import sys, cooklang
from os.path import exists

def parse_recipe(cooklang_source):
    """
    Takes: string cooklang_source
    Returns: [ string ] tex
    
    Takes the recipes source as an argument and returns the cuisine recipe block.
    One element per line.
    """
    
    recipe = cooklang.parseRecipe(cooklang_source)

    title = get_metadata_value("title", recipe)
    servings = get_metadata_value("servings", recipe)
    time = get_metadata_value("time", recipe)

    tex = []
    
    tex.append("\\begin{recipe}{" +
          title + "}{" +
          servings + "}{" +
          time + "}")

    for step in recipe["steps"]:
        ingredients = get_step_ingredients(step)
        
        if ingredients:
            tex += texify_ingredients(ingredients)
        else:
            tex.append("\\newstep")

        step_text = ""
        for part in step:
            if "value" in part.keys():
                step_text += part["value"]
            elif "name" in part.keys():
                # Remove whitespaces from ingredient names
                step_text += part["name"].strip()
        tex.append(step_text)

    tex.append("\\end{recipe}")

    return tex


def parse_recipe_from_file(path):
    """
    Takes: string path
    Returns: [ string ] tex
    
    Takes a recipe path as an argument and returns the cuisine recipe block.
    One element per line.
    """
    if not exists(path):
        raise ArgumentError
    
    with open(path) as file:
        return parse_recipe(file.read())


def get_metadata_value(key, recipe):
    if key in recipe["metadata"].keys():
        return recipe["metadata"][key]
    else:
        return "N/A"

    
def get_step_ingredients(step):
    ingredients = []
    
    for part in step:
        if part["type"] == "ingredient":
            ingredients.append(part)

    return ingredients
    

def texify_ingredients(ingredients):
    tex = []

    for ing in ingredients:
        if ing["units"]:
            
            try:
                quantity = float(ing["quantity"])
                if quantity % 1 == 0:
                    quantity = int(quantity)
            except ValueError:
                quantity = ing["units"]
                
            tex.append("\\ingredient[" +
                       str(quantity) + "]{" +
                       ing["units"] + "}{" +
                       ing["name"] + "}")
        else:
            tex.append("\\ingredient{" +
                       ing["units"] + "}{" +
                       ing["name"] + "}")
            
    return tex


class ArgumentError(Exception):
    def __init__(self):
        self.message = "Please supply the path to a cooklang file as an argument."
        super().__init__(self.message)
        

if __name__ == "__main__":

    if sys.argv[1] == "--":
        tex = parse_recipe(sys.stdin.read())
    else:
        tex = parse_recipe_from_file(sys.argv[1])

    for line in tex:
        print(line)