//
//  ThermalMonitor.swift
//  Poche
//
//  Author:  Simon-Pierre Boucher
//  Contact: contact@spboucher.ai
//

import Foundation
import Observation

/// Watches thermal state so we slow down before the system throttles us
/// (CLAUDE.md §9). Battery and heat are the scarcest budgets of a local
/// chat app.
@MainActor
@Observable
final class ThermalMonitor {
    private(set) var state: ProcessInfo.ThermalState = ProcessInfo.processInfo.thermalState
    // App-lifetime object (owned by AgentSession): the observation is never
    // removed, so no deinit — Swift 6 deinits cannot touch isolated state.
    private var observer: (any NSObjectProtocol)?

    var shouldPauseInference: Bool {
        state == .critical
    }

    init() {
        observer = NotificationCenter.default.addObserver(
            forName: ProcessInfo.thermalStateDidChangeNotification,
            object: nil,
            queue: .main
        ) { [weak self] _ in
            // Delivered on the main queue; re-read from ProcessInfo because
            // the Notification object is not Sendable and carries nothing.
            MainActor.assumeIsolated {
                self?.state = ProcessInfo.processInfo.thermalState
            }
        }
    }
}