import yaml

class PathError(Exception):
    def __init__(self, path):
        self.path = path
        super().__init__(self.path)

class PathNotFoundError(PathError):
    pass

class MissingRequirementError(PathError):
    pass

class NotDictError(PathError):
    pass

class Config:
    def __init__(self, data, delimiter = "/", defaults = {}, requirements = [], **misc_options):
        self.data = yaml.safe_load(open(data)) if type(data) != dict else data
        self.delimiter = delimiter
        self.strict_subscript = misc_options.get("strict_subscript", False)
        self.clobber_subscript = misc_options.get("clobber_subscript", False)
        
        for r in requirements:
            if not self.get(r): raise MissingRequirementError(r)
        for d in defaults:
            if not self.get(d): self.set(d, defaults[d])
    
    def split_path(self, path):
        return path.split(self.delimiter)
    
    def get(self, path, fallback = None, strict = False):
        elementsAll = self.split_path(path)
        
        def g(elems = elementsAll, obj = self.data):
            if not elems or not elems[0] or type(obj) != dict: return obj
            head, tail = elems[0], elems[1:]
            if strict and head not in obj:
                raise PathNotFoundError(path)
            return g(tail, obj.get(head, fallback))
        
        return g()
    
    def set(self, path, value, clobber = False):
        elementsAll = self.split_path(path)
        
        def s(elems = elementsAll, obj = self.data):
            head, tail = elems[0], elems[1:]

            # YANDEV MODE ACTIVATE!!!
            if not tail:
                obj[head] = value
            else:
                if head not in obj or type(obj[head]) != dict:
                    if clobber:
                        obj[head] = {}
                    else:
                        raise NotDictError(self.delimiter.join(elementsAll[:-len(tail)]))
                
                s(tail, obj[head])
                    
        s()
        
    def __getitem__(self, path):
        return self.get(path, self.strict_subscript)

    def __setitem__(self, path, value):
        self.set(path, value, self.clobber_subscript)