from __future__ import absolute_import

import functools
import inspect
import sys

import wsme
import wsme.rest.args
import wsme.rest.json
import wsme.rest.xml

import pecan

from wsmeext.utils import is_valid_code


class JSonRenderer(object):
    def __init__(self, path, extra_vars):
        pass

    def render(self, template_path, namespace):
        if 'faultcode' in namespace:
            return wsme.rest.json.encode_error(None, namespace)
        return wsme.rest.json.encode_result(
            namespace['result'],
            namespace['datatype']
        )


class XMLRenderer(object):
    def __init__(self, path, extra_vars):
        pass

    def render(self, template_path, namespace):
        if 'faultcode' in namespace:
            return wsme.rest.xml.encode_error(None, namespace)
        return wsme.rest.xml.encode_result(
            namespace['result'],
            namespace['datatype']
        )

pecan.templating._builtin_renderers['wsmejson'] = JSonRenderer
pecan.templating._builtin_renderers['wsmexml'] = XMLRenderer


def wsexpose(*args, **kwargs):
    pecan_json_decorate = pecan.expose(
        template='wsmejson:',
        content_type='application/json',
        generic=False)
    pecan_xml_decorate = pecan.expose(
        template='wsmexml:',
        content_type='application/xml',
        generic=False
    )
    sig = wsme.signature(*args, **kwargs)

    def decorate(f):
        sig(f)
        funcdef = wsme.api.FunctionDefinition.get(f)
        funcdef.resolve_types(wsme.types.registry)

        @functools.wraps(f)
        def callfunction(self, *args, **kwargs):
            try:
                args, kwargs = wsme.rest.args.get_args(
                    funcdef, args, kwargs, pecan.request.params, None,
                    pecan.request.body, pecan.request.content_type
                )
                if funcdef.pass_request:
                    kwargs[funcdef.pass_request] = pecan.request
                result = f(self, *args, **kwargs)

                # NOTE: Support setting of status_code with default 201
                pecan.response.status = funcdef.status_code
                if isinstance(result, wsme.api.Response):
                    pecan.response.status = result.status_code
                    result = result.obj

            except:
                try:
                    exception_info = sys.exc_info()
                    orig_exception = exception_info[1]
                    orig_code = getattr(orig_exception, 'code', None)
                    data = wsme.api.format_exception(
                        exception_info,
                        pecan.conf.get('wsme', {}).get('debug', False)
                    )
                finally:
                    del exception_info

                if data['faultcode'] == 'Client':
                    pecan.response.status = 400
                elif orig_code and is_valid_code(orig_code):
                    pecan.response.status = orig_code
                else:
                    pecan.response.status = 500

                return data

            if funcdef.return_type is None:
                pecan.request.pecan['content_type'] = None
                pecan.response.content_type = None
                return ''

            return dict(
                datatype=funcdef.return_type,
                result=result
            )

        pecan_xml_decorate(callfunction)
        pecan_json_decorate(callfunction)
        pecan.util._cfg(callfunction)['argspec'] = inspect.getargspec(f)
        callfunction._wsme_definition = funcdef
        return callfunction

    return decorate