from abc import ABCMeta, abstractmethod

import six

import execjs._exceptions as exceptions

@six.add_metaclass(ABCMeta)

class AbstractRuntime(object):

'''

Abstract base class for runtime class.

'''

def exec_(self, source, cwd=None):

'''Execute source by JavaScript runtime and return all output to stdout as a string.

source -- JavaScript code to execute.

cwd -- Directory where call JavaScript runtime. It may be ignored in some derived class.

'''

return self.compile('', cwd=cwd).exec_(source)

def eval(self, source, cwd=None):

'''Evaluate source in JavaScript runtime.

source -- JavaScript code to evaluate.

cwd -- Directory where call JavaScript runtime. It may be ignored in some derived class.

'''

return self.compile('', cwd=cwd).eval(source)

def compile(self, source, cwd=None):

'''Bulk source as a context object. The source can be used to execute another code.

source -- JavaScript code to bulk.

cwd -- Directory where call JavaScript runtime. It may be ignored in some derived class.

'''

if not self.is_available():

raise exceptions.RuntimeUnavailableError

return self._compile(source, cwd=cwd)

@abstractmethod

def is_available(self):

raise NotImplementedError

@abstractmethod

def _compile(self, source, cwd=None):

raise NotImplementedError