import AppKit

final class OverlayWindowController: NSWindowController {
    private let statusView = StatusView()
    private let visualEffect = NSVisualEffectView()

    init(serviceChecker: ServiceChecker) {
        let style: NSWindow.StyleMask = [.borderless]
        let window = OverlayWindow(contentRect: .zero, styleMask: style, backing: .buffered, defer: false)
        super.init(window: window)
        window.isReleasedWhenClosed = false
        window.level = .floating // below status bar level, above normal windows
        window.collectionBehavior = [.canJoinAllSpaces, .stationary]
        window.hasShadow = false
        window.backgroundColor = .clear
        window.isOpaque = false

        // Visual effect that matches the menu bar
        visualEffect.material = .menu
        visualEffect.blendingMode = .behindWindow
        visualEffect.state = .active
        visualEffect.translatesAutoresizingMaskIntoConstraints = false

        statusView.translatesAutoresizingMaskIntoConstraints = false

        let container = NSView()
        container.wantsLayer = true
        container.translatesAutoresizingMaskIntoConstraints = false
        container.addSubview(visualEffect)
        visualEffect.addSubview(statusView)

        window.contentView = container

        NSLayoutConstraint.activate([
            visualEffect.leadingAnchor.constraint(equalTo: container.leadingAnchor),
            visualEffect.trailingAnchor.constraint(equalTo: container.trailingAnchor),
            visualEffect.topAnchor.constraint(equalTo: container.topAnchor),
            visualEffect.bottomAnchor.constraint(equalTo: container.bottomAnchor),

            statusView.centerXAnchor.constraint(equalTo: visualEffect.centerXAnchor),
            statusView.centerYAnchor.constraint(equalTo: visualEffect.centerYAnchor)
        ])

        statusView.bindTo(serviceChecker: serviceChecker)

        // Initial placement
        recomputeFrameAndVisibility()
    }

    required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") }

    func showIfMenuBarVisible() { recomputeFrameAndVisibility() }

    func recomputeFrameAndVisibility() {
        guard let screen = NSScreen.main else { window?.orderOut(nil); return }
        let frame = screen.frame
        let visible = screen.visibleFrame
        let menuBarHeight = frame.maxY - visible.maxY // 0 if auto-hidden or full-screen space

        if menuBarHeight <= 0.5 { // treat as hidden/no menu bar
            window?.orderOut(nil)
            return
        }

        let barHeight = NSStatusBar.system.thickness // expected to be same as menu bar height
        let y = visible.maxY - barHeight
        let rect = NSRect(x: frame.minX, y: y, width: frame.width, height: barHeight)

        window?.setFrame(rect, display: true)
        window?.orderFrontRegardless()
    }

    func showContextMenu() {
        guard let window = window, window.isVisible else { return }
        let menu = NSMenu(title: "ProleStatus")
        menu.addItem(withTitle: statusView.aggregateStatusSummary(), action: nil, keyEquivalent: "")
        menu.addItem(.separator())
        menu.addItem(withTitle: "Refresh Now", action: #selector(refreshNow), keyEquivalent: "r").target = self
        menu.addItem(.separator())
        menu.addItem(withTitle: "Quit ProleStatus", action: #selector(quit), keyEquivalent: "q").target = self

        let point = NSPoint(x: window.frame.midX, y: window.frame.minY)
        menu.popUp(positioning: nil, at: point, in: nil)
    }

    @objc private func refreshNow() {
        NotificationCenter.default.post(name: ServiceChecker.forceRefreshNotification, object: nil)
    }

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

final class OverlayWindow: NSWindow {
    override var canBecomeKey: Bool { false }
    override var canBecomeMain: Bool { false }

    override init(contentRect: NSRect, styleMask style: NSWindow.StyleMask, backing backingStoreType: NSWindow.BackingStoreType, defer flag: Bool) {
        super.init(contentRect: contentRect, styleMask: style, backing: backingStoreType, defer: flag)
        isOpaque = false
        backgroundColor = .clear
        ignoresMouseEvents = false // allow hover tracking, but we’ll pass clicks through via hitTest
        acceptsMouseMovedEvents = true
    }
}