import Cocoa
import QuartzCore

public enum HUDState {
    case hidden
    case recording(level: Float, isLagging: Bool = false)
    case retrying
    case transcribing
    case success
    case error
}

public final class HUDOverlayController {
    public static let shared = HUDOverlayController()
    
    private var window: NSPanel?
    private var orbView: SolidSiriOrbView?
    private var isVisible = false
    
    // Large transparent canvas so audio-reactive halo never clips
    private let canvasSize: CGFloat = 200
    
    private init() {
        DispatchQueue.main.async {
            self.setupWindow()
        }
    }
    
    private func setupWindow() {
        let panel = NSPanel(
            contentRect: NSRect(x: 0, y: 0, width: canvasSize, height: canvasSize),
            styleMask: [.borderless, .nonactivatingPanel],
            backing: .buffered,
            defer: false
        )
        panel.isOpaque = false
        panel.backgroundColor = .clear
        panel.level = .floating
        panel.collectionBehavior = [.canJoinAllSpaces, .fullScreenAuxiliary, .stationary]
        panel.hasShadow = false
        panel.ignoresMouseEvents = true
        panel.alphaValue = 0.0
        
        let container = NSView(frame: panel.contentView!.bounds)
        container.wantsLayer = true
        
        // Minimal Solid Orb centered in canvas
        let orbDiameter: CGFloat = 50
        let orbOrigin = (canvasSize - orbDiameter) / 2.0
        let orb = SolidSiriOrbView(frame: NSRect(x: orbOrigin, y: orbOrigin, width: orbDiameter, height: orbDiameter))
        container.addSubview(orb)
        self.orbView = orb
        
        panel.contentView = container
        self.window = panel
        reposition()
    }
    
    private func reposition() {
        guard let window = self.window, let screen = NSScreen.main else { return }
        let screenRect = screen.visibleFrame
        // Center horizontally, positioned comfortably higher above the dock
        let x = screenRect.midX - (canvasSize / 2.0)
        let y = screenRect.minY + 75
        window.setFrameOrigin(NSPoint(x: x, y: y))
    }
    
    public func show(state: HUDState) {
        DispatchQueue.main.async { [weak self] in
            guard let self = self else { return }
            if self.window == nil {
                self.setupWindow()
            }
            guard let window = self.window, let orb = self.orbView else { return }
            self.reposition()
            
            switch state {
            case .hidden:
                self.hide()
                
            case .recording(let level, let isLagging):
                if !self.isVisible {
                    window.orderFrontRegardless()
                    window.animator().alphaValue = 1.0
                    self.isVisible = true
                }
                orb.updateAudioLevel(level, isLagging: isLagging)
                
            case .retrying:
                if !self.isVisible {
                    window.orderFrontRegardless()
                    window.animator().alphaValue = 1.0
                    self.isVisible = true
                }
                orb.showRetryState()
                
            case .transcribing:
                orb.showTranscribingState()
                
            case .success:
                orb.showSuccessState()
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.40) {
                    self.hide()
                }
                
            case .error:
                orb.showErrorState()
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.70) {
                    self.hide()
                }
            }
        }
    }
    
    public func hide() {
        DispatchQueue.main.async { [weak self] in
            guard let self = self, let window = self.window, self.isVisible else { return }
            NSAnimationContext.runAnimationGroup({ context in
                context.duration = 0.18
                window.animator().alphaValue = 0.0
            }, completionHandler: {
                window.orderOut(nil)
                self.isVisible = false
                self.orbView?.reset()
            })
        }
    }
}

// MARK: - Minimal Solid-Color Orb with 100% Dynamic Audio-Driven Stroke & Bloom Halo

final class SolidSiriOrbView: NSView {
    private let glowLayer = CALayer()
    private let solidCoreLayer = CALayer()
    private let strokeBorderLayer = CALayer()
    
    private let maxStrokeWidth: CGFloat = 8.0
    
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        wantsLayer = true
        setupLayers()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        wantsLayer = true
        setupLayers()
    }
    
    private func setupLayers() {
        guard let layer = self.layer else { return }
        layer.masksToBounds = false
        
        let bounds = self.bounds
        let radius = bounds.width / 2.0
        
        // 1. Dynamic Outer Atmospheric Glow (100% audio-driven; disappears completely in silence)
        glowLayer.frame = bounds.insetBy(dx: -12, dy: -12)
        glowLayer.cornerRadius = (bounds.width + 24) / 2.0
        glowLayer.backgroundColor = NSColor.clear.cgColor
        glowLayer.shadowColor = NSColor.white.cgColor
        glowLayer.shadowRadius = 0
        glowLayer.shadowOpacity = 0.0
        glowLayer.shadowOffset = .zero
        glowLayer.opacity = 0.0
        layer.addSublayer(glowLayer)
        
        // 2. Chic, Minimal Solid-Color Core (Apple Obsidian Graphite Disc)
        solidCoreLayer.frame = bounds
        solidCoreLayer.cornerRadius = radius
        solidCoreLayer.backgroundColor = NSColor(red: 0.12, green: 0.12, blue: 0.14, alpha: 0.98).cgColor
        layer.addSublayer(solidCoreLayer)
        
        // 3. Dynamic Voice-Reactive Stroke Ring (Disappears completely in silence)
        strokeBorderLayer.frame = bounds
        strokeBorderLayer.cornerRadius = radius
        strokeBorderLayer.borderWidth = 0.0
        strokeBorderLayer.borderColor = NSColor.white.cgColor
        strokeBorderLayer.backgroundColor = NSColor.clear.cgColor
        strokeBorderLayer.opacity = 0.0
        layer.addSublayer(strokeBorderLayer)
    }
    
    /// Updates audio response:
    /// In silence (level <= 0.04): stroke and halo disappear completely.
    /// When speaking: stroke widens powerfully (up to 8px) and halo blooms dynamically.
    func updateAudioLevel(_ level: Float, isLagging: Bool) {
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        
        let rawClamped = CGFloat(min(max(level, 0.0), 1.0))
        let silenceThreshold: CGFloat = 0.04
        
        if rawClamped <= silenceThreshold {
            // Complete silence: Stroke and Halo completely vanish
            strokeBorderLayer.borderWidth = 0.0
            strokeBorderLayer.opacity = 0.0
            glowLayer.shadowOpacity = 0.0
            glowLayer.shadowRadius = 0.0
            glowLayer.opacity = 0.0
        } else {
            // Active speech: scale dynamic intensity noticeably
            let norm = (rawClamped - silenceThreshold) / (1.0 - silenceThreshold)
            
            if isLagging {
                // Amber highlight for network degradation
                let amber = NSColor(red: 1.0, green: 0.65, blue: 0.10, alpha: 0.95).cgColor
                strokeBorderLayer.borderColor = amber
                glowLayer.shadowColor = amber
            } else {
                // Crisp luminous white glow
                strokeBorderLayer.borderColor = NSColor.white.cgColor
                glowLayer.shadowColor = NSColor.white.cgColor
            }
            
            // 1. Noticeably powerful stroke expansion (from 0 to 8px)
            let dynamicWidth = norm * maxStrokeWidth
            strokeBorderLayer.borderWidth = dynamicWidth
            strokeBorderLayer.opacity = Float(0.40 + (0.60 * norm))
            
            // 2. Dynamic bloom halo (expands up to 45px radius)
            glowLayer.shadowRadius = 6.0 + (norm * 38.0)
            glowLayer.shadowOpacity = Float(0.35 + (0.65 * norm))
            glowLayer.opacity = Float(norm)
        }
        
        CATransaction.commit()
    }
    
    func showRetryState() {
        CATransaction.begin()
        CATransaction.setDisableActions(false)
        CATransaction.setAnimationDuration(0.20)
        strokeBorderLayer.borderWidth = 4.0
        strokeBorderLayer.opacity = 1.0
        strokeBorderLayer.borderColor = NSColor.orange.cgColor
        glowLayer.shadowColor = NSColor.orange.cgColor
        glowLayer.shadowRadius = 24
        glowLayer.shadowOpacity = 0.9
        glowLayer.opacity = 1.0
        CATransaction.commit()
    }
    
    func showTranscribingState() {
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        strokeBorderLayer.borderWidth = 3.0
        strokeBorderLayer.opacity = 0.8
        strokeBorderLayer.borderColor = NSColor.white.cgColor
        glowLayer.shadowColor = NSColor.white.cgColor
        glowLayer.shadowRadius = 16
        glowLayer.shadowOpacity = 0.7
        glowLayer.opacity = 0.8
        CATransaction.commit()
    }
    
    func showSuccessState() {
        CATransaction.begin()
        CATransaction.setDisableActions(false)
        CATransaction.setAnimationDuration(0.18)
        let green = NSColor(red: 0.15, green: 0.95, blue: 0.45, alpha: 1.0).cgColor
        strokeBorderLayer.borderWidth = 4.0
        strokeBorderLayer.opacity = 1.0
        strokeBorderLayer.borderColor = green
        glowLayer.shadowColor = green
        glowLayer.shadowRadius = 22
        glowLayer.shadowOpacity = 0.9
        glowLayer.opacity = 1.0
        CATransaction.commit()
    }
    
    func showErrorState() {
        CATransaction.begin()
        CATransaction.setDisableActions(false)
        CATransaction.setAnimationDuration(0.18)
        let red = NSColor(red: 1.0, green: 0.20, blue: 0.20, alpha: 1.0).cgColor
        strokeBorderLayer.borderWidth = 4.0
        strokeBorderLayer.opacity = 1.0
        strokeBorderLayer.borderColor = red
        glowLayer.shadowColor = red
        glowLayer.shadowRadius = 22
        glowLayer.shadowOpacity = 0.9
        glowLayer.opacity = 1.0
        CATransaction.commit()
    }
    
    func reset() {
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        strokeBorderLayer.borderWidth = 0.0
        strokeBorderLayer.opacity = 0.0
        glowLayer.shadowRadius = 0.0
        glowLayer.shadowOpacity = 0.0
        glowLayer.opacity = 0.0
        CATransaction.commit()
    }
}