#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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 time
from typing import List, TYPE_CHECKING

from skywalking import config
from skywalking.trace import ID
from skywalking.utils.lang import tostring

if TYPE_CHECKING:
    from skywalking.trace.carrier import Carrier
    from skywalking.trace.span import Span
    from skywalking.trace.snapshot import Snapshot


class SegmentRef(object):
    def __init__(self, carrier: 'Carrier', ref_type: str = 'CrossProcess'):
        self.ref_type = ref_type  # type: str
        self.trace_id = carrier.trace_id  # type: str
        self.segment_id = carrier.segment_id  # type: str
        self.span_id = int(carrier.span_id)  # type: int
        self.service = carrier.service  # type: str
        self.service_instance = carrier.service_instance  # type: str
        self.endpoint = carrier.endpoint  # type: str
        self.client_address = carrier.client_address  # type: str

    def __eq__(self, other):
        if not isinstance(other, SegmentRef):
            raise NotImplementedError
        return self.ref_type == other.ref_type and \
            self.trace_id == other.trace_id and \
            self.segment_id == other.segment_id and \
            self.span_id == other.span_id and \
            self.service == other.service and \
            self.service_instance == other.service_instance and \
            self.endpoint == other.endpoint and \
            self.client_address == other.client_address

    @classmethod
    def build_ref(cls, snapshot: 'Snapshot'):
        from skywalking.trace.carrier import Carrier
        carrier = Carrier()
        carrier.trace_id = str(snapshot.trace_id)
        carrier.segment_id = str(snapshot.segment_id)
        carrier.endpoint = snapshot.endpoint
        carrier.span_id = snapshot.span_id
        carrier.service = config.agent_name
        carrier.service_instance = config.agent_instance_name
        return SegmentRef(carrier, ref_type='CrossThread')


class _NewID(ID):
    pass


class _NewNoopID(ID):

    def __init__(self):
        self.value = ''


@tostring
class Segment(object):
    def __init__(self):
        self.segment_id = ID()  # type: ID
        self.spans = []  # type: List[Span]
        self.timestamp = int(time.time() * 1000)  # type: int
        self.related_traces = [_NewID()]  # type: List[ID]
        self.is_size_limited = False  # type: bool

    def archive(self, span: 'Span'):
        self.spans.append(span)

    def relate(self, trace_id: ID):
        if isinstance(self.related_traces[0], _NewID):
            del self.related_traces[-1]
        self.related_traces.append(trace_id)


class NoopSegment(Segment):
    def __init__(self):
        self.segment_id = _NewNoopID()
        self.spans = []
        self.timestamp = 0
        self.related_traces = [_NewNoopID()]