Privado-macOS/macOS/Privado/Sources/View/HyperlinkTextField.swift

//
//  HyperlinkTextField.swift
//  Cyberlock
//
//  Created by Juraldinio on 8/31/19.
//  Copyright © 2019 Omicronmedia. All rights reserved.
//

import Foundation
import AppKit

protocol HyperlinkTextFieldDelegate: AnyObject {
    func hyperlinkClicked(target: HyperlinkTextField)
}

final class HyperlinkTextField: NSTextField {
    
    public var hoveredColor: NSColor?
    public var link: String?
    public var normalColor: NSColor?
    public var underline: Bool?
    public var isHighlitedWithUnderline: Bool = false
    
    public var linkIsEnabled: Bool = true {
        didSet {
            self.isEnabled = self.linkIsEnabled
            self.alphaValue = self.linkIsEnabled ? 1 : 0.5
        }
    }
    
    private struct Constants {
        static let linkColor = NSColor(calibratedRed: 173 / 255, green: 179 / 255, blue: 210 / 255, alpha: 0.8)
    }
    
    private var trackingArea: NSTrackingArea?
    
    weak var hyperlinkDelegate: HyperlinkTextFieldDelegate?
    
    
    // MARK: - Initializers
    
    init(frame frameRect: NSRect, font: NSFont?, alignment: NSTextAlignment = .left) {
        super.init(frame: frameRect)
        
        self.translatesAutoresizingMaskIntoConstraints = false
        self.isBezeled = false
        self.drawsBackground = false
        self.isEditable = false
        self.isSelectable = false
        self.focusRingType = .none
        self.usesSingleLineMode = false
        self.alignment = alignment
        if let font = font {
            self.font = font
        }
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layout() {
        super.layout()

        if let trackingArea = self.trackingArea {
            self.removeTrackingArea(trackingArea)
        }

        let options: NSTrackingArea.Options = [.mouseEnteredAndExited, .activeAlways]
        let trackingArea = NSTrackingArea(rect: self.bounds, options: options, owner: self, userInfo: nil)
        self.addTrackingArea(trackingArea)
    }
    
    // MARK: -
    
    func show(hyper link: String, underline: Bool = false, with url: URL?, using color: NSColor? = nil) {
        self.underline = underline
        self.link = link
        self.normalColor = color
        let textAttributes: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.foregroundColor: color ?? Constants.linkColor,
            NSAttributedString.Key.underlineStyle: underline ? NSUnderlineStyle.single.rawValue : NSUnderlineStyle(rawValue: 0).rawValue
        ]

        self.attributedStringValue = NSMutableAttributedString(string: link, attributes: textAttributes)
    }
    
    override func mouseDown(with event: NSEvent) {
        guard self.isEnabled else { return }
        self.hyperlinkDelegate?.hyperlinkClicked(target: self)
    }
    
    /// Always display a pointing-hand cursor
    override func resetCursorRects() {
        super.resetCursorRects()
        self.addCursorRect(self.bounds, cursor: NSCursor.pointingHand)
    }
    
    override func mouseEntered(with event: NSEvent) {
        super.mouseEntered(with: event)
        
        if self.isHighlitedWithUnderline {
            let textAttributes: [NSAttributedString.Key: Any] = [
                NSAttributedString.Key.foregroundColor: self.hoveredColor ?? Constants.linkColor,
                NSAttributedString.Key.underlineStyle: NSUnderlineStyle.single.rawValue
            ]
            self.attributedStringValue = NSMutableAttributedString(string: link ?? "", attributes: textAttributes)
            return
        }
        
        let textAttributes: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.foregroundColor: self.hoveredColor ?? Constants.linkColor,
            NSAttributedString.Key.underlineStyle: self.underline ?? false ? NSUnderlineStyle.single.rawValue : NSUnderlineStyle(rawValue: 0).rawValue
        ]
        
        self.attributedStringValue = NSMutableAttributedString(string: link ?? "", attributes: textAttributes)
    }
    
    override func mouseExited(with event: NSEvent) {
        super.mouseEntered(with: event)
        
        if self.isHighlitedWithUnderline {
            let textAttributes: [NSAttributedString.Key: Any] = [
                NSAttributedString.Key.foregroundColor: self.normalColor ?? Constants.linkColor,
                NSAttributedString.Key.underlineStyle:  NSUnderlineStyle(rawValue: 0).rawValue
            ]

            self.attributedStringValue = NSMutableAttributedString(string: link ?? "", attributes: textAttributes)
            return
        }
        
        let textAttributes: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.foregroundColor: self.normalColor ?? Constants.linkColor,
            NSAttributedString.Key.underlineStyle:  self.underline ?? false ? NSUnderlineStyle.single.rawValue : NSUnderlineStyle(rawValue: 0).rawValue
        ]

        self.attributedStringValue = NSMutableAttributedString(string: link ?? "", attributes: textAttributes)
    }
    
}