__all__ = []

from filters import CloseableIterator, CloseableList

__all__.append("WSGI2to1Adapter")
class WSGI2to1Adapter:
    """Adapts an application with an interface that might somewhen be known as
    WSGI 2.0 to the WSGI 1.0 interface."""
    def __init__(self, app):
        """app is an application with an interface that might somewhen be known
        as WSGI 2.0."""
        self.app = app
    def __call__(self, environ, start_response):
        """WSGI 1.0 interface"""
        assert isinstance(environ, dict)
        status, headers, iterable = self.app(environ)
        assert isinstance(status, str)
        assert isinstance(headers, list)
        assert hasattr(iterable, "__iter__")
        start_response(status, headers)
        return iterable

__all__.append("WSGI1to2Adapter")
class WSGI1to2Adapter:
    """Adapts a WSGI 1.0 application to something that might somewhen be the
    WSGI 2.0 interface."""
    def __init__(self, app):
        """app is a WSGI 1.0 application"""
        self.app = app
    def __call__(self, environ):
        """some interface that might somewhen be known as WSGI 2.0"""
        assert isinstance(environ, dict)
        results = [None, None, []]
        def start_response(status, headers, exc_info=None):
            assert isinstance(status, str)
            assert isinstance(headers, list)
            results[0] = status
            results[1] = headers
            def write_callable(data):
                results[2].append(data)
            return write_callable
        iterable = self.app(environ, start_response)
        assert hasattr(iterable, "__iter__")
        if isinstance(iterable, list):
            # retaining .close attribute this way
            iterable[:0] = results[2]
            return results[0], results[1], results[2]
        close_function = getattr(iterable, "close", None)
        iterable = iter(iterable)
        try:
            first = iterable.next()
        except StopIteration:
            return (results[0], results[1],
                    CloseableList(close_function, results[2]))
        results[2].append(first)
        return (results[0], results[1],
                CloseableIterator(close_function, results[2], iterable))