"""
"""
from . import utility

class Scope(list):
    def __init__(self, init=False):
        super().__init__()
        self._mixins = {}
        if init: self.push()
        self.in_mixin = False
        
    def push(self):
        """
        """
        self.append({
            '__variables__' : {},
            '__blocks__': [], 
            '__names__': [],
            '__current__': None
        })
        
    @property
    def current(self):
        return self[-1]['__current__']
    
    @current.setter
    def current(self, value):
        self[-1]['__current__'] = value
        
    @property
    def scopename(self):
        """
        """
        return [r['__current__'] 
                for r in self 
                if r['__current__']]

        
    def add_block(self, block):
        """
        """
        self[-1]['__blocks__'].append(block)
        self[-1]['__names__'].append(block.raw())
        
    def add_mixin(self, mixin):
        """
        """
        self._mixins[mixin.name] = mixin
        
    def add_variable(self, variable):
        """
        """
        self[-1]['__variables__'][variable.name] = variable
        
    def variables(self, name):
        """
        """
        i = len(self)
        while i >= 0:
            i -= 1
            if name in self[i]['__variables__']:
                return self[i]['__variables__'][name]
        return False
    
    def mixins(self, name):
        """
        """
        return (self._mixins[name] 
                if name in self._mixins
                else False)
        
    def blocks(self, name):
        """
        """
        i = len(self)
        while i >= 0:
            i -= 1
            if name in self[i]['__names__']:
                for b in self[i]['__blocks__']:
                    if b.raw() == name:
                        return b
            else:
                for b in self[i]['__blocks__']:
                    if name.startswith(b.raw()):
                        b = utility.blocksearch(b, name)
                        if b: return b
        return False
        
    def update(self, scope, at=0):
        """
        """
        if hasattr(scope, '_mixins') and not at:
            self._mixins.update(scope._mixins)
        self[at]['__variables__'].update(scope[at]['__variables__'])
        self[at]['__blocks__'].extend(scope[at]['__blocks__'])
        self[at]['__names__'].extend(scope[at]['__names__'])
        
    def swap(self, name):
        """
        """
        if name.startswith('@@'):
            var = self.variables(name[1:])
            if var is False: raise SyntaxError('Unknown variable %s' % name)
            name = '@' + utility.destring(var.value[0])
        var = self.variables(name)
        if var is False: raise SyntaxError('Unknown variable %s' % name)
        return var.value