#!/usr/bin/env python3

import json
import os

from typing import Iterable

class Cookbook(object):
    recipes: dict

    def __init__(self, root: str):
        self.recipes = dict()

        for dirname, dirs, files in os.walk(root):
            for f in files:
                path = os.path.join(dirname, f)
                name, _ = os.path.splitext(f)
                with open(path, 'r') as src:
                    variations = json.load(src)

                self.recipes[name] = variations

    def __getitem__(self, item: str):
        return self.recipes[item]

    def all(self):
        return self.recipes.keys()

    def is_component(self, name):
        return 'component' in self.recipes[name]['type']

    def components(self):
        found = set()

        for target, methods in self.recipes.items():
            for variation in methods:
                for need, _ in variation['input'].items():
                    if need in found:
                        continue
                    found.add(need)
                    if not self.is_component(need):
                        continue
                    yield need

def graph(recipes: dict, targets: Iterable[str]):
    print("digraph G {")

    seen = set()
    remain = set(targets)

    while remain:
        output = remain.pop()

        for need in recipes[output][0]['input']:
            print(f"{need} -> {output}")
            if need not in seen:
                remain.add(need)

        seen.add(output)
    print("}")


def graph_all(recipes: dict) -> None:
    graph(recipes, recipes.all())


def graph_one(recipes: dict, target: str) -> None:
    graph(recipes, [target])


if __name__ == '__main__':
    def main():
        import argparse

        root = os.path.dirname(__file__)
        recipe_root = os.path.join(root, 'data', 'recipes')

        parser = argparse.ArgumentParser()
        parser.add_argument('--data', type=str, default=recipe_root)
        parser.add_argument('--target', type=str, required=False)

        args = parser.parse_args()

        recipes = Cookbook(args.data)

        if args.target:
            graph_one(recipes, args.target)
        else:
            graph(recipes, recipes.components())

    main()