# Copyright (C) 2017-2018  Lars Wirzenius
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


import ick2


class APIbase:

    def __init__(self, state):
        assert state is None or isinstance(state, ick2.FilePersistentState)
        self._trans = ick2.TransactionalState(state)

    def get_routes(self, path):
        resource_path = '{}/<name:re:[^/+][^/]*?(/[^/+][^/]*?)*>'.format(path)
        return [
            {
                'method': 'POST',
                'path': path,
                'callback': self.POST(self.create),
            },
            {
                'method': 'GET',
                'path': path,
                'callback': self.GET(self.list),
            },
            {
                'method': 'GET',
                'path': resource_path,
                'callback': self.GET(self.show),
            },
            {
                'method': 'PUT',
                'path': resource_path,
                'callback': self.PUT(self.update),
            },
            {
                'method': 'DELETE',
                'path': resource_path,
                'callback': self.DELETE(self.delete),
            },
        ]

    def GET(self, callback):
        def wrapper(content_type, body, **kwargs):
            ick2.log.log(
                'trace', msg_text='GET called', kwargs=kwargs,
                content_type=content_type, body=body)
            try:
                if 'raw_uri_path' in kwargs:
                    del kwargs['raw_uri_path']
                body = callback(**kwargs)
            except ick2.ParametersMissing as e:
                ick2.log.log('error', msg_text=str(e), kwargs=kwargs)
                return ick2.conflict(str(e))
            except ick2.NotFound as e:
                ick2.log.log(
                    'error', msg_text='GET Not found', kwargs=kwargs,
                    exc_info=True)
                return ick2.not_found(e)
            if isinstance(body, dict):
                return ick2.OK(body)
            if isinstance(body, str):
                return ick2.text_plain(body)
            raise Exception('this must not happen')
        return wrapper

    def POST(self, callback):
        def wrapper(content_type, body, **kwargs):
            ick2.log.log(
                'trace', msg_text='POST called', kwargs=kwargs,
                content_type=content_type, body=body)
            try:
                body = callback(body, **kwargs)
            except ick2.ExistsAlready as e:
                ick2.log.log('error', msg_text=str(e), kwargs=kwargs)
                return ick2.conflict(str(e))
            return ick2.created(body)
        return wrapper

    def PUT(self, callback):
        def wrapper(content_type, body, **kwargs):
            ick2.log.log(
                'trace', msg_text='PUT called', kwargs=kwargs,
                content_type=content_type, body=body)
            if 'raw_uri_path' in kwargs:
                del kwargs['raw_uri_path']
            try:
                body = callback(body, **kwargs)
            except ick2.NotFound as e:
                ick2.log.log(
                    'warning', msg_text='PUT Not found', kwargs=kwargs)
                return ick2.not_found(e)
            ick2.log.log('trace', msg_text='returned body', body=repr(body))
            return ick2.OK(body)
        return wrapper

    def DELETE(self, callback):
        def wrapper(content_type, body, **kwargs):
            ick2.log.log(
                'trace', msg_text='DELETE called', kwargs=kwargs,
                content_type=content_type, body=body)
            try:
                if 'raw_uri_path' in kwargs:
                    del kwargs['raw_uri_path']
                body = callback(**kwargs)
            except ick2.NotFound as e:
                ick2.log.log(
                    'warning', msg_text='DELETE Not found', kwargs=kwargs)
                return ick2.not_found(e)
            return ick2.OK(body)
        return wrapper

    def create(self, body, **kwargs):
        raise NotImplementedError()

    def update(self, body, name, **kwargs):
        raise NotImplementedError()

    def delete(self, name, **kwargs):
        raise NotImplementedError()

    def list(self, **kwargs):
        raise NotImplementedError()

    def show(self, name, **kwargs):
        raise NotImplementedError()


class ResourceApiBase(APIbase):

    def __init__(self, type_name, state):
        super().__init__(state)
        self._type_name = type_name

    def list(self, **kwargs):
        resources = self._trans.get_resources(self._type_name)
        return {
            self._type_name: [r.as_dict() for r in resources]
        }

    def show(self, name, **kwargs):
        return self._trans.get_resource(self._type_name, name).as_dict()

    def create(self, body, **kwargs):
        ick2.log.log(
            'trace', msg_text='create resource',
            resource_type=self._type_name, body=body, kwargs=kwargs)

        as_dict = self.mangle_new_resource(body)
        rid = self.get_resource_name(as_dict)
        if self._trans.has_resource(self._type_name, rid):
            raise ick2.ExistsAlready(rid)

        with self._trans.new(self._type_name, rid) as resource:
            resource.from_dict(as_dict)

        return as_dict

    def mangle_new_resource(self, resource):  # pragma: no cover
        return resource

    def get_resource_name(self, resource):  # pragma: no cover
        raise NotImplementedError()

    def update(self, body, name, **kwargs):
        rid = self.get_resource_name(body)
        if not self._trans.has_resource(self._type_name, rid):
            raise ick2.NotFound(kind=self._type_name, rid=rid)

        with self._trans.modify(self._type_name, rid) as resource:
            as_dict = self.mangle_updated_resource(resource.as_dict(), body)
            resource.from_dict(as_dict)

        return as_dict

    def mangle_updated_resource(self, old, new):  # pragma: no cover
        return new

    def delete(self, name, **kwargs):
        if not self._trans.has_resource(self._type_name, name):
            raise ick2.NotFound(kind=self._type_name, rid=name)
        self._trans.remove_resource(self._type_name, name)