//
//  LabelAttributeFont.swift
//  VDS
//
//  Created by Matt Bruce on 8/3/22.
//

import Foundation
import UIKit

public struct TextStyleLabelAttribute: LabelAttributeModel {
    
    //--------------------------------------------------
    // MARK: - Equatable
    //--------------------------------------------------
    public func isEqual(_ equatable: TextStyleLabelAttribute) -> Bool {
        return id == equatable.id
        && range == equatable.range
        && textColor == equatable.textColor
        && textStyle == equatable.textStyle
    }
    
    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    public var id = UUID()
    public var location: Int
    public var length: Int
    public var textStyle: TextStyle
    public var textColor: UIColor
    public var textPosition: TextPosition
    public var lineBreakMode: NSLineBreakMode
    
    //--------------------------------------------------
    // MARK: - Initializer
    //--------------------------------------------------
    public init(location: Int, length: Int, textStyle: TextStyle, textColor: UIColor = .black, textPosition: TextPosition = .left, lineBreakMode: NSLineBreakMode = .byWordWrapping) {
        self.location = location
        self.length = length
        self.textStyle = textStyle
        self.textColor = textColor
        self.textPosition = textPosition
        self.lineBreakMode = lineBreakMode
    }
    
    public func setAttribute(on attributedString: NSMutableAttributedString) {
    }
}

extension Label {
    internal func apply(attribute: TextStyleLabelAttribute, on attributedString: NSMutableAttributedString){
        attributedString.removeAttribute(.font, range: attribute.range)
        attributedString.removeAttribute(.foregroundColor, range: attribute.range)
        attributedString.addAttribute(.font, value: attribute.textStyle.font, range: attribute.range)
        attributedString.addAttribute(.foregroundColor, value: attribute.textColor, range: attribute.range)

        //set letterSpacing
        if attribute.textStyle.letterSpacing > 0.0 {
            attributedString.removeAttribute(.kern, range: attribute.range)
            attributedString.addAttribute(.kern, value: attribute.textStyle.letterSpacing, range: attribute.range)
        }
        
        //set lineHeight
        if attribute.textStyle.lineHeight > 0.0 {
            let lineHeight = attribute.textStyle.lineHeight
            let adjustment = lineHeight > attribute.textStyle.font.lineHeight ? 2.0 : 1.0
            let baselineOffset = (lineHeight - attribute.textStyle.font.lineHeight) / 2.0 / adjustment
            let paragraph = NSMutableParagraphStyle().with {
                $0.maximumLineHeight = lineHeight
                $0.minimumLineHeight = lineHeight
                $0.alignment = attribute.textPosition.textAlignment
                $0.lineBreakMode = attribute.lineBreakMode
            }
            attributedString.removeAttribute(.baselineOffset, range: attribute.range)
            attributedString.removeAttribute(.paragraphStyle, range: attribute.range)
            attributedString.addAttribute(.baselineOffset, value: baselineOffset, range: attribute.range)
            attributedString.addAttribute(.paragraphStyle, value: paragraph, range: attribute.range)
            
        } else if attribute.textPosition != .left {
            let paragraph = NSMutableParagraphStyle().with {
                $0.alignment = attribute.textPosition.textAlignment
                $0.lineBreakMode = attribute.lineBreakMode
            }
            attributedString.removeAttribute(.paragraphStyle, range: attribute.range)
            attributedString.addAttribute(.paragraphStyle, value: paragraph, range: attribute.range)
        }
    }
}