from vcr.request import Request
from . import compat
try:
    import simplejson as json
except ImportError:
    import json


def _json_default(obj):
    if isinstance(obj, frozenset):
        return dict(obj)
    return obj


def deserialize(cassette_string):
    data = json.loads(cassette_string)
    requests = [Request._from_dict(r['request']) for r in data]
    responses = [compat.convert_to_bytes(r['response']) for r in data]
    return requests, responses


def serialize(cassette_dict):
    data = ([{
        'request': request._to_dict(),
        'response': compat.convert_to_unicode(response),
    } for request, response in zip(
        cassette_dict['requests'],
        cassette_dict['responses']
    )])
    try:
        return json.dumps(data, indent=4, default=_json_default)
    except UnicodeDecodeError as e:
        raise UnicodeDecodeError(
            "Error serializing cassette to JSON. ",
            "Does this HTTP interaction contain binary data? ",
            "If so, use a different serializer (like the yaml serializer) for",
            "this request"
        )