from types import SimpleNamespace

import attr
from multidict import CIMultiDict
from yarl import URL

from .client_reqrep import ClientResponse
from .signals import Signal


__all__ = (
    'TraceConfig', 'TraceRequestStartParams', 'TraceRequestEndParams',
    'TraceRequestExceptionParams', 'TraceConnectionQueuedStartParams',
    'TraceConnectionQueuedEndParams', 'TraceConnectionCreateStartParams',
    'TraceConnectionCreateEndParams', 'TraceConnectionReuseconnParams',
    'TraceDnsResolveHostStartParams', 'TraceDnsResolveHostEndParams',
    'TraceDnsCacheHitParams', 'TraceDnsCacheMissParams',
    'TraceRequestRedirectParams',
    'TraceRequestChunkSentParams', 'TraceResponseChunkReceivedParams',
)


class TraceConfig:
    """First-class used to trace requests launched via ClientSession
    objects."""

    def __init__(self, trace_config_ctx_factory=SimpleNamespace):
        self._on_request_start = Signal(self)
        self._on_request_chunk_sent = Signal(self)
        self._on_response_chunk_received = Signal(self)
        self._on_request_end = Signal(self)
        self._on_request_exception = Signal(self)
        self._on_request_redirect = Signal(self)
        self._on_connection_queued_start = Signal(self)
        self._on_connection_queued_end = Signal(self)
        self._on_connection_create_start = Signal(self)
        self._on_connection_create_end = Signal(self)
        self._on_connection_reuseconn = Signal(self)
        self._on_dns_resolvehost_start = Signal(self)
        self._on_dns_resolvehost_end = Signal(self)
        self._on_dns_cache_hit = Signal(self)
        self._on_dns_cache_miss = Signal(self)

        self._trace_config_ctx_factory = trace_config_ctx_factory

    def trace_config_ctx(self, trace_request_ctx=None):
        """ Return a new trace_config_ctx instance """
        return self._trace_config_ctx_factory(
            trace_request_ctx=trace_request_ctx)

    def freeze(self):
        self._on_request_start.freeze()
        self._on_request_chunk_sent.freeze()
        self._on_response_chunk_received.freeze()
        self._on_request_end.freeze()
        self._on_request_exception.freeze()
        self._on_request_redirect.freeze()
        self._on_connection_queued_start.freeze()
        self._on_connection_queued_end.freeze()
        self._on_connection_create_start.freeze()
        self._on_connection_create_end.freeze()
        self._on_connection_reuseconn.freeze()
        self._on_dns_resolvehost_start.freeze()
        self._on_dns_resolvehost_end.freeze()
        self._on_dns_cache_hit.freeze()
        self._on_dns_cache_miss.freeze()

    @property
    def on_request_start(self):
        return self._on_request_start

    @property
    def on_request_chunk_sent(self):
        return self._on_request_chunk_sent

    @property
    def on_response_chunk_received(self):
        return self._on_response_chunk_received

    @property
    def on_request_end(self):
        return self._on_request_end

    @property
    def on_request_exception(self):
        return self._on_request_exception

    @property
    def on_request_redirect(self):
        return self._on_request_redirect

    @property
    def on_connection_queued_start(self):
        return self._on_connection_queued_start

    @property
    def on_connection_queued_end(self):
        return self._on_connection_queued_end

    @property
    def on_connection_create_start(self):
        return self._on_connection_create_start

    @property
    def on_connection_create_end(self):
        return self._on_connection_create_end

    @property
    def on_connection_reuseconn(self):
        return self._on_connection_reuseconn

    @property
    def on_dns_resolvehost_start(self):
        return self._on_dns_resolvehost_start

    @property
    def on_dns_resolvehost_end(self):
        return self._on_dns_resolvehost_end

    @property
    def on_dns_cache_hit(self):
        return self._on_dns_cache_hit

    @property
    def on_dns_cache_miss(self):
        return self._on_dns_cache_miss


@attr.s(frozen=True, slots=True)
class TraceRequestStartParams:
    """ Parameters sent by the `on_request_start` signal"""
    method = attr.ib(type=str)
    url = attr.ib(type=URL)
    headers = attr.ib(type=CIMultiDict)


@attr.s(frozen=True, slots=True)
class TraceRequestChunkSentParams:
    """ Parameters sent by the `on_request_chunk_sent` signal"""
    chunk = attr.ib(type=bytes)


@attr.s(frozen=True, slots=True)
class TraceResponseChunkReceivedParams:
    """ Parameters sent by the `on_response_chunk_received` signal"""
    chunk = attr.ib(type=bytes)


@attr.s(frozen=True, slots=True)
class TraceRequestEndParams:
    """ Parameters sent by the `on_request_end` signal"""
    method = attr.ib(type=str)
    url = attr.ib(type=URL)
    headers = attr.ib(type=CIMultiDict)
    response = attr.ib(type=ClientResponse)


@attr.s(frozen=True, slots=True)
class TraceRequestExceptionParams:
    """ Parameters sent by the `on_request_exception` signal"""
    method = attr.ib(type=str)
    url = attr.ib(type=URL)
    headers = attr.ib(type=CIMultiDict)
    exception = attr.ib(type=Exception)


@attr.s(frozen=True, slots=True)
class TraceRequestRedirectParams:
    """ Parameters sent by the `on_request_redirect` signal"""
    method = attr.ib(type=str)
    url = attr.ib(type=URL)
    headers = attr.ib(type=CIMultiDict)
    response = attr.ib(type=ClientResponse)


@attr.s(frozen=True, slots=True)
class TraceConnectionQueuedStartParams:
    """ Parameters sent by the `on_connection_queued_start` signal"""


@attr.s(frozen=True, slots=True)
class TraceConnectionQueuedEndParams:
    """ Parameters sent by the `on_connection_queued_end` signal"""


@attr.s(frozen=True, slots=True)
class TraceConnectionCreateStartParams:
    """ Parameters sent by the `on_connection_create_start` signal"""


@attr.s(frozen=True, slots=True)
class TraceConnectionCreateEndParams:
    """ Parameters sent by the `on_connection_create_end` signal"""


@attr.s(frozen=True, slots=True)
class TraceConnectionReuseconnParams:
    """ Parameters sent by the `on_connection_reuseconn` signal"""


@attr.s(frozen=True, slots=True)
class TraceDnsResolveHostStartParams:
    """ Parameters sent by the `on_dns_resolvehost_start` signal"""
    host = attr.ib(type=str)


@attr.s(frozen=True, slots=True)
class TraceDnsResolveHostEndParams:
    """ Parameters sent by the `on_dns_resolvehost_end` signal"""
    host = attr.ib(type=str)


@attr.s(frozen=True, slots=True)
class TraceDnsCacheHitParams:
    """ Parameters sent by the `on_dns_cache_hit` signal"""
    host = attr.ib(type=str)


@attr.s(frozen=True, slots=True)
class TraceDnsCacheMissParams:
    """ Parameters sent by the `on_dns_cache_miss` signal"""
    host = attr.ib(type=str)


class Trace:
    """ Internal class used to keep together the main dependencies used
    at the moment of send a signal."""

    def __init__(self, session, trace_config, trace_config_ctx):
        self._trace_config = trace_config
        self._trace_config_ctx = trace_config_ctx
        self._session = session

    async def send_request_start(self, method, url, headers):
        return await self._trace_config.on_request_start.send(
            self._session,
            self._trace_config_ctx,
            TraceRequestStartParams(method, url, headers)
        )

    async def send_request_chunk_sent(self, chunk):
        return await self._trace_config.on_request_chunk_sent.send(
            self._session,
            self._trace_config_ctx,
            TraceRequestChunkSentParams(chunk)
        )

    async def send_response_chunk_received(self, chunk):
        return await self._trace_config.on_response_chunk_received.send(
            self._session,
            self._trace_config_ctx,
            TraceResponseChunkReceivedParams(chunk)
        )

    async def send_request_end(self, method, url, headers, response):
        return await self._trace_config.on_request_end.send(
            self._session,
            self._trace_config_ctx,
            TraceRequestEndParams(method, url, headers, response)
        )

    async def send_request_exception(self, method, url, headers, exception):
        return await self._trace_config.on_request_exception.send(
            self._session,
            self._trace_config_ctx,
            TraceRequestExceptionParams(method, url, headers, exception)
        )

    async def send_request_redirect(self, method, url, headers, response):
        return await self._trace_config._on_request_redirect.send(
            self._session,
            self._trace_config_ctx,
            TraceRequestRedirectParams(method, url, headers, response)
        )

    async def send_connection_queued_start(self):
        return await self._trace_config.on_connection_queued_start.send(
            self._session,
            self._trace_config_ctx,
            TraceConnectionQueuedStartParams()
        )

    async def send_connection_queued_end(self):
        return await self._trace_config.on_connection_queued_end.send(
            self._session,
            self._trace_config_ctx,
            TraceConnectionQueuedEndParams()
        )

    async def send_connection_create_start(self):
        return await self._trace_config.on_connection_create_start.send(
            self._session,
            self._trace_config_ctx,
            TraceConnectionCreateStartParams()
        )

    async def send_connection_create_end(self):
        return await self._trace_config.on_connection_create_end.send(
            self._session,
            self._trace_config_ctx,
            TraceConnectionCreateEndParams()
        )

    async def send_connection_reuseconn(self):
        return await self._trace_config.on_connection_reuseconn.send(
            self._session,
            self._trace_config_ctx,
            TraceConnectionReuseconnParams()
        )

    async def send_dns_resolvehost_start(self, host):
        return await self._trace_config.on_dns_resolvehost_start.send(
            self._session,
            self._trace_config_ctx,
            TraceDnsResolveHostStartParams(host)
        )

    async def send_dns_resolvehost_end(self, host):
        return await self._trace_config.on_dns_resolvehost_end.send(
            self._session,
            self._trace_config_ctx,
            TraceDnsResolveHostEndParams(host)
        )

    async def send_dns_cache_hit(self, host):
        return await self._trace_config.on_dns_cache_hit.send(
            self._session,
            self._trace_config_ctx,
            TraceDnsCacheHitParams(host)
        )

    async def send_dns_cache_miss(self, host):
        return await self._trace_config.on_dns_cache_miss.send(
            self._session,
            self._trace_config_ctx,
            TraceDnsCacheMissParams(host)
        )