from __future__ import annotations

import asyncio
import logging
from typing import *

from hippolyzer.lib.base import llsd
from hippolyzer.lib.base.message.message import Message
from hippolyzer.lib.client.namecache import NameCache
from hippolyzer.lib.client.object_manager import (
    ClientObjectManager,
    UpdateType, ClientWorldObjectManager,
)

from hippolyzer.lib.base.objects import Object
from hippolyzer.lib.proxy.addons import AddonManager
from hippolyzer.lib.proxy.http_flow import HippoHTTPFlow
from hippolyzer.lib.proxy.settings import ProxySettings
from hippolyzer.lib.proxy.vocache import RegionViewerObjectCacheChain

if TYPE_CHECKING:
    from hippolyzer.lib.proxy.region import ProxiedRegion
    from hippolyzer.lib.proxy.sessions import Session

LOG = logging.getLogger(__name__)


class ProxyObjectManager(ClientObjectManager):
    """
    Object manager for a specific region
    """
    _region: ProxiedRegion

    def __init__(
            self,
            region: ProxiedRegion,
            may_use_vo_cache: bool = False
    ):
        super().__init__(region)
        self.may_use_vo_cache = may_use_vo_cache
        self.cache_loaded = False
        self.object_cache = RegionViewerObjectCacheChain([])
        self._cache_miss_timer: Optional[asyncio.TimerHandle] = None
        self.queued_cache_misses: Set[int] = set()
        region.message_handler.subscribe(
            "RequestMultipleObjects",
            self._handle_request_multiple_objects,
        )

    def load_cache(self):
        if not self.may_use_vo_cache or self.cache_loaded:
            return
        handle = self._region.handle
        if not handle:
            LOG.warning(f"Tried to load cache for {self._region} without a handle")
            return
        self.cache_loaded = True
        self.object_cache = RegionViewerObjectCacheChain.for_region(handle, self._region.cache_id)

    def request_missed_cached_objects_soon(self):
        if self._cache_miss_timer:
            self._cache_miss_timer.cancel()
        # Basically debounce. Will only trigger 0.2 seconds after the last time it's invoked to
        # deal with the initial flood of ObjectUpdateCached and the natural lag time between that
        # and the viewers' RequestMultipleObjects messages
        self._cache_miss_timer = asyncio.get_event_loop().call_later(
            0.2, self._request_missed_cached_objects)

    def _request_missed_cached_objects(self):
        self._cache_miss_timer = None
        self.request_objects(self.queued_cache_misses)
        self.queued_cache_misses.clear()

    def clear(self):
        super().clear()
        self.object_cache = RegionViewerObjectCacheChain([])
        self.cache_loaded = False
        self.queued_cache_misses.clear()
        if self._cache_miss_timer:
            self._cache_miss_timer.cancel()
        self._cache_miss_timer = None

    def _is_localid_selected(self, localid: int):
        return localid in self._region.session().selected.object_locals

    def _handle_request_multiple_objects(self, msg: Message):
        # Remove any queued cache misses that the viewer just requested for itself
        self.queued_cache_misses -= {b["ID"] for b in msg["ObjectData"]}


class ProxyWorldObjectManager(ClientWorldObjectManager):
    _session: Session
    _settings: ProxySettings

    def __init__(self, session: Session, settings: ProxySettings, name_cache: Optional[NameCache]):
        super().__init__(session, settings, name_cache)
        session.http_message_handler.subscribe(
            "GetObjectCost",
            self._handle_get_object_cost
        )

    def _handle_object_update_cached_misses(self, region_handle: int, missing_locals: Set[int]):
        if self._settings.AUTOMATICALLY_REQUEST_MISSING_OBJECTS:
            # Schedule these local IDs to be requested soon if the viewer doesn't request
            # them itself. Ideally we could just mutate the CRC of the ObjectUpdateCached
            # to force a CRC cache miss in the viewer, but that appears to cause the viewer
            # to drop the resulting ObjectUpdateCompressed when the CRC doesn't match?
            # It was causing all objects to go missing even though the ObjectUpdateCompressed
            # was received.
            region_mgr: Optional[ProxyObjectManager] = self._get_region_manager(region_handle)
            region_mgr.queued_cache_misses |= missing_locals
            region_mgr.request_missed_cached_objects_soon()

    def _run_object_update_hooks(self, obj: Object, updated_props: Set[str], update_type: UpdateType):
        super()._run_object_update_hooks(obj, updated_props, update_type)
        region = self._session.region_by_handle(obj.RegionHandle)
        AddonManager.handle_object_updated(self._session, region, obj, updated_props)

    def _run_kill_object_hooks(self, obj: Object):
        super()._run_kill_object_hooks(obj)
        region = self._session.region_by_handle(obj.RegionHandle)
        AddonManager.handle_object_killed(self._session, region, obj)

    def _lookup_cache_entry(self, region_handle: int, local_id: int, crc: int) -> Optional[bytes]:
        region_mgr: Optional[ProxyObjectManager] = self._get_region_manager(region_handle)
        return region_mgr.object_cache.lookup_object_data(local_id, crc)

    def _handle_get_object_cost(self, flow: HippoHTTPFlow):
        parsed = llsd.parse_xml(flow.response.content)
        self._process_get_object_cost_response(parsed)