from pathlib import Path
from datetime import datetime

def parse_timestamp(timestamp):
    return datetime.strptime(timestamp, '%Y-%m-%d %H:%M:%S')

def parse_foods_file():
    path = Path.home() / 'projects' / 'open-journal' / 'foods'
    text = path.read_text()
    foods, recipes = text.split('---')

    def parse_macro(macro):
        if macro == '...':
            return ('INVALID', 0.0)

        name, value = macro.split()
        value = float(value.removesuffix('g').removesuffix('kcal'))
        return (name, value)

    foods = {
        macros[0]: dict(parse_macro(macro) for macro in macros[1:])
        for macros in [food.split('\n') for food in foods.strip().split('\n\n')]
    }

    def combine_values(fst, snd):
        result = fst.copy()
        for k,v in snd.items():
            if k in fst:
                result[k] += v
            else:
                result[k] = v
        return result

    def evaluate_ingredients(ingredients):
        result = {}

        total_weight = 0.0
        for ingredient in ingredients:
            k,v = parse_macro(ingredient)
            if k == 'TOTAL':
                result[k] = v
                break
            else:
                total_weight += v


            food = foods[k]

            for kk,vv in food.items():
                if kk not in result:
                    result[kk] = 0.0

                result[kk] += vv * (v/100.0)

        if 'TOTAL' not in result:
            result['TOTAL'] = total_weight

        return result

    recipes = {
        ingredients[0]: evaluate_ingredients(ingredients[1:])
        for ingredients in [
            recipe.split('\n') for recipe in recipes.strip().split('\n\n')
        ]
    }

    def get_calories_from_macros(mm):
        calories = 0.0
        for k,v in mm.items():
            calories += v * {
                'Carbs': 4,
                'Fat': 9,
                'Protein': 4
            }.get(k, 0.0)
        return calories

    #for k,v in foods.items():
    #    print(round(v.get('Energy') - get_calories_from_macros(v)), k)

    return foods, recipes