import json
import os


cache_path = 'build/meadow-cache.json'
cache_data = None


class Cache:
    def load():
        global cache_data

        if not os.path.exists(cache_path):
            cache_data = {}
            return

        with open(cache_path, mode='r') as f:
            cache_data = json.load(f)


    def reset():
        global cache_data
        cache_data = {}


    def save():
        global cache_data

        with open(cache_path, mode='w') as f:
            json.dump(cache_data, f, indent=4)


    def get(path):
        parts = path.split('.')
        container = cache_data

        for p in parts[:-1]:
            if p not in container:
                return None

            if not isinstance(container[p], dict):
                print('Err: element "{}" in cache key "{}" is not a dictionary'.format(p, path))
                return

            container = container[p]


        if parts[-1] in container:
            return container[parts[-1]]

        return None


    def set(path, value):
        parts = path.split('.')
        container = cache_data

        for p in parts[:-1]:
            if p not in container:
                container[p] = {}

            if not isinstance(container[p], dict):
                print('Err: element "{}" in cache key "{}" is not a dictionary'.format(p, path))
                return

            container = container[p]


        container[parts[-1]] = value