import db
from sqlalchemy import select, desc
from sqlalchemy.orm import sessionmaker
import bs4
from urllib.request import urlopen
import logging
from argparse import ArgumentParser

parser = ArgumentParser(description="Scrape a recipe site for recipies")
parser.add_argument('site',
                    help='Name of site')
parser.add_argument('-id', '--identifier', dest='id',
                    help='url of recipe(reletive to base url of site) or commma seperated list')
parser.add_argument('-a', '--auto', action='store', dest='n',
                    help='automaticaly generate identifier(must supply number of recipies to scrape)')
parser.add_argument('-v', '--verbose', action='store_true')

args = parser.parse_args()
if args.verbose:
    logging.basicConfig(level=logging.INFO)
    logging.getLogger('sqlalchemy.engine').setLevel(logging.INFO)

eng = db.get_engine()
S = sessionmaker(eng)

with S.begin() as sess:
    site = sess.query(db.RecipeSite).where(db.RecipeSite.name == args.site).one()
    site_id = site.id
        
    recipe_ids = []
    starting_id = 0
    if args.id and not args.n:
        recipe_ids.append(args.id)
        logging.info(f'Retreiving single recipe: {args.id}')
    elif args.n:
        if not args.id:
            last_recipe =  sess.query(db.Recipe).\
                            where(db.Recipe.recipe_site_id == site.id).\
                            order_by(desc(db.Recipe.identifier)).\
                            limit(1).\
                            scalar()
            starting_id = int(last_recipe.identifier) + 1
        else:
            starting_id = args.id
        recipe_ids = range(starting_id, starting_id+int(args.n))
        logging.info(f'Retreving {args.n} recipes from {site.base_url} starting at {starting_id}')
    
    
        
    for recipe_id in recipe_ids:            
        recipe = db.Recipe(identifier = recipe_id, recipe_site_id = site.id)

        recipe_url = f'{site.base_url}/{recipe.identifier}'
        logging.info(f'Loading Recipe: {recipe_url}')
        try:
            with urlopen(recipe_url) as f:
                if f.getcode() == 404:
                    raise Exception(f"Recipe Does not exist: {recipe_url}")
                recipe_page = bs4.BeautifulSoup(f.read().decode())
    
    
            name_candidates = recipe_page.find_all(class_=site.name_class)
            if len(name_candidates) == 0:
                raise Exception(f"Could not extract recipe name: {recipe_url}")
            name_div = name_candidates[0]
        except Exception as e:
            logging.warning(f"Could not download or parse recipe: {recipe_url}")
            logging.warning(e)
            continue
            
        recipe.name = name_div.text
        logging.info(f"Adding Recipe {recipe}")   

        sess.add(recipe)
        sess.flush()

        ingredients = []
        ingred_candidates = recipe_page.find_all(class_=site.ingredient_class)
        for ingredient in ingred_candidates:
            ingredients.append(db.RecipeIngredient(text=ingredient.text,
                                                recipe_id=recipe.id))
            
        logging.info(f"{len(ingredients)} ingredients found. Inserting into DB")
        sess.add_all(ingredients)