"""Atomic state persistence for declarative plugins."""

from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any

from .models import PluginSkillBinding, PluginState


class PluginStateStore:
    def __init__(self, workspace: str | Path) -> None:
        self.workspace = Path(workspace)
        self.root = self.workspace / ".beaver" / "plugins"
        self.path = self.root / "state.json"

    def list_plugins(self) -> list[PluginState]:
        return [
            PluginState.from_dict(plugin_id, payload if isinstance(payload, dict) else {})
            for plugin_id, payload in sorted(self._read_state().get("plugins", {}).items())
        ]

    def get_plugin(self, plugin_id: str) -> PluginState | None:
        payload = self._read_state().get("plugins", {}).get(plugin_id)
        if not isinstance(payload, dict):
            return None
        return PluginState.from_dict(plugin_id, payload)

    def set_enabled(self, plugin_id: str, enabled: bool) -> PluginState:
        state = self.get_plugin(plugin_id) or PluginState(plugin_id=plugin_id)
        state.enabled = enabled
        if enabled and state.status == "discovered":
            state.status = "enabled"
        self.upsert_plugin(state)
        return state

    def upsert_plugin(self, plugin_state: PluginState) -> None:
        state = self._read_state()
        plugins = state.setdefault("plugins", {})
        if not isinstance(plugins, dict):
            plugins = {}
            state["plugins"] = plugins
        plugins[plugin_state.plugin_id] = plugin_state.to_dict()
        self._write_state(state)

    def update_skill_binding(
        self,
        plugin_id: str,
        skill_name: str,
        binding: PluginSkillBinding,
    ) -> PluginState:
        state = self.get_plugin(plugin_id) or PluginState(plugin_id=plugin_id)
        state.skills[skill_name] = binding
        self.upsert_plugin(state)
        return state

    def _read_state(self) -> dict[str, Any]:
        if not self.path.exists():
            return {"plugins": {}}
        payload = json.loads(self.path.read_text(encoding="utf-8"))
        if not isinstance(payload, dict):
            return {"plugins": {}}
        plugins = payload.get("plugins")
        if not isinstance(plugins, dict):
            payload["plugins"] = {}
        return payload

    def _write_state(self, state: dict[str, Any]) -> None:
        self.root.mkdir(parents=True, exist_ok=True)
        tmp_path = self.path.with_name("state.json.tmp")
        with tmp_path.open("w", encoding="utf-8") as handle:
            json.dump(state, handle, ensure_ascii=False, sort_keys=True, indent=2)
            handle.write("\n")
            handle.flush()
            os.fsync(handle.fileno())
        os.replace(tmp_path, self.path)