from engine.ast import ast_node


class expr(ast_node):
    name='expr'
    builtin_func_maps = {
            'max': 'max',
            'min': 'min', 

        }
    binary_ops = {'sub':'-', 'plus':'+'}
    unary_ops = []
    def __init__(self, parent, node):
        from engine.projection import projection
        if type(parent) in [projection, expr]:
            self.datasource = parent.datasource
        else:
            self.datasource = None
        self.udf_map = parent.context.udf_map
        self.k9expr = ''
        self.func_maps = {**self.udf_map, **self.builtin_func_maps}
        ast_node.__init__(self, parent, node, None)

    def produce(self, node):
        if type(node) is dict:
            for key, val in node.items():
                if key in self.func_maps:
                    self.k9expr += f"{self.func_maps[key]}(" 
                    # if type(val) in [dict, str]:
                    self.k9expr += expr(self, val).k9expr

                    self.k9expr+=')'
                elif key in self.binary_ops:
                    l = expr(self, val[0]).k9expr
                    r = expr(self, val[1]).k9expr
                    self.k9expr += f'({l}{self.binary_ops[key]}{r})'
                    
                    print(f'binary{key}')
                elif key in self.unary_ops:
                    print(f'unary{key}')
                else:
                    print(key)
        elif type(node) is str:
            self.k9expr = self.datasource.parse_tablenames(node)
    def __str__(self):
        return self.k9expr