"""In-memory state controller'а."""

from __future__ import annotations

import asyncio
from dataclasses import dataclass, field

from .overlays import Overlay


@dataclass
class InstanceState:
    name: str
    active_layout: str
    overlays: dict[str, Overlay] = field(default_factory=dict)
    audio_output_enabled: bool = True
    # Future: fps_out, dropped_frames, motion_cameras, last_event_ts


@dataclass
class ControllerState:
    instances: dict[str, InstanceState] = field(default_factory=dict)
    _lock: asyncio.Lock = field(default_factory=asyncio.Lock)

    async def set_layout(self, instance: str, layout: str) -> None:
        async with self._lock:
            st = self.instances.get(instance)
            if st is None:
                st = InstanceState(name=instance, active_layout=layout)
                self.instances[instance] = st
            else:
                st.active_layout = layout

    async def get_layout(self, instance: str) -> str | None:
        async with self._lock:
            st = self.instances.get(instance)
            return st.active_layout if st else None

    # ─── Overlay state ──────────────────────────────────────────────

    async def add_overlay(self, instance: str, overlay: Overlay) -> str:
        async with self._lock:
            st = self.instances.get(instance)
            if st is None:
                raise KeyError(f"unknown instance '{instance}'")
            st.overlays[overlay.id] = overlay
            return overlay.id

    async def remove_overlay(self, instance: str, overlay_id: str) -> bool:
        async with self._lock:
            st = self.instances.get(instance)
            if st is None or overlay_id not in st.overlays:
                return False
            del st.overlays[overlay_id]
            return True

    async def update_overlay(self, instance: str, overlay: Overlay) -> bool:
        async with self._lock:
            st = self.instances.get(instance)
            if st is None or overlay.id not in st.overlays:
                return False
            st.overlays[overlay.id] = overlay
            return True

    async def get_overlays(self, instance: str) -> list[Overlay]:
        async with self._lock:
            st = self.instances.get(instance)
            return list(st.overlays.values()) if st else []

    # ─── Audio output mute ──────────────────────────────────────────

    async def set_audio_output_enabled(self, instance: str, enabled: bool) -> None:
        async with self._lock:
            st = self.instances.get(instance)
            if st is not None:
                st.audio_output_enabled = enabled

    async def get_audio_output_enabled(self, instance: str) -> bool:
        async with self._lock:
            st = self.instances.get(instance)
            return st.audio_output_enabled if st else True

    async def clear_overlays(self, instance: str) -> int:
        async with self._lock:
            st = self.instances.get(instance)
            if st is None:
                return 0
            n = len(st.overlays)
            st.overlays.clear()
            return n