import Cocoa


private let kKMSignayureTextMaxFontSize: CGFloat = 28.0
private let kKMSignayureTextMaxWidth: CGFloat = 300
private let kKMSignayureTextEdgeOffset: CGFloat = 5

@objcMembers class KMVerticallyCenteredSecureTextFieldCell: NSTextFieldCell {
    func adjustedFrame(toVerticallyCenterText rect: NSRect) -> NSRect {
        let offset = floor((rect.size.height / 2 - (font!.ascender)))
        return rect.insetBy(dx: 0.0, dy: offset)
    }

    override func edit(withFrame rect: NSRect, in controlView: NSView, editor textObj: NSText, delegate delegateObj: Any?, event: NSEvent?) {
        super.edit(withFrame: adjustedFrame(toVerticallyCenterText: rect), in: controlView, editor: textObj, delegate: delegateObj, event: event)
    }

    override func select(withFrame rect: NSRect, in controlView: NSView, editor textObj: NSText, delegate delegateObj: Any?, start selStart: Int, length selLength: Int) {
        super.select(withFrame: adjustedFrame(toVerticallyCenterText: rect), in: controlView, editor: textObj, delegate: delegateObj, start: selStart, length: selLength)
    }

    override func drawInterior(withFrame cellFrame: NSRect, in controlView: NSView) {
        super.drawInterior(withFrame: adjustedFrame(toVerticallyCenterText: cellFrame), in: controlView)
    }
}

@objcMembers class KMSignayureTextField: NSTextField {
    var originalTextColor: NSColor?

    override func addSubview(_ view: NSView) {
        super.addSubview(view)
        if let view1 = view.subviews.first as? NSTextView {
            let textview = view1
            textview.insertionPointColor = NSColor(red: 102.0 / 255.0, green: 102.0 / 255.0, blue: 102.0 / 255.0, alpha: 1.0)
        }
    }
}

@objc protocol KMChangeSignatureTextDelegate: NSObjectProtocol {
    func changeSignatureText(_ isTrue: Bool)
}

@objcMembers class KMPDFSignatureTextView: NSView, NSTextFieldDelegate {
    @IBOutlet var nameTextFiled: KMSignayureTextField!
    @IBOutlet var labelWidthLayoutConstraint: NSLayoutConstraint!
    @IBOutlet var verticalLineBox: NSBox!
    
    var keyboardColor: NSColor = NSColor(red: 0, green: 0, blue: 0, alpha: 1) {
        didSet {
            self.nameTextFiled.textColor = keyboardColor
        }
    }
    var fontName: String = "" {
        didSet {
            var fontSize: CGFloat = 14.0
            if !self.nameTextFiled.stringValue.isEmpty {
                fontSize = kKMSignayureTextMaxFontSize
            }
            if let maxFont = NSFont(name: fontName, size: fontSize) {
                let size = sizeOfString(self.nameTextFiled.stringValue, withFontSize: maxFont)
                
                var width = size.width + kKMSignayureTextEdgeOffset * 2
                var scale: CGFloat = 1.0
                
                scale = min(kKMSignayureTextMaxWidth / width, 60.0 / (size.height + 2))
                
                if width >= 100 {
                    self.labelWidthLayoutConstraint.constant = width
                }
                
                if let font = NSFont(name: fontName, size: fontSize) {
                    self.nameTextFiled.font = font
                }
                
                let isTrue = !self.nameTextFiled.stringValue.isEmpty
                if let callback = self.changeSignatureTextCallback {
                    callback(isTrue)
                }
                
                if let delegate = self.delegate {
                    delegate.changeSignatureText(isTrue)
                }
            }
        }
    }

    var changeSignatureTextCallback: ((Bool) -> Void)?
    weak var delegate: KMChangeSignatureTextDelegate?
    
    override func awakeFromNib() {
        super.awakeFromNib()
        self.nameTextFiled.placeholderString = NSLocalizedString("Sign Here", comment: "")
        self.nameTextFiled.font = NSFont.systemFont(ofSize: 14.0)
//        self.verticalLineBox.fillColor = NSColor.black
    }

    override func draw(_ dirtyRect: NSRect) {
        super.draw(dirtyRect)
        // Custom drawing code here
    }
    
    func clearImage() {
        self.nameTextFiled.stringValue = ""
        self.nameTextFiled.font = NSFont.systemFont(ofSize: 14.0)
        if let callback = self.changeSignatureTextCallback {
            callback(false)
        }
    }
    
    func signatureImage() -> NSImage? {
        var rect = CGRect.zero
        let string = self.nameTextFiled.stringValue.isEmpty ? "" : self.nameTextFiled.stringValue
        let size = sizeOfString(string, withFontSize: self.nameTextFiled.font!)
        
        if size.width == 0 {
            return nil
        } else {
            rect = CGRect(x: kKMSignayureTextEdgeOffset, y: kKMSignayureTextEdgeOffset, width: size.width, height: size.height)
        }

        let image = NSImage(size: CGSize(width: size.width + kKMSignayureTextEdgeOffset * 2, height: size.height + kKMSignayureTextEdgeOffset * 2))
        image.lockFocus()
        
        var dictionary = [NSAttributedString.Key: Any]()
        dictionary[NSAttributedString.Key.font] = self.nameTextFiled.font
        dictionary[NSAttributedString.Key.foregroundColor] = self.keyboardColor
        string.draw(in: rect, withAttributes: dictionary)
        
        image.unlockFocus()
        return image
    }
    
    func sizeOfString(_ string: String, withFontSize font: NSFont) -> CGSize {
        let dictionary: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.font: font,
            NSAttributedString.Key.paragraphStyle: NSParagraphStyle.default
        ]
        let size = string.boundingRect(with: CGSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude), options: .usesLineFragmentOrigin, attributes: dictionary).size
        return size
    }
    
    func controlTextDidChange(_ obj: Notification) {
        if let textField = obj.object as? NSTextField, textField == self.nameTextFiled {
            let string = textField.stringValue.isEmpty ? nil : textField.stringValue
            var fontSize: CGFloat = 14.0
            if string != nil {
                fontSize = kKMSignayureTextMaxFontSize
            }
            if let maxFont = NSFont(name: self.fontName, size: fontSize) {
                let size = sizeOfString(string ?? "", withFontSize: maxFont)
                
                let width = size.width + kKMSignayureTextEdgeOffset * 2
                var scale: CGFloat = 1.0
                
                scale = min((self.bounds.size.width - 30) / width, 60.0 / (size.height + 2))
                
                if width >= 100 {
                    self.labelWidthLayoutConstraint.constant = width
                }
                if let font = NSFont(name: self.fontName, size: fontSize) {
                    self.nameTextFiled.font = font
                }
                let isTrue = !textField.stringValue.isEmpty
                if let callback = self.changeSignatureTextCallback {
                    callback(isTrue)
                }
                if let delegate = self.delegate {
                    delegate.changeSignatureText(isTrue)
                }
            }
        }
    }
}