PDF_Office/PDF Office/PDF Master/Class/Merge/OCPart/KMBlankView.swift

//
//  KMBlankView.swift
//  PDF Master
//
//  Created by wanjun on 2023/10/8.
//

import Cocoa


@objc enum KMBlankViewMouseEventType: UInt {
    case mouseEnter
    case mouseExit
    case mouseDown
    case mouseUp
}

typealias DragSuccessCallBack = ([String]) -> Void

@objcMembers
class KMBlankView: NSView {

    @IBOutlet var titleLabel: NSTextField!
    @IBOutlet var secondTitleLabel: NSTextField!
    @IBOutlet var imageView: NSImageView!
    @IBOutlet var customView: KMPDFEditAppendCustomView!

    var allowedFileTypes: [String]?

    var mouseActionCallBack: ((KMBlankViewMouseEventType) -> Void)?
    var dragSuccessBlock: DragSuccessCallBack?
    
    private var _button: NSButton?

    override func awakeFromNib() {
        super.awakeFromNib()
        
        titleLabel.font = NSFont.systemFont(ofSize: 14, weight: .semibold)
        secondTitleLabel.font = NSFont.systemFont(ofSize: 14)
        
        titleLabel.stringValue = ""
        secondTitleLabel.stringValue = ""
        addTrackingArea()
        self.wantsLayer = true
        
        customView.addSubview(button!)
        
        registerForDraggedTypes([.fileURL])
    }
    
    override func layout() {
        super.layout()
        
        button!.frame = imageView.frame
    }
    
    //MARK: Drag
    
    override func draggingExited(_ sender: NSDraggingInfo?) {
        
    }
    
    override func draggingEntered(_ sender: NSDraggingInfo) -> NSDragOperation {
        let pboard = sender.draggingPasteboard
        var isCanDrag = false
        var result: NSDragOperation = []
        
        if pboard.availableType(from: [NSPasteboard.PasteboardType.fileURL]) != nil {
            if let fileURLs = pboard.readObjects(forClasses: [NSURL.self], options: nil) as? [URL] {
                for fileURL in fileURLs {
                    if allowedFileTypes!.contains(fileURL.pathExtension.lowercased()) {
                        isCanDrag = true
                    } else {
                        isCanDrag = false
                        break
                    }
                }
            }
        }
        
        layer?.borderColor = NSColor.clear.cgColor
        
        if isCanDrag {
            result = [.copy]
        }
        
        return result
    }
    
    override func prepareForDragOperation(_ sender: NSDraggingInfo) -> Bool {
        let pboard = sender.draggingPasteboard
        if (pboard.pasteboardItems == nil) {
            return true
        }
        var files: [String] = []
        for item in pboard.pasteboardItems! {
            let fileURL = item.string(forType: .fileURL)
            if (fileURL == nil) {
                continue
            }
            let path = URL.init(string: fileURL!)
            if (path == nil) {
                continue
            }
            let filePath: String = path!.path
            files.append(filePath)
        }
        if let successBlock = self.dragSuccessBlock {
            successBlock(files)
        }

//        if let fileURL = pboard.availableType(from: [NSPasteboard.PasteboardType.fileURL]) {
//            let fileNames: String = pboard.propertyList(forType: .fileURL) as! String
//            let path = URL.init(string: fileNames)
//            let filePath: String = path!.path
//            if let successBlock = self.dragSuccessBlock {
//                successBlock([filePath])
//            }
//        }
        return true
    }
    
    //MARK: mouse Methods
    
    func addTrackingArea() {
        let trackingArea = NSTrackingArea(rect: self.imageView.bounds, options: [.mouseEnteredAndExited, .activeAlways], owner: self, userInfo: nil)
        self.imageView.addTrackingArea(trackingArea)
    }

    override func mouseEntered(with event: NSEvent) {
        super.mouseEntered(with: event)
        if let mouseActionCallBack = self.mouseActionCallBack {
            mouseActionCallBack(.mouseEnter)
        }
    }
    
    override func mouseExited(with event: NSEvent) {
        super.mouseExited(with: event)
        if let mouseActionCallBack = self.mouseActionCallBack {
            mouseActionCallBack(.mouseExit)
        }
    }
    
    override func mouseUp(with event: NSEvent) {
        super.mouseUp(with: event)
        let point = event.locationInWindow
        let pointInView = self.convert(point, to: self.imageView)
        if let mouseActionCallBack = self.mouseActionCallBack, self.imageView.bounds.contains(pointInView) {
            mouseActionCallBack(.mouseUp)
        }
    }
    
    //MARK: User Actions
    
    @objc func buttonDidClick() -> Void {
        if let mouseActionCallBack = self.mouseActionCallBack {
            mouseActionCallBack(.mouseDown)
        }
    }
    
    //MARK: Get、Set
    
    var button: NSButton? {
        get {
            if _button == nil {
                _button = NSButton()
                _button?.isBordered = false
                _button?.title = ""
                _button?.target = self
                _button?.action = #selector(buttonDidClick)
            }
            return _button
        }
    }

}