# requests is for downloading data(text) from the web.
import requests

# pattern and beautifulsoup are for navigating through DOM
from pattern import web

import csv

# function 3
def get_food_truck_link(url):
    '''for a given food truck link inside the main_url find the real
    link of food truck and return'''
    
def get_city_url(url):
	'''To fetch and return the dictonary of all cities and 
	their id present on main page.
    Step 1'''
    # making get request to the given url
	r = requests.get(url)
	html = r.text
	'''Since sub-footer of the main page contain list of all countries and their link, 
    parsing is being done only on sub-footer of main page.'''
	subfooter_index = html.find('id="subfooter"')
	footer = html[subfooter_index : html[subfooter_index:].find('</ul></div>')+subfooter_index]
	dom = web.Element(footer)
	city_link = {}
	for li in dom.by_tag('li'):
		city = li.by_tag('a')[0].content
		inner_link = li.by_tag('a')[0].attributes.get('href', '')
		city_link[city] = inner_link
	return city_link
	

def get_food_trucks(url):
	'''For a given city url find all food trucks present on the 
	page of that city.
    Step 2'''
	r = requests.get(url)
	dom = web.Element(r.text)
        truck_name_link = {}
        for li in dom.by_tag('li.squarelisting'):
    	    truck_name = li.by_tag('a')[0].attributes.get('href',)[1:]
            # step 3 for finding links for each truck is being called from here.
    	    truck_link = get_food_truck_link(main_url+truck_name)
            truck_name_link[truck_name] = truck_link
        return truck_name_link
    
def get_food_truck_link(url):
    '''for a given food truck link inside the main_url find the real
    link of food truck and return.
    Step 3'''
    # print('inside get_food_truck_LINK', url)
    r = requests.get(url)
    dom = web.Element(r.text)
    #truck_link = dom.by_tag('a.drawbutton menu_link')[0].attributes.get('href',)   
    truck_link = ''
    for div in dom.by_tag('div.widget cf'):
        truck_link = div.by_tag('a.drawbutton')[0].attributes.get('href',)          
    return truck_link    
	
    
main_url = 'http://roaminghunger.com/'  

if __name__ == "__main__":
    # step 1 is to get a dict of all cities and their link address in roaminhunger.com
    city_link = get_city_url(main_url)
    # print city_link
    
    # step 2 - Now for each of these cities find food-truck
    city_food_trucks = {}
    for city in city_link:
	food_trucks = get_food_trucks(main_url+city_link[city])
	city_food_trucks[city] = food_trucks
    # print(city_food_trucks)
    
    # step - 4 Write whole data in a csv file
    with open('data_food_truck.csv', 'w') as csvfile:
    	filewriter = csv.writer(csvfile, delimiter='\t',
                            quotechar='|', quoting=csv.QUOTE_MINIMAL)
      	filewriter.writerow(['Food Truck', 'City', 'link'])
 	for city in city_food_trucks:
    	    for food_truck, link in city_food_trucks[city].items():
    		filewriter.writerow([food_truck, city, link])
	print('Done!!')