#!/usr/bin/python3 -tt

# Copyright 2012 Jussi Pakkanen

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import parser
import nodes

class InterpreterException(Exception):
    pass

class InvalidCode(InterpreterException):
    pass

class Interpreter():
    
    def __init__(self, code):
        self.ast = parser.build_ast(code)
        self.sanity_check_ast()
        
    def sanity_check_ast(self):
        if not isinstance(self.ast, nodes.CodeBlock):
            raise InvalidCode('AST is of invalid type. Possibly a bug in the parser.')
        if len(self.ast.get_statements()) == 0:
            raise InvalidCode('No statements in code.')
        first = self.ast.get_statements()[0]
        if not isinstance(first, nodes.FunctionCall) or first.get_function_name() != 'project':
            raise InvalidCode('First statement must be a call to project')
            

if __name__ == '__main__':
    code = "project('myawesomeproject')"
    i = Interpreter(code)