import Cocoa
import SwiftUI

class HUDPanel {
    private var panel: NSPanel?
    private var hideTimer: Timer?
    private let hudSize = NSSize(width: 200, height: 200)

    func show(volume: Float, isMuted: Bool) {
        hideTimer?.invalidate()

        if panel == nil {
            createPanel()
        }

        guard let panel = panel else { return }

        // Update content
        let hostingView = NSHostingView(rootView: HUDView(volume: volume, isMuted: isMuted))
        hostingView.frame = NSRect(origin: .zero, size: hudSize)
        panel.contentView = hostingView

        // Center on main screen
        if let screen = NSScreen.main {
            let screenFrame = screen.visibleFrame
            let x = screenFrame.midX - hudSize.width / 2
            let y = screenFrame.midY - hudSize.height / 2
            panel.setFrameOrigin(NSPoint(x: x, y: y))
        }

        // Show
        panel.alphaValue = 1.0
        panel.orderFrontRegardless()

        // Auto-hide after 1.5s
        hideTimer = Timer.scheduledTimer(withTimeInterval: 1.5, repeats: false) { [weak self] _ in
            self?.fadeOut()
        }
    }

    private func createPanel() {
        let panel = NSPanel(
            contentRect: NSRect(origin: .zero, size: hudSize),
            styleMask: [.borderless, .nonactivatingPanel],
            backing: .buffered,
            defer: false
        )
        panel.level = .floating
        panel.isOpaque = false
        panel.backgroundColor = .clear
        panel.hasShadow = true
        panel.hidesOnDeactivate = false
        panel.collectionBehavior = [.canJoinAllSpaces, .fullScreenAuxiliary, .ignoresCycle]
        panel.isMovableByWindowBackground = false
        panel.ignoresMouseEvents = true
        self.panel = panel
    }

    private func fadeOut() {
        guard let panel = panel else { return }
        NSAnimationContext.runAnimationGroup({ context in
            context.duration = 0.4
            panel.animator().alphaValue = 0.0
        }, completionHandler: { [weak self] in
            self?.panel?.orderOut(nil)
        })
    }
}