIMEOUT):
        super(Bing, self).__init__(proxy, timeout)
        self._base_url = 'https://www.bing.com'

    def _selectors(self, element):
        '''Returns the appropriate CSS selector.'''
        selectors = {
            'url': 'a[href]', 
            'title': 'a', 
            'text': 'p', 
            'links': 'ol#b_results > li.b_algo', 
            'next': 'div#b_content nav[role="navigation"] a.sb_pagN'
        }
        return selectors[element]
    
    def _first_page(self):
        '''Returns the initial page and query.'''
        url = u'{}/search?q={}'.format(self._base_url, self._query)
        return {'url':url, 'data':None}
    
    def _next_page(self, tags):
        '''Returns the next page URL and post data (if any)'''
        selector = self._selectors('next')
        next_page = self._get_tag_item(tags.select_one(selector), 'href')
        url = None
        if next_page:
            url = (self._base_url + next_page) 
        return {'url':url, 'data':None}

