import falcon
import json


class RequireJSON:
    def process_request(self, req, resp):
        if not req.client_accepts_json:
            raise falcon.HTTPNotAcceptable(
                description='This API only supports responses encoded as JSON.',
                href='http://docs.examples.com/api/json',
            )

        if req.method in ('POST', 'PUT'):
            if req.content_type == None or 'application/json' not in req.content_type:
                raise falcon.HTTPUnsupportedMediaType(
                    title='This API only supports requests encoded as JSON.',
                    href='http://docs.examples.com/api/json',
                )

class JSONTranslator:
    # NOTE: Normally you would simply use req.media and resp.media for
    # this particular use case; this example serves only to illustrate
    # what is possible.

    def process_request(self, req, resp):
        # req.stream corresponds to the WSGI wsgi.input environ variable,
        # and allows you to read bytes from the request body.
        #
        # See also: PEP 3333
        if req.content_length in (None, 0):
            # Nothing to do
            return

        body = req.stream.read()
        if not body:
            raise falcon.HTTPBadRequest(
                title='Empty request body',
                description='A valid JSON document is required.',
            )

        try:
            req.context.doc = json.loads(body.decode('utf-8'))

        except (ValueError, UnicodeDecodeError):
            description = (
                'Could not decode the request body. The '
                'JSON was incorrect or not encoded as '
                'UTF-8.'
            )

            raise falcon.HTTPBadRequest(title='Malformed JSON', description=description)

    def process_response(self, req, resp, resource, req_succeeded):
        if not hasattr(resp.context, 'result'):
            return

        resp.text = json.dumps(resp.context.result)


def max_body(limit):
    def hook(req, resp, resource, params):
        length = req.content_length
        if length is not None and length > limit:
            msg = (
                'The size of the request is too large. The body must not '
                'exceed ' + str(limit) + ' bytes in length.'
            )

            raise falcon.HTTPPayloadTooLarge(
                title='Request body is too large', description=msg
            )

    return hook

class CreateTaskResource:
    def on_post(self, req, resp):
        quote = {
            'title': 'Получена задача',
            'description': req.context.doc['task']
        }

        resp.media = quote


app = falcon.App(
    middleware=[
        RequireJSON(),
        JSONTranslator()
    ]
)
app.add_route('/create-task', CreateTaskResource())