import SwiftUI
import AppKit
import ServiceManagement

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

    var body: some Scene {
        // The app lives in a floating panel + status item, so there are no
        // real windows; a bare Settings scene keeps SwiftUI happy.
        Settings { EmptyView() }
    }
}

final class AppDelegate: NSObject, NSApplicationDelegate {
    private var statusItem: NSStatusItem?

    func applicationDidFinishLaunching(_ notification: Notification) {
        NSApp.setActivationPolicy(.accessory)

        if CommandLine.arguments.contains("--sync-check") {
            Task { @MainActor in
                await SyncService.shared.runDiagnostic()
                NSApp.terminate(nil)
            }
            return
        }

        // Single instance: stale copies keep their hotkeys alive after an
        // update and eat the events meant for the new instance.
        let myPid = ProcessInfo.processInfo.processIdentifier
        let others = NSRunningApplication.runningApplications(withBundleIdentifier: "dev.tzgyn.prompt")
            .filter { $0.processIdentifier != myPid }
        for other in others {
            other.forceTerminate()
        }

        HotkeyManager.shared.onCapture = {
            DispatchQueue.global(qos: .userInitiated).async {
                Capture.captureSelectionIntoStore()
            }
        }
        HotkeyManager.shared.onTogglePanel = {
            Task { @MainActor in PanelController.shared.toggle() }
        }
        HotkeyManager.shared.start()

        setupStatusItem()
        setupMainMenu()

        // Show the panel on launch so the app is discoverable (it has no Dock
        // icon and the menu bar icon can be hard to spot on a full bar).
        Task { @MainActor in
            SyncService.shared.start()
            PanelController.shared.show()
        }
    }

    /// A launched-again app must reveal itself. Without this, `open` (or
    /// clicking it in Finder/Spotlight) hits the running instance, which does
    /// nothing, so the app looks like it never started.
    @MainActor
    func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
        PanelController.shared.show()
        return true
    }

    @MainActor
    func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
        // Stop the poll timer, any queued push, the event tap and the Carbon
        // hotkeys so termination cannot be held up by a live callback.
        SyncService.shared.stop()
        HotkeyManager.shared.stop()
        return .terminateNow
    }

    /// Accessory apps have no visible menu bar, but the main menu still
    /// services key equivalents — this is what makes Cmd+Q and Cmd+W work
    /// while the panel has focus.
    private func setupMainMenu() {
        let mainMenu = NSMenu()
        let appMenuItem = NSMenuItem()
        mainMenu.addItem(appMenuItem)

        let appMenu = NSMenu()
        appMenuItem.submenu = appMenu

        let hide = NSMenuItem(title: "Hide Panel", action: #selector(hidePanel), keyEquivalent: "w")
        hide.target = self
        appMenu.addItem(hide)

        appMenu.addItem(.separator())

        let quit = NSMenuItem(title: "Quit Prompt", action: #selector(quit), keyEquivalent: "q")
        quit.target = self
        appMenu.addItem(quit)

        NSApp.mainMenu = mainMenu
    }

    @MainActor @objc private func hidePanel() {
        PanelController.shared.hide()
    }

    private func setupStatusItem() {
        let item = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
        item.autosaveName = "Prompt"
        // Seed a visible preferred position on first run so a new item does
        // not land under the notch on a full menu bar; user drags win after.
        if UserDefaults.standard.object(forKey: "NSStatusItem Preferred Position Prompt") == nil {
            UserDefaults.standard.set(100.0, forKey: "NSStatusItem Preferred Position Prompt")
        }
        if let button = item.button {
            button.image = NSImage(systemSymbolName: "text.bubble", accessibilityDescription: "Prompt")
            button.action = #selector(statusItemClicked(_:))
            button.target = self
            button.sendAction(on: [.leftMouseUp, .rightMouseUp])
        }
        statusItem = item
    }

    @MainActor @objc private func statusItemClicked(_ sender: NSStatusBarButton) {
        guard let event = NSApp.currentEvent else { return }
        if event.type == .rightMouseUp {
            let menu = buildMenu()
            statusItem?.menu = menu
            statusItem?.button?.performClick(nil)
            statusItem?.menu = nil
        } else {
            PanelController.shared.toggle()
        }
    }

    private func buildMenu() -> NSMenu {
        let menu = NSMenu()

        let toggle = NSMenuItem(title: "Show/Hide Prompt", action: #selector(togglePanel), keyEquivalent: "")
        toggle.target = self
        menu.addItem(toggle)

        menu.addItem(.separator())

        if AXIsProcessTrusted() {
            let granted = NSMenuItem(title: "Accessibility: Granted", action: nil, keyEquivalent: "")
            granted.isEnabled = false
            menu.addItem(granted)
        } else {
            let grant = NSMenuItem(title: "Grant Accessibility Access…", action: #selector(requestAccessibility), keyEquivalent: "")
            grant.target = self
            menu.addItem(grant)
        }

        let loginTitle = LoginItem.isEnabled ? "Disable Launch at Login" : "Launch at Login"
        let login = NSMenuItem(title: loginTitle, action: #selector(toggleLoginItem), keyEquivalent: "")
        login.target = self
        menu.addItem(login)

        let folder = NSMenuItem(title: "Open Data Folder", action: #selector(openDataFolder), keyEquivalent: "")
        folder.target = self
        menu.addItem(folder)

        menu.addItem(.separator())

        let quit = NSMenuItem(title: "Quit Prompt", action: #selector(quit), keyEquivalent: "q")
        quit.target = self
        menu.addItem(quit)

        return menu
    }

    @MainActor @objc private func togglePanel() {
        PanelController.shared.toggle()
    }

    @objc private func requestAccessibility() {
        let options = [kAXTrustedCheckOptionPrompt.takeUnretainedValue(): true] as CFDictionary
        _ = AXIsProcessTrustedWithOptions(options)
    }

    @objc private func toggleLoginItem() {
        if !LoginItem.toggle() {
            let alert = NSAlert()
            alert.messageText = "Could not update Launch at Login"
            alert.informativeText = "Launch at Login requires a signed app bundle in /Applications. It is not available when running via `swift run`."
            alert.alertStyle = .warning
            alert.addButton(withTitle: "OK")
            alert.runModal()
        }
    }

    @MainActor @objc private func openDataFolder() {
        NSWorkspace.shared.open(Store.shared.directory)
    }

    @objc private func quit() {
        NSApp.terminate(nil)
    }
}

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
        }
    }
}