import ipaddress
import json
import logging
import re

from flask import Blueprint, Response, current_app

from inventory_provider.routes import common
from inventory_provider.db import opsdb, db

routes = Blueprint("inventory-data-classifier-support-routes", __name__)

logger = logging.getLogger(__name__)


class ClassifierRequestError(Exception):
    status_code = 500

    def __init__(self):
        super().__init__()
        self.message = "Unclassified Internal Error"


class ClassifierProcessingError(ClassifierRequestError):
    status_code = 422

    def __init__(self, message, status_code=None):
        super().__init__()
        self.message = str(message)
        if status_code is not None:
            self.status_code = status_code


@routes.errorhandler(ClassifierRequestError)
def handle_request_error(error):
    return Response(
        response=error.message,
        status=error.status_code)


@routes.after_request
def after_request(resp):
    return common.after_request(resp)


def related_interfaces(hostname, interface):
    r = common.get_current_redis()
    prefix = 'netconf-interfaces:%s:' % hostname
    for k in r.keys(prefix + interface + '.*'):
        k = k.decode('utf-8')
        assert k.startswith(prefix)  # sanity
        assert len(k) > len(prefix)  # sanity (contains at least an interface)
        yield k[len(prefix):]


def get_top_level_services(circuit_id, r):
    tls = []
    results = r.get("opsdb:services:children:{}".format(circuit_id))
    if results:
        results = json.loads(results.decode('utf-8'))

        for c in results:
            temp_parents = \
                get_top_level_services(c['parent_circuit_id'], r)
            if not temp_parents:
                tls.append(
                    {'name': c['parent_circuit'],
                     'status': c['parent_circuit_status'],
                     'circuit_type': c['parent_circuit_type'].lower()})
            tls.extend(temp_parents)
    return tls


@routes.route("/juniper-link-info/<source_equipment>/<path:interface>",
              methods=['GET', 'POST'])
@common.require_accepts_json
def get_juniper_link_info(source_equipment, interface):
    r = common.get_current_redis()

    cache_key = 'classifier-cache:juniper:%s:%s' % (
        source_equipment, interface)
    result = r.get(cache_key)

    if result:
        result = result.decode('utf-8')
    else:
        result = {}
        top_level_services = []

        services = r.get(
            'opsdb:interface_services:%s:%s' % (source_equipment, interface))
        if services:
            result['services'] = json.loads(services.decode('utf=8'))
            for s in result['services']:
                top_level_services.extend(get_top_level_services(s['id'], r))

        ifc_info = r.get(
            'netconf-interfaces:%s:%s' % (source_equipment, interface))
        if ifc_info:
            result['interface'] = json.loads(ifc_info.decode('utf-8'))
        else:
            # warning: this should match the structure returned by
            #          juniper:list_interfaces:_ifc_info
            result['interface'] = {
                'name': interface,
                'description': '',
                'bundle': [],
                'ipv4': [],
                'ipv6': []
            }

        def _related_services():
            for related in related_interfaces(source_equipment, interface):
                rs = r.get('opsdb:interface_services:%s:%s'
                           % (source_equipment, related))
                all_rs = []
                if rs:
                    for s in json.loads(rs.decode('utf-8')):
                        top_level_services.extend(
                            get_top_level_services(s['id'], r))
                        all_rs.append(
                            {
                                'name': s['name'],
                                'status': s['status'],
                                'circuit_type': s['circuit_type']
                            })
                return all_rs

        related_services = _related_services()
        if related_services:
            top_level_services.extend(related_services)
        if top_level_services:
            result['related-services'] = top_level_services

        result = json.dumps(result)
        # cache this data for the next call
        r.set(cache_key, result.encode('utf-8'))

    return Response(result, mimetype="application/json")


def ix_peering_info(peer_info):
    """
    TODO: this is probably the least efficient way of doing this
          (if it's a problem, pre-compute these lists)

    :param peer_info: an element from ix_public_peer:address
    :return:
    """

    result = {
        'peer': peer_info,
        'group': [],
        'router': []
    }

    try:
        address = ipaddress.ip_address(peer_info['name'])
    except ValueError:
        raise ClassifierProcessingError(
            'unable to parse %r as an ip address' % address)

    description = peer_info['description']
    assert description is not None  # sanity

    keyword = description.split(' ')[0]  # regex needed??? (e.g. tabs???)

    r = common.get_current_redis()

    for k in r.keys('ix_public_peer:*'):
        other = r.get(k.decode('utf-8')).decode('utf-8')
        other = json.loads(other)

        if other['router'] == peer_info['router']:
            result['router'].append(other['name'])

        assert other['description'] is not None  # sanity: as above...
        if other['description'].startswith(keyword):
            result['group'].append(other['name'])

    return result


def find_interfaces(address):
    """
    TODO: this is probably the least efficient way of doing this
          (if it's a problem, pre-compute these lists)

    :param address: an ipaddress object
    :return:
    """
    r = common.get_current_redis()
    for k in r.keys('subnets:*'):
        k = k.decode('utf-8')
        m = re.match(r'^subnets:(.*)$', k)
        assert m, 'sanity failure: redis returned an invalid key name'
        interface = ipaddress.ip_interface(m.group(1))
        if address in interface.network:
            info = r.get(k).decode('utf-8')
            info = json.loads(info)
            for ifc in info:
                yield ifc


def find_interfaces_and_services(address_str):
    """

    :param address_str: an ipaddress object
    :return:
    """

    try:
        address = ipaddress.ip_address(address_str)
    except ValueError:
        raise ClassifierProcessingError(
            'unable to parse %r as an ip address' % address_str)

    r = common.get_current_redis()
    for interface in find_interfaces(address):

        services = r.get(
            'opsdb:interface_services:%s:%s' % (
                interface['router'],
                interface['interface name']))
        if not services:
            services = []
        else:
            services = json.loads(services.decode('utf=8'))

        yield {
            'interface': interface,
            'services': services
        }


@routes.route("/peer-info/<address>", methods=['GET', 'POST'])
@common.require_accepts_json
def peer_info(address):

    # canonicalize the input address first ...
    try:
        obj = ipaddress.ip_address(address)
        address = obj.exploded
    except ValueError:
        raise ClassifierProcessingError(
            'unable to parse %r as an ip address' % address)

    r = common.get_current_redis()

    cache_key = 'classifier-cache:peer:%s' % address

    result = r.get(cache_key)
    if result:
        result = result.decode('utf-8')
    else:

        result = {}

        info = r.get('ix_public_peer:%s' % address)
        if info:
            info = info.decode('utf-8')
            result['ix-public-peer-info'] = ix_peering_info(json.loads(info))

        info = r.get('vpn_rr_peer:%s' % address)
        if info:
            info = info.decode('utf-8')
            result['vpn-rr-peer-info'] = json.loads(info)

        interfaces = list(find_interfaces_and_services(address))
        if interfaces:
            result['interfaces'] = interfaces

        result = json.dumps(result)
        # cache this data for the next call
        r.set(cache_key, result.encode('utf-8'))

    return Response(result, mimetype="application/json")


@routes.route("/infinera-lambda-info/"
              "<source_equipment>/<interface>/<circuit_id>",
              methods=['GET', 'POST'])
@common.require_accepts_json
def get_trap_metadata(source_equipment, interface, circuit_id):

    interface = interface.replace('-T', '-')
    cache_key = 'classifier-cache:infinera:%s:%s' % (
        source_equipment, interface)

    r = common.get_current_redis()
    result = r.get(cache_key)

    if result:
        result = result.decode('utf-8')
    else:
        result = {}

        services = r.get(
            'opsdb:interface_services:%s:%s' % (source_equipment, interface))
        if services:
            result['services'] = json.loads(services.decode('utf=8'))

        gl = r.get('opsdb:geant_lambdas:%s' % circuit_id.lower())
        if gl:
            t_gl = json.loads(gl.decode('utf=8'))
            t_gl['status'] = t_gl['status'].lower()
            result['geant-lambda'] = t_gl

        if not result:
            return Response(
                response="no available info for {} {}".format(
                    source_equipment, interface),
                status=404,
                mimetype="text/html")

        result = json.dumps(result)
        # cache this data for the next call
        r.set(cache_key, result.encode('utf-8'))

    return Response(result, mimetype="application/json")


@routes.route('/coriant-info/<equipment_name>/<path:entity_string>',
              methods=['GET', 'POST'])
@common.require_accepts_json
def get_coriant_info(equipment_name, entity_string):
    r = common.get_current_redis()

    cache_key = 'classifier-cache:coriant:%s:%s' % (
        equipment_name, entity_string)
    result = r.get(cache_key)

    # this is just for development to save deleting the cache every time
    # result = False

    if result:
        result = result.decode('utf-8')
    else:

        m = re.match(r'^(\d+\-\d+)\.(\d+)', entity_string)
        if not m:
            logger.error(
                'invalid coriant entity string format: %r' % entity_string)
            return Response(
                response="no available info for '{}' '{}'".format(
                    equipment_name, entity_string),
                status=404,
                mimetype="text/html")
        result = {
            'equipment name': equipment_name,
            'card id': m.group(1),
            'port number': m.group(2)
        }

        config = current_app.config['INVENTORY_PROVIDER_CONFIG']

        with db.connection(config['ops-db']) as cx:
            path = opsdb.lookup_coriant_path(
                cx, equipment_name, result['card id'], result['port number'])

        if path:
            result['path'] = path

            top_level_services = get_top_level_services(path['id'], r)
            if top_level_services:
                result['related-services'] = top_level_services
        else:
            logger.error('no path found for {}:{}'.format(
                equipment_name, entity_string))

        # cache this data for the next call
        result = json.dumps(result).encode('utf-8')
        r.set(cache_key, result)

    return Response(result, mimetype="application/json")