# Copyright 2022-2024 ETSI SDG TeraFlowSDN (TFS) (https://tfs.etsi.org/)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import json, logging, requests
from os import name
from requests.auth import HTTPBasicAuth
from typing import Dict, List, Optional


GET_DEVICES_URL = '{:s}://{:s}:{:d}/v1.0/topology/switches'
GET_LINKS_URL   = '{:s}://{:s}:{:d}/v1.0/topology/links'
TIMEOUT = 30

HTTP_OK_CODES = {
    200,    # OK
    201,    # Created
    202,    # Accepted
    204,    # No Content
}

MAPPING_STATUS = {
    'DEVICEOPERATIONALSTATUS_UNDEFINED': 0,
    'DEVICEOPERATIONALSTATUS_DISABLED' : 1,
    'DEVICEOPERATIONALSTATUS_ENABLED'  : 2,
}

MAPPING_DRIVER = {
    'DEVICEDRIVER_UNDEFINED'            : 0,
    'DEVICEDRIVER_OPENCONFIG'           : 1,
    'DEVICEDRIVER_TRANSPORT_API'        : 2,
    'DEVICEDRIVER_P4'                   : 3,
    'DEVICEDRIVER_IETF_NETWORK_TOPOLOGY': 4,
    'DEVICEDRIVER_ONF_TR_532'           : 5,
    'DEVICEDRIVER_XR'                   : 6,
    'DEVICEDRIVER_IETF_L2VPN'           : 7,
    'DEVICEDRIVER_GNMI_OPENCONFIG'      : 8,
    'DEVICEDRIVER_OPTICAL_TFS'          : 9,
    'DEVICEDRIVER_IETF_ACTN'            : 10,
    'DEVICEDRIVER_OC'                   : 11,
    'DEVICEDRIVER_QKD'                  : 12,
    'DEVICEDRIVER_RYU'                  : 13,
}

MSG_ERROR = 'Could not retrieve devices in remote TeraFlowSDN instance({:s}). status_code={:s} reply={:s}'

LOGGER = logging.getLogger(__name__)

class TfsApiClient:
    def __init__(
        self, address : str, port : int, scheme : str = 'http',
        username : Optional[str] = None, password : Optional[str] = None
    ) -> None:
        self._devices_url = GET_DEVICES_URL.format(scheme, address, port)
        LOGGER.info(f'self_devices_url{self._devices_url}')
        self._links_url = GET_LINKS_URL.format(scheme, address, port)
        self._auth = HTTPBasicAuth(username, password) if username is not None and password is not None else None

    def get_devices_endpoints(self) -> List[Dict]:
        LOGGER.debug('[get_devices_endpoints] begin')

        reply_switches = requests.get(self._devices_url, timeout=TIMEOUT, verify=False, auth=self._auth)
        if reply_switches.status_code not in HTTP_OK_CODES:
            msg = MSG_ERROR.format(str(self._devices_url), str(reply_switches.status_code), str(reply_switches))
            LOGGER.error(msg)
            raise Exception(msg)

        json_reply_switches = reply_switches.json()
        LOGGER.info('[get_devices_endpoints] json_reply_switches={:s}'.format(json.dumps(json_reply_switches)))

        result = list()
        for json_switch in json_reply_switches:
            device_uuid: str = json_switch['dpid']
            device_ports = json_switch.get('ports', []) 

            for port in device_ports: 
                port_name = port.get('name', '') 
                device_name = port_name.split('-')[0]
                port_no = port.get('port_no', '')
                hw_address = port.get('hw_addr', '')

                device_url = '/devices/device[{:s}]'.format(device_uuid)
                device_data = {
                    'uuid': device_uuid,
                    'name': device_uuid,
                    'type': 'packet-switch', 
                    'status': 2,  
                    'drivers': 'DEVICEDRIVER_RYU',
                    }
                result.append((device_url, device_data))
        for json_switch in json_reply_switches:
            device_uuid: str = json_switch['dpid']
            device_ports = json_switch.get('ports', []) 
            for port in device_ports: 
                port_name = port.get('name', '')
                port_no   = port.get('port_no','')  

                endpoint_uuid = port_name
                endpoint_url = '/endpoints/endpoint[{:s}]'.format(endpoint_uuid)
                endpoint_data = {
                    'device_uuid': device_uuid,
                    'uuid': port_name,
                    'name': port_name,
                    'type': 'copper',
                }
                result.append((endpoint_url, endpoint_data))
#
        reply = requests.get(self._links_url, timeout=TIMEOUT, verify=False, auth=self._auth)
        if reply.status_code not in HTTP_OK_CODES:
            msg = MSG_ERROR.format(str(self._links_url), str(reply.status_code), str(reply))
            LOGGER.error(msg)
            raise Exception(msg)
        
        for json_link in reply.json():
            dpid_src = json_link.get('src', {}).get('dpid', '')
            dpid_dst = json_link.get('dst', {}).get('dpid', '')
            port_src_name = json_link.get('src', {}).get('name', '')
            port_name_secondpart = port_src_name.split('-')[1]
            port_dst_name = json_link.get('dst', {}).get('name', '')
            port_name_second = port_dst_name.split('-')[1]
            switch_name_src = port_src_name.split('-')[0]
            switch_name_dest = port_dst_name.split('-')[0]
            link_name = f"{dpid_src}-{port_src_name}==={dpid_dst}-{port_dst_name}"
            link_uuid = f"{port_src_name}=={port_dst_name}" 
            link_endpoint_ids = [
                (dpid_src,port_src_name),
                (dpid_dst,port_dst_name) ]
            
            LOGGER.info(f'link_endpoint_ids are {link_endpoint_ids}')
            link_url = '/links/link[{:s}]'.format(link_uuid)
            link_data = {
                'uuid': link_uuid,
                'name': link_name,
                'endpoints': link_endpoint_ids,
            }
            result.append((link_url, link_data))
        LOGGER.debug('[get_devices_endpoints] topology; returning')
        return result