import SwiftUI
import AppKit
import ServiceManagement

@main
struct SimpleTopBarApp: App {
    @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate

    var body: some Scene {
        // The app is a menu bar extra, so it has no real windows.
        Settings { EmptyView() }
    }
}

/// Owns the menu bar status item directly (instead of `MenuBarExtra`) so the
/// item can be given an `autosaveName` and a persisted preferred position. On a
/// full menu bar, a brand new item lands under the notch and is invisible;
/// writing `NSStatusItem Preferred Position <name>` into defaults puts it in a
/// visible slot, and the autosave name lets the user's own drag persist.
final class AppDelegate: NSObject, NSApplicationDelegate {
    private var statusItem: NSStatusItem?
    private var popover: NSPopover?

    func applicationDidFinishLaunching(_ notification: Notification) {
        if CommandLine.arguments.contains("--self-test") {
            runSelfTest()
            return
        }

        if CommandLine.arguments.contains("--dump-items") {
            dumpMenuBarItems()
            return
        }

        // Single instance: stale copies keep a menu bar icon around after an
        // update and swallow clicks meant for the new instance.
        let myPid = ProcessInfo.processInfo.processIdentifier
        let others = NSRunningApplication.runningApplications(withBundleIdentifier: "dev.tzgyn.simpletopbar")
            .filter { $0.processIdentifier != myPid }
        for other in others {
            other.forceTerminate()
        }

        AppListModel.shared.start()
        MenuBarItemManager.shared.start()
        // Create the hamburger before the cover so its own icon is never covered.
        setupStatusItem()
        MenuBarItemManager.shared.refresh()

        if CommandLine.arguments.contains("--diag-press") {
            DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
                if let item = MenuBarItemManager.enumerate().first(where: {
                    $0.title.lowercased().contains("wireguard")
                }) {
                    NSLog("diag-press: pressing \(item.appName)")
                    _ = AXUIElementPerformAction(item.element, kAXPressAction as CFString)
                }
            }
            DispatchQueue.main.asyncAfter(deadline: .now() + 3.5) {
                dumpWindows()
            }
            return
        }

        if CommandLine.arguments.contains("--diag-cover") {
            DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
                dumpWindows()
            }
            return
        }

        if CommandLine.arguments.contains("--diag") {
            DispatchQueue.main.asyncAfter(deadline: .now() + 2.5) {
                dumpMenuBarItems()
            }
            return
        }

        if CommandLine.arguments.contains("--diag-hide") {
            MenuBarHider.shared.enabled = true
            DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
                dumpMenuBarItems()
            }
            return
        }

        // The tray is empty without Accessibility permission, so surface the
        // system prompt once at launch instead of waiting for the user to open
        // the panel and find the button.
        if !AccessibilityPermission.isGranted,
           !UserDefaults.standard.bool(forKey: "didRequestAccessibility") {
            UserDefaults.standard.set(true, forKey: "didRequestAccessibility")
            AccessibilityPermission.request()
        }
    }

    func applicationWillTerminate(_ notification: Notification) {
        // Never leave the menu bar resized behind us.
        MenuBarHider.shared.restore()
    }

    private func setupStatusItem() {
        let name = "SimpleTopBar"
        let positionKey = "NSStatusItem Preferred Position \(name)"
        // Only seed the position on first run so the user's own drag wins and
        // persists through the autosave name.
        if UserDefaults.standard.object(forKey: positionKey) == nil {
            UserDefaults.standard.set(100.0, forKey: positionKey)
        }

        let item = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
        item.autosaveName = name

        if let button = item.button {
            let image = NSImage(systemSymbolName: "line.3.horizontal", accessibilityDescription: name)
            image?.isTemplate = true
            button.image = image
            button.target = self
            button.action = #selector(togglePopover)
            button.setAccessibilityLabel("SimpleTopBar")
        }
        statusItem = item

        let popover = NSPopover()
        popover.behavior = .transient
        popover.animates = false
        popover.contentViewController = NSHostingController(
            rootView: TopBarView(
                model: AppListModel.shared,
                menuBar: MenuBarItemManager.shared,
                hider: MenuBarHider.shared
            )
        )
        self.popover = popover
    }

    @objc private func togglePopover() {
        guard let popover, let button = statusItem?.button else { return }
        if popover.isShown {
            popover.performClose(nil)
        } else {
            NSApp.activate(ignoringOtherApps: true)
            popover.show(relativeTo: button.bounds, of: button, preferredEdge: .minY)
            popover.contentViewController?.view.window?.makeKey()
        }
    }
}

enum LoginItem {
    static var isEnabled: Bool {
        SMAppService.mainApp.status == .enabled
    }

    static func toggle() -> Bool {
        let service = SMAppService.mainApp
        do {
            if service.status == .enabled {
                try service.unregister()
            } else {
                try service.register()
            }
            return true
        } catch {
            return false
        }
    }
}