import AppKit
import SwiftUI

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

    var body: some Scene {
        // A menu bar app: no windows of its own. Settings are a custom window
        // so the app can be opened from the status item on any space.
        SwiftUI.Settings { EmptyView() }
    }
}

final class AppDelegate: NSObject, NSApplicationDelegate {
    private let menuBar = MenuBarController()

    func applicationDidFinishLaunching(_ notification: Notification) {
        if CommandLine.arguments.contains("--self-test") {
            exit(SelfTest.run())
        }
        if CommandLine.arguments.contains("--convert") {
            exit(CLI.run())
        }

        terminateOtherInstances()

        menuBar.install()

        DragMonitor.shared.onBegan = { urls in
            WheelController.shared.begin(urls: urls)
        }
        DragMonitor.shared.onTick = { _, location, modifiers in
            guard Settings.shared.enabled else { return }
            WheelController.shared.tick(location: location, modifiers: modifiers)
        }
        DragMonitor.shared.onEnded = { _ in
            WheelController.shared.end()
        }
        DragMonitor.shared.onKey = { keyCode, modifiers in
            WheelController.shared.handleKey(keyCode, modifiers: modifiers)
        }
        DragMonitor.shared.start()

        NSApp.servicesProvider = self
        NSUpdateDynamicServices()

        // Warm the Quick Look machinery so the first Float is instant.
        DispatchQueue.main.async {
            _ = NSWorkspace.shared
        }
    }

    func applicationWillTerminate(_ notification: Notification) {
        DragMonitor.shared.stop()
        WheelController.shared.cancel()
    }

    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
        false
    }

    private func terminateOtherInstances() {
        let identifier = Bundle.main.bundleIdentifier ?? "dev.tzgyn.konverter"
        let mine = ProcessInfo.processInfo.processIdentifier
        for other in NSRunningApplication.runningApplications(withBundleIdentifier: identifier)
        where other.processIdentifier != mine {
            other.forceTerminate()
        }
    }

    /// Finder Quick Action / Services entry. The wheel needs a pointer to sit
    /// under, so this opens the same options as a native menu.
    @objc func convertFiles(
        _ pasteboard: NSPasteboard,
        userData: String,
        error: AutoreleasingUnsafeMutablePointer<NSString>
    ) {
        let urls = (pasteboard.readObjects(
            forClasses: [NSURL.self],
            options: [.urlReadingFileURLsOnly: true]
        ) as? [URL]) ?? []
        guard !urls.isEmpty else {
            error.pointee = "No files were passed to Konverter." as NSString
            return
        }
        DispatchQueue.main.async {
            QuickMenu.show(urls: urls, at: NSEvent.mouseLocation)
        }
    }
}