import AppKit

// MARK: - DraggableImageView Protocol
protocol DraggableImageViewClickHandler: AnyObject {
    func thumbnailWasClicked(image: NSImage)
}

// MARK: - DraggableImageView
class DraggableImageView: NSImageView {
    var onDragStart: (() -> Void)?
    weak var appDelegate: ScreenshotApp?
    private var mouseDownEvent: NSEvent? 
    private let dragThreshold: CGFloat = 3.0
    private var isPerformingDrag: Bool = false
    
    // 🎨 NEW: Track the file URL for the current image (for BGR mode)
    var imageURL: URL?
    
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        self.imageScaling = .scaleProportionallyUpOrDown
        self.imageAlignment = .alignCenter
        self.animates = true
        self.imageFrameStyle = .none
        self.registerForDraggedTypes([.fileURL, .URL, .tiff, .png])
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        self.imageScaling = .scaleProportionallyUpOrDown
        self.imageAlignment = .alignCenter
        self.animates = true
        self.imageFrameStyle = .none
        self.registerForDraggedTypes([.fileURL, .URL, .tiff, .png])
    }

    override func mouseDown(with event: NSEvent) {
        self.mouseDownEvent = event
        self.isPerformingDrag = false
    }
    
    override func mouseDragged(with event: NSEvent) {
        guard let mouseDownEvent = self.mouseDownEvent else {
            super.mouseDragged(with: event)
            return
        }

        if !isPerformingDrag {
            let dragThreshold: CGFloat = 3.0
            let deltaX = abs(event.locationInWindow.x - mouseDownEvent.locationInWindow.x)
            let deltaY = abs(event.locationInWindow.y - mouseDownEvent.locationInWindow.y)

            if deltaX > dragThreshold || deltaY > dragThreshold {
                isPerformingDrag = true
                self.mouseDownEvent = nil

                guard let unwrappedAppDelegate = appDelegate else {
                    isPerformingDrag = false
                    return
                }

                // 🎨 FIXED: Check for available URL (BGR mode or normal mode) before proceeding
                let sourceURLForDrag = self.imageURL ?? unwrappedAppDelegate.tempURL
                
                guard let finalSourceURL = sourceURLForDrag else {
                    print("❌ DraggableImageView: No valid URL available for dragging (imageURL: \(imageURL?.path ?? "nil"), tempURL: \(unwrappedAppDelegate.tempURL?.path ?? "nil"))")
                    isPerformingDrag = false
                    return
                }
                
                print("🎯 DraggableImageView: Starting drag with URL: \(finalSourceURL.path)")

                if let preview = unwrappedAppDelegate.activePreviewWindow, preview.isVisible {
                    preview.orderOut(nil as Any?)
                }
                unwrappedAppDelegate.gridViewManager?.showGrid(previewFrame: self.window?.frame)
                
                // NIEUW: Start drag session voor proximity monitoring
                unwrappedAppDelegate.gridViewManager?.startDragSession()
                
                let fileItem = NSDraggingItem(pasteboardWriter: finalSourceURL as NSURL)

                if let imageToDrag = self.image {
                    let fullFrame = convert(bounds, to: nil)
                    
                    let scale: CGFloat = 0.05
                    let yOffset: CGFloat = 30
                    
                    let scaledFrame = NSRect(
                        x: fullFrame.midX - fullFrame.width * scale / 2,
                        y: fullFrame.midY - fullFrame.height * scale / 2 - yOffset,
                        width: fullFrame.width * scale,
                        height: fullFrame.height * scale
                    )
                    fileItem.setDraggingFrame(scaledFrame, contents: imageToDrag)
                }
                let items: [NSDraggingItem] = [fileItem]
                beginDraggingSession(with: items, event: event, source: self)
            } else {
                return
            }
        }
    }

    override func mouseUp(with event: NSEvent) {
        if !isPerformingDrag {
            if let image = self.image, let appDelegate = self.appDelegate {
                appDelegate.thumbnailWasClicked(image: image)
            }
            super.mouseUp(with: event)
        }
        self.mouseDownEvent = nil
        self.isPerformingDrag = false
    }
}

// MARK: - NSDraggingSource
extension DraggableImageView: NSDraggingSource {
    func draggingSession(_ session: NSDraggingSession, sourceOperationMaskFor context: NSDraggingContext) -> NSDragOperation {
        return .copy
    }
    
    func draggingSession(_ session: NSDraggingSession, willBeginAt screenPoint: NSPoint) {
        // Drag session beginning
    }
    
    func draggingSession(_ session: NSDraggingSession, movedTo screenPoint: NSPoint) {
        guard let appDel = self.appDelegate,
              let gridManager = appDel.gridViewManager,
              let gridWindow = gridManager.gridWindow else { return }
        
        let gridFrame = gridWindow.frame
        
        let distanceToGrid = min(
            abs(screenPoint.x - gridFrame.minX),
            abs(screenPoint.x - gridFrame.maxX)
        )
        
        // Update visual feedback based on proximity
        if Int(distanceToGrid) % 50 == 0 {
            let minScale: CGFloat = 0.05
            let maxScale: CGFloat = 0.35
            let maxDistance: CGFloat = 300
            
            if distanceToGrid < maxDistance {
                let progress = distanceToGrid / maxDistance
                _ = minScale + (progress * (maxScale - minScale))
            }
        }
    }

    func draggingSession(_ session: NSDraggingSession, endedAt screenPoint: NSPoint, operation: NSDragOperation) {
        isPerformingDrag = false
        
        // NIEUW: Stop drag session direct na drag end
        appDelegate?.gridViewManager?.stopDragSession()
        
        DispatchQueue.main.async { [weak self] in
            guard let self = self, let appDel = self.appDelegate else { 
                return
            }
            
            let didDropOnGridAction = appDel.didGridHandleDrop 
            let didDropOnStashGridAction = appDel.didStashGridHandleDrop
            let didDropOnAnyGridAction = didDropOnGridAction || didDropOnStashGridAction
            let closeAfterDragSetting = SettingsManager.shared.closeAfterDrag

            if !didDropOnAnyGridAction && appDel.gridViewManager?.gridWindow != nil {
                appDel.gridViewManager?.hideGrid(monitorForReappear: false)
            }

            if didDropOnAnyGridAction {
                // Drop handled by grid action (main or stash). Preview management deferred to grid action handler.
                print("🔄 DraggableImageView: Grid action detected (main: \(didDropOnGridAction), stash: \(didDropOnStashGridAction))")
                
                // 🔧 CRITICAL FIX: Handle ALL grid actions (both main and stash) with closeAfterDrag setting
                print("🔄 Grid action completed - applying closeAfterDrag setting: \(closeAfterDragSetting)")
                if closeAfterDragSetting {
                    print("🔄 Closing thumbnail after grid action due to closeAfterDrag setting")
                    appDel.closePreviewWithAnimation(immediate: false, preserveTempFile: false)
                } else {
                    print("🔄 Keeping thumbnail visible after grid action (closeAfterDrag is OFF)")
                    appDel.ensurePreviewVisible()
                }
            } else {
                if operation != [] {
                    if closeAfterDragSetting {
                        appDel.closePreviewWithAnimation(immediate: true)
                    } else {
                        appDel.ensurePreviewVisible()
                    }
                } else {
                    appDel.ensurePreviewVisible()
                }
            }
            
            // Reset both flags
            appDel.didGridHandleDrop = false
            appDel.didStashGridHandleDrop = false
        }
    }
}

// MARK: - NSImage Extension for PNG Data
extension NSImage {
    func pngData() -> Data? {
        guard let tiffData = self.tiffRepresentation,
              let bitmapRep = NSBitmapImageRep(data: tiffData) else {
            return nil
        }
        return bitmapRep.representation(using: .png, properties: [:])
    }
}