GitHawk/Classes/Views/DiffString.swift

//
//  DiffString.swift
//  Freetime
//
//  Created by Ryan Nystrom on 8/12/17.
//  Copyright © 2017 Ryan Nystrom. All rights reserved.
//

import UIKit

func CreateDiffString(code: String, limit: Bool = false) -> NSAttributedString {
    let split = code.components(separatedBy: CharacterSet.newlines)
    let count = split.count

    let lines: [String]
    if limit {
        let cutLines = min(count, 4)
        lines = Array(split[(count-cutLines)..<count])
    } else {
        lines = split
    }

    let attributedString = NSMutableAttributedString()

    for line in lines {
        var attributes = [
            NSAttributedStringKey.font: Styles.Fonts.code,
            NSAttributedStringKey.foregroundColor: Styles.Colors.Gray.dark.color
        ]
        if line.hasPrefix("+") {
            attributes[NSAttributedStringKey.backgroundColor] = Styles.Colors.Green.light.color
        } else if line.hasPrefix("-") {
            attributes[NSAttributedStringKey.backgroundColor] = Styles.Colors.Red.light.color
        }

        let newlinedLine = line != lines.last ? line + "\n" : line
        attributedString.append(NSAttributedString(string: newlinedLine, attributes: attributes))
    }

    return attributedString
}