import AppKit

final class StatusView: NSView {
    private let light1 = TrafficLight()
    private let light2 = TrafficLight()
    private let light3 = TrafficLight()

    private var checker: ServiceChecker?

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        wantsLayer = true
        translatesAutoresizingMaskIntoConstraints = false

        let stack = NSStackView(views: [light1, light2, light3])
        stack.orientation = .horizontal
        stack.alignment = .centerY
        stack.distribution = .equalSpacing
        stack.spacing = 16
        stack.translatesAutoresizingMaskIntoConstraints = false

        addSubview(stack)
        NSLayoutConstraint.activate([
            stack.centerXAnchor.constraint(equalTo: centerXAnchor),
            stack.centerYAnchor.constraint(equalTo: centerYAnchor)
        ])

        // Tracking for hover tooltips
        addTrackingArea(NSTrackingArea(rect: bounds, options: [.mouseEnteredAndExited, .mouseMoved, .activeAlways, .inVisibleRect], owner: self, userInfo: nil))
    }

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

    override func hitTest(_ point: NSPoint) -> NSView? {
        // Pass all clicks through to apps beneath
        return nil
    }

    func bindTo(serviceChecker: ServiceChecker) {
        self.checker = serviceChecker
        NotificationCenter.default.addObserver(self, selector: #selector(updateLights), name: ServiceChecker.statusDidChangeNotification, object: serviceChecker)
        updateLights()
    }

    @objc private func updateLights() {
        guard let c = checker else { return }
        // Light 1: svc.prole.org:443
        light1.state = c.svcReachable ? .green : .red
        light1.toolTip = c.tooltipForSvc()

        // Light 2: aggregate raspberry + pi
        let count = (c.raspberryReachable ? 1 : 0) + (c.piReachable ? 1 : 0)
        light2.state = count == 2 ? .green : (count == 1 ? .yellow : .red)
        light2.toolTip = c.tooltipForAggregateK3s()

        // Light 3: localhost k3d
        light3.state = c.localReachable ? .green : .red
        light3.toolTip = c.tooltipForLocal()
        needsDisplay = true
    }

    func aggregateStatusSummary() -> String {
        guard let c = checker else { return "No status" }
        let svc = c.svcReachable ? "svc.prole.org:443 ✓" : "svc.prole.org:443 ✗"
        let agg = "k3s: raspberry \(c.raspberryReachable ? "✓" : "✗"), pi \(c.piReachable ? "✓" : "✗")"
        let loc = c.localReachable ? "k3d localhost:6443 ✓" : "k3d localhost:6443 ✗"
        return [svc, agg, loc].joined(separator: "  •  ")
    }
}

final class TrafficLight: NSView {
    enum State { case green, yellow, red }
    var state: State = .red { didSet { needsDisplay = true } }

    override var intrinsicContentSize: NSSize { NSSize(width: 14, height: 14) }

    override func draw(_ dirtyRect: NSRect) {
        super.draw(dirtyRect)
        let rect = bounds.insetBy(dx: 1, dy: 1)
        let path = NSBezierPath(ovalIn: rect)
        let color: NSColor
        switch state {
        case .green: color = NSColor.systemGreen
        case .yellow: color = NSColor.systemYellow
        case .red: color = NSColor.systemRed
        }
        color.setFill()
        path.fill()

        // subtle ring for better contrast against menu material
        NSColor.black.withAlphaComponent(0.12).setStroke()
        path.lineWidth = 1
        path.stroke()
    }
}