import AppKit
import ServiceManagement
import os

/// App lifecycle, the Accessibility permission gate, and the menu-bar item.
/// Wires WindowLocator + FocusEnforcer to the events EventTapController
/// reports; owns no event-tap or AX logic itself.
final class AppDelegate: NSObject, NSApplicationDelegate {
    private let logger = Logger(subsystem: "com.local.focusfixer", category: "AppDelegate")

    private let preferences = Preferences.shared
    private let permissionManager = PermissionManager()
    private let eventTapController = EventTapController()
    private let focusEnforcer = FocusEnforcer()

    private var statusItem: NSStatusItem?

    func applicationDidFinishLaunching(_ notification: Notification) {
        setUpStatusItem()
        permissionManager.waitUntilTrusted { [weak self] in
            self?.startEventTap()
        }
    }

    private func startEventTap() {
        eventTapController.start { [weak self] point in
            self?.handleMouseDown(at: point)
        }
    }

    private func handleMouseDown(at point: CGPoint) {
        guard preferences.isEnabled else { return }
        guard let pid = WindowLocator.ownerPID(at: point) else { return }
        focusEnforcer.enforceFocus(forWindowOwnedBy: pid)
    }

    // MARK: - Menu bar

    private func setUpStatusItem() {
        let item = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
        item.button?.image = NSImage(systemSymbolName: "scope", accessibilityDescription: "FocusFixer")

        let menu = NSMenu()

        let enabledItem = NSMenuItem(title: "Enabled", action: #selector(toggleEnabled(_:)), keyEquivalent: "")
        enabledItem.target = self
        enabledItem.state = preferences.isEnabled ? .on : .off
        menu.addItem(enabledItem)

        let loginItem = NSMenuItem(title: "Launch at Login", action: #selector(toggleLaunchAtLogin(_:)), keyEquivalent: "")
        loginItem.target = self
        loginItem.state = SMAppService.mainApp.status == .enabled ? .on : .off
        menu.addItem(loginItem)

        menu.addItem(.separator())
        menu.addItem(NSMenuItem(title: "Quit FocusFixer", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))

        item.menu = menu
        statusItem = item
    }

    @objc private func toggleEnabled(_ sender: NSMenuItem) {
        preferences.isEnabled.toggle()
        sender.state = preferences.isEnabled ? .on : .off
    }

    @objc private func toggleLaunchAtLogin(_ sender: NSMenuItem) {
        do {
            if SMAppService.mainApp.status == .enabled {
                try SMAppService.mainApp.unregister()
            } else {
                try SMAppService.mainApp.register()
            }
        } catch {
            logger.error("Failed to toggle login item: \(error.localizedDescription, privacy: .public)")
        }
        sender.state = SMAppService.mainApp.status == .enabled ? .on : .off
    }
}