#! /usr/bin/env python3
# encoding: utf-8

import jsmin
import json

class Config:
	"""
	A hierarchical key-value container that can be loaded from JSON or a Python dict.
	
	Any contained dicts are automatically converted to Config instances as well.
	
	Supports sequential overwriting - so one can load a default config and then
	progressively overwrite it with overlays:
	
	
	
	
	
	
	
	>>> raw
{'a': 1, 'b': {'ba': 2, 'bb': 3, 'bc': {'bca': None}}, 'c': 4}
>>> overlay
{'b': {'bc': {'bca': 42}}}

	
	
	while stack:
	current = stack[-1]
	
	...
	
	stack.pop()

for key in overlay.keys():
	
	
	
	"""
	
	def __init__(self, d, readonly=False):
		assert type(d) == dict
		object.__setattr__(self, "raw", d)
		object.__setattr__(self, "readonly", readonly)
	
	@classmethod
	def from_file(cls, path, readonly=False):
		with open(path) as f:
			initial = json.loads(jsmin.jsmin(f.read()))
		
		return cls(initial, readonly)
	
	def update(self, d):
		
	
	def keys(self):
		return self.raw.keys()
	
	def values(self):
		return self.raw.values()
	
	def items(self):
		return self.raw.items()
	
	def __getitem__(self, name):
		return self.raw[name]
	
	def __setitem__(self, name, value):
		if self.readonly:
			raise AttributeError("config is read-only")
		
		self.raw[name] = value
	
	def __setattr__(self, name, value):
		if self.readonly:
			raise AttributeError("config is read-only")
		
		self.raw[name] = value
	
	def __getattr__(self, name):
		matches = [key for key in self.raw if key.replace("-", "_") == name]
		
		if matches:
			assert len(matches) == 1
			
			value = self.raw[matches[0]]
			
			if type(value) == dict:
				return Config(value)
			else:
				return value
		else:
			raise KeyError(name)
	
	def __contains__(self, name):
		return name in self.raw
	
	def __repr__(self):
		return "Config(%s)" %(" ".join("%s=%s" %(k, "…" if type(v) == dict else v) for k, v in self.raw.items()))